1 compact memories have flexible capacities a digital data storage system with capacity up to bits and random and or sequential access is described 2 an electronic analogue computer for solving systems of linear equations mathematical derivation of the operating principle and stability conditions for a computer consisting of amplifiers 3 electronic coordinate transformer circuit details are given for the construction of an electronic calculating unit which enables the polar coordinates of a vector modulus and cosine or sine of the argument to be derived from those of a rectangular system of axes 4 the british computer society report of a conference held in cambridge june 5 millimicrosecond digital computer logic a system of fast pulse logic is described which combines the efficiency of transformer coupled stages with digit delay tolerances approaching that of dc coupled systems logical circuits for or and inverter and reclock are shown together with a driver which permits a fan out factor of transistor circuits are used through 6 binary circuits count backwards or forwards a transistorized module is described that can be used to build logical circuits a complete reversible counter measures 7 d packaging reduces size of electronic units greater component densities are obtainable using a module technique in which miniature circuit elements are placed side by side with electrical connection mace on a three dimensional basis by a spotwelding process 8 the square loop ferrite core as a circuit element the shape of the output waveforms when the cores are switched is explained by a quantitative theory which takes into account the residual loss reasonable agreement with experimental evidence is shown 9 switching circuits using bidirectional nonlinear impedances a general review of circuit logic is developed for a bidirectional nonlinear switching element the design of pnp transistor driver sriver stages is considered a binary octal decoder circuit and a simple binary full adder circuit are discussed as examples 10 highspeed microwave switching of semiconductors part 11 design of bistable switching circuits using junction transistors the relations between the different parameters which affect the switching circuit may be obtained by plotting on the same diagram a load line and the theoretical curve of the static characteristic of the circuit 12 perturbation of waveguides and cavities by spheres and cylinders 13 on the theory of the cavity resonator comprising two confocal paraboloids of revolution a solution is found for a system of equations given by buchholz 14 the excitation of cavity resonators by secondary electron resonance multiplication experimental investigation of the suitability for frequency multiplication of the process analysed in below 15 some generalizations of duhamels integral for quadripoles 16 the stable and unstable image parameters in quadripole theory the definition of stable and unstable image impedances by edldtkeller is extended to related parameters and their position in the complex plane is determined 17 matching quadripoles design formulae are derived for ii andt sections and groups of curves are given from which practical design parameters can be obtained 18 optimum tchebycheff third order filters a theoretical analysis is given of a design for the detection of rectangular pulsed signals on a background of white noise and it is shown that resulting signal noise ratios are smaller than those obtained by the use of optimum butterworth filters 19 cascade directional filter 20 transient response of bandpass filters to modulated signals laurents low pass band transformation is used with suitable approximations to obtain the response to a suddenly applied carrier the derived filter is analysed 21 the order of complexity of electrical networks an expression for the order i e the number of natural frequencies is derived for a rlc network complete sets of dynamically independent network variables are obtained from the network equations 22 the stability criteria for linear systems the various criteria can be obtained and interrelated by means of continued fractions the hurwitz determinants are condensed to about half thei original order 23 the efficiency of a ferrite as a microwave mixer it is shown theoretically that a polycrystalline ferrite should behave like a single crystal sample magnetization measurements taken previously are explained by assuming a basic permeability line width of a few gauss and a spread in resonant fields from point to point the efficiency appears to be lower than for a conventional crystal mixer 24 selective properties of an oscillator system synchronized by a harmonic signal theoretical investigation of the dependence of the amplitude and phase oscillations of an oscillator on the interference of a quasiharmonic e m f the effect on the system of harmonic and fluctuation noise is briefly examined 25 on the amplitude fluctuation of oscillations of a selfexcited vale oscillator mathematical analysis of the amplitude fluctuations of an oscillator due to thermal noise and shot effect for the case of weak and strong modes of excitation 26 short time stability of a quartz crystal oscillator as measured with an ammonia maser appreciable improvement in the short time stability is achieved by immersing the crystal in liquid helium control of the pressure of the gas above the liquid improves the long time stability though adversely affecting the short time stability 27 the reactance characteristics of concentric line circuits with interrupted inner conductor oscillator circuits in which the inner conductor is interrupted e g those comprising diskseal valves are investigated to determine the reactance as a function of gap and line section lengths normally the higher resonant frequencies of the circuit are not harmonics of the fundamental frequency 28 application of delayed feedback in electronic circuits a short general theory is given of a method of generating periodic signals of controlled shape two simple applications of a delay line aa feedback loop are given the signal frequency depends on the delay time and under certain conditions on the triggering frequency and this provides a method measuring the delay time of an element in the feedback loop 29 use of relaxation oscillators in the generation of frequency modulated oscillations an analysis of the operation of a relaxation oscillator as a frequency modulator with a series of diode circuits for transformation of the triangular waveform into sinusoidal form 30 millimicrosecond pulse generator capable of million pulses per second the generator has a repetition rate of up to sec pulse rise time less than and pulse widths from to the negative output pulse is adjustable over a range of to into a load there are facilities for gating single pulses and triggering from an outside source 31 electronic probability generator description of a random pulse generator simulating the tossing of a coin times per second the probability of a particular side of the coin can be varied 32 on the problem of starting conditions of the avalanche process in relaxation oscillators on poinoscillators on point contact triodes it is shown that the oscillators can be considered as nonlinear voltage or current amplifiers conditions governing the formation of the avalanche process are given and fomulae are derived for coefficients of voltage and current amplification circuits are shown 33 frequency divider with direct locking investigation is carried out by the phase pulse method the effect of phase shift in the feedback circuit nd of anode reaction on the divider regime is considered the effect of the shape of the synchronized and pedestal pulses on the divider is also examined theoretical data are verified by experimental results 34 generations of harmonics and subharmonics at microwave frequencies with pn junction diodes the performances of a nonlinear resistance and a nonlinear capacitance in a wideband harmonic generator circuit are analysed the nonlinear capacitance is shown to have a considerably higher efficiency results of experiments with a graded junction si nonlinear capacitance diode are given 35 a new microwave harmonic generator microwave power is used to maintain a very short mercury arc between a pool cathode and a tungsten wire anode with an estimated input power of a few watts at kmcs an output in excess of mw was obtained at kmcs a strong signal at kmcs was detected by a spectrum analyser placed close to the arc tube 36 improved diode for the harmonic generation of millimetre and submillimetre waves 37 the stability factor and static gain of transistor amplifiers a general method relating the stability factor of disturbances of thermal origin to static gain is described 38 use of the silicon resistor in the d c stabilization of transistor circuits stabilization of ground emitter small signal stages over a wide range of temperatures is achieved with a si resistor of high positive temperature coefficient in the emitter circuit 39 local feedback in transistor amplifiers the effects of negative feedback on common emitter amplifiers are calculated and compared with the measured results 40 proposal for a tunable millimetrewave molecular oscillator and amplifier 41 the molecular amplifier the principles of molecular amplification and the main characteristics of the various types of maser are reviewed 42 theory of maser oscillation the experimentally observed amplitude modulated nature of the signal from an inverted spin system undergoing maser oscillation or coherent spontaneous emission is explained 43 silvered ruby maser cavity preparation and properties are described 44 noise figure of reactance converters and parametric amplifiers a simple derivation of noise figure correcting a formula of heffner wade 45 phase considerations in degenerate parametric amplifier circuits a theoretical examination of the negative resistance in the signalling circuit as a function of the phase angle between the pump and signal voltages 46 selfquenching in superregenerative parametric amplifiers a qualitative reasoning of the behaviour of cavity time parametric amplifiers in the u h f range using ge diodes is given for the condition of selfbias or external bias with high internal resistance applied to the diode increase in pump power makes frequency response multipeaked as with regenerative valve amplifiers in the coherent state 47 use of the principles of conservation of energy and momentum in connection with the operation of wavetype parametric amplifiers some limitations on operation are explained in simple terms and certain general relations governing behaviour including the manleyrowe relation are derived 48 the quadrupole amplifier a low noise parametric device 49 analysis of a negative conductance amplifier operated with a non deal circulator 50 the gain of travelling wave ferromagnetic amplifiers the gain of an amplifier using a circular waveguide and axial ferrite rod of small cross section is determined by a general perturbation method methods for overcoming the low efficiency are discussed and other possible waveguide configurations and practical aspects of construction are described 51 two maser experiments to test general relativity a comparison of the velocities of light in two directions can be made to an accuracy within using maser techniques the two experiments involve such comparisons to test the principle of equivalence and the local isotropy of the spacet me continuum respectively 52 a model of phosphors on the basis of quantum mechanics transition probabilities with constant defects and a discrete spectrum 53 the quantum mechanical theory of the dielectric orientation polarization of gases the orientation of a dipolar gas consisting of symmetric spin molecules in an attenuating electric field 54 influence of the thomson effect on the relationship for a constrictive resistance in thermal equilibrium 55 investigation of a highfrequency resonant discharge an experimental study of a discharge in a magnetic field in the frequency range a theoretical and experimental analysis is made of the breakdown conditions and characteristics and the properties of the plasma in the discharge 56 the application of schottkys diffusion theory to discharges with several types of ions and excited neutral particles 57 the low pressure plane symmetric discharge 58 pulse technique for probe measurements in gas discharges 59 frequency multiplication by secondary electrons in the centimetre wavelength range fourier analysis of the electron current produced by secondary electron resonance multiplication shows that many harmonics are generated so that the process appears suitable for frequency multiplication in the cm range 60 theory of spatially growing plasma waves 61 on the growth of longitudinal waves propagating in plasma an analytical treatment based on a single solution of the one dimensional linear kinetic equation describing the propagation of highfrequency signals produced by a given external force it is shown that for a low temperature of the electron gas it is possible to use the ordinary single velocity approximation the analysis of the results permits a determination of the direction of propagation of natural waves in a plasma and a solution of the problem of the existence of increasing waves in a rectilinear electron beam 62 anomalous skin effect in ferromagnetics a brief mathematical analysis of the anomalous skin effect which is present in ferromagnetic materials at resonance at low temperature and at high frequencies when the depth of the skin layer is of the order of the length of a free path of the conduction electrons 63 on the singular electromagnetic field in the borniefeld theory it is shown thet for this singular case the borniefeld theory gives the same results as maxwells theory 64 simple derivation of sommerfelds formula for the dipole function 65 transmission and reflection by a parallel wire grid experimental results are given for the transmission and reflection coefficients of a plane grid of parallel wires at frequencies near kmcs the results are compared with theory 66 diffraction by a slit several methods of calculation of the aperture field are compared 67 diffraction of electromagnetic waves by smooth obstacles for grazing angles the diffraction of electromagnetic waves by a convex cylindrical suface is considered attention is confined primarily to the region near the lightshadow boundary the complex integral representation for the field is utilized to obtain a correction to the kirchhoff theory numerical results are presented which illustrate the influence of surface curvature and polarization on the diffraction pattern good agreement with the experimental results of bachynski neugebauer is obtained the effect of finite conductivity is also considered 68 the scattering of electronmagnetic waves by a corrugated sheet the physical optics method is used to determine the scattering of a plane wave by a perfectly conducting sheet having sunusoidal corrugations 69 microwave conductivity of slightly ionized air values computed from experimental data are compared with others derived from simple formulae 70 cavity resonators for dielectric spectroscopy of compressed gases tunable sealed off resonators for frequencies and kmcs at pressures are described 71 dispersion measurements on nacl kcl and kbr between and mm wavelength report of tests made with the spectrometer described in below 72 a grating spectrometer for the far infrared range and short microwaves a special diffraction grating is incorporated in the equipment described which covers the wavelength range mm for measurements blow mm the source is a mercury vapour lamp above mm a klystron with frequency multiplier is used 73 negative and oscillatory longitudinal magnetoresistance a report on the result of numerical calculations of semiconductors and semimetals for the case in which electron scattering is due to the acoustic modes of the lattice vibrations and the magnetic field is so large that the quantization of the electron orbit is important 74 methods of improving the stability in devices based on the hall effect the investigation shows that the main reasons for the temperature instability in these devices are the inhomogeneity of the crystal lattices of the sample the rectification and the insufficient equipotentiality of the hall contacts 75 a comparison of the charges of the electron proton and neutron a report of experiments to determine whether matter in which there is an excess of neutrons is electrically neutral for a comment by h bondi r a lyttleton see sept vol supplement 76 measurement of cosmic noise at low frequencies above the ionosphere a description of the basic design features of a mcs frequency sweep radiometer the equipment is to be launched as an artificial satellite for the measurement of cosmic noise 77 solar investigations in japan a description of interferometric investigations carried out during teh igy by tokio observatory in the range mcs of the intensity distribution over the solar disk the radio noise on mcs seems to originate in the solar atmosphere km above the visible solar surface recordings of radio noise between mcs are shown and the relations of solar flares magnetic storms and radiowave attenuation are considered 78 observations of the fine structure of enhanced solar radio radiation with a narrow band spectrum analyser an extension of the work described earlier 79 association of radio outbursts with solar flares data covering the period july december have been examined for a relation between rf bursts and flares a greater than normal percentage of impulsive flares of importance were accompanied by rf bursts 80 distribution of flares on the solar disk associated with noise results for periods between june and july indicate that present conditions in the solar corona favour noise emission at vhf from flares occurring in the northwest quadrant of the solar disk 81 eclipse observations of microwave radio sources on the solar disk on april results are given of observations of flux density polarization and brightness distribution made in japan four frequencies in the range 82 on the relation of solar eruptions to geomagnetic and ionospheric disturbances a statistical analysis of data indicates that the characteristics of solar rf bursts can be related to s type storms shortwave fades or a combination of both types of disturbance 83 red shift absorption spectrum of the cygnusa radiosource results do not confirm the observations of lilley mcclain 84 terrestrial corpuscular radiation a note on the two van allen zones which are attributed to charged particles moving in closed trajectories formed by magnetic traps due to the earths magnetic field a graph based on american and russian rocket data shows the variation of the intensity of these zones with height a maximum intensity is recorded at a distance between km from the centre of the earth 85 fermi acceleration of electrons in the outer van allen belt 86 the physical nature of the surface of the moon evidence concerning the structure of the lunar rock is reviewed it is probable that it is vesicular in nature 87 apparent observation of solar corpuscular clouds by direct continuous wave reflexion a report of observations in ohio of doppler signals centred on mcs which were first recorded at ut on april the observations are discussed in relation to a solar flare of importance which reached a maximum at about ut on april 88 kellogg and neys model of the solar corona critical comment on of and authors reply 89 some results obtained by measuring the magnetic field at the earth with a space rocket results obtained using magnetometers with a range of and a telemetry channel sensitivity of v where oersted indicate that at a distance of earth radii the magnetic field does not depend only on the earthpotential but also on external sources such as charged solar particles measured values recorded by space rocket are lower than calculated ones the difference between these values reaches a maximum at km and a minimum at km 90 the analytical representation of the geomagnetic field the representation of the geomagnetic field for the epoch by series of spherical functions up to order are discussed within the limits of accuracy reached the permanent geomagnetic field may be derived only with respect to sources within the earth 91 on the characteristic intervals of pulsations of diminishing periods in the electromagnetic field of the earth and their connection with phenomena in the upper atmosphere investigation by highspeed recording of the daily variation of the earths em field has shown that during strong magnetic storms characteristic intervals of pulsation occur the decreasing period of these pulsations can be directly correlated with the sharp atmospheric disturbances and the development of aurora in lower latitudes records obtained during two severe magnetic storms in are discussed 92 evidence concerning instabilities of the distant geomagnetic field pioneer i a report of some preliminary observations suggesting directional instability in the field 93 measurement of the rapid fluctuations of the earths magnetic field a ferroxcube probe in circuit with a photoelectric fluxmeter of sauzade may be used to observe fluctuations at frequencies up to cs 94 geomagnetic storms and the earths outer atmosphere re hydromagnetic oscillations of the ionized outer atmosphere are considered theoretically and discussed in relation to observations of geomagnetic pulsations the geomagnetic storm on february is analysed in terms of hydromagnetic disturbances in the outer atmosphere during such storms a corpuscular cavity earth radii in size is formed enclosing the earths magnetic field a model of the interplanetary space is proposed references 95 on the electric field of the polar magnetic storm it is suggested that proton and electron streams rushing into the ionosphere have a common powerful polarized field between them which might give rise to the currents associated with polar magnetic storms 96 the laws of motion of artificial celestial bodies the critical velocities of artificial satellites are discussed and the observed trajectory of the first cosmic rocket launched on the january is examined a rocket designed to reach the moonmust have an initial velocity of approximately ms 97 an application of dynamic programming to the determination of optimal satellite trajectories 98 orbits of artificial satellites orbits are specified by three nondimensional parameters at rocket burnout and expressions giving the periods of closed orbits in terms of the parameters are derived 99 the continued progress of satellite sputnik report of the progress of the satellite since november and of the methods used for predicting its flight at the radio research station slough earlier progress has been reviewed by kinghele 100 satellite observations of electrons artificially injected into the geomagnetic field the geomagnetically trapped electrons resulting from the high altitude nuclear detonations of the argus experiment have been observed on four radiation detectors in satellite explorer the measurements for several satellite passes through the argus shells are described and the significance of the results is summarized 101 mass spectrometer measurements of the ionic composition of the atmosphere by the third artificial earth satellite discussion of results obtained from an analysis of mass spectrograms taken between the may at heights of km in the latitude interval graphs show the variations of relative ionic intensity as a function of height and latitude above km molecular ions are on longer observed 102 the faraday fading of radio waves from an artificial satellite faraday fading of signals from an artificial satellite is analysed in terms of the difference between the doppler shifts of the ordinary and extraordinary components in the ionosphere a procedure is outlined for determining the vertical distribution of electron density in the upper ionosphere explanations are given forthe apparently excessive values of electron content yielded by measurements of faraday fading and for the observation that the rate of faraday fading is not exactly inversely proportional to the square of the wave frequency 103 radio detection of silent satellites t brief description of the characteristics of reflected signals from a standard frequency transmitter within the skin distance received on mcs see also ofkraus dreese 104 diurnal and semidiurnal variations of wind pressure and temperature in the troposphere at washington dc 105 turbulence at meteor heights an outline of a new method of studying motions at meteor heights by assuming that they are perturbations associated with oscillating waves propagated through the atmosphere 106 study of the new model of the ionosphere the variation with height of the electron density is calculated for three cases and good agreement is obtained between the model and the results of moon echo observations 107 effect of small irregularities on the constitutive relations for the ionosphere a theoretical treatment of the modification of refractive index due to small irregularities the latter may play an important part in the propagation of vlf radio waves 108 stratification in the lower ionosphere a survey of the evidence for stratification at heights below km over references 109 electron collision frequencies in nitrogen and in the lower ionosphere by using an improved version of the electron drift velocity tube in the laboratory measurements and an improved analysis of rocket data the two sets of results are brought into agreement reevaluation of the rocket data involves the energy dependence of the electron collision frequency 110 the possible occurrence of negative nitrogen ions in the atmosphere if negative ions are formed and laboratory experiments show that they may be a strong pressure dependence of the electron ion recombination coefficient is to be expected at the very low f region pressures the rate of disappearance of free electrons could follow an attachment law 111 tides in the f ionospheric layer a brief report of the results of a harmonic analysis of the mean diurnal variation of the layer semithickness during the period at leopoldvillebinza belgian congo 112 a theory of spread f based on a scattering screen mod oblique rays from the sounder are scattered by a scattering screen into the f region whence they are reflected back to the sounder for frequencies appreciably higher than the f region penetration frequency there is a linear relation between the minimum virtual height of the returned signal and the operating frequency all virtual heights above this minimum value and below the normal vertical incidence value are possible this fact accounts for spread echoes being enclosed by two sharp defined boundaries this hypothetical picture agrees with that obtained from actual ionograms but requires that the screen be above e region heights 113 magnetic control of the variations of the critical frequency of the f layer of the ionosphere the true magnetic latitude reference is shown to give more satisfactory results than the idealized geomagnetic latitude reference when considering diurnal and latitudinal variations of f at low latitudes 114 measurement of ionospheric electron densities using an rf probe technique the probe consists of a dipole operating at mcs and has been flown in a rocket over fort churchill above km it behaves as a capacitor the capacitance of which is telemetered to the ground the local electron density in the ionosphere may be calculated from these values by using a simplified form of the appleton hartree equation the electron densities obtained using such probes are in good agreement with those obtained by normal methods 115 investigation of winds and inhomogeneities in the ionosphere using a radioastronomy method description of measurements made using three parabolic meshtype reflectors of area spaced approximately apart and operating at a wavelength of m ionospheric wind velocities of ms were recorded 116 ionospheric investigations using the sweep frequency pulse technique at oblique incidence a review of oblique incidence investigations especially those carried out at the national bureau of standards showing diurnal and seasonal variations on two eastwest paths of km and km there is a discrepancy of about between the observed and calculated muf 117 the d region of the ionosphere 118 the argus experiment a geophysical experiment on global scale was conducted last fall three small abombs were detonated beyond the atmosphere at a location in the south atlantic the purpose of the experiment was to study the trapping of the relativistic electrons produced by the decay fission fragments in the geomagnetic field the released electrons are trapped by this field oscillating along the magnetic lines between two mirror points in addition to this motion the electrons drift eastward creating a thin electron shell around the earth the lifetime and location of the thus created global electron shell were measured by satellite and rocket borne instruments auroral luminescence was observed at the conjugate points the electron shell exhibited remarkable stability during its lifetime no motion of the shell or change in its thickness was detected 119 optical electromagnetic and satellite observations of high altitude nuclear detonations part after each of the high altitude detonations in the argus experiment visual auroras were observed in the detonation area after the third event an aurora was observed in the conjugate area after the second and third events signals attributed to hydromagnetic waves were detected in the conjugate region these signals had a periodicity of about cs the maximum change in the magnetic field was about gamma io propagated along the magnetic line of force the velocity was about km sec sporadic e was observed after the third event in the conjugate area comparative records of the and lines were obtained in the detonation area 120 optical electromagnetic and satellite observations of high altitude nuclear detonations part the radio effects of the argus detonations were measured using mcs radars designed to obtain echoes from the aurora or from the earths surface mirrored in an enhanced ionospheric layer vlf receivers for monitoring distant transmitters or atmospheric noise sources in search of changes in signal strength riometers for recording cosmic noise absorption or vhf shot created noise at and mcs results included auroral echoes in the vicinity of the launch point after all three shots and near the conjugate points after the first and th d shot sudden depressions of to db of the signal from england at madrid and the azores no ionospheric absorption at the conjugate location 121 project jason measurement of trapped electrons from a nuclear device by sounding rockets highaltitude sounding rockets have been used to observe electrons injected into the geomagnetic field from the highaltitude nuclear detonations of the argus experiment the results of these observations agree with those measured by satellite explorer the trapping of neutron decay particles from large yield highaltitude explosions in the pacific was also observed 122 theory of geomagnetically trapped electrons from an artificial source the history of electrons resulting from the highaltitude nuclear detonations of the argus experiment is treated theoretically and the results are compared with the jason rocket data and the explorer satellite data 123 modern theories of thunderstorm electrification critical comparison of theories eg of wilson suggestions are made for investigations to determine the correctness of convection theories references 124 very low frequency radiation spectra of lightning discharges an analysis is given of the ground wave portion of sferics waveforms recorded from cloud to ground discharges between and km from boulder colorado frequencies of peak energy lie between and kcs 125 diurnal variation of aurora and geomagnetic disturbance at new zealand antarctic stations a relation exists between aurora and geomagnetic disturbance but the main features of diurnal variation of auroral incidence are not related to local geomagnetic variations 126 low frequency radio noise from the aurora strong rf noise recorded on one occasion at frequencies up to kcs is reported 127 auroras magnetic bays and protons observational evidence indicates that aurorae and magnetic bays both have the same cause and occur at the same geographic location calculations show that these bays can be explained by a wind movement of positive ions generated by incoming solar protons 128 observations of whistlers and very low frequency phenomena at godhavn greenland 129 a digital remote position control a description of a servo shaft position control system using digital techniques throughout the logical circuit arrangements and methods of stabilizing are discussed together with the design procedure 130 inverse feedback stabilizes drycell current sources a transistor emitter follower circuit enables constant heavy currents to be drawn from dry cells despite variations in cell voltage 131 power supply design using silicon diodes 132 constant current coup transistor power supply by feeding a constant current through a fixed resistor across the supply output an unattenuated error voltage can be applied to the error correcting amplifier of a series regulated power supply 133 designing highly stable transistor power supplies design techniques are summarized and a circuit is described with overall stability and drift 134 transistors and saturable core transformers as square wave oscillators the use of transistors as switches for the dc supply to saturable core transformers is described and it is shown that by this means small and efficient convertors and invertors can be constructed the common base common emitter and common collector configurations are considered and methods of obtaining a multiphase output are described 135 a method of reducing the time lag of transducers which have an exponential response the response of a transducer such as a thermocouple is corrected for phase and amplitude by adding its output voltage to its amplified derivative details of a drift corrected dc amplifier and highly stable power supply are given 136 the stabilization of dc voltages by switched transistors stabilizing circuits are discussed in which transistors function as continuous control devices or as switches driven by a schmitt trigger circuit comparison is also made with a transistor switched rectifier circuit 137 method of amplitude control of ac signals a circuit for controlling the rms value of an ac signal is analysed and practical results are discussed the speed of response is such that for rates of change of per second the output is controlled continuously within an alternative arrangement for maintaining at a preset level the peak value of repetitive pulses is also given 138 zener diodes as reference sources in transistor regulated power supplies a summary of the relevant properties of zener diodes including a figure of merit representing the maximum value by which supply variation may be reduced methods for controlling the overall temperature coefficient are considered 139 ammonia vapour activated batteries 140 the simulation of equations with analogue computers detailed description of the principles of operation of the various computer elements giving examples of programming and computation with reference to an american electronic analogue computer 141 some aspects of the logical and circuit design of a digital field computer a new type of digital computer for the solution of field problems is described by making calculations at all the lattice points of the field simultaneously computation time is greatly reduced an experimental design of a basic unit for potential and other problems is presented 142 the a c writing method for magnetic core matrices description of a writing method suitable for operation in a system using parametron devices two alternating currents of frequency respectively produce an asymmetrical field in a toroidal core one of the writing currents is also used for reading 143 function generation with operational amplifiers errors in analogue computers caused by diode limiters can be reduced by using accurate electronic switches with high gain d c amplifiers and voltage feedback applications of the techniques for comparators multivibrators and integrator reset circuits are described and future applications are indicated 144 reading of recorded signals with a low frequency parametron description of a tape recording system in which parametron devices replace valves to increase the storage capacity some form of multiplex system is required 145 high density recording on magnetic tape a self clocking technique is used to bypass problems of digital recording at a density of bits high reliability is obtained with no information drop out 146 the application of a pattern recognition technique to the synthesis of coding circuits if the coding processes considered are regular and predictable then corresponding translating circuits can be determined to illustrate the technique a pattern recognition method is applied to two coding problems 147 the synthesis of a parallel adder circuit using a pattern recognition technique besides the synthesis a comparison with a conventional adder circuit is given 148 lens designing by electronic digital computer a description of the program used and the results achieved 149 miniaturization and microminiaturizatio description of new techniques giving increased reliability together with a preliminary evaluation of their performance compared with existing techniques 150 signal converter by magnetic cores for parametron device input signals for a parametron device may be switched using ferromagnetic cores whose permeability is controlled by direct voltage 151 transistor switching speed theoretical treatment of the limitations of transistors in high speed switches together with some methods of improving performance by decreasing switching time 152 the breakdown strength of capacitors a formula for breakdown field strength is derived which contains the coefficient of thermal conductivity the dielectric constant and a factor giving carrier mobility 153 the temperature and voltage dependence of the length of life of capacitors the process of deterioration of the dielectric material under various operating conditions is discussed on a theoretical basis and with reference to life tests on paper capacitors 154 contribution to the theory of general quadripoles the matrix characteristics of general linear quadripoles are investigated and a strict definition of a lossless quadripole is given an equivalent circuit of the quadripole formed by three partial quadripoles connected in tandem is derived matching problems and a formula for power gain are discussed 155 design of attenuators of given characteristics design formulae for quadripole attenuating networks are tabulated 156 a reciprocal theorem on quasilinear wave filters under certain conditions the power of an intermodulation product measured at one pair of terminals of a filter equals that measured at the other pair when all signals are transmitted in the opposite direction but at unchanged levels 157 electromechanical filters for use in telecommunication equipment includes descriptions of construction and performance of reed type magnetostrictive and piezoelectric filters 158 a practical electromechanical filter details of materials and fabrication techniques are given for narrow band torsional filters 159 a theoretical analysis of the torsional electromechanical filters the mechanical properties of a torsional system are expressed in terms of electrical equivalents by introducing a transducer transfer ratio with the dimensions of charge a method is developed for the design of electromechanical filters based on equivalent electrical networks pass band ripple spurious modes and transducer matching are discussed 160 digital input for precision variable oscillators details are given of a signal generator for the frequency range the drive unit is a voltage controlled oscillator regulated by the difference in width between standard pulses and pulses whose duration is that of the time required for the oscillations fed to a counter unit to equal a preset number 161 a method of generating pairs of millimicrosecond current pulses separated by a variable interval the first pulse is formed by the discharge of a coaxial line l through a spark gap into a variable length section of identical line a second pulse is produced by the return of the first pulse after reflection at the short circuited end further reflections from the other end of l are prevented by a clipping valve 162 frequency stable oscillators for current and voltage the suitability of bridge type oscillators as current or voltage source under optimum frequency stability conditions is discussed 163 wien bridge oscillators theoretical analysis of wien bridge oscillators and procedure for practical design together with an example of thermistor stabilization 164 pulse modulators using transistors and switching reactors a regenerative circuit is described which uses a power transistor to control the charging of a pulse forming network through a transformer with a sharply saturating core 165 point contact transistor relaxation oscillators the plotting of phase curves for oscillators with emitter collector and collector capacitance are shown and possible operating modes investigated expressions are given for deriving the pulse parameters conditions are expressed for the appearance of step discontinuities as well as for a self oscillatory mode 166 approximate waveform solutions for diodes in pulse circuits with an approximate representation of a diode solutions are obtained for the response of simple circuits to a rectangular wave input applications of the results are discussed 167 an investigation into some aspecst of diode quantizing circuits quantization is defined and work in the field is reviewed three circuits are compared theoretically and by measurement and possible applications are described 168 harmonic generation in a cyclotron resonant plasma the harmonic conversion efficiencies are comparable to those for crystals and over the same power range superior to those for ferrite multipliers 169 a transistor blocking oscillator frequency divider this includes the design of a staircase waveform generator in which all the voltage increments are equal in amplitude 170 design of pulse amplifier a relation between gain overshoot and risetime is derived and applied in the design of a single stage valve amplifier 171 distortion in pentode voltage amplifiers characteristics are given which show that for a fixed screen voltage the distortion varies rapidly with changes in grid bias whilst if the screen voltage is supplied via a series resistance there is a compensating action which maintains the distortion at an almost constant value 172 rc amplifier with bandwidth the effect of stray capacitance is compensated by a cathode follower circuit 173 cathode coupled push pull output stage a theoretical investigation of linear operation shows that for large common cathode resistances the ratio of anode currents in each valve approximates to unity 174 how magnetic amplifier controls transconductance 175 transistor amplifiers for sound broadcasting the application of ge p n p junction transistors to various types of high quality amplifier is described an assessment is made of the suitability of transistors for this field 176 transistors in low frequency amplifiers design formulae are derived and the relations between circuit parameters for the three basic transistor configurations are tabulated the main types of feedback and their effects are discussed 177 possible low noise electron beam plasma amplifier 178 cavity maser experiments using ruby at s band a three level solid state maser was used 179 a double pumping scheme applicable to low frequency masers note on a parallel pumping system of importance for low frequency operation of a ruby maser 180 semiconductor varactors using surface space charge layers 181 alloyed thin base diode capacitors for parametric amplification the design principles are ghven 182 electroluminescent cell applications an account of investigations of the combination of electro luminescent cells and photo receptors as elements in amplifier oscillator demodulation amplifier and bistable multivibrator circuits measurements of the variation of efficiency with frequency and a theoretical analysis of photoconductor amplifier time constants are also ghven 183 diode phase sensitive detectors with load a theoretical and experimental investigation of the nonlinearity introduced by loading a simple diode pushpull phase detector 184 new experimental test of special relativity 185 two coordinate colour 186 on the screening of impurity potential by conduction electrons a modified thomas fermi method is used to calculate the impurity potential and it is shown that similar results are obtained by the method of nakajima and bardeen and pines 187 the effect of field configuration on gas discharge breakdown in microwave cavities at low pressure a new regime of gas discharge breakdown in microwave cavities is shown to be due to gradients in the electric field amplitude experimental results are given 188 necessary and sufficient trajectory conditions for dense electron beams gives conditions for flow in the direction of one coordinate in a number of coordinate systems 189 two alternative definitions of small signal r f power of electron beams lagrangian or eulerian definition is chosen according to the type of problem or method of calculation 190 comments on kluvers paper entitled small signal power conservation theorem for irrotational electron beams 191 measurement of plasma temperature and electron density 192 electron and ion runaway in a fully ionized gas hydrodynamic equations are used to describe the flow of the electrons and ions of a fully ionized gas under the action of an electric field of arbitrary magnitude 193 ionization phenomena in gases report of a conference at uppsala sweden 194 effect of relatively strong fields on the propagation of e m waves through a hypersonically produced plasma 195 possible low noise electron beam plasma amplifier low noise amplification of space charge waves should be achieved by interaction between electron beam and plasma in the negative glow region of a cold cathode discharge 196 plasma configurations with surface currents which are held in equilibrium by a magnetic field the conditions for the existence of various plasma configurations in equilibrium with an external magnetic field are investigated 197 remarks on magnetically dilute systems a re examination of the problem using an ising model 198 a scalar representation of electro magnetic fields ghves transformation properties and the physical energy momentum tensor appropriate to green and wolfs theory 199 a scalar representation of electro magnetic fields extens work in an earlier paper to deal with energy transport 200 diffraction of a dipole field by a unidirectionally conducting semi infinite screen an exact solution of the diffraction problem for a dipole is obtained 201 diffraction of electromagnetic waves in a band of finite width brief mathematical analysis based on a new method for solving integral equations similar to the fredholm equations 202 induced and spontaneous emission in a coherent field the interaction between the electromagnetic field and a number of identical atomic systems individually characterized by an electric dipole moment and tow energy levels is analysed for the case where the atomic systems are inside a lossy cavity and exposed to a coherent driving field resonance being assumed between atomic system cavity and driving field 203 square wave modulator and receiver for stark effect microwave spectrometers 204 superexchange interaction and symmetry properties of electron orbitals a search for neutral atomic hydrogen in globular clusters 205 the relation of cosmic radio emission to the electronic component of cosmic rays the similarity between the spectra of cosmic rays and of the relativistic electrons responsible for cosmic radio waves suggests that the electrons may derive from the collisions of primary cosmic rays with the interstellar gas the relation to be expected from this process is examined 206 the brightness distribution within the radio sources cygnus a and cassiopeia a 207 the source of radiation from jupiter at decimetre wavelengths electrons from the sun which are trapped in jupiters magnetic field may be the source 208 radio emission in the outer corona 209 correlation between the intensity of the umbra of sunspots and enhanced radiation from observations made in norway since april a high correlation is shown to exist between the darkness of the umbra and noise activity of sunspots 210 geomagnetic disturbance and velocity of slow drift solar radio bursts 211 a radio astronomical test of the ballistic theory of light emission a comparison between optical and radio interferometer measurements of the declination of radio star cygnus a is put forward as proof that the ballistic theory of light emission is untenable 212 on the possibility of detecting synchrotron radiation from electrons in the van allen belts 213 proton component of the primary cosmic radiation the proton component has been studied at high altitudes on a series of balloon flighst at various latitudes using the cerenkov scintillation counter technique results are discussed 214 unusual cosmic ray fluctuations a large forbush decrease of cosmic ray intensity which coincided with a magnetic storm exhibited rapid changes of neutron intensity it is diffult to account for these changes on the basis of existing theories of the modulation of cosmic radiation 215 radio echo observations of venus a description of the equipment used and a discussion of the results of observations at kodrell bank no echoes stronger than the noise level of the receiver were observed an analysis of the signals received was therefore made with integrating equipment and the results compared with those of price et al 216 the effect of trail irregularities on the interpretation of meteor echoes a brief discussion of some points raised in a recent paper by manning on obliquely scattered meteor echoes is followed by the suggestion that the initial distribution of ionization along a typical meteor trail is markedly irregular several tentative hypotheses are advanced to account for the irregularities 217 variations in the geomagnetic field at ibadan nigeria 218 effects of the earths oblateness on the orbit of an artificial satellite a mathematical analysis of the perturbations of the radius vector the displacement of the nodal and apsidal lines and the variation of the inclination with latitude a rigorous solution to the second order differential equation is given for an equatorial orbit taking account of the first order effects of the earth oblateness some second order effects on the equatorial orbit and the relativistic effect of the apsidal line displacement are considered 219 density of the upper atmosphere from analysis of satellite orbits further results a method described earlier has been refined to take into account atmospheric rotation 220 the ion trap results in exploration of the upper atmosphere with the help of the third soviet sputnik the interpretation of the data given b krassovsky is queried and an analysis presented which leads to lower values of vehicle potential and electron temperature 221 unusual propagation of satellite signals 222 multiplexing techniques for satellite applications 223 radiosondes for measurements of atmospheric electricity four types of radiosonde are described 224 the earth in the suns atmosphere the extent nature and interrelation of the solar and terrestrial atmospheres are considered 225 solar activity and the altitude of the tropopause near the equator 226 molecular oxygen densities in the mesosphere at fort churchill 227 a contribution to the theory of the motion of weak irregularities in the ionosphere if diffusion is neglected any one dimensional irregularity travels unchanged with a constant velocity which depends on the magnitude and direction of the ionospheric e s and magnetostatic fields in the same way a weak two dimensioal irregularity which is parallel to the direction of the magneto static field travels with a constant velocity and preserves its shape more complicated irregularities do not preserve their shape 228 a discussion of the motion in nitrogen of free electrons with small energies with reference to the ionosphere it is found that the collision cross section of electrons is proportional to their velocity from this result an accurate expression is derived for the velocity of electron drift in terms of the mean energy of the electrons the energy losses are found to be mainly due to excitation of the rotational states of the nitrogen molecules 229 a theory of electrostatic fields in t horizontally stratified ionosphere subject lo a vertical magnetic field a discussion of a possible explanation of spread f and radio star scintillation 230 new methods and some results concerning true ionospheric height calculations 231 transient fine structure of the e layer a note on the fine structure of the e layer and its variability as observed using an ionosonde with high power and slow frequency variation 232 the ionospheric e layer at cape hallett ionograms were examined and the e layer critical frequencies of those unaffected by ionization movements were compared with those expected on a simple chapman model agreement was good when an electron recombination process was considered for the model 233 the gyro frequency in the e layer above slough england 234 the early morning e layer and some evidence of pre sunrise f layer splitting observations at haringhata india show that cusps and ridges are regular sunrise phenomena at that location with marked seasonal variations in character and frequency of occurrence a splitting of the f layer during early morning in winter is also observed and the possible bearing of this on the e layer phenomena observed is discussed 235 annual distribution of sporadic e 236 sporadic e ionization over lindau harz during last year 237 annual wave in the world wide f region ionization 238 note on the cause of ionization in the f region 239 a new theoretical model of the composite f layer it is suggested that bifurcation of the f layer is caused by a fairly rapid variation in temperature gradient and that tidal variations have only secondary effects 240 single and double inflexions on the f arace an attempt is made to explain the bifurcation of the daytime f layer in terms of the appleton lyon theory of the height lag f layer models are considered and since the height lag decreases through the day bifurcation lakes place 241 anomalous ionospheric reflection during solar eclipses analysis of electron densities during an eclipse shows that while the slope and curvature of layer strata are mostly very small effective discontinuities can occur which would produce complexities in ionograms these complexities are due to rays reflected along paths inclined to the vertical 242 on artificial geomagnetic and ionospheric storms associated with high altitude explosions the electron density in the outer ionosphere sudden changes in the virtual height of radio waves reflected from the e region of the ionosphere it is shown that the lower level reflections are from thin layers within the normal e region the changes in amplitude are used to deduce the thickness of these layers and the electronic collision frequency in the e region 243 the interpretation of sudden field anomalies in the long wave range during solar flare effects 244 the height of f layer irregularities in the arctic ionosphere 245 observations of the ionosphere over the south geographic pole 246 motions in the magnetosphere of the earth the magnetosphere is defined as the region above the ionosphere in which the earths magnetic field has dominant control over the motions of gas and fast charged particles conditions in the magnetosphere and the mymamical behaviour of its constituents are discussed 247 horizontal movements of visual auroral features 248 existence of an inner auroral zone study of a population of aurora which seems to form an inner auroral zone 249 type b aurora in the antarctic the results of auroral observations are discussed and an excitation mechanism is suggested to explain the type b spectrum 250 v h f and u h f radar observations of the aurora at college alaska 251 directional observations of radio noise from the outer atmosphere 252 spaced observations of radio noise from the outer atmosphere 253 location of initial sferics of long whistlers sources of atmospherics were located by a u s s r research vessel in the vicinity of ireland in december and coincidences with long whistlers were observed one of the records is analysed 254 synthesis of the waveforms of atmospherics and effective parameters of the lower ionosphere at low frequencies 255 using digital techniques in time encoders a decimal indication of the elapsed time is given every twenty seconds the output is suitable for either magnetic tape or paper chart recorders 256 the design of transistor push pull d c converters the circuit least affected by external influences is a square wave oscillator controlled by a saturating transformer design formulae are given 257 equations for designing transistor power supplies basic design equations and graphs for transistor d c d c converters are given 258 operational and storage life of silicon rectifiers results are given of life test measurements of forward voltage drop and reverse current 259 controlled rectifiers drive a c and d c motors by using saturable magnetic core firing circuits the size and weight of switching devices are reduced half wave and full wave push pull circuits are described 260 contribution to the problem of limiting values for semiconductor circuit elements the danger of exceeding the permissible voltage limits in series connected power rectifier elements is discussed this difficulty can be overcome by the use of parallel resistors or capacitors as shown in the reverse voltage time curves given 261 voltage and current stabilization with power transistors basic circuits and design data and details of two power units are given 262 new digital computer techniques a report of specialist discussion meetings of the measurement and control section of the i e e dealing with character recognition peripheral equipment low temperature storage and switching devices and special aspects of logical design 263 study of certain errors in analogue computers linear and nonlinear imperfections in adding and integrating circuits are related to errors in the solution of differential equations analogue computers using only a c amplifiers are shown to be a practical proposition 264 electronic rotor a method is described for introducing the concepts of bearing and angle into fast cartesian analogue computations without the use of mechanical shafts and servomechanisms 265 microwave computer circuits examples of the use of microwave components and techniques in the construction of simple high speed computing elements are given main problems are the cost and complexity of the waveguide systems required 266 use of a diode ring as a four quadrant multiplier the operation of a diode ring as a passive analogue multiplier is analysed 267 electronic digital computers 268 noise of resistors and resistor combinations without and with load noise due to current flow in carbon film type resistors is particularly considered the increase over thermal noise is controlled by a factor which depends on loading film dimensions and the construction of the resistor from this a formula is derived which contains a constant dependent on film material 269 the impedance of non quasi stationary annular plate capacitors the maximum permissible dimensions for the avoidance of self resonance are calculated for high frequency grid stopper and lead through capacitors 270 the reliability and life of impregnated paper capacitors the construction of paper capacitors and the problems associated with failure in them are reviewed possible methods of prolonging life and reducing failures are discussed 271 coaxial resonators with helical inner conductor resonators of small size can be designed for the v h f and h f ranges design formulae are simple and have been confirmed by experiment 272 general energy relations in nonlinear reactances an alternative derivation to that used earlier is based on conservation of energy and the properties of the device 273 a simplified derivation of the manley and rowe power relationships 274 the determination of canonical reactance quadripoles with prescri ed iterative matrix the iterative matrix of any reactance quadripole is realized by means of canonical circuits the method consists in developing a two pole function into a continued fraction this function represents the impedance of the two pole network which results from terminating by unity resistance the output of a quadripole realizing the given matrix 275 applications of wave matrices for calculations over terminal networks with transverse symmetry an extension of the method used in the classical theory of linear networks and based on bisecting the four terminal network 276 modern network theory in electrical engineering report of a conference held by the department of electrical engineering of the university of birmingham 277 some considerations on the stability of electrical circuits a definition of stability based on an integral equation is proposed it is considered to be more general in applicability than the definitions of bode and james and weiss 278 multistage amplifier stability design criteria the stability of a cascade amplifier is considered for the two cases where the stability factors of all the stages are equal a before cascading and b after cascading a short discussion of the results is given 279 push pull amplifier balance negative voltage feed back may be applied independently to the two sides of a push pull amplifier circuit by the insertion of an inductance and shunt resistance network in the lead to the primary centre tap of the output transformer 280 reducing amplifier distortion a method is described for correcting the nonlinear distortion in valve amplifiers using metallic rectifiers as nonlinear resistances examples of corrected single ended and push pull amplifiers are given 281 some design considerations for high frequency transistor amplifiers the interaction between output and input due to internal feedback in the transistor is illustrated and design data are developed for networks used to overcome this many practical amplifiers are simple and require a minimum of design effort 282 spin spin energy transfer and the operation of three level masers 283 construction of a strong field maser type self oscillator proton spin resonance in a current of magnetically polarized water is applied in the design of a maser which operates in stable conditions without parasitic modulation 284 operation of a zero field x band maser 285 operating characteristics of an ammonia beam maser the simple theory is expanded to predict the angular distribution of the molecules leaving the collimator and the effect of the focuser on the velocity distribution comparison with experimental data shows the importance of collisions and beam divergence 286 parametric amplification and conversion in propagating circuits using nonlinear reactances the case of a time varying reactance coupling three propagating circuits is analysed 287 noise figure for a travelling wave parametric amplifier of the coupled mode type 288 an extremely low noise six kmc s parametric amplifier using gallium arsenide point contact diodes variation of excess noise temperature with diode temperature has been measured a range of values comparable to that for a maser has been obtained 289 x band parametric amplifier noise figures two types of gaas point contact diode with improved gain bandwidth properties have been examined 290 low noise parametric amplifier using germanium p n junction diode at six kmc s experimental arrangements and results are given for noise figure measurements at various bias voltages and temperatures 291 subjective colour tests land colour is found to depend on subjective effects and picture composition to convey the colour information to the mind of the observer it does not therefore offer a practical system for colour television 292 crystal stability and the theory of ferroelectricity 293 influence of an electric field on an optical absorption edge the absorption edge displacement in a crystal with external field strength of the order is interpreted 294 deviation from matthiessens rule and lattice thermal conductivity of alloys the difference in the ideal electronic thermal conductivity between an alloy and a pure metal can be estimated from the corresponding difference in the ideal electrical resistivity using the wiedemann franz law 295 the inverse skin effect the axial current density in an infinite cylindrical conductor is calculated as a function of radius and time rigid and radially expanding conductors are treated current density distributions are obtained which sometimes have no resemblance to the normal skin effect 296 irreversible thermodynamics and kinetic theory in the derivation of thermoelectric relations considerations of irreversible thermodynamics simplify the determination of thermoelectric coefficients using kinetic theory arguments based on boltzmanns equation a new expression for thomsons coefficient has been derived only simple models lave been used but the theory is capable of extension to more complex ones 297 the structure of a stream of electrons and ions drifting and diffusing in a gas when ionization by collision and molecular attachment are present 298 calculation of the thermal conductivity of an ionic current a th rmal conductivity tensor for the ionic part of a plasma is derived from kinetic theory 299 electric field distributions in an ionized gas a method for improving systematically the holtsmark distribution is described it is then applied to the calculation of the distribution of the high frequency component of the electric field in an ionized gas in thermal equilibrium 300 space charge waves in cylindrical plasma columns the existence of space charge waves in stationary plasmas of finite cross section has been demonstrated theoretically and experimentally in addition to forward waves a plasma can support backward waves when there is a finite axial magnetic field this makes possible the design of a back ward wave oscillator in which the plasma is the slow wave circuit other possible applications are noted 301 electromotive force in a highly ionized plasma moving across a magnetic field the e m f is proportional to the flow speed oscillographic probe measurements of flow velocity and plasma resistance are described 302 statistical mechanical theory of a random ferromagnetic system study of the behaviour of solid solutions of paramagnetic impurities which are exchange coupled in a nonmagnetic substrate yields a considerable amount of information about the nature of the exchange coupling and the temperature dependence of the spin system 303 study of the paramagnetic faraday effect from a study of propagation in a gyromagnetic medium the magnitude of the faraday effect is determined as a function of the constant of the medium the theory is applied to rotation in paramagnetic salts and curves are derived for the rotation angle as a function of the applied field a description is given of experimental apparatus and results of measurements on mn and fe salts at wave lengths of one and ten cm are compared with theoretical calculations 304 structure of the electromagnetic field a mathematical study of the structure of a curved space time in which a source free e m field is present 305 helical fields simple analytic helically invariant solutions of the laplace equation are given and combined to describe the e s field of a charged helix and the magnetic field of a helical electric current certain graphical flux plotting methods are out lined and illustrated and network analogies are suggested for solving these fields 306 significance of electromagnetic potentials in the quantum theory contrary to the conclusions of classical mechanics there exist effects of potentials on charged particles even in the region where all the fields vanish the significance of this is discussed 307 microwave magnetic field near a conducting perturbation experiments are described to show that locally intense microwave magnetic field strengths can be obtained with low power levels by using a conductor to perturb the microwave electric field of a resonant cavity 308 radiation produced by the transit of charged particles near ideally conducting bodies expressions are obtained for the energy and radiation spectrum the excitation of oscillations by electrons entering a circular waveguide from an open half space is discussed 309 radiation from particles exceeding the velocity of light and several applications of it in experimental physics the history of the discovery and interpretation of cerenkov radiation is outlined the application of radiation measurements in the investigation of cosmic ray showers is discussed 310 vertex excited surface waves on both faces of a right angled wedge 311 diffraction by an infinite slit a rigorous analysis of the problem for plane waves with special emphasis on short wavelengths and grazing incidence 312 construction of a strong field maser type self oscillator 313 on the asymptotic series expansion of the motion of a charged particle in slowly varying fields 314 self consistent field approach to the many electron problem the self consistent field method in which a many electron system is described by a time dependent interaction of a single electron with a self consistent e m field is shown for many problems to be equivalent to the many body treatment 315 electrodynamics of charge carriers of negative effective mass in crystals the transport properties of negative effective mass carriers in crystals are studied the electrical conductivity of a sample in which the electron distribution function is weakly perturbed from its thermal equilibrium value is always positive even in the presence of a magnetic field cyclotron resonance experiments in equilibrium should therefore display energy absorption 316 optical pumping in crystals an estimate is made of the expected population change in the ground state of a crystal due to optical pumping 317 the coupling of a spin system to a cavity mode a wave mechanics treatment is given in which the expectation value of the component of total spin angular momentum is determined this problem has become important with recent developments in maser technology 318 the determination of the electron density in interplanetary space the average electron density and the arc length of the ray path from a space vehicle to the ground can be measured by transmitting a pulse to the vehicle on one very high frequency and receiving pulses emitted from a transponder in the vehicle on this and on a different frequency in this way electron densities of the order of hundred electrons cm can be estimated 319 the temperature required for nuclear reactions in cosmical electrical discharges 320 technical and astronomical measurements with the bonn twenty five m radio telescope details are given of operational tests on the receiving installation of the bonn university radio telescope on the stockert additions to the receiving equipment and the calibration of the aerial by series of astronomical measurements and comparisons with results from other radio telescopes are also described 321 the positional accuracy of the twenty five m radio telescope of the bonn observatory the tracking system and its adjustment and control are described details are also given of the alignment of the telescope axes and the correction of mechanical inaccuracies of the reflector structure 322 radio star scintillations and ionospheric disturbances spread f phenomena are not adequate to explain scintillations at fifty three mc s at ottawa and precipitation of solar particles seems to be involved at high latitudes 323 cosmic radio noise absorption on twenty five mc s and f scatter a close connection is suggested between the observed anomalous enhancement of scattered v h f signals and the post sunset increase in the attenuation of cosmic noise 324 observation of the central regin of the galaxy at cm with the large radio telescope of the g a o 325 observation of the sagittarius a radio source at high resolution description of observations carried out in april by the pulkovo radio telescope graphs show the complex structure of the source 326 neutral hydrogen gas in the taurus orion region observed with a multi channel twenty one cm line receiver 327 solar radio bursts and low energy cosmic rays events following a solar flare are elucidated from a study of the relation between continuum radiation and the occurrence of enlanced proton flux at the earth 328 on the correlation of solar noise fluctuations in harmonically related bands a method is proposed for the study of the solar corona a delayed correlation between rapid fluctuations of enhanced solar radio emission type two in harmonically related frequency bands would be observed 329 occultations of the crab nebula by the solar corona in june the distribution of radiation on days when the angular separation is less than ten solar radii is not consistent with a symmetrical scattering process better agreement is obtained by postulating the existence of scattering and regular refraction of comparable magnitude 330 energy spectrum of the leavy nuclei in the cosmic radiation 331 the onset times of forbush type cosmic ray intensity decreases 332 a comparison of the cosmic ray intensity at high altitudes with the nucleonic component at ground elevation results of balloon borne soundings with single geiger tubes are compared with those made by a nucleonic detector on mount washington 333 on the structure of extensive cosmic ray air showers the penetrating component 334 absence of craters on the far side of the moon the reported lower incidence of craters on the far side of the moon may be explained by the effect of the earths gravitational field on meteoric material in orbit about the sun 335 observations related to the impact of lunik two a table is given of the results of a number of independent observations of the impact of lunik two with the moon 336 first results derived from the photographs of the moons far side photographs taken by the third soviet cosmic rocket launched october are shown during forty min of cam ra operation numerous photographs were taken of the moons far side at distances from its surface 337 the temporal variation of the heights of reflection points of meteor trails there is no significant seasonal variation in either the mean height or the width of the height distribution the mean height alone shows a diurnal variation with maximum height near midnight both height parameters depend on the zenith angle of the apex of the earths way 338 air motions and the the mading diversity and aspect sensitivity of meteoric echoes a theory is given of meteoric reflection from distorted trails experimental results confirm the predictions and facilitate a determination of the principal properties of the wind profile 339 meteor radiant distributions and the radio echo rates observed by forward scatter the diurnal variations observed by forward scatter over three different paths are found to be in reasonable agreement with predictions made using a simplified model distribution based on the radar data of hawkins 340 turbulence at altitudes of km and its effects on long duration meteor echoes the characteristics of the echoes can be readily explained in terms of multiple reflections from overdense columns of ionization and are not consistent with the theory of incoherent scattering from under dense columns 341 prediction of sunspot numbers for cycle twenty 342 note on conjugate points of geomagnetic field lines for some selected auroral and whistler stations of the i g y a method of deriving conjugate points of some auroral and magnetic stations of the i g y 343 geomagnetic oscillations at middle latitudes parts one and two observations of geomagnetic fluctuations in the frequency range cs are discussed based on measurements at tucson arizona the results favour the hypothesis of intralayer hydromagnetic resonance in the ionosphere as the source mechanism 344 geomagnetic activity at halley bay on disturbed days diurnal variations of geomagnetic activity on disturbed days are related to auroral and ionospheric effects an analysis of five world wide sudden storm commencements ssc shows positive departures of the horizontal field before midnight and negative departures after midnight 345 the relation between h and z variations near the equatorial electrojet small fluctuations in h and z are strongly correlated particularly during daylight hours the ratio of the amplitudes of the components during these fluctuations shows a marked diurnal variation but is almost constant during the day 346 note on the tidal theory of the sq magnetic field the solar quiet day magnetic field has a diurnal component which is roughly a thousand times greater than expected on tidal theory possible explanations are given 347 hydromagnetic propagation of sudden commencements of magnetic storms a brief analysis of hydromagnetic propagation whih gives an expression for the transit time of waves travelling in the earths equatorial plane 348 the international geophysical year research carried out during the i g y in different branches of geophysics is reviewed attention is drawn to new concepts already established and to those probably true 349 space probes and satellites a summary of the main details of all satellite and space vehicle launchings up to april 350 temperature stabilization of highly reflecting spherical satellites 351 a correction necessary for the application of the doppler effect to the measurements of distances to satellites the use of spherical earth geometry gives a value for minimum passing range considerably lower than that obtained from plane earth geometry 352 the fluctuations of the acceleration of satellites the fluctuations are associated with changes in air density at perigee height these density variations may be associated with changes in sunspot activity they are in any case certainly due to variable heating at the perigee height 353 a method for measuring local electron density from an artificial satellite a proposal for a satellite equipped to measure the electric and magnetic fields in the radio wave set up in the neighbourhood of the satellite by whistler mode transmission from a grou d based v l f transmitter from the wave impedance given by the ratio of the fields the local electron density could be deduced 354 applications of the molecular refractivity in radio meteorology a discussion of the advantages of molecular refractivity as a significant parameter in studies of climatic differences and air mass characteristics 355 radio refractive index climate near the ground world wide m ps of refractive index contours are given the index varies systematically with climate and is most accurately deduced from charts of the reduced to sea level index 356 central radio propagation laboratory exponential reference atmosphere a model for the variation of atmospheric refractive index with height is proposed which gives more accurate radio ray profiles than the earth radius treatment a sample table of ray profiles is given 357 analytic and experimental electrical conductivity between the stratosphere and the ionosphere results for the height ran e km obtained from rocket soundings are compared with predicted values based on ion equilibrium and ionization by cosmic rays only 358 detection of an electrical current in the ionosphere above greenla d a description of measurements made on august using a rocket borne magnetometer the average current density of the layer detected was about eleven a km 359 langmuir probe measurements in the ionosphere measurements are described of electron temperature and positive ion number density of the e layer above fort churchill manitoba on november 360 note on quiet day vertical cross sections of the ionosphere along geographic meridian a discussion of results now being obtained from stations on the meridian 361 gyro frequency in the ionospheric regions experimental results show that the magnetic fields calculated from gyro frequencies in the e f and f regions are higher than expected the e region gyro frequency las a marked semidiurnal variation with a minimum at midday 362 an investigation of the ionospheric d region a model of the lower ionosphere is obtained from the observation of weak echoes from the d region and the measurement of ionospheric wave interaction 363 some measurements of collision frequency in the e region of the ionosphere measurements are made by observing how the deviative absorption of a radio echo varies with changes in its group path as a critical frequency is approached collision frequency at a fixed height seems to increase with solar activity 364 e region winds the suggestion that heating of the e region by the sun is responsible for e region winds is supported by some experimental results 365 a relation between giant travelling disturbances and sporadic e ionization ionosonde records for the july show a relation between e anomalies and travelling disturbances sequential e and f cusp type anomalies are also discussed in relation to these disturbances 366 two anomalies in the behaviour of the f layer of the ionosphere report of a study of electron density data at a number of widely distributed observatories during equinox in a year of high sunspot activity results show that the geomagnetic anomaly described by appleton extends much farther from the magnetic equator as lower heights are investigated a diurnal asymmetry also exists with forenoon electron densities greater than corresponding afternoon ones 367 some remarks on motion of ionospheric irregularity the relative motion between irregularities in electron density and their surroundings is discussed two treatments of the problem are considered the surrounding ionization being assumed to be a a hydromagnetic fluid and b a fully ionized gas 368 the motion of irregularities in the ionosphere the mean velocity of irregularities in electron density is determined using simple turbulence theory the irregularities move with the same velocity as the winds in the e region but there is a marked difference from wind velocity in the f region 369 world wide measurements of horizontal ionospheric drifts a critical survey is made of radio techniques for measuring horizontal drifts a comparison is then made of results obtained during the i g y using the closely spaced receiver method which discloses seasonal and latitudinal differences in the diurnal variation of drifts tentative explanations of these results are given 370 ionospheric drifts at xamagawa in japan drift speeds diurnal variations of the drift vector and the relation between speed and geomagnetic activity are discussed using results obtained during about one year from august 371 ionized irregularities and wing motion in the ionosphere the motion of irregularities in electron density are studied on the basis of a three dimensional model electrodynamic effects are slight in the e region under magnetically quiet conditions but are appreciable in the f region and even in the e region for disturbed conditions at high latitudes a general discussion on the stability and lifetime of regions of irregular electron density is given 372 horizontal winds and ionization drifts in the ionosphere from a study of geomagnetic observations during the international polar year it is concluded that ionization drifts in the f region are due to an applied electric field and not to air movement while in the e region the ionization drift is almost the same as the air movement 373 horizontal drifts in the e region at waltair results of an analysis of data obtained over a two year period a twenty four hourly east west component predominates 374 study of winds in the f region of the ionosphere during the unusual days in the i g y calendar fading records were taken at mc s on three spaced receivers at banaras the experimental results are described and the fading records discussed with reference to the random and steady movement of irregularities 375 a theory for determining upper atmosphere winds from radio observations on meteor trails 376 the effects of a solar eclipse on a stratified ionosphere the form of the isoelectronic surfaces in a three layer ionosphere during an eclipse have been calculated tilts in these surfaces may lead to difficulties in the interpretation of ionograms 377 the behaviour of the ionosphere over cape town and johannesburg during the annular solar eclipse of december it was not possible to explain the ionospheric changes at cape town johannesburg and grahamstown in terms of a single solar brightness model oblique reflections may have affected the ionograms 378 the frequency dependence of ionospheric absorption the total absorption was formerly expressed as a function of nondeviative d layer plus deviative e layer absorption the expression has been modified to include the effect of a thin e layer experimental data are discussed in the light of the new theory 379 the absorption of short radio waves in the d e and f regions of the ionosphere values of noon absorption at slough have been analysed the electron collision frequencies for the e and f regions have been calculated and the variations of d region absorption with sunspot number examined the significance of the results is discussed 380 the use of full wave solutions in the interpretation of ionospheric absorption measurements a full wave correction is given which can be made to the usual appleton hartree absorption calculation examples show that for a frequency of two mc s this correction cannot be neglected 381 measurements of ionospheric electron content by the lunar radio technique measurements of the faraday rotation of lunar radio echoes are used to determine the time variation in the total ionospheric electron content absolute values of electron content are derived from data on the electron content below the f peak computed from vertical incidence experiments 382 excitation mechanisms of the oxygen emission in the upper atmosphere photochemical reactions affected by mass motions and direct excitation due to mass motions are examined 383 auroral and night glow observations at as norway more precise wavelength measurements are given for bands of the meinel oh system in the night glow 384 photometric observations of subvisual red auroral arcs at middle latitudes the arcs have been observed on the night following a bright visual aurora at a time whe the magnetic disturbance index had fallen to five or less 385 the southern auroral zone in geomagnetic longitude sector visual auroral observations at antarctic bases are tabulated to show the variation of the frequency of aurora occurrences with geomagnetic latitude 386 antarctic auroral observations ellsworth station a summary of auroral observations made during the antarctic winter evidence is obtained of a spiralling zone of maximum auroral activity 387 spectroscopic observations of the great aurora of february spectrograms show an enhancement of vibrational excitation which can be attributed to a charge exchange process in a strong proton shower these spectrograms also show a large number of atomic lines seldom seen 388 a monochromatic low latitude aurora a particular monochromatic auroral arc which occurred over colorado is described it seems to have been a continuation of a similar one observed in france 389 telluric origin of the whistler medium arguments are presented to show that the medium cannot be of solar or interplanetary origin and a mechanism is suggested for a telluric origin 390 effect of latitude on the diurnal maximum of dawn chorus observations of the local time of diurnal maximum have been made at sixteen stations analysis based on an eccentric dipole field is useful when considering dawn chorus theories 391 cosmic electrodynamics this book bearing a similar title to that by alfven indicates the progress and consolidation achieved in the field during the intervening decade 392 electronic line storage device for the compression of the frequency band of periodically recurring signals particularly of radar displays the operation of a c r tube line storage system is discussed equipment is described for measuring the integrating characteristics of such storage devices 393 a small high voltage regulated power supply with variable output the design of a regulating circuit operating in the range is described which uses a beam tetrode as a series regulator and two double triodes in the feedback circuit 394 a transistorized l t regulator 395 computers and computer equipment design a group of nine papers on practical aspects of digital computer design and recently developed techniques 396 electronic computers and the electronic computer study centre at pisa outline of the program and future development of the centre with details of available equipment 397 solid state digital code to cede converter gray code can be changed to normal binary code by means of the converter described the basic building block is a circuit comprising a magnetic core a junction transistor and a delay network thyratrons are used for the readout display 398 a high speed ferrite storage system a read write cycle time can be achieved in the small store described 399 the magnetic drum store of the mercury computer explanatory circuit diagrams mechanical drawings and performance data of the type drum are given 400 approximation errors in diode function generators errors resulting from fitting a piecewise linear function to a smooth curve are discussed in relation to analogue computor applications a simple integral based on best fis criteria will give the relation between number of segments and error and also the breakpoints between segments numerical results are given for typical functions 401 theoretical study and method of operation of a logarithmic integrator description of a computer circuit based on a diode pump action 402 the construction of a digital computing system from a basic transistor circuit the computer uses identical basic circuits to convert decimal numbers to and from the binary scale diagrams of the basic circuit and the system are given printed circuits are used 403 light pen links computer to operator using a photodiode to read dots produced on a r tube enables an operator to control an associated computer by pointing the light pen at certain dots information can be written into the computer 404 computers aid propagation studies 405 automatic character recognition limitations and future developments of existing machines are discussed further analysis of the semantic features of character patterns and of their recongnition timits leads to a semantic pattern definition which is sufficiently general to permit recognition of nearly illegible characters 406 how analogue networks solve air conditioning problems the thermal properties of a unit area of the structural elements are represented by an equivalent electrical circuit a complelt block diagram shows how these are used to simulate the thermal behaviour of a room and its air conditioning system some detailed circuitry is given 407 three approaches to microminiaturizatio construction methods for extremely small electronic circuits are detailed 408 british appreaches to microminiaturizatio 409 the properties of ferrite u cores for horizontal deflection vut put transformers the results of measurements made with a special core are given and discussed 410 steering circuits control reversible counters a four stage bistable multivibrator system is used to provide decade counting complementary outputs from each stage dre switched to succeeding stages to give either addition or subtraction 411 approximate calculation of bistable switching circuits using junction transistors case of switching circuits with common emitter resistance application of the method described earlier for the case of double bias operation january 412 dielectric devices report of a conference held in the electrical engineering department of the university of birmingham 413 on stochastic linear systems systems governed by nth order linear differential equations having random coefficients are studied and the methods developed are applied to a r l c circuit having random capacitance variations 414 design of open ended microwave resonant cavities two types of cavity for refractive index measurements are described one rectangular in cross section the other cylindrical the cavities are termin ted in short sections partitioned so that each sub division is a waveguide operating below the cut off frequency of the cavity 415 plastic microwave cavities for epr an x band plastic cavity for studies of relaxation in electron par magnetic resonance is described 416 generalization to nonlinear net works of a theorem due to heaviside a theorem enunciated by heaviside and proved by lorentz for linear electromagnetic systems subjected to a suddenly impressed constant electric force is extended to electrical net works comprising nonlinear reactances and linear resistance 417 classes of four pole networks having nonlinear transfer characteristics but linear iterative impedances a graphical representation is introduced which simplifies the analysis of networks containing nonlinear elements the properties of dual nonlinear resistances in which the relation for one resistance is the same as the relation for the other are considered such duals if realizable would permit the design of nonlinear four poles having linear iterative impedances which could be cascaded 418 theory of noisy two pors networks the geometric analytic theory presented is based on the isometric sphere metred and on a three dimensional conformal transformation 419 impedance transformations through lossless two ports represented by fractional linear transformations of the unit circle the automorphism of a unit circle corresponding to an impedance transformation is characterized by three parameters and can be represented by three successive elementary transformations this leads to a simple graphical method using caoter or smith charts for the determination of the transformed impedance and for the treatment of cascades of lossless two ports 420 constant resistance all pass networks with maximally flat time delay practical design tables are given and their use is illustrated by examples 421 the loss attenuation in the pass band of wave filters with differing coil factors the loss contributions of the individual coils are summed using weighting functions application of the method to a crystal filter half section is explained 422 an analysis of a type of comb filter a theoretical analysis and discussion of practical devices for use in radar as moving target indicators and signal integrators 423 calculation of the static characteristic of a nonlinear multipole without inertia when the dynamic characteristic is known 424 high frequency transistor filter synthesis two canonical ladder structures of hybrid two and hybred t type are considered the intrinsic feedback factor is ignored examples of cascaded structures are given 425 the effect of cathode impedance on the frequency stability of linear oscillators long term frequency instability due to the growth of an interface layer between oxide coating and cathode may be reduced by suitably adjusting the ratio of anode to grid voltages 426 voltage sensitivity of local oscillators the dependence of the oscillation frequency of valve oscillators on certain operating conditions is discussed and defined mathematically in terms of independent variables 427 how to generate accurate sawtooth and pulse waves two circuits giving stable sawtooth and rectangular pulse outputs are described in which a high speed switching transistor is controlled by a zener diode pulse width and amplitude and waveform timing are independent of active elements in the circuit 428 a method of combining two frequencies a new method of frequency synthesis is described in which two equal amplitude tones are combined by limiting phase inverting and selecting the correct polarity at a control gate 429 the definition of noise factor when applied to systems containing negative resistance elements the concept of available power and the definition of noise factor are extended to include negative resistance by using the idea of exchangeable power 430 wide band analysis of valve phase splitting circuits accurate and approximate design data are developed and compared with results of measurements near ideal operating conditions can be obtained up to a fow megacycles with suitable load impedances 431 analysis of the transistor cascade configuration neutralization is not necessary more gain per unit volume and weight is achieved than in other transistor configurations while cost per unit gain is about equal to that of more conventional circuits 432 transistor constant volume amplifier design and circuit details of a microphone amplifier providing substantially similar output signal levels for various speech input levels 433 transistors in video equipment the importance of the product current gain bandwidth is discussed a new design method is described which gives greater gain bandwidth factors the conditions for maximum signal noise ratio are determined and confirmed experimentally signal noise ratios aad gain bandwidth factors are comparable to those of valves 434 transistorized distributed amplifier the characteristic impedance of both the base and collector transmission lines 435 solid state maser amplifier the principles of maser operation are introduced and the essential details of a practical cavity maser system are described 436 maser operation with signal frequency higher than pump frequency an x band solid state maser is described using the four zeeman levels in ruby 437 investigation of the oscillation voltage of a strong field maser type self oscillator investigation of a maser of the type described earlier of march in which tie macroscopic polarization of the protons is made antiparallel to the directive field experimental and theoretical curves are thown for different rates of flow 438 experimental verification of parametric amplifier excess noise using transformer coupling a method is described for measuring noise temperature at frequencies where circulators aoe not available 439 an analysis of parametric amplification in periodically loaded transmission lines the propagating structure is considered as a lossless transmission line periodically loaded with nonlinear capacitance in the form of back biased semiconductor diodes information is given about the relation of diode parameters spacing and circuit parameters to the gain and bandwidth of the structure 440 fast wave couplers for longitudinal beam parametric amplifiers 441 three level maser detector for ultra microwaves note on the principles of a device similar to the spectrometer described earlier the absorption at ultra microwave frequencies changes the population of levels and results in an increase or decrease of absorption at a lower microwave frequency 442 mode theory of lossless periodically distributed parametric amplifiers 443 reactance transistor frequency deviation curves calculated from the theoretical output admittance are compared with measurements for oscillator circuit 444 on explanations of electric and magnetic constants and units using dimensional methods the relation of freespace dielectric constant and magnetic permeability constant to four fun amental quantities is considered other constants are also analysed to obtain methods of understanding the submicroscopic nature of electric and magnetic phenomena 445 variational approach to deviations from ohms law kohlers variational method has been used to obtain deviations from ohms law for a nondegenerate electron gas two important applications of the method are discussed 446 many particle approach to the one electron problem of insulators and semiconductors motion of an electron near the bottom of the conduction band in the presence of external electric and magnetic fields whose variation over one lattice spacing is small is governed by a simple schrodinger equation 447 energy levels of conduction electrons in a magnetic field the energy levels can be obtained simply if the spherical approximation is made for the band structure the free energy due to small departures from this assumption may be estimated using perturbation theory inclusion of spin orbit coupling gives the factor as a function of position in the band 448 the current sheet in a gas discharge deals with the trapping of cold gas in the sheet 449 studies of cold cathode discharges in magnetic fields mass spectrometer measu ements were made to determine the ion energies the mechanism of the discharge is discussed 450 theory of secondary electron emission of metals the excitation process 451 theory of secondary electron emission metals the transport process 452 conductivity of a warm plasma a theory for obtaining the conductivity of a uniform plasma as a function of frequency and temperature is presented and compared with a number of recent treatments 453 experiments with plasma rings a brief description is given of a plasma gun discharging into a glass drift tube measurements have been made of the circuit current and the magnetic flux carried by the plasma 454 oscillations in plasma part two discrete oscillations reported are studied in detail oscillations at the higher frequency are generated by the convergent beam in the central part of the tube while those at the lower frequency seem to be generated near the wall of the tube by the divergent beam another oscillation having an intermediate frequency is often observed 455 occurrence of vavilov cerenkov radiation in a high temperature plasma analytical results indicate that radiation is not emitted by a particle moving through a high temperature plasma at a velocity lower than the mean thermal velocity of plasma electrons 456 longitudinal and transverse waves in a lorentz plasma the triple refraction in inhomogeneous plasma is dis ussed 457 radial hydromagnetic oscillations the equation of motion of radial hydromagnetic oscillations of a plasma confined by an axial magnetic field is integrated and shown to give good agreement with experiment 458 discharge phenomena in lorentz type plasmas investigation of electron distribution in the presence of a magnetic field a partial differential equation derived by kahan and jancel is integrated for the case where the collision frequency is constant 459 the half plane diffraction problem for harmonic time dependence greens functions are obtained for the boundary value problems of mixed type describing the general two dimensional diffraction problems at a screen in the form of a half plane sommerfelds problem applicable to acoustically rigid or soft screens and to the full electromagnetic field at a perfectly conducting screen 460 the diffraction of scalar waves on paraboloids of revolution 461 diffraction by an imperfectly conducting right angled wedge an exact solution is given for the diffraction of the fie d of an electric line current by an imperfectly conducting wedge of exterior angle 462 diffraction of an e polarized plane wave by an imperfectly conducting wedge a new and exact solution is obtained for arbitrary wedge angle 463 propagation of electromagnetic waves in a multistream medium at gyromagnetic resonance formulae are derived for the dispersion and the gyromagnetic resonance effects 464 measurement broadening in magnetic resonance phase detection techniques cause broadening a method for correcting observed widths is described 465 form effect in magnetostriction 466 a simplified theory of two carrier space charge limited current flow in solids 467 zeeman splitting of paramagnetic atoms in crystalline fields energy levels of paramagnetic ions in crystalline surroundings are treated as a function of magnetic field 468 theory of bloch electrons in a magnetic field the effective hamiltonian for a no degenerate band the eigenstates of the hamiltonian of a bloch electron in a static magnetic field can be calculated from an equivalent hamiltonian whose properties and formulation are discussed 469 symposium on the exploration of space the text is given with subsequent discussion of twelve papers read at a symposium in washington 470 national radio astronomy observatory the history and development of the radio observatory at green bank west virginia are reviewed 471 the mullard radio astronomy observatory two aperture synthesis radio telescopes installed near cambridge are described and an outline is given of the present research program 472 tie six hundred radio telescope description of of the steerable telescope under construction in west virginia 473 observations on the solar eclipse of october a report of measurements made simultaneously at hamilton at this location the sun rose partially eclipsed nd was totally eclipsed at an elevation 474 nature of corpuscular radiation of the upper atmosphere the concentration of particles in the solar corpuscular stream is sufficient to renew the corpuscles of the outer radiation belt over a period of only a few hours an estimation is made of the energy spectrum of protons and the velocity of generation of hard corpuscles in the inner belt 475 heavy primary cosmic rays at geomagnetic latitude results from nine balloon flights at heights charge spectra flux mean free paths and angular distributions are given 476 primary cosmic ray proton and alpha particle intensities and their variation with time results of a series of high altitude balloon flights made primarily to investigate the short term variations of primary protons and alpha particles 477 cosmic ray measurements in the vicinity of planets and some applications part one primary cosmic radiation the variation of the primary cosmic ray intensity is calculated as a function of distance from a dipole in its equatorial plane scientific applications indicated include the determination of magnetic fields of the moon and planets 478 low energy cosmic ray events associated with solar flares details are given of events during the period which have been detected by the measurement of ionospheric absorption in arctic regions 479 the apparent sidereal daily variation of cosmic ray intensity during the recent sunspot minimum 480 magnetic cut off rigidities of charged particles in the earths field at times of magnetic storms cut off rigidities are calculated for charged particles at various locations and for different distances of the storm sloud from the earth 481 the transmission of geomagnetic disturbances through the atmosphere and interplanetary space the theory of the propagation of slowly varying disturbances through partially ionized gas is developed and applied to the earths atmosphere and interplanetary space the medium is considered as two separate co existing gasses an electron ion plasma and neutral atoms which move to some extent independently quantitative results are given for a model atmosphere extending to several earth rad 482 studies of magnetic field micropulsations with periods of seconds the studies were carried out in southern california 483 geomagnetic storms and ionospheric disturbances a collection of papers covering the morphology of geomagnetic and ionospheric storms an application of the atmospheric dynamo theory to geomagnetic variations uring disturbances and a study of hydromagnetic oscillations of the ionized upper atmosphere 484 the relationship between geomagnetic variations and the circulations a statistical study for a five year period leads to the conclusion that there is no obvious relation between the two sets of data 485 radio and the i g y summaries of the data collected the analyses used and the knowledge obtained about the ionosphere an outer space during the i g y proceedings of fourth meeting of the joint commission on radio meteorology the tept is given of papers presented at the meeting held in new york 486 artificial earth satellites and space travel part one the satellite orbits and their changes with time a table is included giving full details of earth satellites and moon probes successfully launched up to september 487 lunar and solar perturbations on satellite orbits the lunar and solar effects on perigee height for satellite orbits of large eccentricity are investigated 488 determination of the true distribution of electron density in the ionosphere part two the accuracy of the methods summarized in part one results obtained with out consideration of the geomagnetic field are found to be completely uncertain 489 on the seasonal and nonseasonal annual variations and the semiannual variation in the noon and midnight electron densities of the layer in middle latitudes part two previous work is continued using two groups of relatively high and low latitude stations the seasonal variation for the high latitude stations is markedly different from that of the low latitude group while the nonseasonal variations do not show great differences between the groups the semi annual variations in the two graphs are also not markedly different 490 a statistical study of world whde occurrence probability of spread f parts one and two diurnal seasonal and latitudinal variations in the occurrence of spread f during the i g y are analysed marked differences between high and low latitudes suggest an essentially different origin for the phenomenon in the two regions the correlation of spread f with geomagnetic activity is discussed and abnormal occurrences during magnetic storms are examined in detail 491 proceedings of fifth meeting of the mixed commission on the ionosphere of i c s u the text is given of papers presented at the meeting held in new york 492 the ionospheric faraday effect and its applications measurements of ionospheric characteristics by means of lunar radio reflections and satellite radio transmissions using the faraday effect are discussed 493 influence of absorption on the reflection coefficient of the ionosphere the reflection coefficient of a stratified layer is considered assuming that electron concentration varies linearsy with height absorption is represented by a viscous resistance proportional to the velocity of free electrons 494 pre s c polar cap ionospheric black out and typeiv solar radio outburst short wave radio blackouts in polar cap regions are often found to occur well before the sudden commencement magnetic storms and this phenomenon is closely correlated with the occurrence of type iv solar bursts a possible explanation of these effects is given which is consistent with other related phenomena such as cosmic ray storms 495 ionosphere review comparison of the condition of the ionosphere with that of previous years and deduction of the probable state 496 global hydromagnetic wave ducts in the exosphere magnetic field perturbations originating from a high altitude explosion have been observed at a number of stations an analysis of results indicates that hydromagnetic waves at high altitudes travel along great circle paths in ducts which are concentric shells about the earth slow and fast signals are identified respectively with transverse and longitudinal hydromagnetic wave modes 497 aurora like radar echoes observed from latitude a note on anomalous echoes observed regularly at a shipborne radar located in british west indies 498 correlation of audio frequency electromagnetic radiation with auroral zone micropulsations a spectrum analysis has been made of recordings obtained during three one month periods near kiruna sweden there is excellent correlation between auroral zone micropulsations and radiation two distinct frequency bands have been identified 499 rare hiss earth current and micropulsations on november brief report of hiss and micropulsations associated with a sudden commencement at alaska 500 direction findings on whistlers the use of a crossed loop type of direction finder and the information on whistlers to be obtained from it are described 501 the magneto ionic theory and its application to the ionosphere 502 a transistor quadrature suppressor for a c servo systems the spurious quadrature component rn the error signal of an a c servo system is cancelled by a self balancing circuit including thermistors 503 photoece tronic chart reader of recorded ink line design and construction tion details are given of an equipment which samples the level of a recorded line once every second and produces an integrated analogue output voltage 504 transistor regulated converter regulation is controlled by a blocking oscillator whose frequency varies as a function of the error voltage 505 on the nonisothermal diffusion theory of rectifiers a general theory is developed from formal conduction theory the rectification equation obtained depends upon temperature distributions in a barrier values of the dielectric constant of barrier determined by analysis of experimental results using the new theory tend to approach those of the bulk materials 506 stabilization of a direct current or a magnetic field by paramagnetic resonance description of a system for current stabilization based on electron resonance in a sample of paramagnetic material such as diphenyl picryl hydrazyl 507 a simple current stabilizer for electromagnets the design of a stabilizing circuit operating with an amplidyne generator is described 508 a transistorized current stabilizer for an electromagnet 509 computers head for operation report of recent developments in phase locked oscillators tunnel diodes and cross film cryolrons based on papers presented at the computer conference 510 low temperature storage elements very high speeds and compactness are features of the crowe cell in which a persistent current is set up around an aperture in a thin superconducting film 511 pulse height to digital signal converter a transistorized analogue digital converter provides digit binary outputs for an input at a maximum sampling rate fo pulses 512 supersonic delay line memory device for parametron signal results obtained with an experimental brass wire delay line are given suitable coupling circuits are shown 513 factors influencing the applications of magnetic tape recording to digital computers 514 a magnetic disk random access memory alphanumeric characters can be stored with average access time 515 magnetic film file for computer storage oxide coated film store is described in which the pickup head is not in contact with the oxide the high quality backing medium gives complete freedom from drop outs 516 high speed digital storage using cylindrical magnetic films digital stores consisting of closed magnetic circuits deposited on long glass tubes are described 517 a high density file drum as a computer store a packing density has been obtained using specially designed heads floating on an oil film which automatically maintains a head track spacing 518 analysis of quality factor of annular core inductors a summary of formulae used to determine factor is supplemented with a discussion of optimum design procedures in particular eddy currents and dielectric losses and the effects of distributed capacitance are considered 519 the ferreed a new switching device properties of a magnetic reed switch responsive to the resonant field of a ferrite are considered switching times are in the microsecond range and dual wanding facilitates coincident pulse control the application to switching arrays is discussed 520 binocular type parametron the method of manufacture and characteristics of a parametron with a new type of ferrite core comprising a segmented disk with two apertures aoe described power consumption is about one quarter that of the toroidal core type 521 microwave switching with computer diodes characteristics are given of single and double throw junction diode switches satisfactory tests have been made on a coaxial switch 522 an oscillating capacitor of high stability the precision unit described is designed for use with highresistance or direct voltage measuring equipment where high stability is required currents of were detected with an input resistance 523 certain asymptotic relations between frequency and time functions the relations are considered with reference to networks to which a transaent is applied and including the effect of group delay 524 linear network synthesis the rational fraction approximation is obtained dire tly in terms of the pole zero locations in the plane by a process of successive approximation the method differs from others known successive approximation techniques in being purely graphical apart from a final numerical relaxation process a simple step by step account is given of the practical procedure 525 low pass filter for subaudio frequencies details are given of a low pass filter suitable for use in a missile borne telemetry system the filter incorporates a transistor feedback amplifier and has a flat response from an attenuation slope of octave 526 immittance properties of nonreciprocal networks certain known networks are described in terms of the unitor a nonreciprocal circuit element these include lhe batt duffin immittance synthesizing cycle impedance inversion and conversion circuits and the symmetrical lattice network 527 negative feedback in frequency changers two different forms of negative feedback are discussed one has only passive elements in the feedback path and thk other has an active element with characteristics identical to those of the forward path their application to frequency changers is considered with reference to gain stability 528 the quality of oscillators with differently located losses network oscillator with parallel and series losses is investigated to determine whether the factor can be improved by a reduction of load impedance in conjunction with an appropriate increase in oscillator gain the reduction of load impedance is effected by considering the loss impedance to be added in parallel with thk load 529 a voltage tuned resistance capacitance oscillator a circuit is given for an oscillator whose frequency of oscillation is dependent on an applied potential by vartue of the variable capacitance of selenium drydisk rectifiers with reverse bias the characteristics of suitable rectifiers are discussed 530 the generation of short high power pulses by means of spark gap switches the characteristics of the discharge current in spark gap circuits aoe calculated tests were made on a triggered pulse generator caicuit comprising two series connected spark gaps equipment used and results obtained are described 531 parametric oscillations with point contact diodes at frequencies higher than pumping frequency the signal and idler frequencies are symmetrically placed with respect to a multiple of the pumping frequency the results are consistent with the manley rowe relations 532 designing high power transistor oscillators a step by step procedure is ghven for the design of oscillators for operation at frequencies 533 a high speed binary counter based on frequency script techniques an extension of previous experimental investigations into bistable oscillators fast counting circuits using eit tubes a theoretical investigation into the use of type eit counter tubes at pulse repetition frequencies up together with a practical design of circuit 534 efficient harmonic generation practical harmonic generators are reviewed briefly and the most efficient is shown to be the rectifier amplifier type a transistor amplifier provides best efficiency at low powers 535 a stabilized locked oscillator frequency divider the results of an analysis of the divider are presented in a graphical form suitable for design purposes 536 negative capacitance amplifier noise the inheret limitations of negative capacitance feedback due to the finite time constant and internal noise of an actual amplifier are discussed it is shown that the limitation caused by noise applies to any circuit that is designed to reduce the input time constant 537 ferromagnetic amplifiers note on an absorption of microwave power observed with a magnetized garnet sphere in a microwave field at a frequency approximately twice that corresponding to the magnetization 538 maser behaviour temperature and concentration effects maser action has been achieved with ruby at temperatures up to results are ghven for operation 539 a tunable x band ruby maser performance figures and details of simplified tuning arrangements are given 540 the parametric amplifier the mode of operation of parametric devices is explained and generate features of semiconductor diode ferrite and beam type amplifiers are discussed 541 noise consideration of the variable capacitance parametric amplifier a simplified theory assuming the noise source is a resistance in series with the variable capacitance gives calculated gain and noise figures agreeing with measured values for diodes 542 some possible causes of noise in adler tubes 543 wide band with capacitance diodes two circuits are described using voltage variable capacitors to modulate a valve oscillator 544 mathematical problems of the quantum theory of particles and fields the text is given in english of papers presented at an international course held at varenna 545 approximation formulae for the electrostatic energy of a space charge an asymptotic approximation for the potential is derived which does not contain terms denoting the number and magnitude of the individual charges making up a space charge cloud 546 the electromagnetic energy stored in a dispersive medium an expression for energy is derived by treating the dielectric as a two terminal network having a frequency dependent admittance 547 damping method in the theory of electrical conductivity a method as suggested for calculating the conductivity tensor similar to the time fluctuation method used in quantum field theory 548 a more precise theory of plasma recombination recombination coefficients are derived for two models deep traps and third and fifth group impurity traps in ge and si 549 theory of the method of thermal conductivity measurement proposed by a v ioffe and a f ioffe 550 build up of a discharge in argon measurements of the rate of build up at pressures and theoretical interpretation of results 551 time dependent electron flow general relations are given from which a single vector differential equation can be deduced which determines all possible solutions in the case of a constant uniform magnetic field the application of certain time variant solutions of this equation to anomalous behaviour in various magnetron type devices is considered 552 double scattering of electrons with a dipole moment quantum mechanical analysis of the case where magnetic and electric fields are present between the two targets gives the same results as are obtained by treating the electrons as classical spinning tops with magnetic moments and classical electric dipoles interaction between electron beam and magnet the diffraction effect noted when an electron beam grazes a sharp edge of a magnet is described and interpreted 553 the time constant of secondary emission 554 transport phenomena in slightly ionized gases low electric fields calculation of transport properties in the presence of a magnetic field for low electric field the results can be expressed as linear functions 555 asymmetrical triple probe method for determining energy distribution of electron in plasma the method is an improvement on one previously given a much greater range of electron energies can be used in electrodeless discharges 556 action of a electric field on a plasma establishment of the equation giving the distribution function 557 excitation of oscillations in a plasma layer application of theory developed earlier to the excitation of standing waves in a uniform plasma 558 oscillations of a cylindrical cavity in a completely ionized plasma investigation of the oscillations of a cylindrical cavity in a perfectly conducting plasma with applied magnetic field the system is shown to be stable and under certain conditions waves cannot propagate along the cavity 559 sealed room experiments on the equilibrium of ionization in air an attempt to determine the correct form of the equation by making measurements of as many of the quantities appearing in the equation as possible 560 possible explanation of the coexistence of ferromagnetism and superconductivity a discussion based on the suggestion that superconducting regions extend only through the thicknesses of the ferromagnetic domain walls 561 electromagnetic energy momentum tensor in the presence of charged matter 562 the method of group numbers nombres combinatifs in the study of electromagnetic fields maxwells field equations and poyntings theorem are given in group number form the method is proposed for problems where the use of complex numbers would give an ambiguous result 563 radiation from a current carrying ring which moves uniformly in a plasma located in a magnetic field estimation of losses due to vavilov cherenkov radiation for a current carrying ring which moves uniformly in a plasma perpendicular to its plane and parallel to an external magnetic field 564 radiation from high speed particles 565 general characteristics of vavilov cherenkov radiation the application of the theory of cherenkov radiation to problems of plasma physics is considered 566 the exactness of the solution of a radiation or diffraction problem criteria of uniqueness may be applied to various problems of propagation in media satisfying linear equations 567 diffraction of a plane electromagnetic wave by a perfectly conducting paraboloid of rotation exact solution for arbitrary angle of incidence and polarization asymptotic formulae for the surface current distribution are derived for wavelengths small compared with the focal length of the paraboloid 568 approximate calculations of the diffraction of plane electromagnetic waves by some metallic bodies application of the approximate method described in part one to diffraction of a plane wave by a perfectly conducting disk or cylinder results are shown graphically and compared with experimental data 569 scattering by nonspherical particles the small angle scattering approximation of schiff is applied to several nonspherical body sharpes effects of orientation and elongation are discussed 570 signal to noise ratio in nuclear magnetic resonance the amplifier noise is expressed in terms of an equivalent input grid resistance rather than in terms of a noise figure 571 absorption and dispersion of microwaves in flames the dependence of the high frequency electric conductivity and the optical constants of a weakly ionized gas of the microwave frequency the electron molecule collision frequency the electron concentration and an external magnetic field are discussed 572 the influence of lattice vebrations on energy and lifetime of the exciton the exciton is treated as a system of two particles with coulomb potential interaction which are coupled to the quantized field of lattice vibrations 573 new method for calculating wave functions in crystals and molecules advantage is taken of crystal symmetry to construct wave functions which are best described as the smooth part of symmetrized bloch functions 574 interferometer using two aerials with variable spacing at the nancay radio astronomy station radiation it received by two parabolic reflectors which can be moved along a track a signal from a common lacal oscillator is transmitted by coaxial cables to the aerial sites multiplied and mixed with the received signals resulting signals are conveyed via the same caeles to a correlator detector results obtained with the apparatus are shown 575 resolving power of three antenna patterns derived from the same aperture 576 absorption refraction and scintillation measurements with a travelling wave tube radiometer a report of measurements of solar radiation at sunrise during july with a note on the equipment used this consisted of a dicke type radiometer a tuned receiver and a parabola aerial on an altazimuth mount 577 the correlation of bursts of solar radio emission in the centimetre range with flares and sudden ionospheric disturbances statistical investigations of observations during the first six months reveal a close correlation between bursts in the range it is concluded that both the radiation and the ionizing radiation responsible are generated by super thermal electrons 578 sudden increase of cosmic ray intensity report on simultaneous observations in u s a and new zealand which are not in accord with simple solar impact zone theory 579 primary heavy cosmic ways near the geomagnetic equator 580 the sun as a source of cosmic rays of intermediate energies cosmic ray intensity as measured with a narrow angle telescope and thick absorber shows a sunspot cycle variation correlations with layer ionization and solar flux are shown 581 primary cosmic ray intensity near solar maximum results of measurements of proton and particle fluxes and energy spectra are given comparison is made with an electric field model 582 cherenkov radiation in the atmosphere a review of theoretical and experimental work 583 ambipolar diffusion of a meteor trail and its relation with height regression lines have been derived for the relation between log and height where the ambipolar diffusion coefficient 584 a daily index of solar activity based on e layer ionization the electron density in a chapman layer can be related to the intensity of the incident solar ionizing radiation this relation has been adopted as the basis for computing a daily index of the radiation intensity using the critical frequency of the e layer at slvugh precautions have been taken to minimize errors due to irregularities in the behaviour of the layer and to the difficulty in identifying the e layer cusp the standard deviation of the residual errors in the index is estimated to be twv per cent 585 rapid fluctuations during magnetic disturbance a numerically simple ratio is defined and used to examine space relationships of rapid geomagnetic fluctuations during disturbance 586 germagnetic effects of high altitude nuclear explosions the observations discussed were made after the two johnston island explosions effects at the first four observatories are attributed to overhead currents caused by increased ionization by rays while effects at apia are explained as being caused by artificial auroras 587 simultaneous recordings in france at the equator and in the antarctic of magnetic effects caused by the argus experiment geomagnetic disturbances were observed at french i g y stations for all three explosions 588 symposium on pulsations and rapid variations in geomagnetism and earth currents the text is given of the following papers read at a symposium in tokyo a ionizations in the outer atmosphere inferred from whistling atmospherics b hydromagnetics in the earths outer atmosphere c the acceleration of particles in the outer atmosphere d morphology of s s c and s s c e some remarks on the morphology of geomagnetic bays f some characters of geomagnetic pulsation and accompanied oscillation g morphology of the germagnetic pulsation h particles of aurorae and geomagnetic pulsations i hydromagnetic oscillation of the outer ionosphere and geomagnetic pulsation j germagnetic pulsation accompanying the intense solar flare k on the frequency of geomagnetic pulsation i studies of the local character of the geomagnetic pulsation m preliminary studies on the daily behaviour of rapid pulsation 589 micropulsations in the earths magnetic field simultaneous with pulsating aurora preliminary results are given 590 hydromagnetic theory of geomagnetic storms the sudden commencement of a magnetic storm is attributed to the collision of solar plasma with the geomagnetic field the disturbance being propagated to earth by a hydromagnetic wave the initial positive phase is attributed te sustained pressure by the plasma the main negative phase by breakup and diffusion of the plasma which is trapped in orbits in the van allen belt and the recovery by conversion of trapped protons into neutral hydrogen 591 rockets and satellites a report on the moscow meetings august a report of the technical symposia on rockets and satellites which formed part of the proceedings of the fifth meeting in moscow 592 artificial earth satellites and space travel part two satellite and moon probe design a comparison is made of the design of satellites and moon probes and details of their instrumentation are given 593 application of hansens theory to the motion of an artificial satellite in thn gravitational field of the earth a numerical theory suitable for solution by computer which has been applied in the vanguard program 594 reentry of the sputnik rocket 595 decay of spin in sputnik a secular change in spin fading rate which occurred during the period october 596 magnetic damping of rotation of satellite from radio observation of vanguard i eddy current induction theory gives a value for the mean magnetic field normal to the spin apis of the satellite 597 geomagnetic rotational retardation of satellite radio observations indicated a rapid exponential retardation of satellite rotation analysis of couples acting on the conducting and magnetic parts of the satellite gives a value for the mean ambient geomagnetic field and confirms the eddy current theory applied to vanguawd 598 study of the cosmic ray soft component by the soviet earth satellite 599 measurement of solar and diurnal effects in the high atmosphere by artificial satellites 600 observations of the russian satellites and the structure of the outer terrestrial atmosphere radio and optical observations are analysed 601 the determination of the electron distribution in the upper ionosphere from satellite doppler observations by simultaneous reception at two frequencies one of which is an approximate multiple of the other a monotonic electron distribution can be determined exactly the method is illustrated for sputnik one 602 derivation and analysis of atmospheric density from observations of satellite epsilon 603 the density distribution in the upper atmosphere the results of measurements of atmospheric density made by earth satellites are plotted as a function of altitude in comparison with curves for two model atmospheres 604 absorption and electron distribution in the layer determined from measurements of transmitted radio signals from earth satellites a comparison is made between measured and theoretically derived values of field strength of received signals when the satellite is in the region of maximum electron concentration and in regions above and below this level field strength curves for distances are given 605 measurement of the doppler fizeau effect with artificial satellites a simple method is described for measuring the doppler frequency within comparison with the signal from a calibrated oscillator 606 the scintillation of radio signals from satellites signals from satellites recorded during a twenty month period are analysed for evidence of scintillation 607 observations of ionization induced by artificial earth satellites major enhancements of signals occur before and after the time of nearest approach radar echoes which appear to originate at the range of are discussed 608 energy sources of the upper atmosphere variable heating of the upper atmosphere is considered to be caused by electric currents which are induced by magnetic fields frozen into the corpuscular streams 609 an interim atmosphere derived from rocket and satellite data a model atmosphere is proposed for temperate latitudes at altitudes 610 large scale movements of ionization in the ionosphere an instability mechanism for deviations in ionization density is suggested for which the predicted temporal and spatial morphologies appear to be consistent with those of the occurrence of sporadic spread and radio star scintillations 611 fall day auroral zone atmospheric stu ture measurements atmospheric density and pressure profiles aoe obtained using measurements made with ro ket borne ionization gauges 612 a relationship between the lower ionosphere and the night glow emission correlation is found between the emission and radio echoes obtained with a ionosonde 613 the electron density distribution in the region of the ionosphere a theory of electron loss in the ionosphere of is examined in numerical detail under certain conditions which are well defined the theory leads to the type of curve observed in practice for the lower region 614 ionization below the night time layer using the method described the low lying ionization for slough and watheroo has been studied throughout summer and winter nights during periods of maximum and minimum solar activity the decay of ionization was consistent with an effective recombination coefficient 615 travelling disturbances originating in the outer ionosphere the vertical velocity component of travelling disturbances coming from outside and propagation through the ionosphere is determined oscillation like phenomena have a large range of quasi periods 616 international symposium on fluid mechanics in the ionosphere review and verbatim report of the transactions of a symposium held in new york some of the papers presented are listed below others have been abstracted separately a constitution of the atmosphere at ionospheric levels b ionizations and drifts in the ionosphere c measurements of turbulence in the region from the radio echo observations of meteors d scattering of waves and microstructure of turbulence in the atmosphere e effect of a magnetic field on turbulence in an ionized gas f note on some observational characteristics of meteor radio echoes g on the spectrum of electron density produced by turbulence in the ionosphere in the presence of a magnetic field h evidence of elongated irregularities in the ionosphere i geomorphology of spread and characteristics of equatorial spread j an interpretation of certain ionospheric motions in terms of atmospheric k on the influence of the magnetic field on the character of turbulence in the ionosphere l magnetohydrodynamic of the small scale structure of the region m electrodynamic stability of a vertically drifting ionospheric layer n turbulent spectra in a stably stratified atmosphere o relation of turbulence theory to ionospheric scatter propagation experiments 617 geomagnetic distortion of the region on the magnetic equator part two an extension of work described earlier to study the relation between diurnal variations of years of different sunspot number and the phase of germagnetic variations region distortion is explatned by vertical ionization drift due to the field extended from the region 618 constant ionosphere height for audio frequency propagation from an analysis of smooth type waveforms of a constant height has been estimated for winter storms there was no systematic variation with the onset of night time conditions 619 the use of the extraordinary ray in the analysis of ionospheric records it is shown that by using the ordinary and extraordinary traces estimates may be made of the electron content and also the electron density distribution in the region represented by reflections at frequencies in the valley between the layers 620 an example of heavy absorption in the v h f band in the arctic ionosphere observations of meteor echoes and noise from the cassiopeia source in the band show very heavy absorption in the early morning of july 621 observations of unusual radio frequency noise emission and absorption the noise enhancements observed during periods of solar activity are classified as smooth or abrupt while smooth changes occur in both day and night hours the abrupt increases are observed only near local midnight the smooth enhancements occur almost simultaneously with the absorption of radiation in a sector of the northern sky 622 hydrogen emission and two types of auroral spectra various characteristics of auroral activity including radio reflections have been correlated with the hydrogen emission 623 auroral ionization and the absorption and scintillation of radio stars the absorption of radiation from cygnus when observed at low latitudes and radar back scatter echoes are related to a layer associated with auroral activity 624 artificial auroras resulting from johnston island nuclear explosions 625 a daytime maximum of oblique auroral reflexions observed in the auroral zone observations made over the period march and june show a daytime maximum 626 observed characteristics of an ultra high frequency signal traversing an auroral disturbance 627 a comparison of sferics as observed in the very low frequency and extremely low frequency bands the component is almost always followed by a component of extremely low frequency but about one third of these components are not preceded by components positive polarity wave forms predominant during daytime and their median amplitudes always exceed those of the negative polarity waveforms which predominate at night 628 sweepers sweepers are atmospherics which are present in the h f many of them occur in trains where the period between successive sweepers is nearly const nt 629 the propagation of electromagnetic waves in ionized gases 630 more bandwidth for magnetic recorders details are given of the design of recorder circuits having a bandwidth to take advantage of recent increases in recording head response 631 some performance parameters of silicon junction power rectifiers the temperature dependence of the characteristics of rectifiers and temperature control in terms of thermal resistance are discussed a method is given for the calculation of power dissipation and ratings 632 compensation of the effect of temperature on the reference voltage of transistor stabilized power supplies the voltage temperature characteristic of the reference is compensated by that of the base emitter region of the transistor error amplifier 633 a transductor regulator for stabilized power supplies a description is given of a single core full wave transductor circuit and its mode of operation a valve type regulator to deal with rapid disturbances is also described both regulators are incorporated in a stabilized power supply 634 economy in the series stabilizer consideration of the efficiency of series stabilizer circuits under almost constant load conditions a resistive shunt to the series element can improve efficiency 635 generators and storage devices for functions of the form comprehensive review up to the end of function devices for use in analogue computers 636 relaxation times in lead film superconductive storage elements an experiment is described to measure the critical current of a pb film crowe cell during the first microsecond after switching different substrates are used 637 ferroresonant systems of circuit logic characteristics for coupled inductors are presented and and computer circuits based on these elements are described with oscillograms illustrating practing operation 638 ferroelectric memory in the parametron circuits difficulties experienced in the use of ferroelectric materials in pulse type storage systems are shown to be partly overcome in parametron circuits the present limitation is due to unsuitable ferroelectric materials batio shows a high fatigue phenomenon and triglycine sulphate a low switching velocity 639 direct digital conversion of pulse width multiplexed data 640 an analogue elctronic multiplier using transistors as square wave modulators the multiplier is designed for high speed operation at reasonable cost protection circuits for the transistors are provided 641 indicator triode for direct data read out the triode combines amplifier and indicator in one envelope a triode and transistor bistable circuit is described with a required input trigger level and also a shift register in which these circuits are cascaded 642 character generator for digital computers a monoscope lube apparatus is described which operates in the speed range of computers and storage devices and provides read out directly on a c r o or on paper 643 simulation vf inductance by an integrating circuit an operational amplifier used as integrator has an inductive input impedance when a resesthve feedback loop is added between input and output theoretical and measured ualues of inductance qfactor and selfcapacitance are given and the possibility of raising q by positive feedback is examined 644 design considerations for integrated electronic devices discussion of fundamental factors affecting the design of integrated electronic devices with consideration of the effect of shrinkage and methods of overcoming it 645 printed circuits in radio and television receivers review of printed circuit design features in german receivers 646 the climatic fitness of carbon film resistors for use in electrical communications and measurements equipment for climatic tests is described effects observed in resistors subjected to such tests are discussed 647 coils and transformers under normal room climatic conditions the influence of environmental conditions on the operating characteristics of wire wound components with magnetic cores is investigated methods of reducing inductance and q factor changes caused by climatic effects are considered 648 on the problem of brownian motion of nonlinear systems a kinetic derivation is given of the spectral noise intensity in firstorder approximation and for relatively high frequencies for a nonlinear rc circuit consisting of an idealized diode valve in thermal equilibrium and a capacitor the discrepancy with the rusults obtained by macdonald 649 filter crystals for the frequency range the requirements for crystals used in filter networks are considered for atcut crystals operating in the range a triangular shape gives a satisfactory reduction of unwanted modes 650 the stability of negative resistance two poles stability conditions are considered on the basis of the static characteristics of the two pole 651 fundamental and harmonic distortion of waves frequency modulated with a tingle tone 652 echostant matching a new method of matching image parameter filters with the type of impedance matching described better matching conditions are obtained and fewer reactance elements are required than with the use of double m derived image impedances the simulation of tchebycheff type insertion loss and the compensation of losses by ihis method are also considered 653 unified formulae for filters with tchebycheff type insertion loss formulae are derived for the determination of zeros and poles of the transfer function based on the tchebycheff polynomial or on cauer parameters the characteristics and treatment of elliptic functions are discussed and curves are given for relating the insertion loss requirements to the parameters of the transfer function 654 the image parameter theory as a simple aid to the realization of crystal band pass filters of branch network type design formulae and curves are given for ladder type networks with the crystal in the shunt arms 655 a new coaxial resonator filter a band pass filter with an m derived type of characteristic is described consisting of loop coupled coaxial resonators in a reentrant arrangement performance may be described in terms of an equivalent lattice network good agreement is shown between the experimental and theoretical insertion loss characteristics 656 analysis of active networks by admittance matrices admittance matrices of valves and transistors are derived directly and from their indefinite admittance matrices 657 considerations on oscillator stability methods of reducing microphony effects and temperature dependence of oscillators in television tuners 658 a procedure for tuning a bridge stabilized crystal oscillator a meacham bridge circuit is used in which the lamp is replaced by a thermistor and a second thermistor is added to compensate for ambient temperature fluctuations a sensitive method of tuning input and output transformers in this circuit is described 659 theoretical investigation of a tuning procedure for bridge stabilized crystal oscillators the tuning method described above is analysed 660 pulse generator for the production of a spectrum with constant amplitude in the frequency range the equipment described conforms to the german specifications for radio interference measuring sets five different pulse repetition frequencies can be selected in the range 661 on the regenerative pulse generator an analysis of the mus pulse generator of cutler as a multimode oscillator 662 direct digital conversion of pulse width multiplexed data pulse width data are converted to a binary form by relating the incidence of leading and trailing pulse edges to the state of a counter driven by an asynchronous oscillator 663 a further method of coupling loudspeakers to a so called transformerless push pull output stage in the single ended push pull circuit described two pairs of series connected loudspeakers or loudspeaker groups are connected across screen grid and anode of the output pentodes 664 parallel connected magnetic amplifier a mathematical analysis of parallel connected magnetic amplifiers with an inductive and capacitive load is presented the analysis is based on the representation of the normal magnetization curve of the core material by polynomials of thiod and fifth degree respectively 665 the dynamic hysteresis loop as a cause of the free demagnetization in magnetic amplifiers self demagnetization effects are considered with reference to a hysteresis loop modified as a result of eddy current losses 666 design of transistor i f amplifier detector stages with stabilized band pass characteristics an extension of work described earlier 667 junction transistor circuits a method is described for calculating current drift due to changes of junction temperature in a direct coupled transistor circuit with series negative feed ba k the design of drift compensating circuits is considered and a brief comparison is made with parallel feedback circuits 668 the noise and gain properties of molecular and parametric amplifiers analysis is sufficiently general to include both types of amplifier as special cases the concepts of negative noise temperature and negative quality factor are introduced by analysing the energy exchange between a general sample of masser and a quantized cavity field the three level maser of bloembergen and the ferrimagnetic amplifier of suhl are discussed in some detail 669 the present state of solid state molecular amplifiers the principles and properties of solid state masers with two and three energy levels are discussed recent developments and future applications are considered 670 operating characteristics of a molecular beam maser general expressions for the emitted power and the frequency pulling in an ammonia maser have been deduced the operating characteristics of the maser have been deduced by introducing a mean square time of flight of molecules in the cavity 671 ammonia maser oscillator the principle of operation and constructional details of an ammonia maser are described four parameters affecting the frequency of operation have been investigated ammonia flow separator voltage magnetic fields and cavity tuning 672 noise temperature measurement on a travelling wave maser preamplifier 673 pulsed field millimetre wave maser the frequency range of the pulsed field ruby maser has been extended and the peak output power has been increased to several mw 674 submillimetre wave maser 675 some possible arrangements of parametric amplifiers employing lower frequency pumping two arrangements are analysed in desail a combination of a mixer and an amplifier using one pump and two idlers b combination of a mixer and an amplifier using two pumps and two idlers 676 theory of the travelling wave parametric amplifier the theory is based on a nonlinear distributed capacitance excited by a travelling wave losses in lhe capacitance and the effects of saturation on large signals are considered 677 saturation effects in a travelling wave parametric amplifier equations of voltage distribution are solved in terms of elliptic functions and an expression for the maximum power gain is derived the positions of gain maxima are calculated 678 theory of fast wave parametric amplification 679 a microwave adler tube 680 double push pull modulator with valves 681 rectifier modulators a method for reducing the complexity of equations for the series rectifier modulator without undue loss of accuracy is postulated the simplified equations are shown to be soluble by successive approximations the process is applied to a modulator with a constant resistance termination b purely capacitive termination 682 the frequency modulation of tuned circuit and relaxation oscillators the problem of distortionless frequency modulation of oscillators for any modulating frequency is considered the conditions for an ideal nonlinear frequency modulator are formulated and aoolied to the constant amplitude and relaxation oscillator 683 classical electrodynamic equations of motion with radiation reaction a physically reasonable solution for the equations exists for any force field that satisfies certain conditions 684 sauter theory of the photoelectric effect the photoelectric effect cross section for arbitrary x ray polarization and arbitrary initial and final orientations of electron spin is expressed in the form of a transition matrix approximation shows its relation to bremsstrahlung theory 685 higi frequency limit of bremsstrahlung in the sauter approximation the photoelectric process is shown to be inverse to the process of x ray emission at the high frequency limit of the spectrum 686 interference of orbital and spin currents in bremsstrahlung and photoelectric effect interpretation of angular distribution x ray polarization and spin orientation in terms of interference between orbital and spin currents 687 bremsstrahlung and the photoelectric effect as inverse processes a detailed theoretical examination of the inverse processes of the photoelectric effect and of bremsstrahlung at the high frequency limit of the spectrum 688 the motion of an electron in a crystal located in an external field extension of an earlier analysis to the case of uniform magnetic and arbitrary electric fields 689 exclusion factors in transport theory 690 the problem of the optical constants of conductors a mathematical analysis showing that the optical constants of an isotropic conductor comprise in addition to the index of refraction and of the absorption coefficient two real quantities corresponding to a complex boundary impedance the real part of this boundary impedance represents the surface losses in the conductor and the imaginary part of the dielectric constant the volume losses 691 high current superconductivity the barden cooper and schrieffer theory of superconductivity is extended to the case of high current densities by explicitly including in the phonon induced electron electron attraction the modification of the phonon spectrum in a moving coordinate system this modification results from the doppler effect 692 investigation of the high frequency spectrum of periodic discharges the frequency spectrum of h v corona pulse discharges is investigated 693 electric field in a microwave plasma as a function of time investigation of the transient state in a pulsed discharge in deuterium at pressures field strength was determined bi an optical method of noting the stark effect on the balmer lines in the external oscillating field 694 the plasma capacitor the measurements of dattner on a plasma resonator are discussed 695 electron temperature in electrodeless discharge subjected to a transverse magnetic field 696 ion energies in a cold cathode discharge in a magnetic field the current flow after a discharge revealed an approximately maxwellian distribution of velocities at the cathodes with a temperature this gives an ion density in the discharge 697 microwave study of afterglow discharge in water vapour electron loss processes prevailing in decaying water vapour plasmas are interpreted 698 possibility of determining the potential distribution of a plasma from the characteristics of the noise generated in a gaseous discharge a note of noise measurements made on oxide cathode discharges in krypton at pressures and at discharge currents the variation of potential along the axis of the discharge is in close agreement with results obtained by conventional probe methods 699 scattering potential in fully ionized gases a discussion of recent methods for calculating a the scattering potential and b the probability that a test particle experiences an electrical field of magnitude 700 the stability of plasma configurations of cylindrical symmetry with volume currents the stability is investigated by the method of small perturbations 701 energy losses of charged particles due to excitation of platma oscillations a kinetic equation is derived describing the interaction between beam elements and plasma under equilibrium conditions for non equilibrium conditions a nonlinear theory of plasma oscillations excited by an electron beam is developed and results are applied to account for the rapid energy transfer from the beam 702 collision damping of space charge waves in a plasma the general determinantal equation applicable to the propagation of space charge waves including the effect of collisions in the absence of a velocity distribution in a plasma is derived suggestions arising from the solutions are discussed 703 absorption and reflection spectrum of a plasma a re evaluation of the experimental results of rommel and dattner and a development of theory to account for additional resonance peaks 704 penetration of an electromagnetic field into a plasma calculation of the penetration depth for a semi infinite plasma located in a magnetic field perpendicular to the plasma boundary 705 incoherent microwave radiation from plasmas a study of incoherent radiation from an isotropic qxiscent plasma of a low degree of ionization the three cases of transparent semi opaque and opaque plasmas are considered theoretically good experimental agreement is obtained xsing d c glow discharges in helium and hydrogen 706 microwave determination of plasma density profiles a method for the rapid determination of the average electron density and of the spatial electron density distribution in plasmas is presented the technique employed permits time resolved measurements over a wide range of electron densities introducing little or no perturbation into the gaseous discharge 707 structure of a magnetohydrodynamic sho k wave in a partially ionized gas an approximate solution of the equation for the transition zone is given for some special cases 708 the structure of hydromagnetic sho k waves part one nonlinear hydromagnetic waves in a cold plasma waves in a quasi neutral gas consisting of ions and electrons are investigated neglecting collisions but not the inertial effects of the electric current the relation of these waves to hydromagnetic shock waves in low density plasmas is considered 709 electromagnetic properties of high temperature air if the parameters are normalized the e m characteristics of plasmas can be represented in a universal form in the complex dielectric coeficcient plane or the complex propagation constant plane 710 fine structure in the decline of the ferromagnetic resonance absorption with increasing power level a theory of ferromagnetic resonance at high signal powers is developed which accounts quantitatively for observed effects 711 on the phenomenological theory of the voigt effect in paramagnetics a microscopic calculation of the voigt effect in paramagnetic media at centimetre wavelengths 712 influence of exchange interaction on paramagnetic relaxation times 713 relaxation effects in a maser material the rate equations for the occupation of spin levels are augmented to include cross relaxation processes which can impair maser action 714 radiation produced by an electron beam passing through a dielectric medium an electron beam passing through a dielectric medium may produce an instability that is associated with the growth of longitudinal waves having a velocity close to the velocity of the beam if homogeneities are present these longitudinal waves may be converted into transverse waves and radiated into space thus there is a possibility of a luminous effect at bohr frequencies that differ from the vavilov cherenkov frequencies 715 on the doppler effect in an anisotropic and gyrotropic medium investigation of the doppler effect during the motion of an oscillator along the axis of a gyrotropic anasotropic crystam expressions are derived for the radiation energy applicable to the cherenkov radiation field of an electron and of a dipole 716 the increase ie frequency bandwidth of thin four layer absorbers for centimetre electromagnetic waves a type of absorber is investigated which can be made thinner than one thirty of the wavelength in free space if the dielectric constant or permeability of the lossy material is independent of frequency the effective bandwidth of the absorber decreases with absorber thickness to obtain a thin absorber covering a frequency range of ratio one two bielectric constant or permeability would have to follow a frequency law of the type given but no practical material is known which meets these requirements 717 a note on diffraction by an infinite slit previous results for plane waves at longer wavelengths are extended to obtain transmission coefficients at oblique angles of incidence cylindrical waves are considered briefly 718 diffraction by a spheroid the diffracted field is determined by two methods for wavelengths small compared to the spheroid results are applied to evaluate the back scattered fields 719 investigations on artificial dielectrics at microwave frequencies part two the expression for the phase change in transmission of an e m wave incident on a parallel plate type artificial dielectric as a function of the plate spacing has been verified experimentally 720 on the reflection of electromagnetic waves from a medium excited by acoustic waves theory is developed for the variation of density and temperature in a liquid caused by an acoustic wave generating regions of maximum and minimum dielectric constant modulation of a wave reflected from an acoustically disturbed water surface is observed 721 confinement of charged particles by plane electromagnetic waves in free space confining forces associated with nonuniform fields are shown to occur when twr plane waves intersect in free space 722 nuclear resonance absorption circuit the principles of detecting nuclear resonance absorption in a specimen surrounded by a coil forming part of a tuned circuit are discussed in detail and various methods are compared a new circuit is described and two practical designs are given for operation 723 correlation effects in impurity diffusion 724 the shielding of a fixed charge in a high density electron gas a corsed expression for the density of displaced electrons is derived by a systematic application of the many body perturbation theory 725 magnetoplasma reflection in solids the splitting of the reflection edge at the plasma frequency in the presence of a magnetic field has been used to measure the effective mass of the electrons 726 development of highly directive aerials in radio astronomy 727 on the long term variation in the cosmic radiation the variation seems to occur in a series of sudden decreases rather than gradually a possible solar modulating mechanism is discussed 728 decrease of cosmic ray intensity on february the sudden decrease followed by a temporary recovery is attributed to disordering of the outer geomagnetic field by the increase of the solar wind 729 geomagnetic effects on cosmic radiation for observation points above the earth stormer and lemaitre vallarta theories of the principal shadow cone have been adapted for observational points above the earths surface 730 question of the existence of a lunar magnetic field a lunar magnetic field would be distorted by solar corpuscular radiation on the sunlit side it would not extend to high altitudes and would be difficult to detect 731 observations on the general solar plasma instability suggestions are made for satellite experiments during occasional very intense solar streams to determine the nature and geometry of the plasma barrier 732 a relationship between the life of m regions and the rate of change of solar activity an inverse relation is established between the rate of decay of the cycle of solar activity and the lifetime of m regions as manifested by the persistence of recurrence of magnetic storms 733 small effects of solar flares and the energy spectrum of the primary variation of cosmic rays investigation of the relation between small solar flares and the intensity of cosmic oay neutrons at four stations at different latitudes 734 survey of number of solar flares observed during the international geophysical year the i g y flare data show a very high rate of occurrence many of these flares would probably have been classified as subflares by photographic observers 735 motion of geomagnetic field lines motion of the impact regions of the upper atmosphere can only be very slow since the high conductivity of the earths interior limits the field distortion this is at variance with the hypothesis of rees and reid 736 current systems in the vestigial geomagnetic field explorer sixth the results indicate the existence of a temporally variable current system at earth radii 737 some characteristics of the upper air magnetic field and ionospheric currents magnetic scalar intensity from rocket data is compared with that derived by extrapolation from the surface vector field the agreement is good for equatorial regions but is only fair for white sands new mexico 738 a radial rocket survey of the distant geomagnetic field 739 fluctuations in the geomagnetic horizontal field near the magnetic equator earlier work is continued to cover the diurnal characteristics of fluctuations and to examine how they compare with fluctuations due to solar flare effects 740 occurrence frequency of geomagnetic micropulsations pc analysis of the diurnal occurrence frequency shows that a the frequency increases and time of maximum occurrence gets earlier as the turoral zones are approached b the diurnal distribution of frequency depends on universal time as well as local time 741 a giant geomagnetic pulsation the characteristics of the event of july are studied from magnetograms recorded at a large number of european observatories observed effects are compared with existing theories of the cause of gians pulsations 742 on the theory of giant pulsations a mathematical analysis of the propagation of a magneto ionic disturbance originating in the exosphere shows that only the rotational movement perpendicular to the geomagnetic field is propagated without great loss of energy the observed characteristics of giant pulsations suggest that they are mainly caused by this rotational component of the primary disturbance 743 geomagnetic storm theory the penetration of solar ions into the geomagnetic field during the main phase of storms is discussed a model is suggested the principal feature of which is a magnetic tail extending from the earth on the dark side this model would help to explain the gegenschein electrons with auroral energies the position of the van allen zones and diurnal cosmic ray variations 744 the simultaneity of sudden commencements of magnetic storms geographic analysis of magnetograms shows that a sudden commencements always occur first in high or middle latitudes b the average values of their apparent propagation velocity round the magnetic equator 745 charge and magnetic field interaction with satellites when satellite motion is parallel to a magnetic field the satellite will become negatively charged to a potential for motion perpendicular to the field this will be modified by an induced e m f which may be as large as per metre of satellite length the drag caused by induced currents is found to be negligible except for very large satellites 746 satellite orbits in an oblate atmosphere 747 variation of upper atmosphere density with latitude and season further evidence from satellite orbits 748 atmospheric tides and ionospheric electrodynamics a semi empirical treatment of winds in the height range showing their dependence on latitude and height the extension of modern tidal theory into the dynamo region is discussed 749 electron density of the ionosphere utilizing high altitude rockets 750 the comparison method of the station lindau harz for the determination of the true distribution of electron density in the ionosphere an extension of the method described earlier is discussed the advantages of using the extraordinary ray traces for comparisons are shown details are given of the method of calculation and the equipment used for analysis the tables included are calculated for a geomagnetic inclination 751 group refractive index of the ionosphere at low frequency a general expression for the group refractive index at l f is obtained which for the limiting case when electron collisional frequency is small is identical with an approximate expression due to gibbons and rao 752 a theoretical current density ansatz for the quiet day solar semidiurnal tidal mode of oscillation of the ionosphere theoretical expressions which embody the generalized atmospheric dynamo mechanism of the origin of upper atmospheric current systems are derived for the current density vector by numerical integration methods approximate expressions may be obtained for the current density over an ionized shell concentric with the earth 753 use of greens function in the solution of ionospheric diffusion problems the mathematical analogy between diffusion of ions in the ionosphere and heat conduction in a rod is used to solve the problem of diffusion with an attachment type law of electron loss 754 diffusion of ions in a static f region the vertical diffusion of ions under the action of gravity and a rate of electron loss which decreases exponentially with height is shown to correspond to heat conduction in a rod with a heat source distribution and radiation from the lateral surface electron density is determined as a time periodic function of the height and is expressed in the form of an infinite series 755 a model of the f region above h f the electron density distribution above the f layer maximum is approximated using a chapman distribution the scale height has been chosen to agree with the sparse data available for this region this approximation has been used to extrapolate vertical incidence ionospheric data for a chain of observatories 756 correlation of spread f activity with f region height changes the analysis employs a new index of spread f activity suited to equatorial phenomena 757 ionospheric effects associated with the solar flare of july report of observations made in singapore of ionospheric effects associated with the flare a positive pulse in the measured values f similar to that studied by minnis and bazzard was observed immediately after the period of high absorption 758 variation of electron density in the ionosphere with magnetic dip extension of work described earlier to include the northern winter solstice results show a sharp maximum in the average electron density 759 the electron content and distribution in the ionosphere electron content and distribution are determined from an analysis of measurements of the faraday rotation rate on transmissions received near colombus ohio 760 some observations of ionospheric faraday rotation a comparison with vertical incidence ionosonde data suggests that the ratio of the electron contents above and below the level of maximum ionization of the f region does not remain constant between sunrise and noon 761 measurement of the ionospheric absorption at ahmedabad the mean monthly values of the absorption plotted against cos x for each month from august to july obeyed a relation of the type log the results are in agreement with those obtained by appleton and piggott 762 on the rotation of the polar ionospheric regions the depth to which the drag of the interplanetary gas might be expected to penetrate is examined levels as low as the e region may be involved 763 the thermal radio emission of the ground and the atmosphere and its influence on aerial nrise the measurements of radio noise discussed were made with the radio telescope on the stockert a radio image of the horizon is obtained from the thermal emission and compared with the optical image 764 the electrical sandstorm and related phenomena the mechanism of electrical charge generation in sandstorms and volcanic eruptions is discussed with reference to thunderstorm phenomena the world wide distribution of thunderstorms is examined and related to the distribution of land masses over the globe and to the daily fluctuations of atmospheric electricity 765 polar auroral geomagnetic and ionospheric disturbances an integral invariant of auroral particle motion which appeared to predict successfully features associated with auroral isochasms 766 the nightly variation of auroras at a subauroral station the maximum frequency of auras occurs near local magnetic midnight the problem of particle bombardment on the dark hemisphere is considered 767 doppler shifted cyclotron frequency radiation from protons in the exosphere these protons are a possible source of v l f dawn chorus and hiss making reasonable assumptions regarding the physical processes in the outer ionosphere theoretical dispersion curves are obtained which are similar to those observed 768 observations on atmospheric radio noise observations made at camden n s w show that the start of noise bursts usually coincides with bay like variations in the magnetic field 769 correlation of occurrence of whistlers with geomagnetic activities the frequency of occurrence of whistlers has a seasonal variation upon which are superposed daily variations which reach a maximum on the second day after a geomagnetic disturbance 770 thermoelectric temperature stabilization of electrical circuit elements the application of the peltier effect to the cooling of semiconductor rectifiers and transistors is discussed 771 low noise electronic voltage stabilizers with low internal resistance the design of low output impedance stabilizers for voltages 772 an eight digit word generator the theory of operation and the design of a binary word generator using surface barrier transistors and a direct coupling technique are given 773 solving noise problems in digital computer memories details are given of a coincident current storage system in which strobe pulses are obtained directly from driven cores 774 optical analogue computers a general theory of optical analogue computers based on characteristics of the photographic process is developed and applications of photosensitive materials and photocells for performing mathematical operations are reviewed 775 integrated magnetic circuits for synchronous sequential logic machines two approaches to the problems of storage gain and unidirectional transfer of a sequence of bits in a system with a minimum of nonmagnetic components are outlined examples are given of experimental synchronous sequential circuits using commercially available multiaperture cores 776 computer switching with high power transistors a method for selecting the most suitable type of power transistor for particular switching applications is given 777 the digitron a cold cathode character display tube 778 an analogue computer for investigating the directivity characteristics of complex arrays of unit aerials 779 an approximation to the harmonic response of saturating devices an exponential curve is used to approximate the system characteristics 780 electrical and thermal relaxation effects in current carrying metallic conductors the a c admittance of conductors carrying d c is calculated and a relation is found for determining the frequency dependent thermal conductivity results of measurements on lamp filaments confirm this relation 781 some results on the cross capacitances per unit length of cylindrical three terminal capacitors with thin dielectric films on their electrodes the concept of power at complex frequencies the significance of the term negative resistance is discussed with regard to two different aspects one is the behaviour of twopole networks with sinusoidal oscillators and a negative slope characteristic the other is the case of exponentially decaying oscillations where phase shifts greater between current and voltage may arise 782 a method of synthesis of linear passive networks for transient conditions a method of synthesis is described for networks wrth transient response of unit function or dirac function type 783 frequency jumps and pulling effects in coupled circuits the admittance equations for two coupled tuned circuits are formulated and the conditions of oscillation established the minimum width of the frequency jump is derived as a function of coupling and in relation to the pulling properties of the oscillator the limiting conditions for freedom from frequency jumps are given 784 the optimization of a class of nonlinear filters a mathematical treatment shows that use of the nonlinear filter gives a significant improvement in mean square error even when signal and noise have the same spectral densities optimization is not unduly difficult 785 the influence of the time dependent series resistance of a capacitance diode in a mavar up converter an amplifying frequency converter for conversion is investigated theoretically the variable reactance is a semiconductor diode of the type described by uhlir the effect of the loss resistance of this diode on converter stability and band width is evaluated 786 dual frequency oscillator design basic design details are given of circuits in which hartley and colpitts oscillators are combined 787 simultaneous oscillation at three natural frequencies in nonlinear feedback circuits the steady states of a nonlinear feedback loop with three degrees of freedom are investigated under the assumption of quasilinearity with reference to the theory of multimode oscillators experimental results and practical applications of the effect are discussed 788 transfluxor oscillator gives drift free output a voltage controlled transistor multivibrator circuit incorporating a transfluxor magnetic core is described a feature of the arrangement is the stability of the output frequency after removal of the control signal 789 a simple pulse generator and a pulse distribution unit using transistors circuit and performance details are given of equipment for use rn television studio installations 790 time to pulse height converter of wide range the converter is designed to plug in to commercial oscilloscopes and can time several events per time scan relative to one starting event counting losses can be reduced by negative time scanning the circuit diagram is given 791 fast coincidence circuit for slow pulses for pulse timing particularly in coincidence spectroscopy applications 792 practical decimetre wavelength harmonic generator a frequency stable coaxial type harmonic generator is described whose design is based on the rod wavemeter four patterns are available covering different fundamental wavelength ranges the highest usable harmonic frequency 793 harmonic generation using idling circuits a theoretical examination of the conditions necessary for efficient harmonic generation using an element with a square law characteristic 794 tunnel diode as an interstage gain device application of the tunnel diode as a coupling element to provide impedance transformation and power gain between each stage of an i f amplifier 795 distortion in class ab push pull amplifiers fourier coefficients of the current waveform for a single valve or transistor working under varying bias conditions are evaluated as a function of the angle of flow of the output current from these results the harmonic distortion is determined for a balanced push pull system and it is shown that small degrees of unbalance can be responsible for large contributions to the overall distortion principally by the introduction of second harmonics 796 compensation of direct coupled amplifiers against drift caused by heater voltage fluctuations the output from a thermopile heated from the source which supplies the valve heaters of an amplifier is fed back either to the input or to the indicator to compensate for zero drifts the drift is reduced by two thirds without loss of amplifier sensitivity 797 self balancing push pull circuits theoretical aspects of self balancing circuits are discussed and a method is described for making a push pullamplifier self balancing by applying overall push push negative feedback no close tolerance components are needed 798 the new isodyne phase splitter details are given of an amplifier in which the phase splitter is directly coupled and the output to the final stage is taken from a cathode follower 799 unity gain amplifier offers high stability design equations are given for a double triode output stage the gain stability factor of which is the reciprocal of the products of the two gains 800 an overmodulation effect in negative feedback valve amplifiers if the final stage of a multistage rc coupled feedback amplifier is driven into grid current through over loading there is a difference between the input levels at which grid current sets in and that at which it ceases the distortion caused by this effect is investigated measures to eliminate it are discussed but are not considered worth undertaking for multichannel carrier systems 801 temperature stabilization of transistors in class b amplifiers factors affecting stability are discussed and a graphical method is described for estimating the maximum temperature for stable operation experimental results obtained using a thermistor to improve stability are in good agreement with theory 802 transistor circuit design using modified hybrid parameters methods are described for calculating modified hybrid parameters and approximate expressions applicable to the design of practical one and two stage amplifiers with feedback are given 803 masers or parametric amplifiers the main features of the various types of amplifiers in each group are summarized and their relative performance in practical systems is discussed 804 on the theory of masers preliminary note dealing with the effects of phase distribution in the microwave field 805 on the possibility of maser action in nuclear quadrupole systems 806 operation of a chromium doped titania maser brief description of a maser which has been operated at several frequencies 807 parametric amplification along nonlinear transmission lines a pump signal propagating along a dispersionless transmission line with a distributed nonlinear capacitance is subject to deformation since different parts of the signal move with different velocities the deformation will affect the parametric amplification process so that in general a sinusoidal will not be increased inits fundamental frequency bi travelling down the line 808 extension of longitudinal beam parametric amplifier theory 809 note on the noise figure of negative conductance amplifier the noise figure is calculated for the case when the negative conductance amplifier stage is connected directly to a receiver and when it is connected via a lossless step down transformer 810 noise performance theory of esaki tunnel diode amplifiers theory indicates that low noise figures can be achieved only with some sacrifice in gain stability or bandwidth 811 thin film balanced modulator passive balanced modulator circuits are evolved using single domain permalloy film which is vacuum deposited in a magnetic field 812 the use of silicon diodes in d c modulators and their applications to drift correctors for computing amplifiers advantages over the conventional relay modulator include good high frequency response low noise level low switching power requirements and an operational life limited only by the thermionic valves zero stability is comparable wite that of the conventional relay 813 explicit form of f m distortion products with white noise modulation expressions are derived for frequency and amplitude distortion of the output of a network whose phase or amplitude characteristics vary nonlinearly with frequency the evaluation of these expressions using a digital computer is illustrated for the case of fourth order distortion associated with terms in the discriminator amplitude characteristic up to the sixth degree 814 frequency modulation of a transmitter by inductance variation the use of a ferrite cored variable inductor is proposed and its advantages over a reactance valve circuit are discussed an experimental f m master oscillator is described 815 the single ended diode phase sensitive detector the transform ratios for the two diodes are found to vary with signal level the nonlinearity in the output is evaluated and a table is given for assessing the performance of a given detector 816 theoretical considerations on the experimental determination of spontaneous photon fluctuations a method is indicated for measuring fluctuations with a suitable photon detector 817 theory and application of thermally stimulated currents in photoconductors explicit solutions are obtained in the limits of slow and fast retrapping a method of obtaining the ionization energy of the relevant traps is discussed 818 photon momentum effects in the magneto optics of excitons two magneto optic effects due to the small but finite wave vector of light are described 819 an approximation method for the treatment of spherical aberration of objectives using the methods of communication theory the surface of the objective is divided into zones and a simple formula is derived for evaluating the brightness distribution in the image plane 820 charged sphere in cylinder the charge density potential and capacitance of the sphere are calcuotential and capacitance of the sphere are calculated to an accuracy within one part in ten using the method described earlier 821 wave functions and effective hamiltonian for bloch electrons in an electric field 822 transport phenomena in elastically anisotropic metals 823 statistical theory of kinetic phenomena general expressions are derived for kinetic coefficients which are used to obtain approximate formulae for the case of weak electron phonon inter action the derived formulae are used for investigating the thermoconductivity and thermo e m f of semiconductors 824 a dielectric approach to impurity conduction the problem of impurity conduction in valence crystals is formulated on a dielectric basis calculations are made of a the contribution to the permittivity arising from the hydrogenic donor atoms b the donor activation energy and c the effect of screening by conduction electrons 825 on the theory of superconductivity an exact treatment of the strong coupling approximation in the theory of bardeen et al and discussion of the meissner effect 826 development of space charge and growth of ionization in the transient townsend discharge an extension of earlier work 827 cathode work function sparking potentials and secondary ionization coefficients for oxide coated cathodes in hydrogen the contact potential difference between oxide coated cathodes and a gold reference surface has been measured using the kelvin technique 828 influence of the cathode work function on the sparking potential in hydrogen the kelvin vibrating electrode method of measuring contact potential differences has been used to follow changes in work function of evaporated metallic films in a parallel plate electrode system in hydrogen 829 ultimate and secondary electron cold cathode discharge in helium 830 equation of state of high temperature plasma fully ionized plasmas at high temperatures are investigated on the basis of quantum theory and a correction to the debye huckel approximation is evaluated for the free energy and the equation of state 831 electron and ion runaway in a fully ionized gas part two an extension of the treatment presented in part one to give a more exact estimate of the runaway rate under the action of a weak electric field 832 electron velocity distributions in a partially ionized gas investigation of the transition from the non maxwellian distribution characteristic of a poorly ionized gas to the maxwellian distribution as the degree of ionization rises 833 plasma containment by r f and d c field combinations the advantages are discussed of supplementing d c with r f fields which are sometimes more effective and possibly more stable the design of r f plugs for sealing the ends of a plasma column contained by a d c magnetic field is given in some detail 834 propagation of plasma waves across a density discontinuity when longitudinal waves are incident on a plasma density or temperature discontinuity energy can be converted to transverse waves the inverse process also occurs 835 radio emission by plasma oscillations in nonuniform plasmas equations of motion for small amplitude plasma oscillations interacting with the e m field in slowly varying density or temperature gradients are established the r f noise excited by a wave packet of plasma oscillations traversing such gradients is calculated using the wkb approximation a similar calculation is made for a density discontinuity 836 the radiation emitted within ionized gas in the presence of a magnetic field 837 electrohydromagnetic waves in a fully ionized gas part one transport equations are used to determine coefficients which are generalizations for any frequency of electric field of the parallel pedersen and hall conductivities applications are discussed 838 potential distribution between two plane emitting electrodes equations are derived for two plane parallel electrodes made from different materials and kept at different temperatures numerical calculations are given for electrodes at the same temperature with an external potential difference between them all possible potential distributions are shown to be represented by a family of curves 839 theory of spin wave interactions in ferro and antiferro magnetism mathematical treatment of spin wave theory for a ferromagnetic model giving results in agreement with dysons 840 geometrical representation of the maxwell field in minkowski space the electromagnetic field tensor of a classical charged particle is associated with the orientation and density of a family of two dimensional surfaces radially distributed about the world line of the particle in minkowski space 841 on the production of high intensity magnetic fields of short duration the design of capacitor discharge apparatus for pulsed fields is discussed calculations are compared with experimental data for coils producing fields 842 production of very high magnetic fields by implosion fields in the ten fifteen mg range are obtained by use of high explosives which effectively compress the flux inside a metallic cylinder 843 microwave whistler mode propagation in a dense laboratory plasma the thermonuclear machine zeta at harwell is being used for plasma diagnostics measurements of refractive index and attenuation rate at two frequencies will be attempted 844 focusing molecular beams of nh a study of the formation of molecular beams for use in nh masers is described the design and performance of nonuniform focusers and of effusers is considered the operation of a system is described in which lower state molecules produced by maser oscillation may be detected 845 molecular beam formation by long parallel tubes the characteristics of molecular beams formed by sources consisting of long tube arrays are measured for several sources the results agree well with theory some considerations in source design are also discussed 846 analysis of focuser for maser oscillators a mathematical study of the characteristics of eight pole four pole and square well focusers the main conclusions refer to the focusing length and the influence of the velocity distribution in the beam 847 on the possibility of maser action in nuclear quadrupole systems analysis of an apparently promising system shows that the gain in the material is not sufficient to overcome circuit losses 848 allowed and forbidden regions in the motion of electrically charged particles in axially symmetric magnetic fields diagrammatic methods are applied to the case of motion in the field of a magnetic dipole and of a circular line current 849 the motion of charged particles in the magnetic field of a straight current carrying wire the calculated velocity of a particle in the field along an infinitely long wire is in agreement with alfvens approximation 850 quantum theory of transport in a magnetic field 851 comparison of the charges of the electron proton and neutron experimental details are clarified in reply to criticism by bondi and lyttleton 852 systematic study of electron binding energies of some fourth and sixth period elements by means of the photo electron method 853 theory of internal field emission difficulties in the solution of the schrodinger equation in the quantum mechanical treatment of internal field emission are avoided by the use of bloch functions instead of those based on houstons theory 854 on the magnetic field of the galaxy 855 on the interplanetary gas and its magnetic field proposed models of the interplanetary magnetic field are critically examined in relation to known physical phenomena 856 existence of net electric charges on stars this hypothesis accounts for the known orders of magnitude and directions relating to a number of phenomena such as the magnetization of the earth and the outer van allen belt and leads te a simplle qualitative or semi quantitative explanation for others possible sources of the stellar net charge and possible criticisms of the hypothesis are discussed the simultaneous observation of radio star scintillations on different radio frequencies with increasing scintillation activity the amplitude and rate have distributions which contain discontinuities 857 apparent radio radiation at eleven m wavelength from venus from further observation and subsequent analysis it appears definite that signals previously reported were not from venus but were interference of terrestrial origin 858 the freiburg radio spectrograph the design of the solar spectrograph described is based on that of wild and mccready 859 the association of solar radio bursts with auroral stoaems analysis of two years observations of type two radio bursts shows a correlation with auroral and magnetic storms with a mean time delay 860 determination of the extinction in the earths atmosphere of radiation discussion of the results of microwave absorption measurements on solar radiation made at sunset and sunrise in berlin and on rugen in the baltic 861 the thermal radiation of the moon a radiation temperature has been measured showing no variation with the phase of the moon 862 the radio emission from normal galaxies part one 863 changes in the differential rigidity spectrum of primary cosmic rays associated long term and short term intensity variations 864 some properties of the van allen radiation observations of the electron bllt made with explorer four and explorer six are inconsistent with the solar injection hypothesis the electrons released in the decay of cosmic ray neutron albedo may represent a satisfactory source for the outer zone 865 measurement of radiation in the lower van allen belt the maximum of the belt occurred at fifteen n 866 cosmic ray intensity in interplanetary space cosmic ray intensity has been calculated as a function of distance from the sun in the region between the orbits of mars ane venus 867 cosmic ray orbits in interplanetary magnetic fields cosmic ray orbits have been calculated in the interplanetary field suggested by alfven the results are briefly discussed and compared with cosmic ray observations 868 combined photographic and radio echo observations of meteors measurements have been made on a bright geminid meteor by means of a meniscus schmidt camera and two pulsed radio transmitters operating at frequencies near thirty six mcs the radio echo duration is found to be several orders of magnitude less than would be expected from simple diffusion theory this behaviour is explained in terms of the attachment of electrons to neutral oxygen molecules to form negative ions and a value for the attachment coefficient is determined 869 the azimuth distribution of oblique reflections from meteor trails and its relation to meteor radiant distributions the measurements refer to a north south path the distribution of radiants which best fits the observations is a heliocentric distribution uniform over the celestial sphere 870 the effect of attachment on radio echo observations of meteors the observed relation between visual meteor magnitude and echo duration is explained by this mechanism as are the departures from the wavelength squared variation of echo duration predicted by diffusion theory attachment processes also account for the observation that the final heights of enduring meteor echoes all centre about ninty five km even though bright meteors may show a maximum in light intensity below eighty km 871 the character of the next sunspot maximum from an application of probability laws previously used it is concluded that the next sunspot maximum may be weak during the next eleven year cycle 872 an estimate of the peak sunspot number there is a probability that the next smoothed peak sunspot number will be in the range 873 on the origin of solar flares the high concentration of energy stored in the chromosphere can be accounted for by a particular class of magnetic field whose lines of force have the general shape of twisted loops protruding above the photosphere when loops of opposite sense and twist meet energy is dissipated in the form of a solar flare 874 effects of the solar flares an analysis of observations made at kiruna sweden of ionospheric and geomagnetic disturbances following flares 875 lines of force of the germagnetic freld in space the lines of force from points in the northern hemisphere are traced to the southern hemisphere using the first nine gauss coefficients with particular reference to the auroral zones 876 the ring current and the outer atmosphere by hydromagnetic wave propagation through the ionosphere changes in the geomagnetic field at ground level would be delayed less than one min after ring current changes at several earth radii the electric current associated with particle motions in the van allen belts is examined 877 correlated micropulsations at magnetic sudden commencements using wire loops fifty two square miles in area micropulsations were recorded simultaneously in arizona and new jersey during the initial phase of a magnetic storm cross correlation between the two records shows a time difference of two to three seconds which corresponds to that for the sudden commencement 878 diurnal and annual variations of the normalized amplitudes of sudden commencements of magnetic storms at tamanrasset an extension of earlier work 879 three dimensional consideration for current system of geomagnetic variations part one current flow for polar elementary storm within a spherical conducting shell 880 effects of solar radiation pressure on earth satellite orbits calculations show that at a mean altitude radiation pressure can displace the orbit echo balloon for certain resonant conditions this effect accumulates drastically affecting the satellites lifetime 881 perturbations in perigee height of vanguard one the effect of solar radiation pressure on the perigee height of satellite is considered the inclusion of this effect leads to closer agreement between observed orbital data and theoretical results 882 a doppler cancellation technique for determining the altitude dependence of gravitational red shift in an earth satellite description of a technique by which the frequency of a moving source is corrected for first order doppler shifts 883 profile of upper atmosphere air density at the height derived from the orbit of sputnik three 884 satellite orbits and atmospheric densities at altitudes obtained from the vanguard orbit determination program the program is outlined results of vanguard one measurements show that the minitrack and computing systems can be operated with an overall accuracy within one milliradian atmospheric density results are discussed 885 on an aspect of the relations between mechanics and artificial earth satellites it is suggested that satellites which orbit equatorially may offer an opportunity to study fundamental laws of mechanics 886 a report on the symposium on the use of space vehicles at the u r s i meeting a discussion of possible experiments in the following classes a v l f satellite measurements b ion probes c faraday rotation measurements d topside ionospheric sounders e studies of anomalous propagation 887 ionizing radiation detected by pioneer two the total ionizing component of cosmic radiation was measured it shows a steady decrease near this height 888 altitude dependence and time variation of the radiation intensity observed by u s satellite 889 solar activity and deceleration of earth satellites a correlation between the irregularities of the orbital period of satellite and solar radio emission during the period december january is discussed 890 the satellite ionization phenomenon evidence is given of ionization effects due to the passage of satellites they are most noticeable a day or so after large solar flares 891 radiative cooling of satellite borne electronic components the basic principles of radiative cooling in a satellite are discussed it is considered feasible that temperatures could be maintained provided the proper skin coating is used 892 ionospheric scintillations of satellite signals results showing variations from a smooth doppler shift curve for various frequencies and orbits give a measure of frequency scintillation occurring and hence the roughness of the intervening ionospheric path 893 thermal and gravitational atmospheric oscillations ionospheric dynamo effects included the resonance theory of gravitational and thermal oscillations in a rotating atmosphere is extended to include an electron and positive ion gas with a permanent magnetic field superposed expressions are obtained for the variation with height of the electric field current density and ion drift velocitile some comparisons are made with observed ionospheric data 894 atmospheric densities from satellites and rocket observation current data suggest revision of the a r d c model atmosphere to lower densities a revised model is presented 895 artificial electron clouds part one a summary report of the methods techniques and operating procedures used in a series of eight rocket experiments in which artificial electron clouds were produced in the upper atmosphere 896 artificial electron clouds part two theoretical and practical considerations in the creation of artificial clouds are presented the altitude limits for the generation of long lived dense clouds part one above 897 artificial electron clouds part three a cloud was formed by the release of atomic potassium from an aerobee rocket an analysis of results gave approximate values for wind velocity diffusion constant thermal ionization efficiency and initial half width of the cloud part two above 898 the mesopause region of the ionosphere a proposition by gregory that the layer is formed by photo ionization of dust particles is considered to be untenable 899 strongly absorbing layers below fifty km measurements at kiruna sweden during the summer showed the height of the ionized layer causing long duration absorption to be about fifty km this supports the hypothesis that the ionization is produced by protons see below 900 on some characteristics of the e layer some aspects of the dependence of e ionization on the geomagnetic field are discussed an attempt is made to deduce the mean world wide drift direction of e in summer by using the time displacement that occurs for the daily maxima of the hourly median values of e 901 an attempt to measure the collision frequency of electrons in the f region of the ionosphere measurem nts have been made of the change in the f layer reflection coefficient with change in group path results indicate that values of collision frequency obtained from this type of measurement are unreliable but an upper limit is deduced 902 abnormal features of the f region of the ionosphere at some southern high latitude stations the diurnal variation of f at port lockroy shows a maximum near midnight and a minimum near noon during the summer months this abnormal variation is characteristic of the southern west zone only and is not observed at other high latitude stations in either the south or the north 903 generalization of the appleton hartree magneto ionic formula recent laboratory results show that it is not valid to neglect the effect of the electron velocity distribution function an applicable generalized expression for the complex refractive index is obtained 904 the ion distribution above the f maximum recombination is important up to this height the ion distribution is controlled by diffusion protons produced by charge exchange between hydrogen atoms and oxygen ions move upward along the magnetic field lines with an equal number of electrons and produce a medium for the propagation of whistlers 905 on the interpretation of ionization in the lower ionosphere occurring on both day and night side of the earth within a few hours after some solar flares the absorption effect following solar flares may be interpreted as being caused by a high energy ion beam of very small density emitted from the sun the ions moving in stormer orbits 906 large scale irregularities in high altitude winds 907 enhanced ionization in the polar ionosphere caused by solar corpuscular emissions enhanced ionization which follows several hours after a large solar flare is considered to be caused by high energy protons 908 polar blackouts associated with severe geomagnetic storms on sept and feb 909 on the shape of the auroral zones model experiments on alfvens theory of aurorae performed earlier have been extended to study auroral zone eccentricity and include measurements of space charges and the influence of the terrella potential results show that the theory is applicable to the model experiments 910 geometry of the southern auroral zone and the evidence for the existence of an inner zone 911 studies of the upper atmosphere from invercargill new zealand part one characteristics of auroral radar echoes at fifty five mc s full report of work briefly described earlier 912 studies of the upper atmosphere from invercargill new zealand parts two and three analysis of data shows that a the probability of occurrence of radar echoes increases with an increase in local magnetic k index b a radar auroral zone exists whose size is related to the k index c echoes are observed in the daytime to less extent than suggested by the diurnal variation of local k index d there is no direct relation between radar echo regions observed at fifty five mc s and visual aurorae part one above 913 a four year summary of whistler activity at washington d c results are analysed and presented in the form of curves of diurnal and month to month variations of whistlers hiss and dawn chorus 914 the relation between lightning discharges and whistlers observations made near uppsala show that whistler producing atmospherics contain strong components around five kc s and often show multiple discharges atmospherics not producing whistlers often show irregular constitution and a gingle discharge but those giving rise to high field strengths are always followed by whistlers 915 low frequency electromagnetic radiation associated with magnetic disturbances continuous observation of naturally occurring radiation in the band at sydney australia shows major bursts to be associated with strong auroral and magnetic activity 916 effect of temperature on photo voltaic solar energy conversion theoretical investigation of the behaviour of materials with band gaps varying over a temperature range show that the best conversion performance is obtained for the ideal junction current it is degraded by the presence of recombination current experimental data are given for si gaas and cds cells and are compared with theoretical expectations 917 investigation of selenium rectifiers under pulse conditions to investigate the voltage dependence of the resistance in the reverse direction pulse measurements have been made of back resistance capacitance barrier layer thickness and electric field intensity as functions of the applied voltage 918 stabilization of the magnetic field of an electromagnet a system is described for controlling both rapid and slow variations of the magnetic field by means of a transistorized control stage and feedback winding slow variations are detected by the magnetic resonance of protons in a ferric nitrate solution using a technique similar to that described earlier 919 precision thermostat a temperature sensitive resistance bridge controls a crystal oven to give a short period temperature stability 920 a stable thermostat for the measurement of the noise and drift of semiconductor circuit elements the rectified output of a bridge circuit containing a resistance thermometer is used to control the heating of a stirred oil bath the noise voltage of transistors in a power supply circuit and of a zener reference diode have been measured at very low and audio frequencies using the apparatus described 921 an experimental impedance relay using the hall effect in a semiconductor description of a definite impedance relay for the protection of power transmission systems the hall output voltage from an insb crystal is balanced by a voltage from a rectifier unit when a fault occurs in the system an out of balance voltage is produced which operates an electromagnetic relay 922 analogue division circuit the circuit contains only magnetic cores and windings and is suitable for use under severe environmental conditions a detailed analysis is given 923 all transistos magnetic core memories the properties of special small ferrite cores developed for use in high speed transistor drive storage systems are discussed 924 high speed track selection for a magnetic drum store a survey of mechanical and electronic relay switching systems is given and the advantages of transistor switches are discussed 925 high inductance simulation describes a circuit which eliminates the resistance component in a pentode reactance valve giving a simulated inductance of infinite 926 the application of printed wiring to development and small batch production with particular reference to television equipment 927 an equivalent circuit for transformers in which nonlinear effects are present inductive parameters of a transformer are better represented by the two type than by the t type equivalent circuit 928 analysis of series connected saturable reactor with capacitive loading and finite control resistance by use of difference equations observation of transients in the series connected saturable reactor with high impedance control source details are given of apparatus for observing the effects of transients introduced into a reactor operating in the proportional mode 929 the diffusion of moisture in electrical capacitors and their insulation resistance the laws of moisture diffusion are derived mathematically and investigated experimentally on paper capacitors the effect of moisture on the insulation resistance of the dielectric is calculated and comparison is made with measurements on plastic covered capacitors stored under conditions of high humidity 930 the optimum formula for the gain of a flow graph or a simple derivation of coates formula an independent derivation of coates formula based on determinants is given the difference between masons and coates flow graphs is discussed and it is shown how one is obtained from the other 931 the use of iterated laplace transformations in the solution of combined circuit field problems 932 the characteristics of different types of coupling of two coupled undamped electrical oscillating systems without an impressed voltage the effect of various types of coupling on the parameters of oscillatory circuits are considered 933 statistical spectral output of powerlaw nonlinearity methods are given for calculating the output power and the error power for nonlinearities which can be described by power series for gaussian and for certain other special kinds of input signals 934 spectral output of piecewise linear nonlinearity the transference or effective gain of a piecewise linear component is derived 935 topological evaluation of network functions the results are given of an investigation of various combinations of linear passive quadripoles by means of topological identities 936 the analogy between the weissfloch transformer and the ideal attenuator reflection coefficient transformer and an extension to include the general lossy two port 937 matching and bandwidths formulae and curves are given for the bandwidth of different arrangements for input and output matching of single stage and band pass filters 938 the structure of the iterative matrix of reactance quadripoles with a given derived circuit or a given characteristic function the relations between the structure of the characteristic function the irerative matrix and the derived circuit or canonical ladder network are established and the results are tabulated 939 nomenclature of band filters and of band filter design the principal design formulae and symbols and definitions of filter characteristics are summarized in tabular form 940 solution to the realizability problem for irredundant boolean branch networks this type of network is defined for the two terminal and the n terminal case and a general solution is given for the existence and realizability problem 941 basic concepts of the multidimensional space filters the establishment of the basic tensors of a space filter is illustrated by means of a tetrahedron 942 single control element wien bridge the theory of operation of two modified forms of the wien bridge is described the network may be controlled by a single variable l c or r and has applications as a frequency bridge oscillator or selective amplifier 943 a wide band phase shifter a method is described for obtaining a phase shift over a bandwidth determined by the characteristics of the filter used 944 low noise tunnel diode down converter having conversion gain the nonlinearity of the negative resistance characteristic of the tunnel diode can be used for frequency conversion 945 simple amplitude stabilized twin t audio oscillator the stabilization is achieved by a clipping feedback loop 946 electromechanical low frequency oscillator the sinusoidal linear movement of a slider is converted to a sinusoidal angular motion of a rotary potentiometer contact arm to provide electrical oscillations 947 frequency control of an oscillator by nuclear magnetic resonance a description of a simple superregenerative oscillator that produces a coherent signal at the magnetic resonance frequency of a sample in its coil 948 design problems of multivibrators design calculations for free running and for cathode coupled and anode coupled monostable multivibrator circuits are discussed 949 blocking oscillator circuit for very short pulses of high repetition frequency the design of a double triode circuit is given which is capable of generating pulses 950 some recent improvements in low power pulse generators three miniature thyratron circuits used as submodulators for radar transmitters are described high stability free running and triggered versions are discussed with methods of overcoming duty ratio limitations of the valves used 951 theory of a fast switching electron beam frequency coherence and bandwidth of a gas discharge harmonic generator long time delays from a single magnetic storage core time delays up to several minutes can be accurately achieved using an assymetrical bidirectional core voltage the delay may be controlled by a d c voltage or current change or by a change of resistance 952 analysis and design of a transistor linear delay circuit an analysis of the emitter coupled linear delay circuit is given maximum to minimum output pulse width ratios of several hundred have been obtained 953 the anode cathode follower a two stage circuit of near unity gain which inverts negative pulsesis described 954 analysis of magnetic amplifiers without diodes a general method of magnetic amplifier analysis is developed 955 analysis of magnetic amplifier with diodes an analysis restricted to amplifiers terminated in a resistive load and to voltage waveforms typical of such amplifiers 956 graphical evaluation of magnetic amplifier performance based on constant voltage reset test core characteristics for various reset fluxes are determined experimentally leading to a graphical evaluation of the performance of a two core self saturating magnetic amplifier 957 capacitively coupled magnetic amplifiers the amplifier described operates at a high carrier frequency with capacitive coupling of the signal to the load this technique realizes the advantages of true a c amplification an experimental three stage amplifier is described 958 the winding capacitances in magnetic amplifiers the distributed winding capacitance can be replaced by a lumped capacitance for which an empirical formula is found 959 calculations and measurements for the optimum design of low noise transistor amplifiers the conditions for making the transistor noise factor a minimum are calculated for white noise equations are given for the most favourable combination of source impedance and emitter current measurements were made of these optimum values as a function of various transistor parameters and of temperatures 960 transistor amplifier has hundred megacycle bandwidth 961 analysis of the split load stage transistorized expressions are derived for the current and voltage gain output impedance and output return loss of a single stage negative feedback circuit results are incorporated in an analysis of a three stage feedback amplifier with split load output 962 contribution on the stabilization of the operating point of transistors direct current positive and negative feedback over two or more stages in earthed emitter transistor amplifiers provides effective stabilization against temperature variations and differences in transistor characteristics 963 the optimum line width for the transition used in a reflection cavity maser amplifier the line of the amplifying transition in a reflection cavity maser is shown to have an optimum value which will give maximum amplification bandwidth at a fixed gain difficulties associated with achieving the optimum line width in practice for the paramagnetic maser are briefly discussed 964 relaxation time and multiple pumping effects in masers optimization of relaxation times combined with multiple pumping cannot by itself extend the operation of masers past the liquid nitrogen range without degrading the performance below that now attainable at liquid helium temperatures with three level masers 965 packaged tunable l band maser system a maser tunable with a voltage gain bandwidth product is combined with an l band circulator and auxiliary equipment into an operational unit 966 spontaneous emission from an inverted spin system a summary of results of calculations made in an attempt to explain the origin of the observed modulation effects in two level masers 967 c w millimetre wave maser characteristics are summarized and some useful properties of the paramagnetic material are described results indicate that the material will be useful far beyond the frequency range investigated 968 some notes on the history of parametric transducers 969 a ferromagnetic amplifier using longitudinal pumping describes early experimental results indicating a gain with an x band pump power 970 parametric phase distortionless l band limiter the diode loaded helix as a microwave amplifier application of the sampling function to circuit analysis of modulators and demodulators using diodes takes into account the forward and reverse resistance of the diodes 971 a broad band cyclotron resonance r f detector tube operation is based on the cyclotron resonance of an electron beam in a static magnetic and r f electric field in the pencil beam tube described spiralling electrons are detected by a honeycomb mesh grid the current intercepted by the grid is greatest at resonance and is proportional to the r f signal power mechanical details and operating conditions are given a simplified energy transfer analysis enables the electrical characteristics to be predicted 972 universal units of magnetism mechanics and temperature 973 some new aspects of colour perception computed theoretical figures based on mathematical analysis are shown to be in good agreement with empirical results of land an explanation is given in terms of classical colour perception theories in conjunction with the experimental psychological phenomenon of colour transformation 974 efficiency of field ionization at a metal surface theoretical analysis of the dependence of the field ion current on various parameters 975 variational principle for transport phenomena the variational principle for interband scattering is derived and generalized by the introduction of an external magnetic field and lattice vibrations 976 quasi particles and gauge invariance in the theory of superconductivity theory of electrical conduction in high magnetic fields the role of space charge in gas break through between equal parallel plane electrodes below the paschen p d minimum the paschen characteristic for discharges is discussed in detail and some explanations are found with the help of the field emisson theory 977 sim litude and anode material effects in h and d discharges below the critical pressure the breakdown potentials of h and d gases were determined below the critical pressure in two similarly shaped discharge valves of different size with stainless steel anodes and cathodes both gases obeyed paschens law when the anodes were made of pb or al some deviations were observed possibly resulting from deposition of anode material on the cathode 978 microwave noise from low pressure arcs experimental data indicate that the ignition of an arc discharge is accompanied by considerable microwave noise 979 solutions of the equations of space charge flow for radial flow between concentric spherical electrodes the solutions are formulated so that arbitrary initial conditions may be introduced by this means a variety of physical problems can be solved with the aid of a table of airy functions 980 some solutions to the equations of steady space charge flow in magnetic fields earlier analysis is extended to include the case of magnetic field components perpendicular to the cathode sets of solutions are given for the flow from conical and cylindrical cathodes for a broad class of magnetic field configurations 981 the possibility of electron total energy distribution analysis in a quasi spherical capacitor the energy distribution of electrons emitted at various angles from a plane disk shaped target at the centre of a spherical collector is determined from an analysis of electron trajectories the discrepancy between these and those for a spherical capacitor does not exceed one per cent the provision of an aperture in the collector for an electron gun results in a five per cent error 982 the formulation of electron diffraction by means of a scattering matrix and its practical applicability electron diffraction by a crystal plate is treated by dynamic diffraction theory 983 apparatus for direct observation of low energy electron diffraction patterns the equipment designed for high vacuum gives the diffraction pattern on a fluorescent screen 984 on the magnetic perturbation of an electron beam 985 a new method for measuring the attachment of slow electrons in gases simultaneous measurements of attachment coefficient and the ratio of drift velocity to diffusion coefficient are reported 986 measurement of plasma temperature and electron density the value of electron density deduced earlier is twice the true value 987 microwave investigation of plasma in shock tube experimental details and results obtained 988 on the diffraction of electromagnetic pulses by curved conducting surfaces starting with the known steady state solutions for diffraction by a perfectly conducting convex surface the corresponding transient responses are derived using fourier laplace inversion explicit results are given for an incident wave which varies with time as a step function 989 total electromagnetic cross sections of imperfectly conducting cylinders experimental and theoretical results are discussed for the case of scattering from cylinders with length comparable to and with diameter small compared with the wavelength of illumination 990 use of chebychev polynomials in thin film computations from herpins expression for the mth power o a multilayer matrix very simple closed formulas are derived for the matrices and optical constants of any multilayer with a periodic structure 991 high resolution n m r spectrometer with the radio frequency controlled by the magnetic field 992 prec sion zeeman modulation microwave spectrometer a spectrometer is described for measuring the rotational fine structure of oxygen 993 anomalies in the absorption of radio waves by atmospheric gases reasonable agreement is shown between the losses predicted by van vleck and recent measurements for oxygen but for water vapour the measured loss is greater reasons for the discrepancy are discussed 994 remarks on the mass energy and momentum of photons electrons and other elementary particles relations between the corpuscular velocity of a particle and the phase velocity of the corresponding wave are considered and the theoretical equivalence of particle and wave are discussed with reference to a possible experimental verification of the particle concept 995 a note on the polar absorption event of may galactic noise measurements at five stations showed an increase rn absorption lasting up to thirty six h possible solar control mechanisms are discussed 996 extraordinary noise disturbance following a mogel dellinger effect during the large solar eruption of march an initial decrease of cosmic noise intensity observed was followed by a high intensity noise burst lasting several hours 997 a relation between solar radio emission and polar cap absorption of cosmic noise a statistical study has been made of the relation it appears that the polar cap absorption events are closely associated with the occurrence of wide band cm wave outbursts of type four events and their duration is related to the presence on the sun of active regions of noise storms 998 radio astronomical measurements of the sun with particular regard to the phenomena during chromospheric eruptions survey of the measurements of solar r f emission in relation to various types of solar disturbance 999 a shell source of radio emission report of observations made with the mc s interferometer at the mullard radio astronomy observatory cambridge 1000 the eta carinae nebula and centaurus a near mc s part one 1001 a twenty one cm survey of the southern milky way 1002 elementary particles in cosmic radiation review of present state of knowledge and measurement techniques 1003 cosmic radiation intensity decreases observed at the earth and in the nearby planetary medium measurements made simultaneously at earth radii at balloon altitudes and on the earths surface at the time of a large forbush decrease show the same magnitude of decrease of primary cosmic radiation these results do not therefore agree with hypotheses which invoke the presence of the earth and the geomagnetic field to account for the forbush decrease 1004 maximum total energy of the van allen radiation belt the results of the spherical harmonic analysis of the geomagnetic field show an upper limit for the ener y that can be stored in the van allen radiation belt 1005 distribution of trapped radiation in the geomagnetic field an examination of the altitude dependence of trapped radiation from explorer one measurements shows that the radiation intensity data in the vicinity of the magnetic equator can be well represented by the scalar intensity b of the real geomagnetic field the value of b at the lower boundary of the inner zone increases with magnetic dip latitude 1006 magnetic storms and the van allen radiation belts observations from satellite explorer fourth a marked decrease in intensity of particles in the outer belt was observed during magnetic storms it is suggested that this is due to atmospheric heating and expansion at fairly high latitudes the absence of intensity changes in the inner belt is consistent with a cosmic ray albedo neutron origin of inner zone protons 1007 radio frequency scattering from the surface of the moon sensitive radars show the presence at mc s of a scattered component in addition to the quasi specular high light from the moon centre 1008 measurements of lunar reflectivity using the millstone radar highly stable coherent pulse measurements made at mc s enable range doppler frequency contours to be plotted for the rotating moon a precision of two parts in ten for the observed doppler frequency has been obtained a number of measurements are described substantial echoes are observed out to the lunar limbs 1009 lunar echoes received on spaced receivers results obtained imply that a minimum diversity distance of about one km on the earths surface is adequate to achieve diversity reception for communications via the moon 1010 radar echoes from the sun details are given of tests made in april transmitter operating with an aerial system consisting of four rhombics in broadside array covering a rectangular area data were analysed by computer cross correlation curves are reproduced and discussed 1011 solar limb surges accompanied by x ray emission simultaneous observations of hx radiation and recordings of atmospherics at twenty seven kc s indicate a pronounced coincidence in time of sudden enhancements of atmospherics with surge appearances the sudden enhancements could be interpreted as x radiation emitted by an adjacent region of the solar corona 1012 correlation in geophysics the advantages of using a correlation number based on a counting process are discussed in comparison with the limitations inherent in the use of a correlation coefficient examples are given of the correlation of ionospheric data 1013 earths main magnetic field to one hundred and fifty two kilometres above fort churchill a report on rocket flight measurements under magnetically quiet conditions in the daytime 1014 rockets and satellites in the service of geophysics a review of measurements made by artificial satellites with an outline of future plans 1015 space science a report of the international space science symposium held in nice reviewing in particular the results of earth satellite and lunar probe measurements 1016 magnetic damping of rotation of the vanguard one satellite comment on an error in calculations given of may and authors reply 1017 density of the upper atmosphere and its dependence on the sun as revealed by satellite orbits an extension of earlier work 1018 triangulation a precise method for satellite tracking the theory of triangulation is described and applied to a photographic system 1019 determination of corrections to mark two minitrack station coordinates from artificial satellite observations corrections may be deduced from a comparison of radio observations with the predicted orbit 1020 radio observations during the decay period of the soviet satellite delta two measurements made at jreisach west germany on sputnik three during the period march april show irregularities in the period of revolution 1021 faraday effect in the transmissions from fast spinning satellites a note on signal strength variations for the case of a satellite rotation period small compared to the faraday fading period 1022 scintillations of the twenty mc s signal from the earth satellite information on the structure and movements of ionospheric irregularities has been obtained by studying fading patterns on spaced receivers 1023 electron density measurements in the upper ionosphere using the faraday rotation of radio signals from artificial satellites agreement between observations and the calculated faraday rotation curve is improved when account is taken of horizontal variations of the ionosphere estimated from hourly ionograms 1024 the vector field proton magnetometer for i g y satellite ground stations vector magnetic field measurements of high accuracy can be obtained by applying homogeneous bias fields to a proton precessional magnetometer 1025 radiation damage and transistor life in satellites 1026 artificial electron clouds part four report of radio radar and optical observations of an electron cloud created by the night time release of caesium at km from a nikecajun rocket an analysis of experimental data indicates that the electrons observed can reasonably be ascribed to thermal ionization 1027 a theory of electrostatic fields in the ionosphere at nonpolar geomagnetic latitudes es coupling between the dynamo and f regions and between magnetically conjugate parts of the regions themselves the electric source field produced by winds in the dynamo region and the possibility of significant electron density variations in the f region due to es fields are examined 1028 development of the maximum electron density of the e layer at leopoldville binza e layer data obtained during the period february december are analysed the diurnal variation of maximum electron density conforms closely to chapmans law 1029 sporadic e as observed by back scatter techniques in united kingdom using a rotating aerial back scatter sounder during the i g y diurnal seasonal and geographical e characteristics have been obtained on particular occasions the movement of e clouds has been tracked and their size and ionization determined 1030 peculiarities of the ionosphere in the far east a report on i g y observations of sporadic e and f region scatter oblique incidence observations at fifty mcs show that for any given transmission loss sporadic e is three to five times more prevalent in the far east than in the caribbean 1031 height and thickness parameters for region f of the ionosphere more useful parameters may be obtained by replacing measurements of hm by measurements of heights at fixed submultiples of the maximum density 1032 theoretical world curves of maximum ion density in a quiet f region the curves plotted in terms of latitude and local time for solstice and equinox conditions are generally the same as those obtained from ionosonde date the analysis shows that diffusion plays a significant part in controlling f ionization 1033 asymmetry between the f region of the ionosphere in the northern and southern hemispheres an explanation is sought of the asymmetry in the seasonal variations of the critical frequency of the f layer at high latitude stations in the northern and southern hemispheres during years of minimum sunspot number an extensive survey suggests that horizontal wind systems in the f region may be the cause 1034 spread f in baguio through half a solar cycle a statistical survey over six years shows that the occurrence of spread f is associated with periods of downward movement of ionization the seasonal and diurnal variation of occurrence is also markedly different between periods of high and low solar activity 1035 critical remarks on the description of the ionization in the ionospheric e layer changes from nominal value in the exponent of the cos law of e layer ionization are discussed these are necessitated by the difference between seasonal and daily variation of e layer noon values harnischmachers empirical formult for this exponent is not confirmed by an analysis of data the derivation of a world wide e layer character figure from data obtained at one locality is considered impossible in view of geographic differences in ionization characteristics 1036 some abnormalities in the variations of f layer critical frequency during the period of high solar activity of solar cycle the values of taipet become independent of sunspot numbers at high solar activity this saturation effect is related to other abnormalities in the variations at this station 1037 the ionosphere and solar activity the correlation between monthly median critical frequencies and solar activity was determined for washington d c results were compared with those from a similar study made for six arctic stations for noon data a greater value at zero sunspot number and a slightly greater slope were obtained for washington than for the arctic locations the influence of increased solar activity on the behaviour of the midnight ionosphere is discussed 1038 the valley effect in the interpretation of ionospheric eclipse records the spurious maxima in electron density curves at fixed heights can be explained by the presence of a valley between the f and f layers effect of annular solar eclipse of april at sunrise on the f layer of the ionosphere results are given of observations made at three stations in south india a marked decrease in ionization density with the progress of the eclipse was observed 1039 a theory of the origin and geomagnetic control of two types of high latitude e the auroral belt type of e may be caused by electrons from a region of trapped particles indicated by the extent of a night time peak in f type es thule type es may be caused by an influx of electrons approaching from the direction of the sun at geomagnetic noon 1040 outline of a theory of magnetic separation of auroral particles and the origin of the sd field diurnal variations of sporadic e ionization at macquarie island are identified with magnetic separation of incoming protons and electrons associated visual aurorae are discussed 1041 geomagnetic and current control of e region absorption 1042 magnetic storm effects on the f region of the ionosphere a preliminary report on the results of a true height analysis carried out for washington d c during three severe sc type magnetic storms 1043 ionospheric thermal radiation at radio frequencies in the auroral zone the temperature of the lower ionosphere is estimated for observations of radio noise at two mc s temperature range and seasonal variation of temperature are the same as for temperate latitudes 1044 an unusual ionospheric disturbance in the antarctic on june to july unusually high values were obtained for twelve hours at two ionospheric observatories during a magnetic storm 1045 auroral research at the hillhead experimental station general information is given about the paraboloid installed at hillhead scotland to study the effects of aurora on the propagation of radio waves 1046 a theory of trapping of whistlers in field aligned columns of enhanced ionization using ray theory it is shown that the condition for whistler propagation in ducts depends on the ratio of the electron density in the column to that of the background the theory explains part of the variation of whistler rate with latitude 1047 directional observations of five kc s radiation from the earths outer atmosphere an account is given of the estimation of the position and size of sources of l f noise bursts associated with geomagnetic disturbances 1048 h f noise radiators in ground flashes of tropical lightning a detailed analysis of h f noise sources in tropical ground flashes v l f phase characteristics deduced from atmospheric waveforms 1049 a z transform describing function for on off type sampled data systems the derivation of the function for a sinusoidal error signal is fully described 1050 a note on the steady state response of linear time invariant systems to general periodic input 1051 a class of optimum control systems a class of optimum control systems is defined and investigated with special emphasis on time domain concepts this class is particularly suitable for feed back control applications where adaptability to changing conditions is desired 1052 linear circuits regulate solid state inverter 1053 a more stable three phase transistor core power inverter a square wave inverter for driving gyroscope motors is described which could provide up to one kw continuous power 1054 a circuit for the protection of a stabilized transistor power supply details are given of a transistorized protection circuit providing switch off times and activated by currents below the full load value 1055 small universal computing machine with magnetic ferrite elements lem one description of the development and operation of a digital computer using contactless ferrite core storage and logic elements and a capacitive permanent store 1056 chemically deposited nico layers as high speed storage elements 1057 direct metering for a transformer analogue computer descriptions are given of the phase shift and combining networks of the witton network analyser wina 1058 procedure for designing reciprocal computer circuits circuits with outputs approximately inversely proportional to their inputs can be constructed with diodes resistors and d c supplies 1059 semiconductor networks for microelectronics both active and passive components are fabricated in a single crystal semiconductor wafer the development from a circuit diagram by combining vxide masking diffusion metal deposition alloying and surface shaping is described 1060 inductive elements for solid state circuits a resonant circuit is described in which a ge diffused base transistor with an open circuit base connection functions as a negative resistance diode with an effective inductance of fifteen uh the low frequency noise generated by the diode is attributed to avalanche multiplication occurring in localized non stationary areas 1061 clear method for the determination of transformer equivalent circuit diagrams the electrical equivalent circuits are derived directly from the magnetic equivalent circuit using principles of circuit duality 1062 the variation of cryotron current amplification factor with temperature the factor increases as the penetration depth decreases and there is probably a lower limit to the film thickness which can be used 1063 monitoring multiple inputs simultaneously description of an electronic switch and sensing circuit which may be used for detecting a signal or absence of signal on one of many channels 1064 u h f resonator with linear tuning 1065 a different approach to the approximation problem an approximation method for the synthesis of network curves 1066 a constant resistance network 1067 general properties of the propagation constant of a nonreciprocal iterated circuit formulae are given and the use of such circuits in travelling wave valves is considered 1068 method for simplifying filter design using cauer parameters zobel filters may be simply designed with a minimum number of elements 1069 narrow band filtering of random signals shows that the output of a narrow band filter is not necessarily more gaussian than the input 1070 selecting rc values for active filters the circuit configuration described facilitates the design of filters with zero transmission at either infinite or zero frequency component values are determined from the symmetry of the network voltage transfer function by the technique of coefficient matching 1071 theory of a frequency synthesizing network by the introduction of sideband algebra and a frequency symbolic network a formal method of designing frequency combining and selecting circuits is developed 1072 general n port synthesis with negative resistors 1073 noise spectrum of phase locked oscillators 1074 voltage tuning in tunnel diode oscillators 1075 high frequency negative resistance circuit principles for esaki diode applications 1076 phase shift oscillator an analysis based on the describing function method for nonlinear control systems which takes account of the nonlinear limiting process and allows the oscillator to be designed to give specific values of harmonic distortion 1077 a voltage modulated variable pulse rate generator a pulse generator is described the output frequency of which is a linear function of the input voltage the circuit is a screen coupled double phantastron pulse circulating system with suitable modifications to improve the accuracy of transfer at low output frequencies achieving stable discriminator levels with a biased input diode 1078 counting and timing circuits use saturable reactors method of frequency division using a controlled rectifier and saturable reactor are described 1079 the application of phase locking techniques to the design of apparatus for measuring complex transfer functions the principles of phase lock synchronization are described and details of two instruments for measuring complex voltage ratios 1080 nonlinear distortion including cross modulation in high frequency transistor stages harmonic distortion and cross modulation are calculated for the earthed base transistor treated as a nonlinear quadripole and assuming low current densities the solutions obtained are applied to the earthed emitter configuration and experimental results of tests on earthed emitter circuits confirm the theory even for relatively high collector currents an interpretation is given of a pronounced minimum in cross modulation depth as a function of collector current 1081 negative l and c in solid state masers gives an equivalent circuit for a maser which includes negative l and c components 1082 effect of nuclear polarization on the behaviour of solid state masers an account is given of experiments conducted on a ruby sample placed in a doubly resonant microwave cavity with bloembergen stimulation the application of r f power to a coil round the sample produced an increase in amplifier gain the effect being greatest at the resonance frequency of the free ai nuclei 1083 proposed molecular amplifier and coherent generator for millimetre and submillimetre waves the difficulties of obtaining maser action increase with frequency owing to the increasing number of energy sublevels and to decreasing sensitivity of molecules to field gradients a proposed method of avoiding these difficulties is to use special types of stimulated emitter and to separate molecules with different energy levels by a combination of inhomogeneous and homogeneous fields respectively outside and inside the cell 1084 can the landau levels of free carriers be utilized for a submillimetre wave semiconductor maser of using cyclotron resonance in semiconductors for obtaining maser action is discussed the difficulty of having signal and pumping frequencies of the same order can be overcome with the aid of the oscillatory magneto absorption effect 1085 theory of a negative resistance transmission line amplifier with distributed noise generators a transmission line with distributed positive and negative resistances as well as with distributed noise factor are derived as a function of boundary conditions matching conditions and distributed noise it is found that low noise amplification can be achieved on such a line provided the lien is characterized by high gain per unit length high total gain good matching and low distributed noise a distortionless active line for such low noise amplifiers appears attractive 1086 comparison of gain bandwidth and noise figure of variable reactance amplifiers and converters it is shown theoretically and experimentally that the converter has a greater bandwidth than the amplifier for the same gain and noise figure 1087 theoretical limitations to ferromagnetic parametric amplifier performance 1088 microwave parametric amplifier using silver bonded diode 1089 operation of an esaki diode microwave amplifier 1090 a technique for cascading tunnel diode amplifiers the simple tunnel diode amplifier does not lend itself readily to cascading but the addition of a second tunnel diode to each stage gives an amplifier which can easily be cascaded 1091 an extension of the mode theory to periodically distributed parametric amplifiers with losses 1092 rectifier modulators with frequency selective terminations the effects of even order modulation products are examined and the conditions for the elimination of such products determined the theory is confirmed by experimental results 1093 the input impedance of rectifier modulators the impedance is calculated for a number of cases of shunt series and ring type modulators 1094 a pulse width modulator modulation is achieved using the hole storage effect in a junction transistor 1095 on the additivity of photocurrent and secondary electron current measurements on ai provide confirmation of the existence of additivity as asserted by ekertova and contrary to the findings of dember which may have been affected by an internal photoeffect in the oxide layer of the target 1096 nonlocal current field relationship in metals chambers analysis of the response of the conduction electrons in a metal to an internal electric field is extended to cover the case of longitudinal fields 1097 the theory of elementary excitations in atomic semiconductors the simplest model of an atomic semiconductor is considered in which every atom has a saturated valence shell with two electrons electrons holes ortho and para exitons are considered as elementary excitations and the hamiltonian describing the system is derived taking account of interaction between them 1098 charge localization on the surface of oxide coated cathodes anomalous results obtained while using the kelvin method of determining contact potential differences are investigated very high contact potential differences which occur only after the passage of a discharge are attributed to both positive ions and electrons which remain on the oxide surface for long periods depending on the conductivity of the oxide 1099 plasma stability and boundary conditions 1100 an approximate solution of a problem concerning the motion of a conducting plasma a new method for the asymptotic integration of linear differential equations with partial derivatives of the hyperbolic type has been applied to the integration of equations of plasma oscillations 1101 theory of electron oscillations in nonuniform plasmas deals with the case of an externally injected electron beam in a plasma 1102 excitation of plasma oscillations the apparent paradox between the theory of bohm and gross and the experiments of looney and brown on the excitation of plasma oscillations by the two stream mechanism is resolved 1103 experimental two beam excitation of electron oscillations in a plasma without sheaths coherent standing waves of longitudinal electron oscillations have been excited in a plasma bx two independent oppositely directed electron beams whose axes coincided there were no sheaths on the electrodes from which the electron stream entered the plasma results of single beam experiments looney and brown using either equal or unequal sheaths are verified 1104 influence of negative ions on ambipolar diffusion of electrons a note on microwave measurements of the afterglow properties of plasmas in ne ar mixtures 1105 propagation of acoustic and electromagnetic waves in a half space a half space is considered in which the impedance at the boundary is given in the form of an arbitrary complex number and a general solution of the wave equation is formulated by introducing a function which reverts to zero at the boundary expressions for the acoustic and e m potential are derived in terms of this function 1106 the diffraction at apertures in nonplanar screens the approximation method given is applied to the case of a circular aperture in a funnel shaped screen for a scalar plane wave and for an e m plane wave propagating in the axial direction 1107 diffraction of electromagnetic waves according to braunbeks approximation braunbeks approximation method is applied to problems of e m wave diffraction in particular to that of a linearly polarized plane wave normally incident on a circular aperture in a perfectly conducting plane screen and on a perfectly conducting plane circular disk the near field distribution is calculated and compared with results of the rigorous method of solution and of kirchhoffs approximation other approximation methods are discussed 1108 diffraction by a unidirectionally conducting half plane a solution is obtained by transform methods for diffraction of a plane e m wave 1109 second approximation in the method of small perturbations the propagation of a plane wave in a medium containing random inhomogeneities is considered a second approximation in the perturbation method is obtained assuming that the correlation coefficient of refractive index fluctuations is gaussian this is applied to determine the form of the normalizing factor in the wave equation 1110 the scattering of a olane wave by a row of small cylinders 1111 variational method for the propagation of electromagnetic waves in a plasma using a variationalprinciml a first approximation is obtained for the propagation constant of the te mode in a rectangular waveguide containing a thin layer of gyroelectric plasma 1112 action of a progressive disturbance on a guided electromagnetic wave a method of approximations is applied to the investigation of the modes of action of a medium on a guided e m wave the results are discussed in relation to parametric amplification 1113 the relation between the polarization and the magnetic field intensity in the exiton absorption region extension of pekars electromagnetic wave theory to molecular crystals with a weak interaction between the exciton and the lattice vibrations 1114 giant spin density waves an analytical treatment of energy states in an electron gas in which the lowest energy state is proved not to be the hertree fock ground state but to have a spiral antiferromagnetic structure implications of this are discussed 1115 interplanetary space and the earths outermost atmosphere 1116 radar astronomy symposium report the subjects were radar studies of the moon the planets the sun meteors and aurorae and the exosphere and interplanetary medium 1117 radio astronomical measurements from earth satellites ionospheric and atmospheric absorption limit measurements made on earth a summary is given of some of the problems whose solution can best be sought by measurements with apparatus mounted in earth satellites 1118 polarization and angular extent of radiation from jupiter it is found that the source is strongly linearly polarized especially in the outer regions which extend to about three times the diameter of the planet 1119 on the polarization of sources of solar activity on three cm wavelength about sixty per cent of the bursts observed were polarized the probability of observing a polarized burst being greater when the source had a small diameter great bursts associated with metre wave bursts of type four have been found in most cases to be polarized 1120 solar radio bursts and cosmic rays the correlations between the various types of bursts are discussed 1121 periodicities in solar radio noise emission attention is drawn to the presence of sweeper trains gerson and gossard in the work of roberts 1122 on the theory of protons trapped in the earths magnetic field 1123 the unusual cosmic ray events of july intensity variations recorded at six stations are discuss the cosmic ray increase of july variations in the intensity of ionospheric scatter signals for the paths iceland england and massachusetts labrador are plotted decreases in intensity indicate a large excess of ioniging particles with rigidities above geomagnetic cut off at the path mid points 1124 roughness of the moon as a radar reflector measurements have been made at a wavelength of ten cm and pulse duration of five of the angular scattering properties of the moons surface from the results a law of scattering has been obtained which is consistens with scattering from a rough surface which has irregularities much greater than a wavelength and a horizontal scale equivalent to about twenty times the vertical deviations 1125 electric discharge caused by meteorites moving in the earths atmosphere the passage of meteorites through the atmosphere is followed by the formation of a trail of ionized gas about ten km long and of five m radius the luminosity of the meteorite is attributed to a corona discharge in the front of the trail and in the case of bright meteorites in strong electric fields this discharge becomes a spark discharge of the lightning type 1126 relations between the electric and magnetic fields of very long period induced in a medium of variable conductivity a model of ground conductivity distribution is derived which closely represents the conditions indicated by observations of geomagnetic and geoelectric pulsations 1127 magnetic storms and cosmic radio noise in addition to changes in absorption due to the d layer nd to the proximity of the f layer critical frequency a storm time variation was found the magnitude of which depends on local time 1128 solar terrestrial relationships a note on the proton density in interplanetary space required to explain geomagnetic disturbances in terms of the hydromagnetic wave theory 1129 some radio aspects of the international geophysical year a brief review of the results of investigations into long distance radio propagation polar regions of the ionosphere and rocket and satellite measurements of electron density in the upper atmosphere 1130 amateur radio participation in the i g y outline of the u k amateur program and a brief report of some results obtained from studies of auroral propagation 1131 radiation measurement during the flight of the second cosmic rocket the equipment used consisted of tix gas discharge counters and four scintillation counters measurements were carried out from the centre of the earth and from the surface of the moon graphs show the trajectories of the first and second rocket in the earths magnetic field the space location of the radiation belt is examined and the dependence of the radiation intensity on the distance from the earth considered 1132 motion of a satellite in the earths gravitational field the equations of motion of a satellite are given in a general form taking account of the precession and nutation of the earth 1133 secular and periodic motions of the node of an artificial earth satellite 1134 analysis of the orbits of the ruttian satellites 1135 experiments on cosmic radiation by means of artificial satellites 1136 radiation information the data indicate that the radiation intensity varies with altitudes 1137 corpuscular radiation experiment of satellite iota the equipment including the calibration of the detectors and the telemetry code are described and samples of recordings are shown international participation in recording the signals is invited 1138 the determination of ionospheric electron content and distribution from satellite observations the theory of the determination is given for measurements of total rotation of angle of polarization and also of its rate of rotation modifications to the simple theory and sources of errors are discussed observations made using sputnik three have disclosed a diurnal variation in totol electron content and data relating to the proportion of the total content which lies below the f layer peak the effect of magnetic disturbances is described 1139 statistical consideration of the structure of atmospheric refractive index 1140 artificial electron clouds values have been derived for diffusion coefficients chemical yield thermal ionization efficiency and wind velocity and shear 1141 the origin of nitrogen ionization in the upper atmosphere 1142 some problems concerning the terrestrial atmosphere above about the hundred km level rocket and satellite data are considered in a survey concerned with the general structure of the thormosphere 1143 measurement of positive ion density in the ionosphere the design of a suitable rocket borne probe is discussed and a small meshed spherical type is adopted laboratory experiments designed to investigate the characteristics of such a probe are described 1144 vertical transport of electrons in the f region of the ionosphere an expression is developed for the velocity and can be evaluated using n profiles the results for equatorial stations show that the velocity is mainly downwards at night and upwards by day 1145 on the question of the continental effect of the f layer analysis of f data indicates an increase in day time ionization during the summer months observed by u s s r stations in central asia compared with data obtained by west european stations the evening rise in f appears much less pronounced for stations in central asia where the maximum usually occurs at local noon this continental effect causes difficulties in the interpolation required for the preparation of m u f charts 1146 further studies of spread f at brisbane vertical incidence ionograms and directional measurements on oblique incidence signals indicate that the spread f phenomenon is due to large ripples with a wavelength of twenty to over one hundred km seasonal and sunspot variations in the phenomenon are described model ionization distributions are constructed and ray paths drawn which may explain various types of spread f the amplitude of the ripples seems to increase with the height of the f layer 1147 ionospheric absorption investigations at hawaii and johnston island the absorption of cosmic noise at thirty mcs varies in such a way as to suggest that the patches of absorption are less than one thousand km in size the variations are not correlated with the spread f or with the sporadic e phenomena but are correlated with f suggesting partial reflection of the cosmic noise by the f layer 1148 radio wave propagation characteristics of a simple ionospheric model based on rocket data 1149 the reflexion of radio waves from a stratified ionosphere modified by weak irregularities part two 1150 entry of high energy particles into the polar ionosphere 1151 the height of f layer irregularities in the arctic ionosphere 1152 the exploration of the terrestrial exosphere a review of scientific investigations of the composition and structure of the exosphere dealing particularly with the observation of whistlers and with results obtained from satellite and rocket measurements 1153 properties of the upper atmosphere and their relation to the radiation belts of the earth a new theory is outlined which gives the distribution of density with altitude for a planetary exosphere in the absence of thermodynamic equilibrium the results differ considerably from those based on a hydrostatic equation 1154 a comparison of intracloud and cloud to ground lightning discharges experimental results are discussed together with possible discharge mechanisms 1155 atmospherics on twenty kcs at the time of local aurorae atmospherics have been recorded on each of the thirty occasions when a strong aurora has been observed this enhancement is attributed to reflections from ionized strips associated with the aurorae 1156 controlled rectification using transistors the suitability of a transistor as a switching device is discussed in terms of its operating characteristics and an equivalent circuit is derived a switched rectifier circuit for use in a chopper type d c amplifier is described which incorporates a transistor oscillator providing the control frequency 1157 electronic computers annual review of international developments in digital and analogue computer design and installations 1158 physical versus logical coupling in memory systems an evaluation is made of the optimum size of cell for maximum information storage 1159 a small high speed transistor and ferrite core memory sistem a description is given of the design and operation of a four hundred bit storage system used in a time division switching system where the number of circuits controlled required a simultaneous read out of twenty bits 1160 the persistor a superconducting memory element the persistor consists of a superconducting inductor in parallel with a normally superconducting element a current pulse causes a current to be established in the persistor another similar pulse causes no change but one of opposite sign reverses the current 1161 tunnel diode logic circuits equations tre derived relating diode tolerances to those of tther circuit components for analogue threshold logic and majority logic use practical lunnel diode logic circuits are believed to be possible 1162 a new class of switching devices and logic elements with switching devices employing microwave valve elements switching at one mus intervals becomes possible an experimental travelling wave interaction type valve has been built to demonstrate the ability of one microwave signal to control another 1163 parametron computer circuits the characteristics of parametrons and applications are discussed 1164 ripple type time delay networks using elliptic functions the design of simulation networks in the frequency domain is presented 1165 magnetic amplifier binary to analogue conversion three saturable reactors are used to convert a ten digit input to an analogue voltage driving a servo magnetic amplifier 1166 composing with electronic computers twr basic methods of musical composition by computer are discussed to illustrate the simulation of luman thought processes 1167 synthesis of switching functions by linear graph theory 1168 survey of thermistor characteristics characteristics and applications are tabulated for different constructions of the two basic types of thermistor 1169 the long term stability of fixed resistors an investigation of the causes of long term failure nder practical conditions of use or storage test methods are critically discussed 1170 a mathematical model for a magnetic amplifier reactor core form domain theory a model for the prediction of core behaviour is proposed 1171 two step switching of saturable reactors the performance of the mathematical model of woodson when subjected to abrupt flux reversals is compared with experimental data for orthonol cores 1172 d c charged magnetic pulse modulator design details and performance results are quoted for an experimental modulator consisting of one charging and two pulse modulating stages and capable of delivering a peak power output with a pulse width into a restive load 1173 the persistor a superconducting memory element 1174 some mechanisms of failure of capacitors with mica dielectrics an analysis of failures with a description of some methods of examination and dissection giving minimum loss of evidence 1175 the representation of multipoles by scattering matrix the scattering matrix is defined and its properties are summarized the application of the matrix to the calculation of multipole networks including quadripoles is detailed with tables giving the matrices of some basic circuits 1176 differentiating and integrating circuits with positive operational feedback a general method of analysis and design is presented and illustrated with a particular circuit 1177 valve circuits with normalized transfer function for distortionless electrical differentiation the circuit parameters and operating characteristics of several differentiating circuits for obtaining first and second order derivatives are given 1178 an equivalent circuit for transistor mixers an equivalent circuit is derived for the earthed emitter configuration based on giacolettos circuit moortgat pick experimental confirmation of the validity of this theory is obtained 1179 oscillators and their modes of oscillation a classification of oscillators in three types is proposed based on the parameters of the passive frequency determining quadripole which together with an active quadripole constitutes the oscillator several basic circuits are analysed in this way and the q factor of their modes of oscillation is evaluated 1180 a microwave meacham bridge oscillator a high stability microwave oscillator has been constructed consisting of a travelling wave amplifier cavity microwave bridge and bolometer experimental results are compared with theory 1181 quantitative analysis of a nonlinear second order differential equation of a self oscillating system with a limited increment region 1182 stability problems in monostable multivibrators the influence of the amplitude of trigger pulses on multivibrator operation and the dependence of pulse width on the trigger frequency are discussed 1183 a graphical analysis of the blocking oscillator a detailed analysis of the circuit and its mode of operation is given and a practical design precedure is described 1184 transistor monostable circuits cross coupled and emitter coupled circuits are analysed to determine the circuit characteristics results obtained with two practical circuits show good agreement with theory 1185 a passive waveform shaping circuit an inductance and suitable semiconductor diodes are combined applications discussed include a change in phase of a square wave b mark space ratio modulation of a square wave c pulse generation lengthening and delay 1186 a simple circuit for producing a voltage proportional to the width of a repetitive pulse details are given of a circuit for deriving a direct voltage from train pulses of width proportional to the flow rate of a liquid the voltage drives an integrating motor via a push pull cathode follower 1187 complementary transistor circuits by the use of p n p and n p n transistors connected back to back a series of circuits become available for which there is no valve equivalent they are symmetrical in operation but do not necessarily require balanced transistors 1188 derivation of a frequency multiple of a variable frequency a mask is placed across the face of k c r o displaying the variable frequency f the mask outline is sinusoid representing the frequency multiple n it is viewed by a photocell whose output varies at a frequency nf equations defining the mask outline for any value of n are given 1189 a pulse delay system details are given of a phase shift circuit followed by a pulse shaping stage a maximum delay of about one ms can be achieved 1190 stagger tuned and bandpass coupled circuits in wide band i f valve amplifiers formulae are derived for the replacement of any two equally detuned circuits in a stagger tuned amplifier by a single bandpass coupled pair 1191 a new asymmetric push pull amplifier with extremely low internal impedance an output amplifier circuit is described in which the phase splitting triode is incorporated in one of the push pull arms 1192 contribution on the amplifier with extremely low internal impedance detailed investigation of the operation of a two stage valve amplifier with combined negative voltage feedback and positive current feedback 1193 elimination of coupling problems in multistage magnetic amplifiers operational principles and design criteria are considered for two stage half wave and full wave amplifiers with synchronous switch coupling 1194 theory of three phase bridge magnetic amplifier part one steady state a discussion of operation at minimum load with the control circuit either open or closed is followed by a study of conditions under normal excitation from minimum to half load 1195 miniature high frequency magnetic amplifiers or magnetic memory sensing a report of measurements on ferrite and metal tape cores with single turn control windings and asymmetrical excitation at frequencies 1196 transistors in audio and carrier frequency amplifiers the characteristics of common emitter transistor amplifiers in relation to requirements for communication systems are discussed 1197 an introduction to the theory of solid state masers basic theory is summarized and used to evaluate the engineering characteristics of a travelling wave maser employing the comb type of slow wave guide 1198 nuclear magnetic resonance maser 1199 quantum mechanical semiconductor generators and amplifiers of electromagnetic oscillations a note of the possibility of using the electron transitions between the conduction or valence band and the donor or acceptor impurity levels to obtain maser action 1200 theory of single resonance parametric amplifiers a parametric amplifier that supports a resonance at the idler frequency only is capable of unlimited gain when operated either as a straight through amplifier or as a lower sideband ur converter this makes feasible a continuously tunable parametric receiver 1201 unidirectional paramagnetic amplifier design the theory and design of a cavity paramagnetic amplifier are given the faraday effect is used to obtain unidirectional amplification which can result in noise figures an order of magnitude better than other systems 1202 theory of the diode reactance amplifier with parallel circuits detailed treatment of the theory and design of parametric amplifiers consisting of a variable reactance semiconductor diode coupling two resonant circuits minimum noise conditions are evaluated and design parameters are tabulated for three basic types of circuit 1203 low noise parametric amplifier the n ise temperature and pump power xsing a semiconductor diode can be accurately predicted from a measurement of the diode and circuit parameters the ultimate lower noise limit depends on the product of diode cut off frequency and the normalized capacitance swing 1204 space charge wave parametric amplifiers 1205 diode capacitors for parametric amplification 1206 limitations in squaring with simple valve circuits of wide bandwidth the errors to be expected from squaring circuits based on curvature of a valve characteristic with input applied to one electrode and b using separate control electrodes with antiphase inputs are compared measurements have been made on the latter type 1207 network response to transient frequency modulation inputs an approximate method is developed for calculating the response when the input modulation varies rapidly during short periods e g when television or pulse signals are used for frequency modulation 1208 modulation distortion in frequency modulation by special frequency band the distortion factors are calculated which arise in two three or four double tuned critically coupled band filters used in f m receivers under the assumption of linearized phase characteristics and for two different selectivity specifications the amplitudes of combination tones are calculated for the case of three filters when two f m signals are applied 1209 light waves in crystals in the region of exciton absorption and the impurity photoeffect in the frequency range for which the refractive index is much less than unity the amplitudes of normal and longitudinal waves in a cubic crystal greatly exceed the amplitude of the incident wave the photoionization of impurities is therefore much more intense this explains the sharp maximum in the internal and external photoeffects observed experimentally in the frequency range corresponding to exciton absorption 1210 experimental investigation of charge formation on a dielectric surface under the influence of electron bombardment part two the kinetics of the formation of an actual charged spot produced on the surface of a dielectric by an electron beam have been investigated the instrument and method are described and it is shown that the conditions for the formation of positive and negative spots are different 1211 contribution to the theory of ferroelectric polarization curves the principles of the polarization theory for single and many domain ferroelectric crystals with one or two curie points are developed for weak strong and medim fields in contrast to magnetization curve theory rotation can be neglected in the first approximation 1212 electron resonance in crossed electric and magnetic fields a note on the electric field dependence of the period of revolution of an electron in a semiconductor in crossed fields 1213 thermoelectric phenomena in strong magnetic fields in metals possessing various mermi surfaces the asymptotic variation of the thermoelectric force peltier and thomson coefficients for metals with closed fermi surfaces and open surfaces of the corrugated cylinder and space net types is investigated on the basis of the quasiclassical theory of kinetic phenomena 1214 determination of the shape of a relativistic electron beam brief mathematical analysis of an axially symmetric thin electron beam the cross section of which varies along the axis of the beam the movement of the electron beam being assumed adiabatic 1215 determination of trajectories of relativistic charged particles in electric and magnetic fields by the adams method of finite differences 1216 plasma oscillations of a large number of electron beams longitudinal oscillations of a large number of electron beams are investigated the problem of passing to the limit of a continuous velocity distribution is considered in detail 1217 electric field distribution in an ionized gas part two the method described earlier baranger and mozer is used to calculate the probability distribution of the l f component of the field at a neutral point and also the distributions of the l f component at an ion and of the h f component at an electron 1218 transport phenomena in slightly ionized gases high electric fields an investigation of the variation with electric field of a number of transport properties in the presence of a magnetic field perpendicular to the electric field and temperature gradient in the gas 1219 the equation of state of a plasma the free energy of a completely ionized gas is given in the form of an expansion in terms of the density of interacting particles 1220 anomalous electron scattering and the excitation of plasma oscillations an investigation of the interaction of an electron beam with an independently formed plasma the observed data can be explained by assuming that the electrons form clusters which interact coherently with the plasma 1221 oscillations of a plasma beam in a magnetic field at frequencies close to the cyclotron frequency a method is described by which plasma oscillations have been observed in hydrogen at frequencies lower than the ion cyclotron frequencies the absorption of r f power by ions which rotate in the magnetic field is detected by the change in q of an oscillator circuit 1222 hydromagnetic waves in plasmas theoretical investigation of wave propagation along and across a strong magnetic field in plasma taking account of electron diffusion 1223 note on perturbation of a uniform magnetic field by a cube of magnetic material 1224 on the theory of weak ferromagnetism 1225 ferromagnetism of an electron gas a study is made on the basis of the bohm pines collective description of electron interactions 1226 excitation of spin waves in ferromagnets eddy current and boundary condition effects the boundary condition for transverse magnetization is derived when there is a surface anisotropy field spinwave modes can be excited by a uniform r f field and the power absorbed in each mode in an insulator can be calculated the eddy currents have a large effect only on long wavelength spin waves 1227 theory of paramagnetic resonance in systems containing two kinds of magnetic moment equations are derived for the partial magnetizations in a weak variable magnetic field relaxation times and resonance frequency shift are calculated 1228 spin lassice relaxation effects observed in the continuous power saturation of paramagnetic lines the dependence of the conventional saturation parameter on the incident microwave power is considered for lorentzian shaped paramagnetic lines 1229 reciprocity theorems for electromagnetic fields whose time dependence is arbitrary 1230 multilayer absorbers for electromagnetic waves the absorbing power of structures is discussed which consist of two or more layers of loss free dielectric and thin resistive material arranged alternately the reflection coefficients are calculated for a number of such structures which are treated as resonance absorbers 1231 high frequency diffraction of plane waves by an infinite slit for grazing incidence 1232 high frequency diffraction of electromagnetic waves by a circular aperture in an infinite plane conducting screen 1233 reflection of an electromagnetic wave from a plasma moving through a dielectric in a constant magnetic field mathematical treatment of the reflection of a retarded e m wave from a moving plasma in a magnetic field directed parallel to the plasma motion expressions are derived for the frequency and amplitude of the reflected wave the dependence of phase velocity on magnetic field intensity is determined and two refracted waves are defined 1234 validity of the theory of double stream amplification recent misunderstandings concerning the validity of the original analysis of the interaction of moving ion or electron streams are clarified 1235 theory of diffraction in microwave interferometry the theory is applicable to michelson and fabry perot interferometers 1236 some solutions for electromagnetic problems involving spheroidal spherical and cylindrical bodies results are given for the l f response to an oscillating magnetic dipole by conducting bodies of simple shape 1237 effect of specimen shape on ferromagnetic resonance in a strong radio frequency field an analysis of the exact solutions of the landau lifshits equations an expression is derived for the threshold field above which instability in the motion of the magnetization vector begins for resonance field strengths the height of the absorption peak decreases and its width increases 1238 nuclear magnetic resonance maser a detailed investigation of a two level weak field maser type self oscillator based on nuclear spin rotation in a circulating liquid under conditions of rapid adiabatic passage through resonance applications for magnetic field and relaxation time measurements are discussed 1239 broadband millimetre wave paramagnetic resonance spectrometer the specimen and waveguide which can be cooled by means of a cryostat are placed between close pole pieces giving high uniform magnetic fields design details and some measurements on zero field splittings are given 1240 new analysis of the polarization of radiation and the faraday effect in terms of complex vectors the properties of the polarization ellipse are deduced in terms of the ratio of the cartesian components of the complex electric vector of a beam of radiation by utilizing the argand representation of a real two dimensional vector as a complex number the two components of a beam that are accepted and rejected by a polarizer or a radio antenna are considered as orthogonal components in the directions of two complex orthonormal vectors the intensities of the corresponding components of a polarized beam are derived and represented on the poincare sphere the methods are then applied to the important radio case of the faraday effect in a uniform magneto ionic medium finally the measurable quantities characterizing a beam of partially polarized radiation are obtained from a diagonalization of the complex polarization tensor that specifies the beam 1241 absorption and emission spectra of an electron in a one dimensional deep trap 1242 generalization of band theory to include sefl energy corrections an investigation of the corrections to ordinary band theory due to dielectric effects 1243 maximum angular accuracy of tracking a radio star by lobe comrarison 1244 the north south branch of the great interferometer of the nancay station a brief description of the aerial system and receiving equipment which is being used in conjunction with the e w interferometer for a detailed study of the sun the n s branch operates at mc s and has eight parabolic mirrors ten m in diameter spaced along a track provision is made for adjusting the declination of the beam 1245 microwave absorption and emission in the atmosphere of venus theoretical considerations are presented suggesting that measurements in the mm range may give information on the atmosphere below the cloud layer of the planet 1246 the source of radiation from jupiter at decimetre wavelengths part two cyclotron radiation by trapped electrons 1247 ionospheric modification of the radio emission from jupiter the experiment of gardner and shain has been repeated using two identical receivers some correlation is found between records at the two sites but there is also evidence of serious distortion due to terrestrial effects 1248 balloon study of high altitude radiations during the international geophysical year 1249 observations of the van allen radiation regions during august and september part one results are given of a preliminary analysis of data obtained from equipment flown on explorer sixth in addition to the inner and outer zones a stable intermediate zone was detected the outer zone intensity showed a large decrease following a sudden commencement but subsequently increased to be greatly in excess of its prestorm level comparison is made with other measurements of the radiation zones 1250 particle fluxes in the inner radiation belt 1251 roughness of the moon as a radar reflector radar observations of the distribution of slope of the lunar surface made by hughes are found to be in good agreement with optical measurements when the slope angle is greater 1252 radar determination of the scattering properties of the moon results obtained by feinstein are modified to take into account the curvature of an irregular reflecting surface and applied to problems associated with scattering from a lunar surface which has two dimensional corrugations 1253 sporadic shower properties of very small meteors a long term radar survey shows sporadic meteoric particles to be distributed in a vast number of relatively small groupings 1254 observed magnetic effects from meteors an analysis of subaudio fluctuations in the geomagnetic field indicates that meteoric activity and the average level of fluctuations are related 1255 experimental studies of meteor echoes 1256 properties of the solar wind during sunspot minimum 1257 three dimensional considerations for current system of geomagnetic variations part two sq field 1258 on the position of the focus of the geomagnetic sq current system a review of present knowledge of the sq foci discussion of the cause of changes in the sq field and a description of problems relating to the determination of the sq focus the foci in the potential fields of geomagnetic dq variations may be taken as approximately indicating the positions of ionospheric sq current foci 1259 concerning the nature of short period magnetic micropulsations world wide and local effects are discussed from the point of view that the pulsations originate within the ionosphere 1260 magnetic micropulsations pulsating aurora and ionospheric absorption increases in cosmic noise absorption coincide with magnetic and auroral pulsations 1261 studies on sudden commencements of geomagnetic storms using i g y data from united states stations report of a study of geomagnetic storm variations recorded over a period of one year from july at a network of stations 1262 three dimensional consideration for current system of geomagnetic variations part one current flow for polar elementary storm within a spherical conducting shell 1263 preliminary results from the space probe pioneer fifth cosmic ray measurements show that a forbush decreases are not dependent on the presence of the earths field as they occur out in space b solar flare particles producing polar cap absorption are not stored in the geomagnetic field and c solar production of energetic electrons is not restricted to periods of flare activity 1264 characteristics of the extraterrestrial current system explorer sixth and pioneer fifth magnetometer measurements of the earths field are consistent with a toroidal ring current flowing in the magnetic equatorial plane 1265 some preliminary results of the pioneer fifth magnetometer experiment the sudden increase in magnetic field strength during solar activity suggests that collisionless magnetoacoustic waves may be formed at the boundary between the earths field and the interplanetary field which is put at thirteen earth radii 1266 induction drag on a large negatively charged satellite moving in a magnetic field free ionosphere 1267 the influence of the solar radiation pressure on the motion of an artificial satellite results of theoretical investigations of the radiation pressure perturbation have been applied to orbital calculations for vanguard one producing significant perturbations in its perigee height in the case of a satellite with a large area mass ratio the major terms introduced by solar radiation pressure can reduce the perigee distance at the rate of km day 1268 final months and descent of satellite sputnik three a report of the progress from may until its descent on april and a brief discussion of the main features of its lifetime for earlier progress see january 1269 the upper earth atmosphere according to satellite measurements review of results obtained from measurements on the first five earth satellites 1270 first results of satellite observations for information on wave propagation review of early radio and radar observations of earth satellites and summary of results obtained relating to ionospheric phenomena 1271 frequency scintillations of satellite signals before and after the argus experiments 1272 a convenient method of getting representative ionospheric heights a simple method is described for obtaining electron density profiles monthly median hf curves are drawn for each hour and then reduced to true height profiles by any standard method 1273 the joint use of the ordinary and extraordinary virtual height curves in determining ionospheric layer profiles an extension of buddens matrix method for determining ionospheric layer profiles errors are reduced by using the extraordinary virtual height curve as well as the ordinary curve 1274 the formation of the d region of the ionosphere a review of theoretical studies of the ionization process in the d region it is possible to explain normal conditions of ionization by cosmic rays and lyman radiation conditions due to solar flares must be explained by x rays above km the ionization is related to the formation of the e layer 1275 field aligned ionization field aligned ionization in the e and f regions may result from leakage of particles from the radiation belts 1276 longitude effect in temperate zone sporadic e and the earths magnetic field a correlation is shown to exist in both northern and southern temperate zones between the magnitude of the horizontal component of the earths magnetic field and the percentage of time this is considered with reference to the longitude effect investigated by smith and finney and it is suggested that the movement of ionization by winds or electric fields is the most likely source of e 1277 drift measurements at kjeller on the ionospheric f region results are given of measurements made at kjeller norway mostly during january and february the mean drift velocity was found to be towards the west at night and the east during the day some measurements on sporadic f echoes are reported 1278 inferred temperature variations at the f peak the scale height at the f peak has been estimated using data on the total electron content of the ionosphere obtained from the faraday rotation of lunar radio echoes and data obtained from vertical incidence soundings the scale height varies with time probably as a result of temperature variations the observed scale heights are in good agreement with a model atmosphere based on rocket and satellite observations 1279 vertically travelling shock waves in the ionosphere ionospheric phenomena at vertical incidence observed in the vicinity of ground based atomic explosions are interpreted in terms of acoustic and hydromagnetic wave propagation 1280 oxygen red line in the night airglow and ionospheric f region a statistical analysis of spectroscopic data indicates that the intensity of the red radiation and the maximum electron density of the f region are related 1281 some characteristics of the d region ionization during auroral activity in north sweden d layer ionization during aurorae is closely associated with sudden increases in auroral activity and extends down to about sixty five km the latitude variations of this layer are discussed and it seems likely that the ionization is due both to primary electrons and secondary x rays 1282 v l f propagation effects of a d region layer produced by cosmic rays 1283 a new mechanism for accelerating electrons in the outer ionosphere an experiment is outlined to produce high energy electrons in the ionosphere using e m radiation from a ground based l f transmitter the principle is adaptable for use in a satellite or space probe 1284 scattering of radio waves by electrons above the ionosphere by measuring the overall intensity of the scattered spectrum it should be possible to estimate electron density and temperature if better resolution were possible the atomic weights of the ions present could be obtained 1285 lightning and charge storage a lightning flash consisting of current surges of which twenty six were leader return stroke combinations and having a total duration of two seconds is described 1286 the design and use of instruments for counting local lightning flashes the instrument adopted as a standard for assessing local activity triggers on a field change of three vm the need for an international standard is stressed 1287 theory of auroral structures a simplified theoretical examination of the structure of visual aurorae 1288 movement of auroral ionization a ote on the apparent discrepancies between movements deduced from visual and radar observations 1289 observations of the aurora australis at new zealand antarctic stations during i g y 1290 correlation studies of radio aurora magnetic and earth current disturbances the diurnal variation of the rate of auroral echo occurrence appears to be similar to that of moderate perturbations of h a relation is suggested between magnetic perturbations and the reversal of direction of auroral ionization drift from west to east at about local midnight 1291 on the geometry of radio reflections from aurora the observed characteristics of auroral radar echoes are explained by assuming that echoes arise by means of volume scattering from configurations of ionization similar to those observed visually the importance of allowing for the radar pulse length and aerial beam width is stressed 1292 the association of visible auroral forms with radar echoes an extension of earlier work to detect a more detailed correlation between echoes and specific visible auroral forms 1293 an analysis of some statistical properties of auroral radar reflections and their relationships to the detection capabilities of the radar expressions are derived from an analysis of protracted observations relating radar parameters to echo statistics 1294 very low frequency atmospherics report on measurements of atmospherics in the frequency range by means of specially designed equipment the results are discussed with reference to measurements made by others a sinusoidal signal of about nine cs was observed which may be due to resonance of the system earth ionosphere 1295 geomagnetic noise results of observations made are compared with estimates of the noise intensity to be expected from a cherenkov radiation mechanism 1296 geomagnetic disturbances and five kilocycles per second electromagnetic radiation out of isolated noise bursts at five kcs in australia associated with positive bays in the h component of the earths field noise bursts followed the occurrence of thirty magnetic sudden commencements with a delay of hours but on four occasions there was no delay 1297 on the stability of random systems and the stabilization of deterministic systems with random noise a general theory of mean square stability of random linear systems in which parameters may vary as white noise processes is developed and applied to a rlc circuit the possibility of stabilizing unstable deterministic systems by means of random noise is predicted 1298 a condenser memory unit for improving signal to noise ratios description of a unit containing thirty low leakage capacitors which can store information for periods up to several hours thirty two channels may be scanned in ten sec the unit has been used in investigations of twilight spectra with photoelectric and photo conductive spectrometers 1299 a sensitive transistor recording pen amplifier details of a bridge circuit with low temperature drift are given 1300 a magnetic amplifier silicon transistor power supply for missile application a detailed description of a power supply system producing seven regulated direct voltages and two r m s regulated alternating voltages a magnetic amplifier is incorporated in each channel for regulation and al direct voltages are derived from the same h f transistor inverter 1301 a stabilized and programme controlled power supply using positive feedback a power supply for a mass spectrometer magnet is described with an output continuously variable 1302 limitations and possibilities for improvement of photovoltaic solar energy converters part one considerations for earths surface operation the possibilities of improving the performance of the single si solar cell are considered as these are limited the use of other materials and the development of a multilayer and a multiple transition cell are examined and found to give larger theoretical efficiencies 1303 the wind driven power supply for the decimetre wve radio relay station schoneberg eifel and the experience gained with it details are given of the wind driven generators and ancillary equipment used in a twenty two month trial of the system as the main power supply for radio link stations records of wind power availability and utilization made by specially designed apparatus are analysed and discussed 1304 the parallel and series operation of germanium rectifiers the permissible ratings of germanium rectifiers operated in series and parallel connections have been calculated for the cases where load balancing resistors are placed in parallel and in series respectively with the individual rectifiers transistorized power supplies for a mass spectrometer magnet current supply and filament emission control circuits of low power dissipation are described 1305 hall effect multipliers the design of the hall generator comprising between ferrite plates is given together with details of suitable transistor amplifier circuits curves showing the performance of the unit for frequencies included 1306 an improved film cryotron and its application to digital computers a crossed film cryotron formed by deposition on an insulated superconductor is described and its operation is analysed 1307 electrical read out from thin ferromagnetic films a metred of a static coupling and amplification is described which gives a read out with good signal noise ratio 1308 electronic digitizing techniques a electronic digitizing techniques b a simple analogue to digital converter with nonlinearity compensation c the step by step potentiometer as a digitizer d an analogue digital converter with long life e a wide range fully automatic digital voltmeter f an all electronic four digit digital volmeter 1309 three hole cores for coincident fluy memory coincident flux operation permits pulse currents that are not limited by coercive force threshold shorter read write times and greater tolerance to temperature and pulse current variations are obtained 1310 conical coaxial capacitors and their advantages in an example cited the ratios of maximum to minimum capacitance for disk cylindrical and conical capacitors are respectively an approximate equation is derived for the conical capacitor and close agreement is shown between computed and measured values of capacitance 1311 capacitor calibration by step up methods 1312 a tive power tr nsfor by linear quadripoles the transfer of power through an arbitary linear quadripole is considered as a function of matching conditions source impedance input and output impedances and gain of the quadripole 1313 connection and measurement of transform functions on an analogue computor the transfer function of linear systems is split into products of partial transfer functions which facilitates the solution of network problems by analogue computer circuits representing the partial functions are given and methods of measuring the frequency and time characteristics of filter networks are described 1314 three branch reactive sections for ladder filters with one or two cut off frequencies a graphical method is proposed for the synthesis of three branch networks consisting of reactances which have no mutual inductive coupling 1315 dissipative networks with third order maximally flat amplitude characteristics an analysis is made of dissipative low pass networks a simple chande of t e frequency variable allows the results to be applied to bead pass networks for the case of narrow band operation the concept of quarter wave coupling is developed and the equivalent triple tuned circuit conf guration is derived 1316 zig zag filters a systematic method of calculating zig zag sections for baedpass ladder filters is described 1317 filter calculations using the template method a part graphical method for calculating filter characteristics is described which has been developed using frequency transformations 1318 echostant matching systematic matching of filter ladders calculated section by section 1319 ricurrence formulae for the calculation of the characteristic function of filters with tchebycheff pass band behaviour 1320 matching of image parameter filters and associated problems 1321 the physical realizability and realization of linear phase shift networks 1322 restrictions imposed upon the unit step response of linear phase shift networks limits are defined for the rise time and overshoot of the unit step response of networks free from phase distortion 1323 the design of delay equalizers using the analogue method a resistance network analogue and its application to the design of a television circuit delay equalizer are described 1324 a circuit for the electrical integration and differentiation of periodic phenomena integration or differentiation is carried out by means of two independent rc or rl sections separated by a valve stage 1325 synthesis of driving foint impedances with active rc networks a general metrod is presented for realizing any real rational driving point function using rc networks and one type of active element leading to a simple structure biquadratic impedance functions are considered in detail 1326 noise in oscillators effects of white noise of thermal of electronic origin on the initiation of oscillations and on perturbations in amplitude and phase of sustained oscillations are analysed 1327 background noise in nonlinear oscillators an examination of the effects on self excited oscillators of wide bead noise at or near the frequency of oscillation 1328 the behaviour of nonlinear oscillating systems fn the presence of noise 1329 on the resolving time and flipping time of magnetoresistive flip flops the time constant of the exponential approach to the stable states is shown to be a fair approximation for the flipping time of a bridge type magnetoresistive flip flop is of the order for materials at present available the method of calculating flipping time is extended to more general networks and the dependence of the flipping time on t e incoming pulse is considered 1330 impulse governed oscillator techniques part one the general principles of i g o techniques are discussed special circuits and theoretical data will be given in subsequent issues 1331 monochromaticity and noise in a regenerative electrical oscillator expressions are derived for the departure from monochromaticity of a regenerative oscillator represented by an equivalent rlc circuit haing a negative resistance in parallel with r the intensity and band width of the thermal noise generated in the oscillator by resistance r are also considered 1332 frequency stability of a stable multivibrators using transistors the dependence of multivibrator frequency on transistor characteristics and operating conditions is investigated and rules for an optimum design are derived 1333 synthesis of a circuit for flywheel synchronization 1334 a special effect in some pulse systems the order of the transfer function of pulse driven closed circuit systems can under certain conditions be increased by one degree relative to the corresponding steady state system the reasons for this effect are given with experimental confirmation 1335 parametric excitation of harmonic oscillations in a linear oscillating circuit with nonperiodic variation of its parameters with time conditions for harmonic generation by nonperiodic variation of r l and c are established 1336 harmonics from a microwave gas discharge 1337 amplifier with stagger tuned circuits with maximum linearity of the phase and attenuation characteristics the design of wide band amplifiers for signals is detailed with tabulated data on various types of stagger txned circuit whose group delay and attenuation characteristics are also given 1338 transient analysis of the white cathode follower the circuit provides an output impedance and transmits pulses of either polarity with minimum distortion transient analysis is made and the effect of varying circuit parameters is discussed 1339 amplifier compensates for speech level variations an automatic gain adjusting amplifier produces constant output without peak clipping for input variations of forty db 1340 influence of fluctuations of the number of molecules on the frequency of a molecular beam maser oscillator 1341 a parametric device as a nonreciprocal element an arrangement is proposed for combining an up converter with a down converter to obtain a nonreciprocal phase shifting device measurements made at a signal frequency on both a circulator and an isolator are discussed 1342 parametric amplification power control and frequency multiplication at microwave frequencies using cyclotron frequency devices 1343 an electrostatically focused electron beam parametric amplifier 1344 lower frequency pumping electron beam parametric amplifier 1345 phase sensitive demodulation with interpolation details are given of a pulse sampling system for demodulation of a low frequency carrier errors may be reduced by inter olation if the general form of the modulation envelope is known in advance 1346 the calculation of static and dynamic amplitude and frequency distortion of frequency modulated oscillations with the transmission factor given in series form the cases of frequency amplitude and limiting distortion distortion due to non ideal limiting conditions are investigated to derive general expressions for the treatment of signal distortion 1347 theory of ultrasonic attenuation in metals and magneto acoustic oscillations 1348 the possible role of the electrical double layer in the contact of solids and in adhesion phenomena calculations are made of the surface charge density and the component of adhesive force for the case of a contact between a metal and a semiconductor film and b a semiconductor film between two metals 1349 evidence for a configurational e m f in a conducting medium by analogy with hydrodynamic effects an is expected to be associated with a current constriction experimental evidence for such an effect is given 1350 theory of superconducting contacts a generalization of the bardeen cooper schrieffer theory of superconductivity for the case of a position dependent energy gap and application to several problems involving supercondu ting contacts 1351 diagrams representing states of operation of a general theopocouple for a wide range of possible thermocouples the operating characteristics depend on the current and the junction temperatures as an example the calculation of a cooling region of a diagram for a general couple is given 1352 pre breakdown phenomena in uniform fields observations were made of pre breakdown phenomena in uniform field gaps under ambient atmospheric conditions and measured irradiation intensities in which current and light pulses were recorded from measurements of the current pulse duration a value for the mobility of positive ions was obtained at field strengths approaching the breakdown value 1353 some sparkover phenomena with enclosed gaps breakdown characteristics of an unventilated and nonirradiated uniform gap are examined and compared with those obtained uneer a variety of conditions of venti ation 1354 experimental determination of the individual secondary ionization coefficients in hydrogen and their dependence on cathode work function 1355 the space charge retardation of electron avalanches the electric field generated by the positive and negative space charge of a single electron avalanche moving in a homogeneous electric field is calculated a growth formula is derived which differs from the townsend formula good agreement is obtained between the theoretical results and statistical data given by other authors 1356 negative current voltage characteristics in hydrogen at high pressure using plane parallel electrodes measurements of the characteristics are described and studied theoretically 1357 comments on necessary and sufficient trajectory conditions for dense electron beams 1358 high voltage electron extraction frov an arc discharge plasma a method is described for obtaining stable electron beams of current densities using stable electron beams of current densities using a magnetically confined mercury pool 1359 shift of an electron interference pattern by enclosed magnetic flfx experiments to confirm the shift are described and the results discussed 1360 the propagation of oscillations in electron beams with uncompensated space charge mathematical treatment of an electron cloud rotating in a uniform magnetic field 1361 theory of longitudinal oscillations of an electrons ion beam generalization of results of earlier analysis to the case of arbitrary deformation of the beam 1362 a paraxial formulation of the equations for space charge flow in a magnetic field 1363 stability of uniform plasmas with respect to longitudinal oscillations 1364 excitation of waves in plasma mathematical analysis of plasma excitation by external currents based on two component plasma theory applicable to wave excitation at any frequency 1365 statistical mechanical theory of ferromagnetism high density behaviour the partition function of the ising model of ferromagnetism is examined in the limit of high density 1366 surface magnetostatic modes and surface spin waves the general existence of surface wave modes in the frequency region above the spin wave band is shown 1367 on the propagation of a discontinuous electromagnetic wave a treatment of a variant of sommerfields problem in which the oscillating dipole is replaced by a dipole whose moment jumps form zero to one a solution for the general case is given in torms of complete elliptic integrals 1368 electromagnetic waves in gravitational fields ssudy of the scattering of plane e m waves by the gravitational field of an isolated physical system 1369 boundary layer problems in diffraction theory 1370 planar problem of diffraction of electromagnetic waves by an ideally conducting strip of finite width an application of the method of solution proposed earlier to the case of small values ts the wave number and the half width of the strip 1371 distribution of current densities on the edges oo an ideally conducting rectangular wedge placed in the field of a plane electromagnetic wave simplified formulae for calculating current densities are derived which in their final form contain only well known tabulated functions 1372 high frequency diffraction of plane waves by an infinite slit parts one and two 1373 on the plane weve extinction cross section of an obstacle the relation between the extinction cross section of an obstacle which both absorbs and scatters power and the amplitude and phase of a scattered time harmonic plane wave is proved using an explicit representation of the scattered field the result is valid for a plane wave with arbitrary elliptic polarization 1374 electromagnetic waves in a plasma located in a magnetic field mathematical analysis for the case of a cylindrical plasma rod located in an uniform external field and isolated from the metallic walls of a waveguide a dispersion equation is derived and the e m field configuration is determined it is shown that e m waves can be propagated in the system at frequencies significantly lower than the langmuir and larmor frequencies 1375 the absorption coefficient of a plasma at radio frequencies 1376 passage effect in paramagnetic resonance experiments paramagnetic resonance signals under various experimental conditions are classified theoretically and some experimental checks carried out 1377 study of damping by coherent radiation in nuclear magnetic resonance the general equations derived are applied to a calculation of the range of oscillation and frequency pulling in a maser type oscillator 1378 influence of fluctuations of the number of molecules of the frequency of a molecular beam maser oscillator 1379 charged particle orbits in varying magnetic fields a magnetic field with time variation but with azimuthal symmetry about an axis is considered the movement of the charged particle is found by considering it to move nearly in a circle about a guiding centre whose motion can also be calculated 1380 drift of a charged particle in a magnetic field of constant gradient 1381 giant fluctuations in a degenerate fermi gas arguments are presented that for sufficientsy weak intoractions the ground states in two or more dimensions are the familiar plane wave states 1382 electronics probes nature a general review of ppesent investigations into space our atmosphere the earth the oceans and living matter the instrumentation of satellites and probes successfully launched by the united states 1383 measurement of the neutron flux in space the experimentally determined count rate agrees well with that calculated from multigroup diffusion theory if allowance is made for a background flux 1384 the synthesis of large radio telescopes 1385 the spectrum of the galactic radio emission 1386 an experimental investigation of the effects of confusion in a survey of localized radio sources surveys of sources have been made using total power equipment and an interferometer the results are compared 1387 radio emission from the gygnus loop good positional agreement has been obtained between several of the radio and optical features but an intense extended source lying south of the centre of the loop is not correlated with any outstanding optical feature 1388 a spectral analysis of the radio sources in cygnus x the results support the conclusions of other workers showing that the emission is from optically thin regions except for the strongest source in the region tie source which was found to have a nonthermal component 1389 the ionosphere of jupiter an approximate analysis based on chapman theory suggests that jupiter may possess an ionosphere of critical frequency existing a few hundred kilometres above the visible clouds 1390 radio emission from jupiter report on measurements made by the four element interferometer at cambridge of the relation between flux density and the diameter of the jupiter comparison is made with flux density observations of other authors 1391 the planning and results of the program of observations of the department for ionospheric research and radio astronomy of the p t t radio observations of the sun made during the recent perid of maximum solar activity at the observatories are discussed 1392 solar radio bursts of spectral sype two an analysis of sixty spectral type two bursts is used to review the properties of such bursts in addition to features already well recongnized a herringbone structure is described statistical methods are used to study the association of type two bursts with solar flares and geomagnetic storms 1393 location of the sources of solar bursts an improved method of observing positions is described from correlations with optical data the radial distances of the radio sources from the centre of the sun have been deduced 1394 an association between solar radio bursts at metre and centimetre wavelengths it appears that type three events which coincide with cm bursts are frequently followed by a wide band emission termed type v mechanisms for generation the cm and type v radiation are considered 1395 an investigation of the speed of the solar disturbances responsible for type three radio bursts simultaneous directional observations at a number of frequencies between forty and seventy ms s are described the results support the hypothesis that type three bursts are due to plasma oscillations excited in the coronal gas 1396 solar radio events and geomagnetic storms an attempt is made to identify solar r f bursts of importance three plus with subsequent sudden commencements of geomagnetic storms for the period april 1397 solar radio emission of spectral type four and its association with geomagnetic storms a study of spectral records has been used to distinguish between type one and sype four storms the association of type four storms with lvlar flares and geomagnetic storms is described 1398 the eta carinae nebula and centaurus part two physical discussion of eta carinae nebula the temperature density and mass of the object are inferred from observations of august and other radio data 1399 the extended component of centaurus a 1400 physical state of outer atmosphere and the origin of radiation belts the trapping of high energy particles is explained by the interaction of hot plasmas with the geomagnetic field 1401 cosmic ray storms and lvlar radio outbursts an analysis has been made of type four r f bursts results suggest that a large corpuscular cloud with an associated strong magnetic field is emitted simultaneously with the r f burst the cloud has a small core and when this core covers the earth cosmic ray and magnetic storms occur 1402 a theory of radar scattering by the moon a detailed discussion of available experimental evidence leads to the theory that the scattering is composed of a number of individual returns from twenth thirty single scattering areas with those nearest to the earth providing a specular return information about the material of which this area is composed can then be obtained 1403 radio elho observations of the geminid meteor stream 1404 on the current system of solar flare effects the current system associated with large solar flares is symmetric about the magnetic equator it is shown that the current must flow in a region where electron decay is due to attachment 1405 coupling of the solar wind and the exosphere possible physical processes at the geomagnetic boundary are considered in order to resolve the different estimates of its position obtained from rocket magnetometer experiments and from the study of cometary tails of type one 1406 interaction of the solar plasma with the earths magnetic field cal ulation of the reshaping and termination of the earths magnetic field by the solar flux of protons and electrons 1407 the geomagnetic field in space ring currents and auroral isechasms the relations between positions of maximum auroral frequency and the geomagnons of maximum auroral frequency and the geomagnetic field lines were studied by using a spherical harmonic representation of the field 1408 steady component of the interplanetary magnetic field pioneer v satellite magnetometer measurements suggest the existence of a galactic interstellar field which is uniform over the solar system 1409 on the magnetic damping of rotation of artificial satellites of the earth previous theoretical work is criticized and suggestions are made for removing some of the analytical limitations 1410 some simple formulas for latitude effects and lifetimes of satellites empirical equations are presented and their validity checked by considering the air drag expected 1411 new petred of solution for unretarded satellite orbits an axially symmetric solution of laplaces equation in oblate spheroidal coordinates is found which may be used as the gravitational potential about an oblate planet this potential which makes the hamilton jacobi equation for a satellite orbit separable has an expansion in zonal harmonics in which the amplitudes of the zeroth and second harmonics can be adjusted to agree exactly with the values for any axially symmetric planet and a fourth harmonic which then agrees approximately with the latest value for that of the earth 1412 the sudden discontinuity in the orbital period of sputnik four satellite 1413 ionospheric information from satellite signals results of observations made over a two year period of the fading rate of satellite signals are briefly described and compared with ionization profiles for the same poriod the fading rate changed abruptly during september form winter to summer values within two days this effect was preceded by a change in the direction of travelling disturbances 1414 the determination of ionospheric electron content by observation of faraday fading fading was observed on satellite signals derived electron densities agreed with those deduced form vertical incidence soundings up to the maximum of the f layer 1415 the use of geostationary satellites for the study of ionospheric electron content and ionospheric radio wave propagation a proposed experiment for measuring the total electron content of the ionosphere and for propagation studies 1416 an analysis of radiosonde effects on the measured frequency of occurrence of ducting layers 1417 artificial electron clouds part six low altitude study release of cesium the electron clouds were detected by radar at several frequencies and the measured duration was in reasonable agreement with theory 1418 on the determination of the true height of ionization at high latitudes the matrix metred of bubben for determining true height electron density profiles form ionograms is modified to allow the use of the third magneto ionic z component when the ordinary component is unsuitable 1419 the general methods of the station lindau harz ffr the determination of the true electron density distribution in the ionrsphere three methods assuming longitudinal propagation for the extraordinary ray and two correction methods for the reduction of the ordinary and extraordinary ray traces these two metrods are used to determine the corrections to be applied to the profile of the reference layer previously obtained by a comparison method to obtain the true profile 1420 performance of an r f impedance probe in the ionosphere new values of electron density agree with those from other techniques earlier data were found to be to be too low owing to distortion of the environment by the potentials applied to the probe 1421 diurnal variation of the electron distribution in the ionospheric e layer 1422 some aspects of sporadic e at midlatitudes it is found that e ionization often occurs where the trough and crest slope lines of f layer irregularities meet the e layer level this suggests that e and spread f are caused by the same mechanism a possible structure of e is pro osed and its relation to the occurrence of the green line of the airglow is discussed 1423 the equatorial f region of the ionosphere critical frequencies in the f region at panama and chimbote are negatively correlated in the afternoon this phenomenon together with the diurnal variation in height thickness and electron density of the equatorial f region is consistent with the theory of ionization transportation from the equator to the subtromics suggested by martyn 1424 electron distribution in the f layer of the ionosphere over haringhata calcutta on quiet and disturbed days electron density height profiles have been reduced and compared with similar results for sloxgh and maui it was found that the scale height in the model given by ratcliffe et al 1425 the geographical distribution of ionization in the f layer existing data are not sufficient to prove conclusively that the equatorial trough in f exists in the western hemisphere at certain times of the year 1426 equilibrium electron distributions in the ionospheric f layer the equilibrium equation has been solved numerically for the daytime f region using isothermal and actual ionospheric models at the f layer peak the effects of production loss and plasma diffusion are approximately equal below the peak diffusion is unimportant but becomes dominant above it where the electron distribution takes on an exponential form 1427 the temperature of the f region of the upper atmosphere as deduced from ionospheric measurements chapmans theory has been extended to include the variation of an attachment like loss coefficient with height in the f region application of the theory to data obtained in the form of kelso distributions shows that the region may be regarded as isothermal 1428 triple splitting with the f region of the ionosphere at high and mid latitudes occurrence of the third z ray component is investigated at various times of day season and sunspot cycle and at different magnetic inclinations a connection with the occurrence of spread f is suggested 1429 possibility of detecting ionospheric drifts from the occurrence of spread f echoes at low latitudes observations of the times of occurrence of spread f echoes have been made at four stations in peru results suggest that ionospheric drifts may flay an important part in the occurrence of spread f echoes at low latitudes 1430 diurnal variations of density and scale height in the upper atmosphere the radio echo meteor technique has been used to calculate the neutral particle densities diurnal oscillations in density are found with amplitudes semidiurnal oscillations are also present having approximately half these amplitudes 1431 photochemical rates in the equatorial f region from the eclipse it is deduced tiat temperature changes and transport of electrons were probably negligible during the eclipse formulae are given for the rate of photoionization and the linear recombination coefficient as a function of height and the total rate of absorption of energy in the f region is deduced 1432 geophysical effects associated with the high altitude nuclear explosion collected papers on observations of atmospheric and gelmageetic disturbances associated with the explosions at johnston island on august 1433 hydromagnetic wave propagation in the ionosphere general equations are obtained governing hydromagnetic wave propagation assuming approximations valid for the ionosphere for wave periods of less than one h the equations are very similar to those for the propagation of radio waves in the ionosphere 1434 on the ionospheric heating by hydromagnetic waves connected with geomagnetic micropulsations heat production and consequent temperature increase are negligible 1435 the size of the moving irregularities in the f region and the spread angle of the radio waves scattered from them analysis of fading patterns obtained by a three receiver method discloses an average length of irregularity 1436 incoherency of pulse echoes and the measurement of ionospheric absorption incoherently scattered energy gives rise to errors in absorption measured by the pulse echo method calculations of the magnitude of the error are confirmed by experimental observations 1437 polar ionospheric disturbances associated with a severe magnetic storm a detailed investigation is made of the storm on october using world wide geomagnetic and ionospheric data 1438 morphology of the ionospheric f disturbances in the polar region 1439 anomalous f variations in the antarctic the daytime minimum in the f layer critical frequency which is often observed in the antarctic is explained on the basis of a vertical shear in the horizontal wind and the resulting movement of charged particles in the presence of the earths magnetic field 1440 models of the atmospheric radio refractive index 1441 lightning counter and results obtained in sweden during the thunderstorm period tests performed on a pierce golde cold triode counter show that it records both strokes to earth and discharges between clouds 1442 the electrical structure of thunderstorms a model representing the structure of thunderstorm electricity has been developed from an analysis of simultaneous observations of thunderstorms in the vicinity of kyoto japan 1443 the scattering of thirty six mc s radio waves by weak auroral ionization 1444 the distribution of radio aurora in central canada the results of five mlnths observations using bistatic v h f radio systems are described night time and daytime events are detected and their distributions compared 1445 association between aurorae and very low frequency hiss observed at byrd station antarctica 1446 observations of whistlers and chorus at the south pole 1447 a study of chorus observed at australian stations the variation of occurrence with geomagnetic latitude time of day and k index has been studied possible movements of the generating region are deduced 1448 the current jet hypothesis of whistler generation the suggested mechanism involves the interaction between an electron stream travelling upwards as the result of a lightning discharge and the e m radiation from a second discharge 1449 some comments on the penetration of whistlers through ionospheric layers ionospheric irregularities smaller than the whistler wavelength may prevent penetration of the layer and lead to the cessation of whistlers at certain times 1450 hyperbolic direction finding with sferics of transatlantic origin description of a system for locating thunderstorms by measurement of the time difference of arrival of atmospherics at several stations position lines for sources in the atlantic were established from a network in the u s and compared with fixes from a u k d f network 1451 some measurements of atmospheric noise levels at low and very low frequencies in canada values are expressed in terms of mean noise power and are compared with predictions effects of location of source and propagation conditions are discussed amplitude frequency curves are studied in detail 1452 v l f attenuation for east west and west east daytime propagation using atmospherics 1453 static inverter delivers regulated three phase power silicon controlled rectifiers in conjunction with magnetic amplifiers are used 1454 the characteristics and protection of semiconductor rectifiers 1455 design of static relays for signalling and control the advantages of static relays and the replacement of mechanical relays by semiconductor devices are discussed circuit diagrams are given 1456 analogue multiplication using time as one variable if one analogue quantity appears as a time interval accurate electronic multiplication is simplified transistor circuits giving products proportional to average or peak output voltage are described 1457 the minimization of the effect of drift in d c analogue computers 1458 the elliott sheffer stroke static switching system a system is described in which interconnections between a number of logic elements all of the same type the sheffer stroke permit any logical configuration or switching sequence 1459 all purpose computer circuits automatically connected to solve specific problems different connections may be made automatically using a photo conductor matrix which may also be used to detect and replace faulty parts 1460 the resistance network a simple and accurate aid to the solution of potential problems a method applicable to two dimensional problems and to three dimensional problems where there is rotational symmetry is described in either case laplaces equation for given boundary conditions reduces to a differential equation involving two independent variables only 1461 theory of a monolithic null device and some novel circuits a semiconductor structure which behaves as a twin t filter network is described and applied to a tuned amplifier oscillator and transducer 1462 the miniaturization of resistors review of available types of carbon and metal film resistors resistance materials and resistor cooling systems with tabulated results of climatic tests on film type resistors 1463 semiconducting diamonds as thermistors the performance and construction of diamond thermistors are described which have high thermal conductivity and resistance to corrosion 1464 conducting hard rubber and its use as composition resistor 1465 thin film cryotrons discussion of the characteristics of evaporated superconductive films as applied to cryotrons and details of a thin film cryotron made by vacuum deposition which is much smaller than the wire wound component the performance of this cryotron is given and it is applied to flip flop circuits finally its use in ring oscillators is analysed by two different methods 1466 piezoelectric voltage transformers possible modes of operation are considered and the design and performance of a ceramic transformer with respect to one of these modes is examined the advanect to one of these modes examined the advantages and possible applications of such devices are discussed 1467 irreversible thermodynamics of a nonlinear rc system the solution is compared with those of other investigators 1468 i r e standards on circuits definitions of terms for linear signal flow graphs 1469 ire standards on circuits definitions of terms for linear passive reciprocal time invariant networks 1470 partial equivalence with reference to a theorem of cocci cauer the equivalence of two terminal networks containing r c and l elements is discussed 1471 on network synthesis with negative resistance a procedure is outlined which results in realizable networks with lossy elements arranged in foster terms 1472 solution of ladder networks containing nonlinear resistances a graphical method of solving network problems involving nonlinear and or negative resistances is described such networks have been used for the solution of nonlinear differential equations 1473 design of networks with prescribed delay and amplitude characteristics a general analytic method is described for designing reactive quadripoles with specified group delay characteristics means of equalizing attenuation without affecting the delay are discussed 1474 image parameter theory for mechanical quadripoles in compressional or torsional oscillation the equivalence of the parameters of a mechanical system transmitting compressional or torsional oscillations and the parameters of an electrical transmission line is established the design of mechanical filters is described and design formulae with response characteristics are given for the basic filter sections 1475 special band pass half sections the design of crystal filters of branch network type is described 1476 a decimal attenuator a network combining the properties of a conventional voltage or current divider with those of a constant resistance attenuator 1477 a multiple isolated input metoork with common output design equations are developed for the general case of n isolated inputs with a common output measurements made on two input and three input units are given 1478 frequency of the three phase rc coupled oscillator part two inductive anode load resistance 1479 the optimum design of rc valve oscillators nonlinear distortion is analysed and optimum operating conditions are determined by means of an analytical method using nonlinear co efficients 1480 shock excitation of a radio frequency power circuit by means of a saturable core reactor 1481 circuit applications of field effect transistors applications of photosensitive cds transistors in sawtooth generators amplifiers and phase shift oscillators are described 1482 microwave detection and harmonic generation by langmuir type probes in plasmas rectification effects are obtained with co d cathode d c discharges in he or ne 1483 a travelling wave harmonic generator a scheme is outlined in which a series of delay line outputs displaced in phase relative to one another are combined to deliver pulsed power at a predetermined harmonic of the input frequency 1484 systems using transistors and transductors amplifier modulator and switching systems are described in which transistors and transductors are combined 1485 high input impedance transistor circuits 1486 linear phase transistor amplifier the design of a simple shunt compensated linear phase amplifier is described 1487 a low drift transistor chopper type d c amplifier with high gain and large dynamic range 1488 narrow band amplification with transistors the design formulae for tuned circuit coupling of amplifier stages with resistance and with reactance matching are considered and design curves are given for optimum circuit conditions 1489 a nonlinear effect in transistor amplifiers with feedback 1490 inversion by fast passage in a multilevel spin system some measurements of adiabatic fast passage in a multilevel electron spin system are described with particular reference to a recent proposal for a staircase maser 1491 optimum noise and gain bandwidth performance for a practical one port parametric amplifier analysis shows that the conditions necessary for minimum noise temperature are compatible with those necessary for maximum gain bandwidth product if the diode has a high self resonance frequency there is a characteristic figure of merit for the diode and an optimum pump frequency a series of design curves is given 1492 symmetrical matrix analysis of parametric amplifiers and converters expressions are derived for gain bandwidth and noise figure and by regarding the matrix as a nodal admittance array an equivalent conductance c rcuit is constructed it is shown that for low no se figure and wide bandwidth the idler frequency should be much higher than the signal frequency 1493 a transmission matrix analysis of the cavity parametric amplifier 1494 interaction of two microwave signals in a ferroelectric material 1495 on stabilizing the gain of varactor amplifiers use of the varactor d c to comtrol pump level improved the gain stability 1496 an x band parametric amplifier using a silver bonded diode a wafer type construction is used for the silver bonded diode 1497 parametric amplifier theory for plasmas and electron beams a theory is given for a parametric amplifier which uses a gas discharge plasma an experimental amplifier is described 1498 the theory of magnetic ring modulators the equivalent circuit of the magnetic ring modulator is derived for idealized b h characteristics and the design of a modulator circuit is given 1499 a new use of the junction transistor as a pulse width modulator the base pulse current is modulated in a common emitter configuration 1500 fluctuations from the nonequilibrium steady state a macroscopic treatment of noise is presented using markovian and stationary assumptions 1501 the electrostatic energy of a space charge 1502 microwave measurements of dielectric absorption in dilute solutions 1503 acceleration of charged particles in travelling or stand ng electromagnetic waves the average lorentz force acting on a charged particle in an e m field depends on the resonance properties of the motion of the particles and on the spread in their transverse momentum conditions under which continuous acceleration can be achieved by spatial variation of the particle oscillation parameters are discussed 1504 determination of the effective scattering mechanism parameter of electron transport theory fermilevel energy effective scattering mechanism parameter effective mass and relaxation time can be obtained from the magneto seebeck effect for corbino disk geometry when combined with other transport measurements 1505 an analogue solution for the static london equations of superconductivity measurements of field distributions in the space around the normal conductors of a growing exponential function generator provide useful cryogen c circuit design data 1506 gauge invariant formulation of the bardeen cooper schrieffer theory of superconductivity 1507 an analogy between the effects of fluctuating electric fields and steady magnetic fields in isotropic conductors when a universal relaxation time cannot be defined 1508 propagation of perturbations in a one dimensional two beam electron flow using a difference kernel integral equation method a solution is obtained for drift in two beam flow in the presence of a transverse electric field 1509 three dimensional space charge flow gives theory and experimental results for stationary beams allowing for e s interaction between the particles 1510 equilibrium conditions for electron beams the conditions are determined for a beam in which the density of secondary particles is much greater than that of primary electrons 1511 nonlinear behaviour of a modulated electron beam in the presence of a velocity distribution the harmonic currents in an electron beam with a velocity distribution can be evaluated by a procedure based on the boltzmann equation 1512 the electrokinetic power theorem the electrokinetic power theorem is shown to be valid also for arbitrary electron velocities relativistic conditions if certain definitions are adopted 1513 on the properties of the electron beam in the presence of an axial magnetic field of arbitrary strength a study of the effect of an axial magnetic field on the propagation of waves in an idealized electron beam using small signal theory and neglecting collisional effects the possibility of angular asymmetric excitation is considered and special attention is paid to the influence of the a c drift lorentz terms and of the relativistic corrections in the derived equations 1514 the electromagnetic interaction between two crossing electron streams parts one and two the interaction between two infinitely extended velocity modulated streams has been studied in part one where beam velocities common to microwave valves are considered the lorentz term in the equation of motion has been omitted it is introduced in part two for higher beam velocities the distribution of ions formed by attachment of electrons moving in a steady state of motion through a gas the distribution of ions formed by attachment of electrons diffusing through a gas is solved exactly and the results are compared with an approximate calculation given earlier by huxley 1515 ionic conductivity of highly ionized plasmas values of plasma resistivity as measured by a current entering and leaving the plasma and the flow velocity in hydrogen at various gas pressures are given together with a discussion of the theoretical aspects of the problem 1516 propagation and production of electromagnetic waves in a plasma a general review of nonthermal mechanisms for the emission of e m waves in a plasma 1517 linearized theory of plasma oscillations 1518 microwave conductivity of a plasma in a magnetic field the boltzmann equation for electrons in a uniform isothermal plasma is solved the microwave conductivity is simply related to certain coefficients of the solution 1519 the transport phenomena in cylindrical discharges in the presence of magnetic fields 1520 microwave detection and harmonic generation by langmuir type probes in plasmas 1521 waves in a conducting sheet situated in a strong magnetic field the hydromagnetic approximation is applied to the elementary linear theory of transverse waves in a thin uniform plane conducting sheet in which the inertia is provided by the sheet and the restoring forces by strong vacuum magnetic fields on either side of the sheet the dispersion relation and damping are obtained the waves should be observable in the laboratory 1522 nuclear spin lattice relaxation caused by paramagnetic impurities 1523 on the uniqueness theorem for electromagnetic fields resonant modes and mixed boundary condition in the steady state are considered 1524 impulse excitation of a conducting medium 1525 electromagnetic transients in conducting media 1526 a reciprocity theorem for the electromagnetic field scattered by an obstacle 1527 propagation at oblique incidence over cylindrical obstacles the effect of oblique incidence can be considered as a change in the effective radius of curvature of the diffracting obstacle 1528 diffraction by smooth conical obstacles expressions obtained earlier are generalized to oblique incidence and conical surfaces the derivation is based on a generalized concept of the greens function and on the use of corrective factors results are compared with scale model measurement 1529 a new method of solving the problem of the diffraction of electromagnetic waves by a thin conducing disk the problem is reduced to the determination of two functions each of which satisfies a fredholm integral equation which can be solved by numerical methods a simple formula for the scattering coefficient is derived 1530 the planar problem of the diffraction of electromagnetic waves by two ideally conducting strips of finite width located one below the other mathematical analysis based on the method of successive approximations using special approximation formulae 1531 reciprocity and scattering by certain rough surfaces 1532 backscattering from a finite cone 1533 the interaction between an obliquely incident plane electromagnetic wave and an electron beam parts two and three the work described earlier is extended in part two to include the case where there is no static magnetic field present in part three results obtained are analysed for possible resonance conditions to provide a more direct physical interpretation of the formulae derived 1534 depth of penetration as a measure of reflectivity of thin conductive films 1535 electromagnetic theory of d c effects in ferromagnetic resonance deals with propagation through thin sheets of ferromagnetic conductors 1536 paramagnetic resonance along the direction of the polarizing field a radio frequency susceptibility along the polarizing field is observed when the electron spin resonance of dpph is partly saturated at microwave frequency the variations of the real and imaginary parts as a function of the radio frequency have been studied theoretical calculations are in good agreement with experiment in some cases a negative susceptibility appears which has been used in a molecular amplifier experiment 1537 space research slightly abridged text of a survey paper prepared by the national aeronautics and space administration washington on space research techniques and recent experimental data with a summary of a discussion by experts from n a t o countries at a meeting at aachen 1538 a new limit to the galactic magnetic field set by measurements of the zeeman splitting of the hydrogen line results give no positive evidence for a magnetic field in any of the clouds studied 1539 an attempt to detect the galactic magnetic field field using zeeman splitting of the hydrogen line 1540 the possibili y of detecting a gravitational red shift in twenty one cm radiation form the galaxy there seems to be little possibility of recognizing a gravitational red shift as suggested by landovitz and marshall until the detailed structure and motions have been established more definitely 1541 on the spectra of radio sources expressions are derived which suggest that there should be a progressive increase in the slope of the frequency spectrum of the flux density for more distant sources than cygnus a 1542 relation between the solar emission of cosmic rays and type four bursts 1543 influence of hall effect on the induced current in the earth owing to magnetic disturbances earlier theory of the origin of geomagnetism is modified by allowing for hall effect which accelerates the build up of induced currents in the earths crust 1544 some characteristics of geomagnetic micropulsations 1545 measured electrical properties of snow and glacial ice in general the conductivity of snow and glacial ice is much higher than that of pure ice 1546 rocket and satellite instrumentation 1547 the radiation from artificial earth satellites the various factors affecting e m wave propagation from satellites are reviewed and discussed with reference to results obtained by radio observations and c r d f equipment 1548 satellite perturbations from extra terrestrial gravitation and radiation pressure the equations of motion of a satellite are written in terms of displacement components relative to the unperturbed elliptic orbit a moving system of co ordinates is used which consists of an orthogonal triad whose origin is always located at the nominal satellite position on the elliptic orbit 1549 fading of satellite transmissions and ionospheric irregularities the orientation of the irregularities is suggested as an explanation of the observations of kent 1550 earth satellite observations and the upper atmosphere temperature inversion in the f layer the suggested wiggle in the curve for logarithmic density has been derived exactly from satellite observations 1551 earth satellite observations and the upper atmosphere diurnal and seasonal density variations in the upper atmosphere 1552 the use of polarization fading of satellite signals to study the electron content and irregularities in the ionosphere a ray tracing program and a model ionosphere have been used to evaluate electron content refraction and where necessary path splitting are taken into account 1553 second order faraday rotation formulas 1554 determination of satellite orbits from radar data procedural stages in an optimum computer routine using two orbital points and the transit time between them incorporate a differential correction based on short range data 1555 power spectra of temperature humidity and refractive index from aircraft and tethered balloon measurements 1556 a relation between ionospheric drifts and atmospheric dynamo current systems geomagnetic data suggest that the focus of the atmospheric dynamo current system moves from north to south of sydney as solar activity increases this would explain the reversal in the direction of ionospheric drifts at sydney during recent years 1557 effects of vertical diffusion of electrons near the magnetic equator the effects are shown to account for the major features of the geomagnetic anomaly discussed by croom et al the anomaly is an excess of ionization due to diffusion away from the equator rather than a deficiency of ionization due to diffusion away from the equator rather than a deficiency of ionization at the equator 1558 anisotropic field aligned ionization irregularities in the ionosphere near the magnetic equator equatorial scatter echoes were measured at huancayo during the i g y 1559 experimental relations between ionospheric true height group height and phase height 1560 the determination of the true height of maximum ionization by the ten point method 1561 true height and thickness of the ionospheric e layer a method proposed by schmerling has been applied to calculations of the true height and thickness of the e layer results given for a single daytime period show irregularities in the fine structure of the layer 1562 nonseasonal variation in the e layer ionization appreciably greater ionization is found in december than in june a relation to the van allen radiation belts is tentatively suggested 1563 the world wide semi annual cycle in the e layer of the ionosphere the monthly mean values of the e layer character figure for eight stations in the northern and southern hemispheres have been calculated 1564 theory of spread f based on aspect sensitive back scattered echoes a large class of spread f echoes in equatorial regions may be explained by assuming that back scatter echoes are aspect sensitive with regard to irregularities aligned along the earths magnetic field 1565 equatorial spread f and f layer heights extension of earlier work to include a study of the high correlation between the rise in height of the f layer just after local sunset and the subsequent occurrence of spread f 1566 ionospheric refraction in radio astronomy expressions are derived for the apparent displacements of cosmic radio sources at transit resulting from ionospheric refraction the theory includes the effects of horizontal electron density gradients which often outweigh those due to a spherically symmetrical ionosphere the relation of ionospheric refraction to the total thickness and the total electron content in a vertical column are discussed 1567 scintillation spread f and trans equatorial scatter both radio star scintillation and spread f show little dependence on magnetic activity during sunspot minimum at sunspot maximum they are strongly negatively correlated whilst transequatorial scatter is positively correlated with magnetic activity 1568 short term differences in the behaviour of two daily indices of solar activity during the i g y 1569 sunrise and eclipse effects on the ionosphere at brisbane 1570 dynamic characteristics of the ionosphere and their coherency with the local and planetary magnetic index 1571 geomagnetic field and ionospheric drift drift measurements at new delhi do not show the semi diurnal periodicity which would be expected if the drifts were in the form of lunar or solar tides some correlation with the magnetic index k is looked for but is not found except on disturbed days when the northward velocity of the north south component increases with increasing k 1572 on the effect of the magnetic field of the earth on winds in the ionosphere a theoretical treatment of electrodynamic and hydrodynamic processes in the ionosphere 1573 ionospheric electrostatic fields and the equatorial electrojet 1574 fading of c w signals as a means of spread f study 1575 a study of two mc s ionospheric absorption measurements at high latitudes from a study of the data of five stations in canada during the i g y it is found that a the winter anomaly of noon absorption occurs at churchill but is absent at resolute bay b the effect of solar zenith angle as illustrated at the diurnal variation of absorption decreases with increasing latitude c midnight absorption is a maximum in the auroral zone but is also high over the polar cap 1576 identification of mode in low frequency sweep ionospheric sounding and interference patterns between overlapping echoes the echo is received on a pair of crossed coplanar horizontal dipoles and split into its two circular components by means of a two channel receiver the resulting video signals are electrically subtracted and applied as brilliance modulation to a conventional c r tube where the echo is displayed as a light or dark trace depending on its sense of rotation the technique is convenient for observing interference fringes and these effects are discussed 1577 some magneto ionic phenomena of the arctic e region unusual phenomena at thule are described and are attributed to the effects of electron collisions on radio wave propagation at high latitudes 1578 vertical distribution of radio refractive index in the medium height of atmosphere an examination of radiosonde and captive balloon data from japanese stations indicates an exponential variation for the lower atmosphere but not for the upper 1579 simultaneous v h f auroral back scatter measurements 1580 some e l f phenomena electric field fluctuations at frequencies below one kcs are discussed with reference to e m changes associated with atmospherics and e s variations in atmospheric electricity 1581 energy fluxes from the cyclotron radiation model of v l f radio emission further consideration of the cause of dawn chorus 1582 an optimal discrete stochastic process servomechanism an extension of mills theorem 1583 the influence of impurities on the strong field effect in selenium rectifiers the reverse i v characteristic of se rectifiers depends chiefly on the purity of the materials used with pure se the reversal of the sign of the temperature coefficient is displaced towards lower temperatures and higher voltages 1584 the design of controlled rectifiers using triode transistors polyphase rectifiers are described with switching elements of p n p and n p n transistors and stability conditions are investigated graphically 1585 highly stable medium voltage direct and alternating voltage sources part two addition to earlier review dealing with short term stabilization by valve circuits or transductors and with the reduction of long term drift in d c power units 1586 electronic computers and the engineer an outline of the form and function of the main units of a digital computer the basic techniques of programming are described 1587 the physical realization of an electronic digital computer input and output continuation of a series of papers and back references electromechanical input output equipment is described 1588 universal tape amplifiers for digital data systems read and write amplifiers covering a wide range of input characteristics can be used with both return to zero and non return to zero pulse techniques at rates up to 1589 designing ultrasonic delay lines the significant operational characteristics of delay lines and their influence on design are examined 1590 the minimality of rectifier nets with multiple outputs incompletely specified 1591 a computer oriented toward spatial problems a stored program computer is described which can handle spatial problems by operating directly on information in planar form without scanning or other methods for transforming the problem into some other domain 1592 analogue computation a survey of the principles practice and current applications of computers together with a tabulated analysis of british models 1593 new job for an old method capacitor storage used in analogue memory a delay of for signals of frequency up to with negligible attenuation and an error of can be obtained by the unit described 1594 fourier analysis by a general purpose electronic analogue computer a method for use with a high speed differential analyser is described in which the period of the harmonic function generated by the computer is kept constant and the period of the arbitrary function made variable 1595 electron gun operates high speed printer a method of converting pulse code data from a shaped beam c r tube into printed records on untreated paper at a rate of characters min is described 1596 resistance potentiometers as function generators the generation of functions of a single variable by means of resistance potentiometers is reviewed see also 1597 end fired memory uses ferrite plates magnetic flux is induced around corresponding holes in two adjacent plates and in this way irregularities in the material from hole to hole do not affect the accuracy storing and switching systems using plates are described and suitable transistor drive and regeneration circuits are given 1598 impedance matched or optimum examples are given of situations where matched impedance is the ideal condition and of cases in which other impedance relations prove to be better 1599 through connections for printed wiring in the process described a metal eyelet is passed through the printed circuit board staked and soldered ine one operation 1600 a voltage sensitive switch the controlled dielectric breakdown of oxide films has been investigated a small shock resistant device requiring no additional power supply has been developed which consists of an oxide layer between an al base and a ag film before breakdown the device has a resistance of at least on switching the resistance drops to about some circuit applications are described 1601 solving thermistor problems the methods of designing circuits incorporating thermistors are illustrated by giving three particular cases 1602 non linear properties of carbon resistors a method of determining the nonlinear characteristics is proposed which is based on the measurement of harmonics produced when a pure sinusoidal current flows through the resistor 1603 the versatile vamistor construction specification and performance data of a resistor incorporating the best features of wire wound and carbon types 1604 designing transistor circuits switching statics the basic switching properties of junction transistors are examined and examples of single and multiple switches are given 1605 an electronic transmit receive switch incoming signals are fed via the tank circuit to a r f pentode which is cut off by grid bias when the transmitter is on see also 1606 a temperature sensitive ceramic reactance element a sintered mixture of and gives within the range to a nearly linear repeatable capacitance temperature curve with a change of capacitance the effects of different percentages of are examined and applications are mentioned 1607 a voltage variable capacitor details of a subminiature junction device with a variable capacitance controllable by bias voltage are given applications of the varicap to an f m transmitter an amplifier and a variable filter are described see also of 1608 response of a capacitance resistance divider to the step function exponential function and ramp function 1609 a four pole analysis for transistors an algebraically convenient analysis for four pole networks is presented based upon determinant techniques it is applied to transistor circuits and introduces two new comprehensive parameters for the transistor 1610 additional tables for design of optimum ladder networks tables for networks with characteristics given by butterworth tchebycheff and bessel polynomials are presented they are classified on the basis of the conductance ratio see also 1611 estimation of dissipative effects in tchebycheff symmetrical filters comment on of 1612 low pass rc filter with optimum response formulae and graphs for one and two section filters are given 1613 narrow band magnetostrictive filters filters each with a bandwidth of are arranged with inputs in series and outputs isolated from one another to form a bank with a centre frequency of about design and construction are described and applications of single resonators and arrays are considered temperature effects are reduced by using cobalt substituted ferrites 1614 a waveguide filter theory on the basis of the matrix theory used by hessel et al formulae are derived giving insertion loss and envelope delay for multistage filters having as parameters the ratios of the bandwidth of the stages to the bandwidth of the total filter 1615 wide range rc oscillator a frequency range exceeding in a single sweep can be obtained with the tone source described elements having continuously distributed series resistance and shunt capacitance are used which can be made from standard high stability resistors 1616 negatively biased multivibrator description of a multivibrator which has its grids returned to a negative bias it has high frequency stability and is suitable for use as a variable frequency source or a source of special wave shapes and can be frequency modulated the frequency varies linearly with bias voltage 1617 transistor blocking oscillator circuits circuit characteristics are examined and methods for varying the output waveform are discussed 1618 increased sensitivity of trigger circuits in the cathode coupled monostable multivibrator described the use of a crystal diode in the feedback loop allows one valve to amplify the trigger pulse before it is applied to the other valve the circuit is sensitive to a few millivolts 1619 latching counters the causes of low reliability of single pulse counter chains are examined a circuit with a multiphase output is described which has a frequency range from d c to and eliminates spurious pulses reset facilities and general design features including the use of transistor circuits are discussed 1620 sensitive single channel pulse height analyser the analyser operates with input pulses of amplitude and a dead time of about the stability over a period of several days is better than 1621 harmonic generation with ideal rectifiers the harmonic cannot be generated with an efficiency exceeding at least of the power converted to d c and harmonics is d c dissipation this cannot be reduced by an arrangement of selective circuits 1622 harmonic generation with nonlinear reactances a simple theory of frequency multiplication using nonlinear reactances is derived and compared withe the results obtained with the nonlinear capacitance of a ge point contact diode the theory and the experimental results are in agreement at low input powers possible reasons for the discrepancies at high powers are mentioned 1623 linear amplifier for negative pulses a two valve amplifier is described which has a gain of and a rise time of for outputs up to 1624 three valve preamplifier a description and performance specification of a circuit with inputs and crystal pickups tape recorder and radio receiver simultaneous outputs for tape recording and for a power amplifier are provided see also of 1625 broad band amplifier for radar and scatter the design of a low noise two stage amplifier and mixer for the range is described overall power gain is with noise figures varying from to over the frequency band 1626 design considerations for direct coupled transistor amplifiers it is shown that the maximum obtainable signal drift ratio of an amplifier is achieved by choosing the optimum source resistance the signal drift capability of a transistor and the optimum source resistance are nearly the same for the three configurations common emitter common collector and common base negative feedback can change the optimum source resistance and generally degrades the signal drift ratio improved signal drift ratio can be obtained at reduced emitter currents 1627 circuit designed for high voltage gain from transistors in the circuit described a common emitter stage feeds into a modified common collector stage with low output impedance 1628 transistor audio amplifier design principles are outlined for using multiple push pull stages in series the construction of a amplifier for battery operation and of a low noise preamplifier is described 1629 public address amplifiers using transistors the amplifiers work from or supplies and may be fully driven by a low impedance microphone 1630 a transistor video amplifier having volts output 1631 transistorized if strip design the performance of tetrodes in grounded emitter and grounded base circuits is compared a nine stage if amplifier using grounded emitter tetrodes is described with transformer coupling between stages providing for neutralizing and matching 1632 temperature stable transistor circuit based on the half supply voltage principle the principle is applied to the design of a transformerless af output stage and is used in each stage of a six transistor superheterodyne receiver see of 1633 masers and related quantum mechanical devices theoretical aspects are considered leading to the computation of the dielectric constant of a gaseous medium in a form which can be directly applied to the solution of problems in waveguides and cavities 1634 behaviour of a two level solid state maser it is shown under simplifying assumptions that when a system of spins is in resonance with the cavity and when damping effects caused by relaxation phenomena and cavity losses are not excessive modulation of the cavity power output is exactly what is to be expected on the basis of a dynamical analysis see also of 1635 proposed method for tuning a maser cavity a method is described for determining the small difference between the cavity resonance frequency and the frequency of the microwave spectral line 1636 circuit conditions for parametric amplification it is shown that signals may be amplified in a circuit which consists exclusively of passive elements if a nonlinear or time varying reactance is present the circuit conditions which must be satisfied are established and the differences between parametric amplifiers and mixers or modulators are discussed 1637 parametric amplification and frequency mixing inpropagating circuits an analysis is given of the properties of time varying distributed reactance in propagating structures which may have positive or negative phase and group velocities power at different frequencies may be converted from one frequency to the others and the amplitudes of the waves may vary exponentially or periodically depending on the relation of the frequencies and of the phase constants between the propagating waves and the variable coupling reactance applications to wide band frequency converters frequency channel selectors wide band amplifiers tunable narrow band amplifiers and oscillators are described 1638 gain bandwidth and noise characteristics of the variable parameter amplifier increased gain is achieved by raising the of the idling resonant circuit or the amount of variation in the variable coupling reactance the bandwidth is inversely proportional to and to the voltage gain and directly proportional to the ratio of idling resonance frequency to amplifying frequency very low noise figures should be attained by artificially cooling the idling resonant circuit the use of the parametric principle as applied to frequency conversion is discussed 1639 a low noise electron beam parametric amplifier 1640 the mavar a low noise microwave amplifier the operation of the maver mixer amplification by variable reactance requires a lossless nonlinear reactance exhibiting negative resistance under certain conditions low noise amplification is achieved at room temperature the performance and the operation of the main types of parametric amplifier are outlined 1641 strongly nonlinear oscillations mathematical analysis of a special class of nonlinear oscillations in systems without or with losses 1642 a note on thermodynamics of the harmonic oscillator with radiation damping it is shown that the impedance of an irreversible thermodynamical system must be positive and real the argument is based on representation of the system by langevin equations of the second order corresponding to the construction of any passive network from elementary rlc circuits the conclusion is illustrated by an examination of the properties of the harmonic oscillator 1643 theory of the cathode sheath in a low density gas discharge the space charge equations of a low density gas discharge are derived and applied to the study of potential distributions in the cathode sheath one conclusion is that a positive column will begin to evolve when the number of ionization mean free paths in the discharge gap is of the same order as the square root of the ratio of electron to positive ion mass 1644 the effect of a uniform magnetic field on electrodeless discharge in a tube and measurement of electronic mobility 1645 perveance and the bennett pinch relation in partially neutralized electron beams the concept of perveance is extended to take account of relativistic conditions and the effects of space charge neutralization see also of 1646 magnetic forces and relativistic speeds in stationary electron beams comment on of 1647 a variational calculation of the equilibrium properties of a classical plasma 1648 correlations in the charge density of a classical plasma 1649 nonlinear theory of plasma oscillations and waves an exact differential equation for density oscillations is found considering only coulomb interactions between electrons a number of properties of plasma oscillations are then derived including the form of stationary spherical waves in an isotropic plasma see also of 1650 thermal diffusion in ionized gases the thermal diffusion factor which is less than unity in a neutral gas mixture is of order in an ionized gas where is the ionic charge in a mixed ionized gas containing also a small proportion of heavy ions the factor can be much greater and give increased heavy ion density in the hotter regions this effect may be of importance in the solar corona 1651 experimental determination of the field of a permeable alloy cylinder placed in a uniform magnetic field parallel to its axis of revolution 1652 effective parameters in ferrimagnetic resonance the steady state solution for the susceptibility tensor of a two sublattice system has been found by using sublattice equations of motion which include complete landau lifschitz relaxation terms with individual relaxation parameters and which describe relaxation toward the instantaneous total field acting on the sublattice 1653 spherical vortices in magnetohydrodynamic 1654 propagation of waves through a sheet of the medium with a cubic periodic structure an approximate solution to the wave equation is obtained for the case of normal and oblique incidence of the ingoing wave and a detailed investigation is made of the case for which the wave equation is separable 1655 some electromagnetic transmission and reflection properties of a strip grating 1656 a general theory of magnetic resonance saturation a general theory for describing a spin assembly due to a nearly resonant rotating magnetic field arbitrary strength is given two different cases are treated dependent on the relation between the static field and the frequency of fluctuation of the environment 1657 a microwave electron spin resonance spectrometer a general description is given of equipment which operates in the x and k bands and has highly stable magnetic and microwave frequency systems 1658 masers and related quantum mechanical devices 1659 paramagnetic resonance in copper proprionate monohydrate results of an investigation at cm of absorption in single crystals 1660 the influence of the anomalous magnetic moment on the spin kinematics of electrons in a uniform magnetic field high energy particles in a beam are considered 1661 proceedings of the third symposium on cosmical gas dynamics held at the smithsonian astrophysical observatory cambridge massachusetts june papers presented deal with velocity fields in the interstellar medium cooling and condensation of interstellar matter conditions at the ionization and shock fronts in collisions of gas clouds and related problems 1662 polarization measurements of the three spectral types of solar radio burst a frequency sweep technique was used in the range most data being obtained between and data for type and type bursts cover the period january october and for type the years and many type bursts were highly polarized and there were strong indications that the polarization was due to the radiation source 1663 evidence of echoes in the solar corona from a new type of radio burst the bursts contain two elements spaced by sec the second being a repetition of the first with a frequency increase with time of per sec an explanation is derived in terms of echoes from lower levels of the solar corona 1664 evidence on the spatial distribution of radio sources derived from a survey at a frequency of some results from a survey of radio sources at are available for limited regions of the sky these are discussed in relation to the spatial distribution of sources 1665 short ray burst from a solar flare observations of a burst of radiation are compared with simultaneous records of solar radio emission at and 1666 a suggested improvement to the cw technique for measurement of meteor velocities 1667 a search for magnetic effects from meteors no magnetic pulses could be detected as a result of meteors having visual magnitudes between and the sensitivity of the magnetometer used allowed pulses of and later to be recorded see also of 1668 behaviour of the present sunspot cycle 1669 geomagnetic dynamos a rigorous proof is given of the dynamo theory of geomagnetism by postulating a velocity pattern in a sphere filled with conducting fluid so that the arrangement acts as a dynamo producing an external magnetic field 1670 a method for analysing values of the scalar magnetic intensity the method uses a series for the square of the scalar intensity the terms of which are obtained from the spherical harmonics generally applied to each component of the intensity those magnetic characteristics normally given by analysis of the vector intensity are obtained 1671 large amplitude hydromagnetic waves above the ionosphere arguments are presented for the existence of waves of amplitude about times that of geomagnetic fluctuations at the earths surface it is assumed that the latter are generated at six to ten earth radii and carried to earth by the waves it is suggested that the waves produce irregularities in electron density which cause radio star scintillation and that they are also responsible for high intensity particle radiation above about km 1672 scientific reports of the french polar expeditions magnetic activity in the polar regions 1673 measurement of the earths magnetic field with a rubidium vapour magnetometer the instrument described makes use of the relationship between the earths field and the absorption lines in rb vapour caused by ground state zeeman transistions an absolute accuracy of is quoted see also of 1674 geomagnetic activity and eruptions statistical analysis of observational data to determine the relation between various types of solar flare and increases in geomagnetic activity 1675 igy progress report a general report of contributions made by members of the rsgb to the igy program 1676 igy vhf programme progress to date the report compiled from observations made by members of the rsgb deals with an analysis of the origin of different air masses in relation to tropospheric propagation conditions fading auroral reflection propagation and solar noise 1677 hit rates of radio propagation disturbance warnings and swi warnings in order to improve the hit rate defined as the number of hits divided by the number of issued forecasts it is suggested that long distance propagation characteristics should be studied to account for the fall in hit rate in winter that forecasting should be reduced to three or four days ahead and that although swi warnings are fairly good there should be a further study of solar radio noise 1678 gravitational torque on a satellite vehicle 1679 motion of the nodal line of the second russian earth satellite and flattening of the earth 1680 air drag effect on a satellite orbit described by difference equations in the revolution number difference equations are derived whose solutions express changes in orbital size and shape and give the satellites time behaviour as functions of the revolution number the results are obtained from a first order perturbation theory using a small air drag parameter and assuming the air density function to be locally exponential see also of 1681 on the reception of radio waves from russian earth satellite i observations of bearing and field strength are used to determine the orbit and to estimate regions of reception taking into account the various modes of ionospheric propagation 1682 radio reflections from satellite produced ion columns the records of signal strength of wwv transmission on measured at the university of illinois were examined for periodic variations due to reflection from ion columns the results do not indicate the presence of such columns for extremely high satellites see also of 1683 satellite tracking its methods and purpose radio radar and optical techniques are discussed 1684 keeping track of earth satellites details are given of an interferometer type aerial array having dipoles proximity coupled to a two wire transmission line a receiver with inputs switched at is used to detect signals below receiver noise level calibration methods are described and some transit passage records accurate to within sec are shown 1685 telemetering information from satellites the data given cover both ussr and us satellites channel assignments for the lyman environmental satellites are tabulated and general notes on recording technique are included 1686 pressure and temperature variation of the electron ion recombination coefficient in nitrogen the variations have been investigated in the pressure range mm hg and for electron temperatures between and at mm hg varies from at dissociative recombination is the most probable mechanism 1687 computations of electron density distributions in the ionosphere making full allowance for the geomagnetic field jacksons method of for computing the distributions from records has been slightly modified for use on an electronic computer each reduction takes about secs it is assumed that the electron density between two layers falls to of the lower layer value night time distributions for brisbane australia are found to be nearer to the chapman than to the parabolic form 1688 long term variations of the sporadic e layer in japan statistical analysis of layer reflections at four observatories during shows marked diurnal and seasonal variations in no annual variation is observed nor any correlation with sunspot number an analysis of the occurrence of reflections above certain limiting frequencies at one observatory yields similar results 1689 on the influence of electron ion diffusion exerted upon the formation of the layer the maximum electron density of the layer and its height are obtained theoretically as functions of latitude and solar zenith distance the theoretical height distributions derived are thinner than chapman distributions and the effective recombination coefficient decreases with height at low altitudes but becomes constant at high altitudes no better agreement between theory and observation is obtained when a vertical electron ion drift velocity is considered see also of 1690 on the world wide distribution of the coefficients a and b in the relation where sunspot number are separated into components which are constant and those which vary diurnally and annually see of examination of these components for stations shows a geomagnetic latitude control of the constant component while there is no significant difference between control by geomagnetic or geographic latitude for the varying components 1691 solar cycle influence on the lower ionosphere and on vhf forward scatter seven years results at for the cedar rapids sterling path have been analysed to determine the effect of the solar cycle the monthly median signal intensity for the noon and afternoon period is found to follow the same trend as the sunspot number and the magnetic disturbance index 1692 ionospheric observations made at freiburg during the solar eclipse of june 1693 lunar tides in at brisbane 1694 the magnetic field in the layer at dakar the gyrofrequency is calculated from observed values of and its variations as a function of reflection height and time are analysed 1695 anomalous changes in the ionosphere related to a severe magnetic storm oct examination of world wide geomagnetic and ionospheric data shows the existence of a short lived electrojet stream with associated anomalous changes in layer electron density two possible mechanisms are suggested the formation of a new layer due to corpuscular streams and the vertical drift of electrons resulting from interaction of the geomagnetic field with currents in the layer returning from the main electrojet in the e region see also of 1696 layer deduced from the frequency spectrum of radio propagation figures at long distance routes the hourly radio propagation quality figures for wwv received at many stations in canada were used as basic data assuming a suitable height for the layer its critical frequency at the reflection point of a transmission path could be obtained the values calculated compared fairly well with those obtained from vertical incidence soundings provided the correct mode of propagation had been used for the transmission path this analysis was also carried out during magnetic storms where no vertical incidence observations were obtainable 1697 thermal structures in the lowest layers of the atmosphere temperature variations recorded simultaneously at heights of and were examined statistically correlation between a pair of such records was greatest at a time displacement depending on wind speed difference between the two heights the evidence suggests organized thermal structures of great vertical extent 1698 the geometry of auroral ionization new evidence is presented which shows that vhf radio echoes from auroral ionization are reflections from aspect sensitive columns aligned with the earths magnetic field 1699 displacements of the radiant point during the auroral disturbance of september photographs of auroral corona enabled the position of the radiant point and its motion to be determined accurately the motion was unrelated to the displacement of the magnetic zenith as determined from measurements on the ground 1700 auroral radiation at observations of rf noise emissions from aurorae were made udring a type a red auroral display on october this unusual display was linked to a large flare on the sun some earlier theoretical considerations indicate that a large particle flux would produce such auroral radio emission 1701 a comparison of radio echoes from the aurora australis and aurora borealis observations of echoes on made at halley bay antarctica for the period may october are compared with contemporary observations made at jodrell bank the great aurorae of the northern hemisphere are probably accompanied by greatly enhanced simultaneous activity of aurora australis 1702 vhf observations on the aurora australis an investigation of radar echoes at is reported the range exponent in the radar equation is calculated as and a maximum value of reflection coefficient was mechanisms of reflection are discussed and only those involving column models are substantiated see also of 1703 some properties of lightning impulses which produce whistlers results obtained at stanford california and boulder colorado show that a characteristic waveform having an intense energy peak near is frequently associated with the impulse which produces a whistler whistler producing discharges appear to be more frequent over sea than over land identification of the causative impulse should be based on waveform analysis as well as the time of occurrence 1704 polarization of atmospheric pulses due to successive reflections from the ionosphere explanations are offered of the more complex patterns observed on a crossed loop cr tube direction finder for atmospherics in addition to the normal straight line display of an atmospheric pulse elliptic traces or groups of straight lines within a small angle are produced elliptic traces are explained by polarization at ionospheric reflection and groups by radiation from branch points in a nearly horizontal cloud to cloud lightning flash see also of and of 1705 solar activity and whistler dispersion the time delay between the occurrence of a local lightning flash and the beginning of the associated whistler is correlated with the monthly mean sunspot number the correlation coefficient is greatest when the sunspot number is related to whistler measurements made months later 1706 designing transistor dc to ac converters nomograms are presented for the design of the basic two transistor saturable core symmetrical circuit 1707 silicon power rectifiers a technique is described for the construction of alloy junction rectifiers 1708 germanium and silicon industrial rectifiers a review of methods of construction and applications 1709 the theory of ballast tubes or barretters results are given which explain the observed behaviour of various low voltage barretters a better combination than iron wire in hydrogen is unlikely to be found 1710 stabilization by zener diodes elementary design principles are discussed 1711 computation in the presence of noise an analysis of the problem of performing reliable computation with elements which are themselves unreliable the effects of the coding procedures on the reliability are discussed 1712 control apparatus for a serial drum memory a detailed circuit description of equipment used for obtaining design data for fast track switching on a serial drum magnetic storage device 1713 matrix programming of electronic analogue computers the technique is based on establishing a correspondence between the matrically formed differential equations and the computer networks this simplifies the setting up of the computer and reduces the possibility of errors examples are given of the use of the method 1714 a magnetic drum store for analogue computing large storage capacity combined with relatively short access time is obtained the drum can be used for generating nonlinear functions and as a delay network 1715 an electrical multiplier utilizing the hall effect in indium arsenide details are given of the construction and performance of a multiplier for computer applications in which an inas hall plate is mounted in the gap in a ferrite core 1716 multiplication by semiconductors the modes of operation of analogue computer multipliers using the hall effect in semiconductors are discussed some experimental multipliers and the results obtained with them are described the application of the magnetoresistive effect is outlined 1717 the design of logical circuits using transistors and square loop ferrite cores some basic circuits are reviewed and a range of practical designs and design procedures is given 1718 some aspects of the network analysis of sequence transducers an algebraic formulation is presented for use in the analysis of networks of the synchronous type of sequence transducer see also of 1719 design and performance of air cooled chassis for electronic equipment future electronic components to obtain substantial reduction in size components will probably consist of thin films of resistive dielectric magnetic and conductive materials and film type or flat plate semiconductor devices will be used 1720 foil clad laminates in printed circuitry 1721 simplified mains transformer design the power handling capabilities of various laminations are tabulated and the design procedure is illustrated by an example 1722 measurement of parameters controlling pulse front response of transformers 1723 a study of the neon bulb as a nonlinear circuit element 1724 a method of electrolytic etching of tantalum for capacitor use etching of foil in a bath of trichloroacetic acid sodium trichloroacetate and methanol produced an increase of in capacitance relative to a capacitor formed of unetched foil the lagrange equations in electrical networks 1725 ultrasonic mercury delay lines the construction and characteristics of lines and transducers are discussed 1726 analysis of millimicrosecond rf pulse transmission the analysis assumes a quadratic approximation for the complex propagation constant and a transmitted pulse with gaussian envelope the theory is applicable to uniform microwave transmission systems and relates pulse shapes with the cw properties of the system 1727 fabrication techniques for ceramic x band cavity resonators techniques are described for constructing cavity resonators for the x band from low thermal expansion ceramics a variety of mechanical arrangements is discussed q values as high as and frequency temperature coefficients as low as part in per have been obtained using simple processes 1728 a correlation between stagger tuned and synchronously tuned coupled circuits application of a network theorem enunciated by green 1729 time symmetric filters methods are described for simulating filters that have impulse responses symmetrical in time and their application to the analysis of gliding tones is discussed the response of a narrow band time symmetric filter to a gliding tone is evaluated and shown to consist of an oscillation bounded by a slowly varying envelope the shape is governed by a parameter involving the bandwidth of the filter and the rate of variation of the instantaneous frequency of the tone 1730 design curves for simple filters charts are given for the design of simple lc ladder filters with either butterworth or tchebycheff type of response 1731 nomographs for designing elliptic function filters 1732 simplified design of resonant notch filters for servo applications data are given in graphical form for the design of stagger tuned constant band stop filters applications to error rate damping in servo systems are discussed 1733 the reduction of low frequency noise in feedback integrators a considerable improvement in signal noise ratio compared with that of a conventional direct coupled integrator is obtained either by using an error amplifier containing a single cr coupling or by applying phase correction to the output from a low accuracy direct coupled integrator 1734 thermally compensated crystal oscillators frequency stability is achieved by using thermistors in a temperature sensitive phase shifting network incorporated in the oscillator circuit a stability of about in is obtained over a wide frequency range without thermostats or ovens it is suggested that even better compensation would be achieved by attaching the thermistor bead to the crystal 1735 a quartz servo oscillator a description of a quartz oscillator stable to parts in with dual stabilization by resonant loop balance and bridge operated servo control 1736 checking crystal oscillators simple measurements are suggested to ensure that a crystal will oscillate in a specified circuit without damage and at the required frequency 1737 a constant amplitude random function generator a generator is described for producing a wave shape with constant peak to peak amplitude but whose path between peaks is random circuits for random sawtooth triangular cosine and square waves operating in the af range are described 1738 some novel circuits employing cold cathode tubes the circuits described are based on cold cathode diodes and triodes the diode being used to stabilize the anode breakdown voltage of the triodes details are given of a stable relaxation oscillator a voltage discriminator trigger circuits a staircase waveform generator and decade counters 1739 pulse forming networks 1740 the excitation of ionic spectra by high frequency pulses equipment previously described has been developed and provided with a power amplifier containing a water cooled triode pulse powers up to approximately are applied to a discharge tube with pulse duration and repetition frequency sec 1741 a distributed circuit pulse height analyser a multichannel analyser using distributed circuits and having a resolving time of is briefly described 1742 frequency dividers using transistors regenerative frequency dividers using junction and point contact transistors are described and results are given of an experimental investigation 1743 video amplifier design using the pcl optimum gain is achieved by the use of anode compensation bias methods for this condition are discussed 1744 ultra high frequency power amplifiers a general review of the design and construction of power amplifiers operating in the range travelling wave valves designed for a bandwidth of one octave are limited in their mean power output by overheating of the helix backward wave amplifiers based on crossed field interaction require a variable beam voltage for wide band operation but have a high efficiency and low operating voltage 1745 a note on the design of transductors for maximum power transfer magnetic amplifiers giving maximum power output for a given size of core are designed by known graphical and numerical methods theoretical and experimental results are compared 1746 ac controlled magnetic amplifiers a method is described for controlling full wave amplifiers with ac signals the response characteristic is similar to that of dc controlled amplifiers and high gain is achieved with no current limiting resistors or demodulator the method is based on cancelling the induced emf in the control circuit 1747 proposed standard terms and definitions for magnetic amplifiers an aiee committee report on the terminology used terms are defined 1748 a sliding bias amplifier using an the two stage circuit described and analysed in detail gives nearly twice the output power obtainable in conventional class a operation using a heat sink of the same size 1749 videa amplifiers using alloy junction transistors grounded emitter video amplifier stages are analysed theoretically using compensated and uncompensated circuits abacs and charts are given to facilitate design procedure for multistage amplifiers together with the practical design of an amplifier with gain and bandwidth 1750 pulse amplifier with nonlinear feedback the transistor amplifier described provides constant output over a range of input signals 1751 transistor tape preamplifier the play back head is used as the inductance in a feedback inductance resistance integrating circuit a signal noise ratio is obtained and the frequency response is flat within from to 1752 proposal for a maser amplifier system without nonreciprocal elements a system noise temperature of or less should be obtainable by using two matched masers and a lossless power dividing network such as a hybrid t 1753 characteristics of the beam type maser part an experimental investigation of the characteristics of an ammonia maser for use as a frequency standard measurements of the effect of focusing voltage and cavity tuning on frequency are compared with theory and the effect of the velocity spread of the molecules is estimated part of 1754 parametric amplifier ups scatter range a sidiode parametric amplifier see of january is used and extends the range of a link from to miles receiver noise factor is reduced from to 1755 the wider scope of optics the development and applications of new optical and optical electronic devices are considered references 1756 the application of onsagers theory to dielectric dispersion a new equation for the complex dielectric constant which includes the proper effect of the reaction field is developed for the case of an alternating applied field it is shown to yield results very close to those obtained with the simple debye equation for the complex dielectric constant 1757 experimental evidence for an energy gap in superconductors 1758 wire cylinder electric discharges in air in relation to the space charge field emission hypothesis study of experimental data on wire cylinder discharges in relation to the field emission hypothesis yields graphical and arithmetic methods of finding the effective field at the time of flash initiation and the space charge field at the wire the effective field is of the order of and is interpreted as a measure of the emission field of the cathode metal or of the ionized air see also of 1759 ultra high frequency gas breakdown between ragowski electrodes breakdown voltage electrode spacing electrode size and gas pressures are observed for air and at 1760 the relativistic flow of electrons in parallel and radial straight lines with no externally imposed magnetic field analysis is given of the possibility of producing relativistic electron flows it is shown that they could not start from a cathode surface where the electrons have zero speed the analysis also applies to flows normally considered nonrelativistic in diodes where the linear dimensions of the electrode surfaces are large compared with the electrode spacing of 1761 electron cooling by heat exchange a new method for obtaining homogeneous electron streams is described by making the electron stream part of a plasma beams with densities of up to and currents exceeding have been achieved 1762 coherence requirements for interferometry an analysis of the theory of double beam interferometry based on that of d gabor gabors restrictive assumptions are clarified and generalized 1763 energy spectrum of a electron beam reflected by a metallic object the energy spectra of electrons reflected from different metallic targets are investigated by means of a magnetic spectrograph 1764 transport phenomena in a completely ionized two temperature plasma a theoretical investigation of particle motion and heat transfer in a plasma of electrons and positive ions under the influence of both electric and magnetic fields the electron and ion temperatures being considered different 1765 the amplification of a magnetic field by a high current discharge it is shown theoretically that a helical current flow discharge is set up by a longitudinal magnetic field in which the plasma pressure is balanced by electrodynamic forces the direction of the helix is such that the initial longitudinal field is amplified some experimental evidence supports this theory 1766 transport phenomena in completely ionized gas considering electron electron scattering hall mobility and other transport properties of electrons in a completely ionized gas have been investigated when a magnetic field is applied taking into account electron electron scattering results have been presented for different mean ionic charges 1767 the magnetic fields of a ferrite ellipsoid approximate expressions are found for the internal and the adjacent external magnetic fields of a small ferrite ellipsoid under plane wave excitation consideration is given to the variation of apparent susceptibility with the size of the ferrite 1768 classical electrodynamics as a distribution theory part 1769 application of distributions to the equations of maxwell and helmholtz distribution theory is applied to give a new concept of an element of current 1770 singular electromagnetic induction extension of the concepts discussed in of 1771 algebraic study of the electromagnetic tensor in the presence of induction see above 1772 electromagnetic radiation from electrons rotating in an ionized medium under the action of a uniform magnetic field the radiation is shown to be predominantly in the extraordinary mode at the harmonics of the gyrofrequency of the fast electron the power radiated in the ordinary mode is a small percentage of that in the extraordinary mode but at the fundamental gyrofrequency it is lower by a factor where is the velocity of the fast electron and is the velocity of light the gyro theory of the suns nonthermal radiation is discussed this mechanism cannot explain the phenomena associated with noise bursts of type and although it is conceivable that type bursts may be of gyro origin 1773 theory of electromagnetic waves in a crystal with excitons 1774 the characteristics of an electromagnetic wave reflected from a moving object 1775 diffraction by a wide slit and complementary strip the diffraction of e and h polarized waves by an infinite slit is considered induced current densities aperture and far fields and the transmission coefficient are calculated in the form of infinite series in inverse powers of the slit width wavelength ratio the solution for diffraction by a strip is also obtained a comparison is made with previous results this method appears to provide accurate information when the slit width is greater than a wavelength 1776 variational principles in high frequency scattering two variational principles are formulated for two dimensional scattering by obstacles the more successful of these treats the obstacle like an aperture coupling two half spaces the zero order calculation for the cross section of a circle is found to have the correct frequency dependence 1777 scattering from a small anisotropic ellipsoid scattering of an electromagnetic wave by a small ellipsoid having tensor permeability and dielectric properties is dealt with by expanding the fields as power series in consideration has been given to the first three terms of the expansion 1778 contribution to the theory of electromagnetic wave propagation in media with random heterogeneities of the refractive index a correlation function is derived which can be used in connection with em wave diffraction problems 1779 scattering of plane waves by locally homogeneous dielectric noise when plane waves are scattered by locally homogeneous dielectric noise random refractive index fluctuations and observed in the fraunhofer region it is found that the local structure of the noise determines the average scattered power received at a fixed point whereas its overall structure determines the space correlations of the radiation received at two different points 1780 criteria determing the design and performance of a source modulated microwave cavity spectrometer an analysis is given of the radio and audio frequency modulation method employed in microwave spectroscopy the results of the theory are compared with measurements taken on a microwave spectrometer and are found to be in close agreement the calculations are extended to include the case where an absorbing gas is enclosed in a resonant cavity 1781 direct measurement of electron spin lattice relaxation times a discussion of the experimental problems encountered in making spin lattice relaxation measurements in electron paramagnetic systems at low temperatures gadolinium and chrome ion spin lattice relaxation times are given the relation of these spin lattice relaxation times to relaxation times measured in the frequency domain by observing a saturation parameter is discussed 1782 the electron structure of transition metals and alloys and heavy metals 1783 energy spectrum of particles bombarding the earth the estimated fluxes of interstellar and auroral particles appear to fit the straight line portion of the cosmic ray integral energy spectrum extrapolated to lower energies 1784 osnic radio astronomy a brief description of the fields of exploration opened by developments in radio astronomy 1785 on the radio emission of hydrogen nebulae random variations in electron density and electron temperature through the nebulae are shown to alter the optical depth radio emission of stromgren spheres is also discussed and an empirical method for determining stromgrens constant is described 1786 an investigation of the strong radio sources in centaurus fornax and puppis 1787 a catalogue of radio sources between declinations and 1788 investigations of persistent solar sources at centimetre wavelengths measurements of the brightness distribution and apparent size of solar rf sources made at cm with an interferometer alon et al show that small apparent diameters are associated with periods of eruptive solar activity 1789 the dimensions of sources of bursts of solar radiation at centimetre wavelengths sources are classified the growth and decay in their apparent size are observed and their equivalent temperature estimated on the basis of interferometer measurements at cm 1790 outer corona of the sun radio emissions from the crab nebula passing through the corona are observed by an interferometric method the results indicate that the outer corona extends to a distance of sun radii 1791 amplitude scintillation of extraterrestrial radio waves at ultra high frequency measurements are described which show that at latitude ionospheric scintillation effects are still significant at when the radio star is near the northern horizon 1792 electromagnetic radiation from electrons rotating in an ionized medium under the action of a uniform magnetic field see 1793 ionizing radiation associated with solar radio noise storm comparison of records obtained during a storm on august from three balloon borne detectors a single counter counter telescope and ion chamber indicates the appearance of protons with kinetic energy of mev 1794 solar brightness distribution at a wavelength of centimetres part localized radio bright regions observations were taken with a element interferometer with a beam width of min of arc from july to march sources of radio brightness were found to be closely correlated with sunspot areas their estimated size lay between and min of arc sometimes their slowly varying component showed marked changes in intensity over periods of half an hour the largest radio brightness temperatures measured were about part of 1795 flare puffs as a cause of type radio bursts type bursts occur within min of two thirds of the flare puffs most puffs are followed by surges and this suggests two ejections of differing velocities one at about the velocity of light causing the burst and the other at km sec causing the surge see also of loughhead et al 1796 optical observations of the solar disturbances causing type radio bursts type radio bursts have been identified with ejections having velocities exceeding that of sound in the corona for events near the limb and with very bright flares with dark filament activity when the event is on the disk 1797 on the great solar flare which started at february as the likely source of geomagnetic storm february it is shown that there is a high probability that the flare caused the magnetic storm experimental evidence is given supporting a connection between the early part of a solar noise burst and a short wave fade out and between the late part and magnetic storm occurrence 1798 radio wave propagation and soil conductivity description of a scheme for mapping the soil conductivity throughout the soviet union by radio techniques 1799 the external magnetic field of the earth the discrepancy between the equivalent geomagnetic dipole based on cosmic ray observations and that derived from surface observations is investigated see also of 1800 reversals of the earths magnetic field calculations made by rikitake have been extended by the use of a digital computer 1801 balloon gear monitors cosmic radiation the balloon with a lb load can be flown at altitude for hours equipment carried includes an omnidirectional geiger counter a spherical integrating ionization chamber and telemetry equipment 1802 electron density profiles in the ionosphere during the igy note on a program organized by the radio research station slough england of using electronic computers in the preparation of profiles from ionograms obtained at four observatories 1803 investigation of upper layers of the atmosphere by means of rockets and artificial earth satellites description of possible methods of investigation and the nature of the instrumentation required 1804 scientific investigations by means of artificial earth satellites a description of sputnik and the scientific equipment carried by it 1805 the determination of the trajectory of artificial satellites methods and the arrangement of ground equipment are described 1806 exact determination of the velocity of an artificial satellite doppler measurements enable the velocity of the satellite to be measured to an accuracy within part in 1807 doppler measurements on soviet satellites the first two soviet satellites were successfully tracked by means of doppler measurements alone the apparatus and the method of analysis used are described 1808 observations of radio signals from the first man made earth satellite 1809 radio observations on the first russian artificial earth satellite doppler measurements made at johannesburg at are reported orbit calculations are made neglecting ionospheric effects see also of 1810 radio observation of the earth satellite describes observations of field strength bearing and doppler shift of the signal it is considered that to explain anomalous field strengths and doppler shifts propagation involving ground scattering followed by ionospheric reflection must be considered anomalous doppler effects include rapidly varying shift and apparent recession when the satellite is approaching the receiver 1811 last minutes of satellite 1812 cosmic rays observed by satellite an analysis of the telemetered cosmic ray information received in japan except during magnetic storm conditions the number of cosmic rays decreases exponentially with height diurnal and storm variations are discussed 1813 effect of solar flares on earth satellite fluctuations in the rate of decrease of the period of the satellite are apparently connected with variations in the total intensity of solar flares 1814 faraday fading of earth satellite signals a corrections to the existing method of estimation of the integrated electron content of the ionosphere from earth satellite signals is given 1815 incoherent scattering of radio waves by free electrons with applications to space exploration by radar a powerful radar can detect the incoherent back scatter from free electrons in and above the earths atmosphere and the received signal is spread in frequency by the doppler shifts associated with the thermal motion of the electrons many practical applications are discussed including measurements of electron density electron temperature auroral ionization and radar echoes from the sun venus and mars 1816 main results of meteorological research done in hungary during the years work on the ionosphere carried out by the central meteorological institute is noted 1817 prevailing wind in the ionosphere and geomagnetic variations it is shown theoretically that the prevailing ionospheric wind makes no contribution to the geomagnetic current system despite the diurnal variation of ionospheric conductivity see also of 1818 a study of spread f ionospheric echoes at night at brisbane part range spreading from an examination of the variation of the amount of range spreading produced by sweeping the gain of a fixed frequency ionospheric recorder it is possible to gauge the degree of roughness of ionospheric layers the effective roughness is a function of the separation of transmitter and receiver being less the greater the distance between them the intensity of z ray echoes recorded in brisbane is consistent with elliss theory part of 1819 on the short wave transmission disturbance of 1820 measurement of the size and electrification of droplets in cumuliform clouds charge distributions in clouds with fair weather electric fields at a mountain site in the united states were gaussian with symmetry about zero charge thundercloud droplets were highly electrified and in a given volume could be all negatively or all positively charged or a mixture of the two 1821 auroral echoes in the ionograms obtained in the minauroral region the observation of auroral echoes on a frequency sweep ionosonde at kokabunji in japan is reported echoes were seen on three magnetically disturbed days on one of which visual aurora was observed in japan the echo range corresponds to normal incidence reflection from scattering centres at f layer heights 1822 correlation of whistlers and lightning flashes by direct and visual observation lightning was observed simultaneously with whistlers at hanover nh on may but it is concluded that most lightning flashes do not generate whistlers 1823 waveforms of atmospherics a classification and interpretation of observed waveforms is given see also of tantry et al and for a description of the equipment of tantry 1824 transistor stabilized power supply for circuit details of a unit with output resistance and output voltage variation or less for change in input voltage 1825 a transistor regulated power supply for video circuits 1826 solar battery the battery consists of silicon plates about mm thick covered by thin boron films forming junction photo elements the efficiency of the battery is approximately and a possible improvement up to is indicated 1827 some basic physical properties of silicon and how they relate to rectifier design and application 1828 a constant voltage constant current stabilizer 1829 current balancing reactors for semiconductor rectifiers in both semiconductor and mercury arc rectifiers of high current capacity where many diodes are connected in parallel the currents in the separate units must be balanced balancing arrangements for semiconductor rectifiers are described including the use of punched laminations as strip type reactors 1830 the analysis and design of constant voltage regulators 1831 rapid testing of electronic direct voltage stabilizers routine tests of voltage stabilizers at an electron optics laboratory in toulouse are described 1832 semiconductor thermostat for self oscillators the thermostat provides control for an ambient temperature range of to 1833 how to improve relay reliability practical advice is given on the choice and use of electromechanical relays 1834 electronic computer exhibition short notes on special features of computers shown in london from november to december 1835 learning machines a conditional probability computer and character recognition machines exhibited at the symposium on the mechanization of thought processes held at the national physical laboratory from to november are discussed 1836 ferroelectric storage devices the switching characteristics of ferroelectric materials as required for use in digital storage systems are examined the properties of single crystal capacitors are investigated experimentally 1837 a track switching system for a magnetic drum memory 1838 phase selective gate rejects quadrature a phase reference voltage controls two unmatched diodes which conduct only when the in phase component is at maximum and the quadrature component at minimum a circuit designed for a servo amplifier is described 1839 transformer design for zero phase shift 1840 bounds for thermistor compensation of resistance and conductance 1841 an introduction to the use of transistors in inductive circuits the mechanism of a delayed switch off effect which is due to avalanche multiplication is described and a method of avoiding it in relay switching circuits is given 1842 transistor switch design switching parameters are tabulated for eight types of transistor 1843 an experimental gas diode switch the ac impedance is a stable negative resistance of about for frequencies up to 1844 dielectric films in aluminium and tantalum electrolytic and solid tantalum capacitors 1845 ferrite cored capacitors details are given of british capacitors with ferrite loading for improving their attenuation characteristics 1846 ire standards on audio techniques definitions of terms 1847 a review on the analysis of transients in electrical circuits using the laplacian transformation 1848 general power relationships for positive and negative nonlinear resistive elements the method developed by manley and rowe for the treatment of reactive elements is extended to resistors relations are derived which yield modulation efficiency efficiency of harmonic generation and stability criteria 1849 how quickly does a twin t respond the response to three different input waveforms is examined using the laplace transformation in all cases the output transient is negligible after cycles of the resonance frequency of the network 1850 filter attenuation characteristics the use of hyperbolic functions is avoided aad formulae are derived which permit slide rule computation 1851 the magnitude of the permissible circuit impedances of the filters in if amplifiers for fm systems application of results obtained in of 1852 a three band aerial combining network three prototype filter sections of low pass band pass and high pass characteristics respectively for bands and are combined in a masthead unit to provide a common output for the three aerial inputs 1853 normalized input admittance curves of two stage band filters and the smallest mismatch circles for a given frequency range 1854 band filters with electronic bandwidth control the design of a two stage filter with amplification in the feedback line is considered 1855 null point band filters and their theoretical treatment 1856 the frequency and time characteristics of all pass filters for delay equalization in television transmission the basic circuits given by bunemann are considered 1857 some properties of a frequency stabilizing circuit 1858 the wave mechanical damped harmonic oscillator a wave mechanics treatment is given of damped harmonic motion for the charge in a tuned circuit and the em field in a resonant cavity the classical frequency appears in the time dependence of the eigenfunctions and the classical damping as a decay in the eigenvalues 1859 high q echo boxes an investigation of the occurrence of unwanted modes in a tunable h cylindrical cavity suggestions for the suppression of these modes are given 1860 generations of oscillations with equally spaced frequencies in a given band 1861 the application of pulse forming networks 1862 miller sweep circuit circuits are described in which both miller integrator and puckle flyback circuits are combined to produce a very linear time base 1863 bistable circuits using unijunction transistors the design and operation of various circuits are explained use of the negative resistance region as one stable state decreases power requirements and increases switching speed the application to ring counter circuits is shown 1864 transistor oscillator with output a design procedure is described for transistor oscillators employing external feedback and an lc resonator an example is given which delivers an output of at and which operates from a battery it is suitable for use as a bias oscillator for dictation machines 1865 graphical designing of transistor oscillators a method is described which is simple but yields results accurate enough for most engineering design calculations a design example is given for a crystal controlled oscillator to operate at 1866 summary of the theory of wide band distributed amplifiers suitable for the amplification of very short pulses 1867 dc amplifiers for control systems 1868 an electronic multicoupler and antenna amplifier for the vhf range 1869 a triode connected pentode with stabilized anode current drift in dc coupled circuits caused by heater supply voltage variation is minimized by the use of a triode connected pentode stabilized by variation of grid current with emission 1870 the influence of the output time constant of a cathode follower a nomogram is derived for determining the maximum pulse amplitude as a function of rise time and output time constant that may be applied without causing positive grid current 1871 a low capacitance input circuit methods of reducing the effect of coaxial cable capacitance are discussed a probe containing only passive elements is used with a single triode pentode valve feedback amplifier to give an input capacitance of and a gain of unity over a bandwidth of 1872 properties of hook transistors in switching and amplifying circuits an analysis is given of the most significant properties of hook and pnpn transistors in common base common emitter and commmon collector configurations stagger tuned transistor video amplifiers 1873 transistor circuits based on the half supply voltage principle analysis shows that temperature stabilization of a transistor can be effected by a preceding dc coupled amplifying stage stabilized on the half supply voltage principle practical circuits are described for af amplifiers and stabilized supply units see also of january dammers et al 1874 analysis of the emissive phase of a pulsed maser a discussion of the emission from a matched cavity at paramagnetic resonance results are given for transverse moment output field output power and power gain as a function of time 1875 transistor circuit engineering 1876 report of the meeting of the swiss physical society the text is given of papers read at a meeting held at neuchatel september including the following electrical properties of silver selenide oscillatory magnetic resistance variation of n type insb at low temperatures and high field strengths the field parameters of galvano and thermo magnetic effects in ferromagnets hall and righi leduc effects in ferromagnetics effect of a cubic electric field on the fundamental level of the gd ion hyperfine splitting in the paramagnetic resonance of pr in ceramic in german improvements in an nh maser 1877 magnetic susceptibility of an electron gas at high density 1878 the electrostatic interaction of two arbitrary charge distributions 1879 molecular theory of the dielectric constant a theory of the static dielectric constant is developed on a quantum mechanical basis by introducing the concept of local field a molecular version of the general theory is obtained it is shown that such a molecular theory is fundamentally ineffective in accounting for the observed results within the experimental accuracy 1880 quantum theory of the high frequency conductivity of metals development of the theory of conductivity of a metal in a high frequency em field and a constant magnetic field the amplitude of the quantum oscillations in the high frequency case is usually larger than in the static case 1881 quantum oscillations of the high frequency surface impedance a quantum mechanical formula is derived and cases involving constant magnetic fields both parallel and inclined to the surface are considered from an experimental study of surface impedance in a strong magnetic field the shape of the fermi surface and the velocity of the electrons in it can be determined 1882 solution to the equations of space charge flow by the method of the separation of variables the steady state behaviour of electron beams with high space charge densities is analysed the equations for irrotational electrostatic laminar space charge flow are set up in terms of the action function these equations are reduced by separation of variables in cylindrical polar coordinates the method may be extended to include the effect of magnetic fields 1883 energy spectrum of plasma electrons brief report on results obtained by the graphical method described earlier of 1884 thermal conductivity of an electron gas in a gaseous plasma experimental techniques used with ne and he plasmas are described conductivity values obtained by two separate methods are in agreement and consistent with theory 1885 kinetic theory of magnetohydrodynamic waves analysis of the propagation of magnetohydrodynamic waves in an ionized gas when the wave frequency is much greater than the frequency of short range collisions see also of 1886 microwave method for measuring the probability of elastic collision of electrons in a gas a plasma in a dc magnetic field has a transverse condductivity component whose reactive part depends on the magnetic field by measuring the magnetic field necessary to make the reactive part zero the probability of the elastic collision of electrons in he is obtained 1887 scattering of microwave radiation by a plasma column experiments conducted by to determine the angular distribution of the em radiation scattered by the positive column of a mercury discharge under resonant conditions are described results support the theory of mackinson and slade 1888 microwave faraday rotation design and analysis of a bimodal cavity an equivalent circuit is developed for the cavity and the coupling between degenerate modes is expressed in terms of the susceptibility tensor of the material producing the rotation the results are compared with experimental data 1889 propagation of plane electromagnetic waves in inhomogeneous media the laws of propagation along the direction are derived for infinite inhomogeneous media in which dielectric constant and electrical conductivity are functions of and the magnetic permeability is constant homogeneous media are treated as special cases 1890 electromagnetic scattering by thin conducting plates at glancing incidence a large signal is scattered back from a thin plate illuminated edge on by a field whose magnetic vector is normal to the plate experimental measurements show that the currents in the plate are predominant near the edges their relation to theoretical results is discussed 1891 a helical coordinate system and its applications in electromagnetic theory the system described enables problems involving helical symmetry to be solved exactly 1892 the edge condition in diffraction problems the diffraction of an em wave by a perfectly conducting solid is considered 1893 theory of wave scattering on periodically uneven surfaces description of six approximate mathematical methods for calculating the scattering of sound or em waves over the sea or uneven ground references 1894 magnetic double refraction of microwaves in paramagnetics investigation at of the rotation of the plane of polarization of an wave in a circular waveguide containing a paramagnetic salt and its dependence on the intensity of the static magnetic field perpendicular to the direction of wave propagation 1895 spin wave analysis of ferromagnetic resonance in polycrystalline ferrites dipolar interaction is taken into account by means of the spin wave formalism crystalline anisotropy and the polycrystalline nature of the material cause the homogeneous mode of precession to interact with spin waves whose wavelength is of the order of or larger than the average linear grain size the theory predicts a very strong frequency and shape dependence of the line width when the homogeneous mode is approximately degenerate with long wavelength spin waves propagating normal to the dc field 1896 paramagnetic resonance the quantum mechanical theory of the phenomenon is discussed with reference to results of experimental investigations 1897 technical applications of microwave physics particular reference is made to electron resonance techniques 1898 paramagnetic resonance spectrum of gadolinium in hydrated lanthanum trichloride the paramagnetic resonance spectrum of gd in was measured and found to agree quite well with a spin hamiltonian with dominant coefficients at room temperature and at liquid air temperature 1899 theory of plasma resonance in solids the modes of a confined plasma are studied for simple geometries modes are closely spaced in frequency and unresolvable unless the sample size is comparable to the debye length observation in small samples is made difficult by line broadening due to surface scattering but might be possible in a suitably designed experiment 1900 fourier coefficients of crystal potentials a method is developed for the calculation of the fourier coefficients of the electrostatic potential of a given distribution of valence electrons in a solid taking full account of the nonspherical character of the atomic polyhedron 1901 interplanetary magnetic field and its control of cosmic ray variations a model interplanetary magnetic field is described which may explain some features of solar cosmic ray increases and also fluctuations in the primary radiation an attempt is made to show how localized solar fields may create the field which should be largely radial in form 1902 a theorem on force free magnetic fields a variational principle is proved which provides a more direct and satisfactory approach than that given in of chandrasekhar and woltjer 1903 nonuniformity in the brightness of the suns disk at sunspot minimum a comparison is made between the nonuniformity as derived from ionospheric measurements during eclipses observed in and the results suggest that there are significant differences for the two epochs 1904 observation of a solar flare at wavelength scans made across the sun on september with a radio telescope of are compared with corresponding scans for a quiet sun 1905 solar radiation on decimetre waves as an index for ionospheric studies the solar noise radiation flux at is compared with other indices of solar activity it seems to be as good as any other index for ionospheric studies on a monthly time scale and better for shorter time intervals 1906 the trapping of cosmic radio waves beneath the ionosphere when there is a horizontal gradient in the critical frequency of a layer incoming extraterrestrial radiation may be trapped between the layer and the ground and propagated over large distances this would account for the reception of cosmic noise at frequencies lower than the local critical frequency 1907 sudden cosmic noise absorption associated with the solar event of march 1908 the relationships between the secular change and the non dipole fields the drift and decay contributions to the secular variation have been estimated from isomagnetic and isoporic charts for in canada the westward drift in recent years was found to be significantly smaller than the world wide average relations are obtained between the gaussian coefficients in the spherical harmonic analyses of the earths main field and the secular variation it is shown that one half of this variation is produced by westward drift and that the decay terms are unimportant 1909 electron density profiles in the ionosphere during the igy see of february smith rose 1910 use of artificial satellites to explore the earths gravitational field results for sputnik 1911 seasonal illumination of a circumpolar earth satellite at its extreme latitude orbit point 1912 polyhedral satellite for more accurate measurement of orbit data of earth satellites a face polyhedron would reflect to an observer a light pulse of intensity more than times that from a sphere 1913 rotation of artificial earth satellites radio signals received from sputnik were subject to deep regular fading with a semiperiod of about probably due to free motion of the satellite about its centroid these fluctuations were less noticeable in the field strength record of sputnik the advantages of a disk shaped satellite and methods of eliminating rotational effects are discussed 1914 the faraday rotation rate of a satellite radio signal 1915 an irregularity in the atmospheric drag effects on sputniks and satellites 1916 satellite tracking by hf direction finder a twin channel cr df with an adcock aerial was used on the signals from satellites and the results obtained and their accuracy are discussed 1917 comparison of phase difference and doppler shift measurements for studying ionospheric fine structure using earth satellites 1918 on the electron production rate in the f region of the ionosphere the region between bottom and height of maximum density is divided into four equal columns the mean production rate in each being calculated the results show a diurnal variation of the rate with a single peak at about half an hour before noon 1919 drift observations evaluated by the method of similar fades a regular interference model is considered as opposed to the usual purely random model some of the observed features are well explained by a model which lies between these two views provided a finite lifetime is assumed for the irregularities large changes of drift velocity can be explained by assuming small vertical velocities 1920 bifurcations in the f region at baguio a five year statistical survey of bifurcations at baguio phillipines is presented and it is shown that the condition for bifurcation is mainly governed by the parameters and of the f layer depends on latitude whilst depends on solar activity 1921 the diurnal variation of near the auroral zone during magnetic disturbances 1922 horizontal drifts and temperature in the lower part of region e drift velocities deduced from the fading of cw signals at oblique incidence are related to results obtained using other techniques a minimum velocity at km is indicated and a possible connection with a temperature minimum at the same height is discussed 1923 height gradient of electron loss in the f region a theoretical expression is derived for an exponential height gradient of the electron loss coefficient in the f region on the assumption that this gradient completely accounts for bifurcation five models are investigated they are second power linear cosine parabolic and quasi parabolic distributions of electron density with height 1924 the electron distribution in the ionosphere over slough part disturbed days the results are analysed of the distribution with height for three months in a year of low and three months in a year of high sunspot number it is shown that the variation in is not a quantitative guide to the changes in height of the layer during storms the electron distributions for five individual storms are thoroughly investigated some important ionospheric changes have been noticed during a world wide sudden impulse part of 1925 on instrument effect in ionosphere data 1926 abnormal ionospheric behaviour at metres wavelength during observations at hyderabad india of cosmic radio noise total reflection of cosmic noise was observed on three occasions near sunrise the effect is assumed to be caused by a locally high concentration of matter in the upper ionospheric layers 1927 on the approximate daytime constancy of the absorption of radio waves in the lower ionosphere the lower part of the d layer is due to photo detachment of electrons from negative ions the concentration of which is large and nearly constant from day to night the optical depth is small for the photo detachment radiation but large for the radiation which can ionize neutral particles 1928 ionospheric absorption over delhi an analysis of further measurements made at until october 1929 a new antenna to eliminate ground wave interference in ionospheric sounding experiments 1930 radio reflections on low frequencies from height during intense aurora activity 1931 simultaneous recording of atmospherics on four different frequency bands in the low frequency region the number and intensity of atmospherics are recorded simultaneously on four narrow bands at and results show atmospherics with large field strengths to be less frequent than those with small field strengths on all bands and the field strength of atmospherics to be a maximum in the band 1932 the relationship between atmospheric radio noise and lightning in europe atmospherics in a bandwidth of at have median amplitude amplitude range and frequency occurrence in accordance with that expected from lightning discharges to the ground in australia atmospherics from tropical storms were found to consist of numerous pulses the largest of which probably originated in ground strokes the origin of the smaller pulses is not clear some observations on atmospherics in the hf band are also described 1933 waveforms of atmospherics with superimposed pulses recorded with an automatic atmospherics recorder the recorder design is briefly outlined and observations are discussed in which stepped pulses from one lightning discharge are superimposed on the waveform from a second discharge see also of tantry 1934 boosting power transistor efficiency high efficiency is obtained by carefully controlling the instantaneous voltage and current through the transistor 1935 precision current regulator using transistors a regulator for electromagnets of field strength between and is described which is accurate to within two parts in 1936 transistor voltage regulators design considerations are discussed for series type regulators and the magnetic amplifier type designed for the tridac computer is described 1937 an electronic ratio calculator use is made of the principle that the amplitude ratio of two signals is approximately linearly related to the phase angle of the sum 1938 digital analogue conversion with cryotrons 1939 a high speed logic system using magnetic elements and connecting wire only square loop magnetic elements having multi aperture or multipath variations of the toroid shape are used to provide unilateral information flow properties information bit rates above have been obtained with commercial ferrite material advantages include simplicity of wiring and the inherent nondestructive read out properties of the system 1940 automatic data reduction of spot diagram information the redistribution of energy falling on a photo cathode during scanning by a mechanical image dissector is evaluated 1941 measurements of nonlinearity in cracked carbon resistors frequencies used were and mcs resistors measured ranged from w the degree of nonlinearity would be negligible for most purposes 1942 millimicrosecond microwave ferrite modulator description of a switching device similar to the resonance type isolator described by enander of but with ferrite rings placed inside the helix and with a single straight wire along the axis carrying the modulating current 1943 photoelectronic circuit applications the characteristics of switching circuits using combinations of electroluminescent cells and photoconductors are discussed applications are described in computer operations where the highest speed is not essential 1944 a temperature stabilized photo transistor relay circuit a photo transistor and an ordinary junction transistor are used in a long tailed pair arrangement to reduce the variation in dark current 1945 a reversible dekatron counter 1946 recent advances in the solid state electrolytic capacitor 1947 design of aperture coupled filters 1948 network synthesis a method is outlined for the synthesis of balanced asymmetrical rc networks which may have a lower pad loss than the corresponding symmetrical types 1949 definition of lossy quadripoles by voltage node displacements in the microwave range equations are derived giving the voltage swr and the position of the voltage node on the input line of a lossy quadripole in terms of the position of the short circuit on its output line 1950 determination of transistor performance characteristics at vhf an immittance chart a development of the smith chart is described and its application in the design of adjustable matching networks for transistor measurements is illustrated 1951 general physical relations in ladder type filters the improvement of filter characteristics by mismatch conditions between the ladder sections is considered and a design method is outlined 1952 minimum insertion loss filters the generalized criterion for butterworth and tchebycheff filters of arbitrary bandwidth is chosen for minimum loss in the centre of the band 1953 the design of two section symmetrical zobel filters for tchebycheff insertion loss 1954 a voltage controlled continuously variable low pass filter the filter has a octave cut off characteristic and the cut off frequency at is continuously variable from to by a control voltage variation of v 1955 the exact design of two types of single crystal wide band crystal filters 1956 the sy metrical transfer characteristics of the narrow bandwidth four crystal lattice filter 1957 the bifilar t circuit the circuit is critically examined using lattice network theory see also of hendry and mcintosh 1958 the calibration of microwave attenuators by an absolute method a bridge method is described and results of measurements at are given 1959 alternatives to the wien bridge oscillator circuits with two gang control having higher output voltages and greater selectivity than the basic wien ridge circuit are described 1960 a wide band voltage controlled swept frequency rc oscillator oscillators based on the principle of parallel network tuning are examined new equipment using this principle is described in detail frequency variations can be restricted to any limits in the range and the maximum duration of the sweep cycle can be varied from to min 1961 incremental frequency control of rc oscillators an auxiliary phase shifting network is introduced to provide a continuously variable incremental frequency control a practical method is described for systematically correcting the error which exists for large increments 1962 construction and properties of high quality oscillator crystals details are given of the shape processing and mounting of crystals for use in quartz clock standards the influence of various design parameters on crystal characteristics and performance is discussed and a method of frequency control is described see also of scheibe et al 1963 a monostable circuit using a transistor a pulse generating circuit is described using a simple pulse transformer and a transistor pulse duration is adjustable over a wide range greatly exceeding that usually associated with the pulse transformer used 1964 crystal controlled transistor oscillators the design of parallel resonant circuits is considered 1965 the use of dekatrons for pulse distribution specific methods are discussed for increasing the number of output lines available from cold cathode selector tubes used for distributing pulses in a fixed time sequence 1966 a transistor decade counter 1967 investigations on harmonic frequency dividers to determine the prerequisite conditions for achieving high division ratios and large locking ranges at high frequencies 1968 a regenerative modulator frequency divider using transistors 1969 magnetostrictive delay line for video signals 1970 pulse amplifier with submillimicrosecond rise time the rise time is about the dc pulses modulate a carrier and the rf pulses are amplified by a travelling wave valve demodulation then gives the amplified dc pulses the maximum power gain is and the maximum output voltage v 1971 a low noise wide band amplifier for the investigation of electron avalances 1972 low level dc amplifier with whole loop feedback a vibrating contact modulator and whole loop negative feedback are used and a stabilized gain of from dc to is obtained the zero drift is less than per hour and less than per day 1973 amplitude and phase response of an amplifier operating on an interrupted cycle analysis of class c amplifier characteristics 1974 transistor amplifiers common base versus common emitter the gain stability and frequency response of the two circuits are compared theoretically and experimentally if a generator with a relatively low impedance is used these characteristics need be no worse for the common emitter than for the common base amplifier 1975 transistor bias design from thermal incremental properties explicit formulae for design of single stage bias networks are given two thermal parameters need to be known one related to and the other to the rate of change of input current applications and experimental verification of the theory are included see also of 1976 an introduction to matrices and their use in transistor circuit analysis brief details are given for analysing both simple and complex circuits using transistors with emphasis on application to practical circuits 1977 low noise transistor amplifier stages with negative feedback theoretical investigation of the grounded emitter connection with feedback resistance in the emitter circuit the relation of source impedance to optimum noise figure is determined 1978 maser action in the region of k a three level solid state maser using a ruby with a cr concentration has given a stable gain of at 1979 a tunable maser amplifier with large bandwidth the bandwidth is at gain with a bath temperature of k the centre frequency is tunable in the range operation depends on a phonon saturation mechanism in a ruby crystal 1980 a chromium corundum paramagnetic amplifier and generator note on the operation of a paramagnetic amplifier and generator using a single crystal of levels characterized by the quantum numbers when the crystalline axis is oriented parallel to the constant external magnetic field are used absorption lines for different power levels of the auxiliary radiation are shown 1981 molecular amplifier and generator for submillimetre waves the rotational transitions of nh molecules lie in the wavelength region below mm an amplifier can be constructed using a device in which radiation from one horn crosses a number of molecular beams and falls on a second horn the maximum power obtainable is about 1982 new method for pumping a fast space charge wave 1983 four terminal parametric amplifier a lumped constant model using ge junction diodes at a signal frequency of has a gain of a bandwidth of and a noise factor of db 1984 microwave parametric amplifier by means of germanium diode construction and performance of an amplifier for using gold and silver bonded ge diodes 1985 the reactatron a low noise semiconductor diode microwave amplifier two nonlinear capacitor microwave junction diodes are used in a balanced hybrid with a pump frequency of about twice the signal frequency of power gains greater than with a noise figure of were obtained for a bandwidth of 1986 amplitude modulation of centimetre waves by means of ferroxcube losses in a ferroxcube rod caused by a modulating magnetic field vary the amplitude of a centimetre wave reflected from it the nature of the losses and the maximum frequency at which they occur are examined theoretically an experimental circuit has been constructed operating at with a modulation frequency of wide bandwidths are not possible 1987 diode phase detectors the general case of unequal voltages applied to simple and balanced push pull phase detectors is studied curves for design and evaluation of accuracy are given the use of a signal greater than the reference voltage appears to be desirable in some applications 1988 the use of beam defocusing to provide a microwave detector 1989 stokes equations and their application to the refractivity of thin films the problem of determining the microwave optical properties of n parallel planes of artificial dielectric from the properties of a single planar array is solved by using an extension of stokes equations 1990 oscillographic study of rf oscillations in silent electrical discharges oscillations produced under conditions of light or darkness in iodine vapour and hydrogen gas in discharge tubes fitted with external sleeve electrodes are described 1991 certain phenomena observed on coupling an oscillator and a tube of ionized gas introduced in the oscillator inductance an experimental study is reported in which an oscillator coil carrying a current surrounds an energized gas discharge tube the effects of the hf current on the discharge are considered in particular the luminous effects and the maintenance of the discharge after the energizing voltage is removed 1992 a new phenomenon of electron emission from thin mercury films report of an experimental investigation of film emission in a specially designed discharge tube indicating that neither extremely high current densities nor cathode evaporation are intrinsic requirements for emission from liquid metal surfaces 1993 spectral distribution of thermal noise in a gas discharge by means of thermodynamic considerations it is shown under which conditions microwave noise power generated by a gas discharge can be considered thermal a critical analysis of mumfords hypothesis is made 1994 the statistics of plasma fundamental dynamic equations are derived comprising a system of partial differential equations 1995 calculation of fields on plasma ions by collective coordinates 1996 the electrical conductivity of a plasma the exact theory of electrical conductivity of a plasma in the presence of a weak electric field is obtained by the integration of boltzmanns equation for ionized gases taking account of electron interaction 1997 the structure of strong collision free hydrodynamic waves a theoretical study has been made of the structure of strong hydromagnetic waves which are propagated across a magnetic field in a low density plasma where collisions can be neglected 1998 oblique shock waves in a plasma with finite conductivity 1999 the fourth reflection condition for electromagnetic waves in a plasma the introduction of a term generally neglected in applying boltzmanns equation modifies the expression for refractive index normally used in magneto ionic theory 2000 coherent spontaneous microwave emission by pulsed resonance excitation this paper describes an investigation of the coherent microwave emission from pulse excited ammonia molecules coherent and periodic pulses of near resonance frequency and duration excited the gas from its initial thermal condition self induced coherent emission molecular ringing continued after the excitation field was removed this radiation was observed during a period of in an actual experiment performed a new doppler bandwidth reduction method was used in the gas cell the observed spectral width of the ammonia line was about the emission was used to stabilize the excitation signal source to a short term frequency stability of 2001 propagation of an electromagnetic field in a medium with spatial dispersion investigation of the propagation of a transverse wave along a magnetic field in a plasma taking account of the thermal motion of electrons strong absorption occurs in the region at which cherenkov radiation is possible 2002 on the diffraction and reflection of waves and pulses by wedges and corners various problems arising in the theory of the excitation of a perfectly reflecting wedge or corner by a plane cylindrical or spherical wave are dealt with the incident wave is represented by a line source acoustic or electromagnetic parallel to the edge the spherical wave is emitted by an acoustic point source or by a hertz dipole with its axis parallel to the edge the case of an incident plane wave field is obtained as the limiting case for large distances of the source from the edge of the cylindrical or spherical wave excitation 2003 the diffraction of an electromagnetic plane wave by a perfectly conducting half plane electromagnetic waves in isotropic and crystalline media characterized by permittivity with spatial dispersion the necessity of taking account of spatial dispersion in non gyrotropic media in relation to the permittivity tensor and also in the analysis of longitudinal plasma waves propagating in an isotropic medium or along the principal dielectric axes in crystals is stressed collrvyive energy losses and the cherenkov effect are also considered 2004 attempt to interpret the shape of paramagnetic resonance signals by the introduction of a high frequency demagnetizing field the theory accounts for the asymmetry of the resonance curve of organic radicals such as diphenyl picryl hydrazyl at 2005 microwave physics discussion of resonance techniques particularly as applied for microwave amplification with reference to three papers read at the british association meeting held in glasgow september 2006 comparison of the sensitivities of paramagnetic electron resonance spectrographs in the band modification of the coupling between a waveguide and a cavity is discussed for the following cases negligible background noise signal intensity of the same order as background noise 2007 the elastic model of lattice defects it is showastic continuum there is a repulsive interaction if the spheres are bonded to the medium the effect of other boundary conditions is discussed and a simplified method is given for calculating the interaction between various types of defect 2008 energy states of a one dimensional crystal with vacant lattice sites 2009 relations between the concentrations of imperfections in solids imperfections haeing opposite effective charges tend to increase each others concentrations foreign atoms are incorporated in a manner dependent both on energy levels caused by them and on the type of imperfection prevailing in the crystal in their absence 2010 on a feature of galactic radio emission observations of the intensity distribution of radio emission have shown a bright belt approximately normal to the galactic plane and passing through the the anti centre an explanation is suggested in terms of the highly anisotropic radiation from relativistic electrons moving in the magnetic field of the local spiral arm this suggestion avoids the supposition that the sun is in a special position in the galaxy 2011 a phase sensitive interferometer technique for the measurement of the fourier transforms of spatial brightness distributions of small angular extent the rf interferometer described consists of three aerial systems tuned to 2012 on the power spectrum of solar radio outburst and its relation to swf dellinger phenomenon and geomagnetic storm solar radio outbursts are classified according to their power spectra those with power spectra increasing towards lower frequencies are associated with magnetic storms but not with sids while those with spectra increasing towards higher frequencies are associated with sids without an accompanying magnetic storm outbursts with flat power spectra appear to combine the attributes of the other two types 2013 the possibility of forecasting solar phenomena and their terrestrial repercussions by the study of the intensity of cosmic radiation an analysis of observations made from april to march shows that a decrease in cosmic ray intensity of occurs before chromospheric eruptions which are followed by intense geomagnetic and ionospheric disturbances this decrease also precedes or coincides with an increase in solar rf noise see also 2014 discrimination between chromospheric eruptions associated with geomagnetic disturbances during the present solar maximum an analysis of observations from april to march shows that some but not all solar flares are accompanied by a marked increase of rf noise at about mcs 2015 a simple method of detecting solar flare effects in the lower ionosphere field strength records of transmitters operating at frequencies over a distance of provide a sensitive means of detecting and identifying solar flare effects 2016 intensities polarization and electron density of the solar corona from photographs taken at the total solar eclipse of february 2017 sudden commencements of magnetic storms at tamanrasset an analysis of observations made at tamanrasset from to inclusive 2018 scale height of the upper atmosphere the effect of air drag on the orbit of an earth satellite is calculated allowing for the ellipticity of the earth 2019 sputnik as a tool for securing geodetic information 2020 a possible cause of air resistance changes in satellite orbits the variation in the extent of the atmosphere in accordance with geomagnetic activity particularly in the auroral zones is suggested as a possible cause of observed changes in satellite orbital period 2021 the rotation of the first russian earth satellite fading records obtained during transits over cambridge at about ut october have been examined the records show a discontinuous change in fading rate at the time of nearest approach this is attributed to changes in polarization in certain aspects of the satellite relative to the observer caused by the generation of a cone by the rotating aerial it is concluded that the satellite rotated at rev min generating a cone of semi angle the direction of the rotating axis being at to the direction of the arbit at perigee 2022 determination of the orbit of an artificial satellite theory of a method depending on doppler measurements at four stations no initial assumptions about the orbit are required 2023 a new method of tracking artificial earth satellites a photoelectric method of optical tracking has been developed which appears to have a precision comparable with astronomical observations a record of observations of the rocket of sputnik on july at tatsfield surrey is shown 2024 tracking orbits of man made moons description of the minitrack interferometer type system designed to measure satellite position to an accuracy within seconds of arc with a time precision of one millisecond 2025 doppler satellite measurements a note on records obtained during successful and unsuccessful launchings 2026 further radio observations on artificial satellites report on data obtained in florence italy from radio observations of satellites and 2027 signal strength recordings of the satellite sputnik at college alaska 2028 world data centre for rockets and satellites slough it was agreed at the recent moscow meeting of the special committee for the igy to accept a british offer of a third centre where data from british investigations would be collected and exchanged with the centres in washington and moscow 2029 radiosonde measurement of vertical electric field and polar conductivity a field mill and a gerdian type conductivity apparatus are described for use with a modified kew mk radiosonde these are used for measuring the electrical properties of the lower atmosphere and clouds 2030 on the semi diurnal lunar variations in the critical frequency semithickness and height of maximum ionization of the f layer in the daytime results obtained for show reasonable agreement with those of other workers but contradict a theory of f layer formation previously postulated of january yonezawa results for other parameters are doubtful owing to statistical errors but appear to be exactly opposite in phase to those of other workers 2031 back scatter ionospheric sounding experiments report on tests at made near rome from august to october large discrepancies are found with results derived from vertical soundings subsequent tests are proceeding at and 2032 ionospheric drift measurements in the long wave range as a contribution to the problem of general circulation of the upper atmosphere spaced receiver measurements at of ionospheric drift at altitude indicate distinct seasonal reversals in the circulation of the upper atmosphere small diurnal variations are superimposed on the normal drifts and an additional ns component is observed during magnetic storms 2033 ionosphere review solar activity f layer ionization and ionospheric and magnetic disturbances were less than those recorded in 2034 the ionosphere a translation of the original ferman book see of 2035 atmospheric electricity enlarged and revised edition of an earlier work see of 2036 electronic magnetic field stabilizer with feedback fluctuations in the magnetizing current of an electromagnet are integrated using a vibrator amplifier in a circuit with a time constant of ms and the derived signal energizes a compensating coil 2037 the effect of radiation on silicon solar energy converters the solar cells are unaffected by irradiation with ultraviolet light and x rays high energy electrons protons and particles produce a time decay in such characteristics as maximum power output open circuit voltage and short circuit current the lifetime of the cells to of the initial power output is estimated to be years when exposed to the radiations assumed to exist at earth satellite orbit heights 2038 forward current surge failure in semiconductor rectifiers a semiconductor current limiter a constant current device is described which uses the field effect at a junction the reverse bias applied controls the conductance of a thin sheet of semiconductor various models and a particular design are discussed and some applications to switching and waveform generation are given 2039 compensation for fluctuations in the anode current of a valve due to heating in the method described an antiphase rectified voltage proportional to heater current variations is applied to the control grid of the valve to stabilize the anode current 2040 digital techniques for small computations a special digital method of computing simple algebraic functions with one to four variables is described and analysed the method is particularly suited to division and root extraction 2041 automatic failure recovery in a digital data processing system a program is described which automatically compensates for computer malfunctions so that recovery from errors may be effected with a negligible loss of operational time 2042 representations grouping and processing of information in automatic data processing 2043 a sensing system for punched cards or continuous punched foil 2044 logic synthesis of some high speed digital comparators logical schemes are derived by boolean algebra methods circuits satisfying the synthesis requirements and giving either exact or approximate proportional comparison are described 2045 function generator for sines or cosines operation of the transistorized unit described is based on the fact that the area under a sine curve varies as a cosine function basic components required are a linear pulse width modulator an ideal switch two pnp transistors connected emitter to emitter an integrator and a sine wave source 2046 an analogue multiplier divider using thyrites a new analytical method is proposed for determining quadratic elements using thyrite resistors a description is given of a new multiplier with thyrite units which requires only two operational amplifiers experimental results are given 2047 logic for a digital servo system a cr tube beam in a photographic storage system is positioned by comparing a binary address with a digital indication of the present position digital servo logic circuitry is described for obtaining the sign and magnitude of the positional error 2048 an electron analyser of contact circuits a description is given of an apparatus for rapid determination of possible combinations in the operation of a circuit comprising six relays one of the possible uses of the apparatus is the simplification of the existing circuits by removing the unnecessary contacts 2049 the multipurpose bias device part the efficiency of logical elements the efficiency of a logical element can be equated with the set of subfunctions it realizes upon biasing or duplication of inputs various classes of elements are considered and optimum or near optimum examples are presented some related areas of study are suggested part of 2050 millimicrosecond magnetic gating and storage element the element consists of a round glass rod which is first chemically plated with a silver conductor and then electroplated with an fe ni film the element has an almost square saturation loop 2051 the laddic a magnetic device for performing logic the laddic is a ladder like structure cut from rectangular hysteresis loop ferrite all magnetic paths are flux limited by controlling the actual switching path any boolean function of n variables can be produced 2052 tape recording system speeds data processing a pwm tape recording system is described with a capacity of digits the tape is in wide and carries channels the transport mechanism is electronically controlled and can start stop and reverse within a few milliseconds 2053 an analogue computer for evaluating radar performance describes briefly the basic design of an analogue computer developed to evaluate the statistical information needed to assess radar tracking performance 2054 application of analogue calculation to flight simulators computer elements for simulating the reactions resulting from the effects of gyration pitch and roll are described 2055 the transformer as a two terminal network the equivalent two terminal networks are derived for various types of transformer 2056 on hybrid transformers design formulae are derived from basic assumptions and the properties and some common uses of these circuit elements are discussed 2057 premagnetization of the core of a pulse transformer by means of ferroxdure premagnetization to improve the loading of the core of a transformer carrying unidirectional pulse currents is examined theoretically a practical transformer is described 2058 high power transistor dc converters circuits are considered for dc dc or dc ac converters using ge and si power transistors which can give power outputs of up to w 2059 saturable transformer switches a switch using cores in a balanced saturable transformer is considered an on off impedance ratio adequate for switching magnetic recording heads for reading and writing operations can be obtained circuits are described for operation of a matrix selection system with a switching time of a few tens of microseconds 2060 ferroelectrics tune electronic circuits circuits are described in which carying bias is used to change the capacitance of ferroelectric capacitors used as tuning elements 2061 direct voltage instantaneous breakdown of oil impregnated paper capacitors as a function of area the experimental results given show that the variation of mean breakdown voltage with increasing area is represented adequately by milnors equation the coefficient of variation appears to be independent of area but decreases with increasing thickness of dielectric 2062 a comparison of wool wax and petroleum jelly as impregnants for paper capacitors results given show that wool wax impregnants give about higher capacitance without any serious loss in performance 2063 the equivalent circuit of oscillating piezoelectric crystal rods formulae are derived for calculating the circuit parameters for longitudinal torsional and flexural oscillations taking account of internal damping and the air gap between electrodes and crystal 2064 voltage and current controlled negative resistance two poles the mechanism of voltage and current control in two pole networks is discussed equations for obtaining the equivalent circuits from direct measurements at the network terminals are given 2065 the geometrically simplest form of representation of the general lossy quadripole the transformation discussed is based on a construction of four planes perpendicular to each other in pairs in a non euclidean system it can be represented in a drawing by stereographic projection 2066 coupling coefficients of ladder networks with maximally flat amplitude response the coefficients are expressed in terms of the dissipations in the input and output branches using a generalized theory of greens method of solution 2067 hf wide band electronic integrator design compensation for distortion of the integrated waveform due to valve output capacitances can be introduced by the addition of a capacitor in parallel with the integrating network resistance an exprression is derived for calculating the capacitance for the basic rc integrator and the miller integrator 2068 impedance converters the quadripole relations and equivalent circuits of negative impedance converters are summarized and applied to practical unbalanced converter circuits with valves and transistors 2069 a laguerre function equalizer a waveform corrector is described in which the input signal is successively differentiated and the differentials added to or subtracted from the input the waveforms being given by laguerre functions results are given for an experimental equalizer which need contain only passive elements 2070 constant frequency oscillators without stabilized voltage supplies four valve oscillators controlled by thermistor bridge circuits are described 2071 the design of crystal controlled three terminal valve oscillators design formulae for the pierce miller and pierce colpitts circuits are derived taking account of the effect of crystal resistance on frequency 2072 stable low cost oscillator description of a crystal controlled transistorized oscillator with frequency stability within part in per day at normal room temperatures total weight of oven and oscillator is 2073 frequency stepper for radio propagation tests full circuit details are given of a stepped frequency exciter unit controlling a pulse transmitter and receiver at widely separated locations the range is covered in steps at sec intervals and crystals are used as reference frequency sources and frequency control is achieved by means of a beam deflection tube transmitter and receiver circuits are briefly described the transmitter radiates pulses with repetition frequency or and output power 2074 a barkhausen kurz oscillator at centimetre wavelengths 2075 dual cavity microwave discriminator intended for stabilizing reference klystron oscillators used in doppler shift radar systems tuning range is thermal drift part in per and discriminator sensitivity per 2076 the generation of extremely steep pulse edges in multistage nonlinear amplifiers the pulse generator described incorporates three transformer coupled amplifier stages for sharpening the multivibrator pulses it can supply pulses with a rise time into a load 2077 transistorized fm oscillator 2078 the amplification of very wide frequency bands various techniques for amplification in bandwidths exceeding are discussed and the suitability of cascade and distributed amplifiers is investigated direct and indirect methods of delay line equalization are outlined and details are given of a seven stage distributed amplifier with gain over a band 2079 wide band amplifier design data design data are tabulated for three basic types of coupling rc shunt peaked and series peaked gain is calculated using a series of approximations taking account of the gain reduction factor for a number of stages 2080 extended range distributed amplifier design a distributed amplifier employing a straight wire transmission line is described the amplifier has a gain of db from to and input and output impedances of detailed electrical and mechanical design considerations are included 2081 an inexpensive ultralinear output stage a circuit is described which uses two cathode followers in place of a tapped output transformer 2082 operational amplifier without a stabilized power supply a new operational amplifier is proposed in which two parallel circuits for low and high frequencies are used with a summing amplifier and two feedback circuits the theory of the amplifier is discussed and some experimental results are given for a mains voltage variation of the output voltage of the amplifier varies by with a drift rate of sec 2083 on the theory of a half wave magnetic amplifier a detailed theoretical analysis is given of an amplifier proposed by ramey see and of experimental results confirm the theoretical conclusions 2084 differential amplifier features dc stability drift in transistorized amplifiers is analysed and circuits for reducing drift are described for a particular amplifier a h test showed the equivalent input drift to be less than from to c 2085 nomographs for designing transistor narrow band amplifiers 2086 transistor amplifiers for dc signals basic direct coupled and chopper type amplifiers are examined and compared 2087 a low noise transistor amplifier for acoustic measurements the portable equipment described has a gain of about and a frequency range of with noise output above the theoretical minimum 2088 the maser a new form of microwave oscillator a short review of the principles of operation of molecular beam and solid state masers 2089 small signal analysis of molecular beam masers a perturbation calculation gives the resonance polarization of a molecule in an electric field as a function of time an analysis is then made of maser operation with a divergent univelocity beam 2090 three level solid state maser the maximum values of the real and imaginary components of the paramagnetic susceptibility of a three level solid state maser are calculated general expression for the gain and bandwidth of a travelling wave maser are given 2091 low noise in solid state parametric amplifiers at microwave frequencies the principles of parametric amplification are described through the use of simple low frequency electrical circuits and their mechanical analogues extension of these principles to low noise amplification at microwave frequencies is made in a qualitative way which emphasizes the physical processes involved amplification is only achieved when energy is transferred from a microwave oscillator or pump to the signal frequency and it is shown why such a transfer may take place in circuits exhibiting variable capacitance or inductance but not in circuits where only a resistance is varied major noise sources are discussed and the special role of the image or idler frequency is noted finally experimental data on four different types of parametric amplifier using semiconductor diodes and using ferrite are given 2092 calculation of harmonic distortion in sinusoidal frequency modulation cases of a waveguide of any cross section and an amplification stage with a tuned transformer 2093 potential of an electrostatic field and trajectories of charged particles a procedure is described for calculating the electric potential in the path of a charged particle 2094 solutions for the static junction discussion of certain classes of solution of the nonlinear differential equation for the potential distribution near a pn junction an inverse series solution is developed which is appropriate for diverse impurity distribution 2095 a new method for the evaluation of electric conductivity in metals a method is developed for evaluating the closed formal expressions for electrical conductivity which have recently been developed see eg of and of greenwood 2096 secondary positive ion emission from metal surfaces secondary positive ions ejected from surfaces of mo ta and pt under bombardment by inert gas ions of low energy have been studied in high vacuum using a mass spectrometer with a radius of curvature and a sector field 2097 current voltage behaviour in a plasma an exact solution for the current voltage relation in a planar diode filled with a uniform plasma 2098 electron recombination and negative bands in afterglowing active nitrogen the emission of negative bands in the auroral afterglow of nitrogen is interpreted as being due to excitation of molecular ions this is supported by recent measurements of the decay of light intensity of these bands 2099 a note on the confinement of a plasma by rf fields a rigorous derivation of certain results previously obtained by boot et al by inferior methods 2100 microwave emission from high temperature plasmas energy losses from cyclotron radiation are concluded to be negligible for plasma temperatures less than and probably for those greater than emission at the fundamental frequency and first few harmonics is detectable and measurement of the relative intensities offers a means of determining the plasma temperature 2101 excitation of oscillations in a plasma layer development of a linearized theory of plasma oscillations excited by an electron beam injected into a uniform plasma 2102 laws of magnetism and of static electricity in any given frame of reference a study of maxwells equations in terms of the general theory of relativity is made as a preliminary to attempting to solve practical electrical problems 2103 on the diffraction of electromagnetic waves at infinitely thin ideally conducting flat screens a new method is described based on the solution of two independent equations as an example the case of diffraction of a wave at an infinitely thin conducting disk is discussed 2104 electromagnetic diffraction by dielectric strips 2105 the analytical study of scattering by thin dielectric rings 2106 a statistical model for forward scattering of waves off a rough surface 2107 light scattering by small particles 2108 propagation of electromagnetic waves radio location and radio astronomy 2109 ionization of the upper atmosphere by low energy charged particles from a solar flare discussion of recordings made at thule greenland and barrow and college alaska of cosmic noise absorption at at the time of a class solar flare on july 2110 radio observations of the planet jupiter details are given of observations outlined previously together with unpublished information from earlier observations in june correlation of the observations with rotation polarization and frequency characteristics is discussed most of the radio noise bursts were strongly circularly polarized and the spectrum does not appear to be continuous over the frequencies observed critical reflections by an ionosphere around jupiter are discounted 2111 cosmic ray intensity variations during two solar cycles from ionization chamber data the decrease of cosmic ray intensity from its maxima near sunspot minima is shown to lag a year or more behind the increase of solar activity following sunspot minima the variability of daily mean values was particularly great in 2112 cosmic rays in the earths magnetic field discrepancies between centre dipole predictions using the stormer equation and experimental observations of cosmic ray intensities and cut off phenomena are attributed to differences between the earths real field and the dipole approximation to it rather than to distortion of the earths outer magnetic field by ionized interplanetary matter an empirical expression for the cut off phenomena is deduced which is in good agreement with experimental results over a wide range of latitude and longitude 2113 comparison of measured and computed values of the rapid fading rate of ultra high frequency signals reflected from the moon observations made in august during a bistatic moon reflection experiment carried out at are reported they show good agreement with values calculated from the effective libration rate of the moon 2114 meteors in the ionosphere the nature of radio reflections from the trails of ionization produced by meteors is reviewed and the principal uses of meteors as research tools are described some further directions in which meteor research may be pursued are suggested 2115 concerning bookers theory of meteoric reflections the assumption of small scale ionospheric turbulence see of conflicts with many known facts about meteor echoes such as the persistence of aspect sensitivity for as long as ten seconds and the known variation with time of the angular correlation function 2116 electromagnetic scattering by low density meteor trails 2117 the zurich sunspot number and its variations for monthly and auroral mean values of relative sunspot number are tabulated for estimates of annual values by wolf for the period are also given together with derived data 2118 radiation and particle precipitation upon the earth from solar flares a brief survey in which the energies of these emissions are estimated and their effects on the ionosphere discussed 2119 centenary of melbourne toolangi magnetic observatory brief history of the observatory since 2120 possible causes of geomagnetic fluctuations having a six second period the fluctuations described by duffus et al may be due to small oscillations of the earths crust microseisms or more probably atmospheric oscillations with the same period microbaroms 2121 the diurnal variation of irregular geomagnetic fluctuations part using the eight daily k numbers three hour range indices for six observatories in moderately low latitudes and fairly well distributed in longitude a universal time component of the daily variation of irregular geomagnetic fluctuations having an apparently significant amplitude in the yearly average has been found in the data for the nine years it is suggested that a portion of magnetic disturbance may be produced by dynamo action in the ionosphere and give rise to this yearly average universal time component for part see of 2122 lunar geomagnetic tides at kodaikanal tschus method has been applied to the calculation of the lunar semi diurnal variation of the horizontal intensity of the earths magnetic field at kodaikanal the solar diurnal variation is also determined 2123 time constants in the geomagnetic storm effect an estimate is made of the delay between formation of a ring current round the earth and the occurrence of a geomagnetic storm at ground level parker has estimated the delay as several months but by taking proper account of the fluidity of the medium and the presence of the main geomagnetic field the delay is found to be small enough to be consonant with the ring current theory of geomagnetic storms 2124 inadequacy of ring current theory for the main phase of a geomagnetic storm there appears to be insufficient dissipation to allow significant diffusion during a magnetic storm of the magnetic fields in the vicinity of the earth a ring current field can therefore only increase the horizontal component of the geomagnetic field and cannot account for the main phase of a geomagnetic storm 2125 studies on geomagnetic storm in relation to geomagnetic pulsation for the recurring geomagnetic storm m type the cone of avoidance model of pecker and roberts of is supported by both geomagnetic and cosmic ray data for the sporadically occurring storm s type a shock front in interplanetary space may be responsible for the sudden commencement an exhaustive study should be made to determine whether the sudden commencement is only associated with the s type the storm time variation of the geomagnetic pulsation should also be measured during world wide storms to aid the study of the shock wave 2126 the international geophysical year the organization which made possible the large international cooperative research effort is described and arrangements for collecting and storing the observational data are outlined 2127 the day to day coordination of igy observations in addition to regular observational programs the igy included special series of observations made during outstanding solar and geophysical events the organization of these series and the necessary ancillary communication facilities are described briefly 2128 the earth and its environment a general outline of the many fields of investigation included in the igy program of observations particular attention is given to the earths atmosphere and the flow of heat through it from the hot interplanetary gas 2129 motion of a satellite around an unsymmetrical central body if a central body does not have an inversion centre the eccentricity of a satellite orbit varies periodically with low frequency and large amplitude details are worked out for a central body composed of a large spherical mass and a small point mass contained somewhere within it 2130 change of inclination of a satellite orbit comment on of march 2131 irregularities of satellite drag and diurnal variations in density of the air the theory is applied to satellites and 2132 moon rocket tracking a interferometer situated at lasham hampshire was used to track the third american moon rocket on november a satisfactory record was obtained from to gmt 2133 progress of the russian earth satellite sputnik orbital data based chiefly on optical observations are given for the instrument carrying vehicle and its rocket 2134 the explorers extracts from a paper presented at the congress of the international astronautical federation amsterdam details are given of the rocket firing procedure and satellite instrumentation as well as the tracking system used during the launching of the explorer satellites 2135 instrumenting the explorer i satellite a description is given of the phm and mw am transistorized transmitters operating on and respectively total power consumption was obtained from four mercury type cells information was transmitted on skin temperature nose cone temperature meteorite counts and impacts and cosmic rays details are also given of the test program for the completed apparatus 2136 earth satellite observations of the ionosphere the various methods of deriving integrated electron content below a satellite are critically reviewed although the methods are theoretically capable of giving information of the diurnal seasonal and latitude variations of content interpretation of the measurements is difficult because of all these variations are present simultaneously hence some assumptions about one or two of the variables must be made in order that the third one may be studied 2137 investigation of the ionosphere using signals from earth satellites possible effects of the ionosphere on radio signals from artificial earth satellites are discussed with reference to theoretical results noted earlier of 2138 exploration of the upper atmosphere with the help of the third soviet sputnik the instruments carried are described and some of the preliminary results of observations are given up to km the principal ionospheric constituent is nitric oxide above this height ions of atomic oxygen and nitrogen become more important electron density falls off slowly above the f region maximum positive ion density at a height of km is about ie about half the corresponding electron density the number of collisions with micrometeorites at heights of km is 2139 the constitution and composition of the upper atmosphere a survey of the observational data and the theoretical problems involved dissociation of molecular o and n diffusion in the thermosphere and the conduction of heat through the atmosphere are discussed 2140 the distribution of electrons in the ionosphere the methods of deriving profiles are reviewed with particular emphasis on those which include the effects of the earths magnetic field attention is drawn to the use of the extraordinary ray for estimating the electron density below the peak of the e layer some results are given of typical diurnal seasonal solar cycle and latitude variations in the electron density distribution references 2141 the normal d region of the ionosphere a discussion of low frequency sounding of the lower ionosphere indicating the radio transmission characteristics to be satisfied it is suggested the recent measurements of parameters such as reaction rates will provide an improved model of the d layer 2142 the normal e region of the ionosphere an outline of the structure and behaviour of the e layer with particular emphasis on how it differs from an ideal chapman layer the normal f region of the ionosphere a review which includes comments on the physical conditions of the layer as determined from rocket and satellite observations bradburys hypothesis spread f and radio star scintillations 2143 motions in the ionosphere the theoretical factors involved in the interpretation of observational data are discussed particular attention is given to tidal motions and the need for theoretical advances in studies of drifts scintillations auroral forms turbulence and large scale travelling disturbances 2144 horizontal drift measurements in the ionosphere near the equator drift of the e and f layers has been measured regularly at ibadan nigeria by the spaced receiver method the westward daytime drift velocity in the f layer is about 2145 the interpretation of night time low frequency ionograms two types of retardation of the extraordinary ray on passing through a region whose frequency is below the gyro frequency are discussed one is observed near the critical frequency of the ordinary ray and the other near the gyro frequency information about the total number and distribution of electrons below the f layer can be deduced from them 2146 rocket observations of the ionosphere a review of the electron density profiles obtained at fort churchill and at white sands a comparison of similar data obtained in russia up to km is made the effects of polar blackouts and of flares are discussed with particular reference to the nature of the solar ionizing radiation comments are also made on the radiation which can be detected at night interplanetary hydrogen and the electron density in interplanetary space 2147 summer day auroral atmospheric structure measurements from to kilometres density and pressure determined during a rocket flight at cst july at manitoba canada are compared with earlier measurements 2148 polar e published ionosonde data are analysed over the period and show three distinct types of e for northern polar stations each type occurring in a particular geomagnetic zone a strong correlation between e and magnetic activity existing along the auroral belt points to the influence of corpuscular radiation 2149 abnormal ionization in the lower ionosphere associated with cosmic ray flux enhancements two separate abnormalities in ionization were recognizable during the great solar event of february the early effects observed at the time of the sudden cosmic ray enhancement and the late effects which reached a maximum an appreciable time later a difference in composition between streams of solar particles of cosmic ray energies and ordinary cosmic rays is postulated to explain the former effect while the latter is explained in terms of ionization at heights of km produced by the passage or stopping of solar particles predominantly protons the absence of auroral and magnetic effects is consistent with these explanations a provisional evaluation is also made of the coefficient of collisional attachment of electrons from negative ions and the negative ion electron ratio and effective recombination coefficient at night between and km 2150 the f region during magnetic storms magnetic storms are investigated using the variation of and over a wide range of latitude it is shown that ionization drift theory in association with the dynamo theory is satisfactory in explaining the observed variations 2151 automatic sweep frequency ionosphere recorder model c a description of an improved equipment for use during the igy in addition to the virtual height frequency records time lapse motion pictures are taken 2152 the igy three frequency back scatter sounder the equipment consists of three transmitters operating at and each coupled to its own horizontal yagi aerial on a single rotating pole and by a tr switch to a receiver whose tuning is interlocked with the transmitter a camera records the plan position displays for the three frequencies together with a short range display preliminary results from stations in polar temperate and equatorial regions are discussed phenomena reported include sporadic e movements tilted f layer propagation large irregularities in the f layer and echoes from field aligned ionization 2153 the riometer a device for the continuous measurement of ionospheric absorption a description of an instrument for the measurement of ionospheric absorption at high latitudes during the igy using the cosmic noise method see of the circuit details of this self balancing equipment are given and its advantages over the system of total power measurement are discussed 2154 the night airglow a phenomenological description of the night airglow is presented reviewing the historical background and what is known about height temporal and spatial variations in intensity and movements the very important relationship to aurora and evidence for latitude seasonal effects are examined 2155 auroral phenomena present knowledge of the formation of the aurora is summarized mechanisms of particle acceleration are considered and it is emphasized that there is no consistent theory of auroral phenomena references 2156 a man made or artificial aurora an auroral dispplay with which were associated radio fade outs and a magnetic storm was observed at apia on august these phenomena were probably due to the explosion of a nuclear bomb over johnston island on the same date 2157 auroral ionization and magnetic disturbances the literature on radio studies of the aurora the relation between aurora and magnetic storms and the movements of the ionosphere and auroral forms is co ordinated references an average density of electrons cm is sufficient to explain normal radar echoes magnetic disturbances are closely related to ionization and luminosity of the aurora magnetic variations are also associated with increases in the speeds of motion of the ionization 2158 radio echoes from auroral ionization detected at relatively low geomagnetic latitudes 2159 the geometry of auroral communications uhf auroral radar observations describes auroral doppler spectra obtained at ottawa with bistatic radars operating at and mcs klystron amplifiers with and parabolic reflectors were used with transmitter receiver separations of and km echoes indicating cross sections of several thousand square metres were obtained on occasions at 2160 a low power vhf radar for auroral research 2161 the very low frequency emissions generated in the earths exosphere types of noise other than whistlers have been examined using high resolution spectrograms which show the frequency distribution as a function of time most of these noises are excited in the exosphere by streams or bunches of high speed ionized particles trapped in the earths magnetic field the excitation mechanism is similar to that of a travelling wave valve most of the observations required that particle velocities be about kms a model in which the ratio of electron density to magnetic field strength is almost constant along a line of force in the exosphere seems to be indicated by several types of noise 2162 atmospheric whistlers the historical background of the discovery of whistlers and the development of an adequate theoretical explanation of their behaviour are reviewed the program of study during the igy is described and some examples of results obtained are presented and discussed 2163 path combinations in whistler echoes a note describing groups of whistler echoes recorded at unalaska geomagnetic latitude and explaining them in terms of a combination of alternative propagation paths and multiple trips over each path 2164 a note on whistler propagation in regions of very low electron density calculations made on a model ionosphere indicate that nose whistlers may exist although attenuation may prevent their observation 2165 a sudden enhancement of atmospherics anomaly on may two anomalous solar flares caused a sharp drop in the signal level recorded at pittsburgh pa instead of the usual enhancement enhancements were recorded elsewhere 2166 study of the atmospheric radio noise at and at delhi preliminary survey of observations extending over a year with particular reference to sudden enhancement effects 2167 a simple temperature control system for transistors a description of a closed loop servomechanism in which a power transistor which supplies the current for a heating coil is controlled by an error signal produced by a temperature sensing af transistor 2168 loop controls scatter power to offset fading a closed loop servo system is described where by the transmitted power of an uhf tropospheric scatter link is reduced under conditions of good reception and increased under fading conditions a statistical analysis of the system is given 2169 converting recorders to rectilinear outputs a computer circuit generating variable transport time delays is described for transforming pen recordings from arcs to straight lines see also of massa and massa 2170 stabilized variable frequency ac instrument calibration source a network is described which renders a amplifier insensitive to variations of signal input power supply and load 2171 high stability mains operated valve heater supply details are given of a circuit using a high gain tuned amplifier with feedback controlled by a thermistor bridge 2172 a four transistor dc converter circuit for use with relatively high voltage supplies an experimental bridge circuit is described with a power output of and conversion efficiency 2173 digital computers available in britain information on computers is given in tabulated form 2174 digital differential analysers principles of operation are described and details are given of the design of the avro dda machine addam 2175 ferroelectrics and computer storage the polarization reversal process in ferroelectric single crystals and its application to data storage is reviewed an optical system for reading information from a ferroelectric store is described 2176 magnetics for computers a survey of the state of the art a review of the application of magnetic materials to storage and switching devices 2177 transistorized core memory 2178 transistors provide computer clock signals switching circuits capable of high speed and controlling peak currents up to are described 2179 digital storage on punched tape 2180 the storage and processing of digital data on magnetic tape 2181 the noise problem in a coincident current core memory 2182 the printed circuit summary of manufacturing and assembly techniques 2183 circuits for ternary switching variables applications of a ternary switching algebra are considered and the synthesis of a ternary adder is described 2184 design of toroidal coils with ferrite cores operating in the audio frequency range a method of determining the optimum relation between core dimensions is outlined this gives the minimum coil size for a given q factor or the maximum q factor for a given size 2185 auto self excited transductors basic circuits are examined nonmathematically considering only resistive loads 2186 coincidence diodes gate electronic switch a transistor switching circuit for radar indicators is described six channels are used in each coordinate axis of a cro presentation 2187 hydromagnetic capacitor 2188 accurate determination of the capacitance of rectangular parallel plate capacitors the subarea method is recast and applied to derive a universal curve for a square plate capacitor values calculated by other methods are compared 2189 elements of electronic circuits part time constant and differentiation first of a series of articles reviewing basic electronic circuits with emphasis on physical explanations of their operation 2190 analogous transistor system design and nodal methods of construction with applications to research equipment and prototype evaluation transistor action and circuits are described in terms of the thermionic valve analogy a modular technique of circuit construction based on this principle is described in which stages are assembled individually using a method which simplifies their interconnection 2191 on the reactance theorem any passive quadripole with foster type short circuit and open circuit impedances at either end transforms any foster type two terminal network into a foster type two terminal network again polygons consisting of foster type two terminal networks are also considered see also of 2192 group delay and group velocity the concepts are defined and their relation to the transfer function of a network is given see also of 2193 radio engineering use of the minkowski model of the lorentz space 2194 the condition of passivity for the linear quadripole with complex characteristic impedances reciprocal and non reciprocal two port networks are considered 2195 an analysis of lossy symmetrical quadripoles in the decimetre and centimetre wavelength ranges using voltage node displacements see also of 2196 a combined pulse width filter for television receivers synchronization by means of a combined integrating and differentiating filter network is described performance data are tabulated 2197 intermediate frequency circuits with three coupled resonators the operation of triple tuned wide ba d bandpass filters is analysed and design formulae are tabulated for data on double tuned filters see of 2198 theory of the crystal controlled inductive three terminal circuit conditions of oscillation equivalent circuits and methods of compensation for the crystal controlled hartley oscillator are discussed 2199 transistorized crystal controlled marginal oscillator circuit details of a small non microphonic oscillator unit for nuclear magnetic resonance observations 2200 operating conditions of the symmetrical multivibrator an approximate method for the division of a multidimensional phase space into sub spaces is described and applied to analyse the operation of a symmetrical multivibrator taking account of parasitic capacitance and grid current three modes of operation are considered 2201 multivibrator with negative feedback a description is given of a multivibrator circuit with very good frequency stability 2202 improved rc oscillator a modified version of the bridged t circuit described by sulzer this oscillator operates at a single frequency in the range 2203 the conditions for the onset of oscillation in transistor oscillators the condition for self oscillation is established and oscillators are considered in two groups with frequency either dependent on or independent of transistor parameters 2204 transistorized nuclear resonance magnetic field probe description of a marginal oscillator type of nuclear resonance detector 2205 frequency stable transistor oscillators in carrier frequency techniques the design of a meacham bridge oscillator is given 2206 reversible dekatron counter a counter circuit is described which has two inputs one of which allows addition to and the other subtraction from an existing count 2207 the static characteristics of the cathode coupled limiter clipper 2208 cathode compensation the design of a cathode compensated pentode video stage is discussed particularly the selection of values for the cathode resistor and capacitor and the use of a bleed resistor 2209 response of cascaded double tuned circuits the transient and steady state responses are developed in terms of the location of the poles of the transfer function the results can also be applied to networks with a response asymmetrical about the band centre but with a narrow relative bandwidth 2210 design of transistor rc amplifiers 2211 transistor nonlinearity dependence on emitter bias current in pnp alloy junction transistors 2212 radiation damping effects in two level maser oscillators analytical note on the modulation effects occurring in a spontaneously radiating inverted two level spin system 2213 phase distortionless limiting by a parametric method nearly ideal limiting can be obtained by using the signal to be limited as the pump frequency nonlinear capacitance amplifiers an account of the physical principles and the design of variable capacitance amplifiers the effective noise temperatures achieved are compared with those of other low noise amplifiers and of terrestrial and extraterrestrial noise sources 2214 a three frequency electron beam parametric amplifier and frequency converter 2215 gain bandwidth and noise in a cavity type parametric amplifier using an electron beam 2216 travelling wave couplers for longitudinal beam type amplifiers 2217 the physical principles of a negative mass amplifier negative effective masses for relatively low energies may be obtained if the energy contours are reentrant near the edge of the frequency band as in the case for heavy holes in germanium and certain other semiconductors with degenerate band edges operation at frequencies up to mm is envisaged 2218 microwave ferrite modulators for high signal frequencies methods are suggested for avoiding ferromagnetic resonance skin effects are overcome by using the waveguide as a modulating helix performance details of two experimental modulators for x band frequencies are given 2219 frequency modulator for a marginal oscillator a voltage sensitive capacitor with dc bias is used in the tank circuit of the oscillator 2220 the accuracy obtainable with transistors in pulse amplitude and pulse width modulation the effects of ambient temperature and power supply fluctuations on transistor pm circuits for telemetry applications are analysed the design of a pam pwm converter is given 2221 photoconductivity as a function of optical absorption a theoretical analysis of the dependence of photoconductivity on optical absorption based on the concept of a schubweg or mean range for the optically liberated charge carriers of each sign 2222 correlation function for a system of particles carrying like charges a description of a mathematical method for the determination of correlation functions for systems of particles carrying like charges this method could be extended to charges of different sign and also to the kinetic theory of charged particles see also of tyablikov and tolmachev 2223 a dielectric formulation of the many body problem application to the free electron gas 2224 theory of the contribution of exciton to the complex dielectric constant of crystals 2225 graphical analytical construction of the space trajectory of charged particles in magnetic fields two methods are described for plotting the trajectory of relativistic charged particles an acceleration method and the radii of curvature method 2226 effect of space charge in cold cathode gas discharges townsends basic ionization equations for cold cathode discharges between parallel plates are modified by poissons equation to account for space charge effects numerical calculations have been made for argon 2227 high frequency breakdown in air at high altitudes breakdown field is computed for and from atmospheric data the validity of which is discussed considerably more power per unit area can be transmitted at the higher frequencies 2228 longitudinal oscillations of electron ion beams investigation of the stability of electron ion beams leads to a differential equation that is difficult to solve a qualitative method based on self conjugate differential operators is used which avoids solution of this equation 2229 compensation of space charge in an electron beam measurements of the electric field of the space charge in the beam were carried out to evaluate the lifetime of the virtual cathode 2230 calculation of the spatial and angular distribution of a stream of particles with multiple scattering scattering of electron beams is considered taking account of absorption and retardation effects 2231 energy spectrum of secondary electrons emitted by a metal under the action of a fast ion beam spectra have been analysed by means of a magnetic spectrograph 2232 solar proton stream forms with a laboratory model 2233 a transit time relation for plasma electron oscillations 2234 microwave propagation in hot magneto plasmas the refractive indices for circularly polarized waves propagating along the magnetic field in an ionized gas at high temperature are calculated they are found to depend sensitively on electron density and temperature 2235 conductivity of plasmas to microwaves a new derivation of an expression previously obtained for plasma conductivity see of and an alternative expression which avoids previous difficulties with negative conductivities 2236 hydromagnetic capacitor very high dielectric constants can be achieved with an ionized gas in a strong magnetic field when an orthogonal electric field is applied resultant particle drift stores electrical energy dielectric constants from to have been measured in a coaxial capacitor using a rotating plasma disk potential use in fast discharge work is considered 2237 on the question of quantum effects in the interaction of electrons with high frequency fields in resonators it is shown that the quantum effect corresponds to the interaction of electrons with a neutral oscillatory field in the resonator methods of quantum mechanics are avoided by using the nyquist formula 2238 the band between microwave and infrared regions difficulties that have hitherto prevented microwave generation in the region are discussed schemes which might overcome these difficulties are considered 2239 multistage resonance absorbers for centimetre electromagnetic waves a three stage dipole resonance absorber is drived from the two stage absorber described in of schmitt by the addition of a second dipole grid at a distance of in front of the metal surface the frequency characteristics of the reflection coefficient are calculated and compared with the results of measurements 2240 the absorption of centimetre electromagnetic waves in artificially anisotropic media two methods of equalizing the complex permeability and dielectric coefficient of a medium to obtain absorption at are discussed in one case the medium consists of thin parallel layers in the other use is made of gyromagnetic resonance in ferrite material subjected to a static magnetic field experimental results are given 2241 the group velocity of damped waves the group velocity is shown to be equal to where is the component of the poynting vector along the direction of propagation and w the energy density the electromagnetic energy and group velocities are calculated for a simple medium a plasma and a dielectric with bound electrons 2242 kinematics of growing waves analytical treatment of the problem of distinguishing between amplifying and evanescent waves 2243 asymptotic development of double integrals encountered in diffraction theory 2244 a new method for the solution of a problem of diffraction of electromagnetic plane waves at an unlimited rectilinear slit and related problems using the method described a good approximation to the exact solution of the diffraction problem can be obtained for normally incident plane waves of wavelength much smaller than or equal to the width of the slit 2245 radio frequency spectra of hydrogen deuteride in strong magnetic fields 2246 steady state free precession in nuclear magnetic resonance description of a new technique for observing nuclear magnetic resonance 2247 an x band spectrometer for the demonstration of paramagnetic resonances a bridge type spectrometer with frequency stabilization is described 2248 theory of cyclotron resonance in metals analysis of the low temperature case in which the mean free path of the electrons is greater than the skin depth 2249 multiple quantum transitions in paramagnetic resonance at high rf field strengths the normal paramagnetic resonance spectrum of in cubic mgo is found to be modified by additional absorption lines which are interpreted as double quantum transitions occurring between nearly equally spaced energy levels at high rf power calculation of the relative absorption intensity for which transitions agrees with experimental results 2250 infrared and optical masers theoretical aspects of maser like devices for wavelengths much shorter than cm are discussed the short wavelength limit for practical devices is examined design principles are illustrated by a system for the infrared region using potassium vapour 2251 the effective radius of the electron in crystal lattices the effective radius of electrons in metals determined by different methods is found to be 2252 relation between the constants characterizing the interaction of electrons with phonons and impurities in metals a mathematical analysis 2253 unusual cosmic ray intensity fluctuations observed at southern stations during october the fluctuations observed have unusual features which suggest the existence of a short lived and highly directional anisotropy of the primary radiation during the period immediately preceding a forbush type decrease 2254 international convention on cosmic rays the text is given of over papers presented at a convention held at varenna the subject matter is divided into the following groups solar and geomagnetic effects on cosmic rays problems of origin composition of primary radiation air showers and interactions of cosmic radiation 2255 latitude variation of day cosmic ray intensity decreases the latitude variation of decreases in cosmic ray intensity due to the modulation effects of a geocentric nebula of disordered magnetic fields has been measured experimental data provided by neutron monitor observations during the period of intense solar activity show that equatorial variations exceed calculated values by a factor of two or more 2256 radio observations of the lunar surface information about the moons surface can be obtained from a statistical consideration or radar scattering from the surface 2257 solar proton stream forms with a laboratory model a stormertron tube is described for simulating the streams of charged particles in the earthsdipole magnetic field photographs of stream forms and contacts are presented the same techniques can be used to study stream forms in other complicated magnetic fields 2258 recurrent geomagnetic storms and solar prominences an examination of the association of prominence areas with days of recurrent storms during t period the identification of m regions with solar prominences is not confirmed 2259 motion of a satellite around an unsymmetrical central body comment on of 2260 a determination of the coefficient j of the second harmonic in the earths gravitational potential from the orbit of satellite 2261 vanguard igy satellite beta the instrumentation used the measurements made and the uses of the satellite are described information on satellite temperatures and rotation rate is given orbital data are being used for measuring the oblateness of the earth and for correcting mapping errors 2262 information by radio from the satellites an account of some early results obtained mainly from observations of satellite 2263 igy conference in moscow soviet papers presented at the rocket and satellite symposium summary of preliminary data presented at the general assembly of csagi moscow august 2264 densities and temperatures of the upper atmosphere inferred from satellite observations the atmospheric density between and km altitude appears to be appreciably higher than that derived from rocket data the temperature in this region must therefore be higher than that given by present model atmospheres the density is still below that derived from meteor data 2265 investigation of the upper atmosphere by means of the third artificial earth satellite a brief description of geophysical investigations carried out in ussr the temperature variation and the distribution of the electron density with height up to about km are discussed and the collision of an artificial satellite with micro meteorites is considered 2266 the ionosphere and artificial earth satellites two methods for investigating the ionosphere are briefly described the doppler shift of emitted signals and the observation of the times of radio rise and radio setting of the satellites from the difference between the optical and the radio observations of the rising and setting the electron concentration can be calculated 2267 satellite doppler measurements and the ionosphere simultaneous doppler measurements of satellite at frequencies of and were shown to be in agreement with an approximate model of the ionosphere for the same period 2268 transoceanic communication by means of satellites 2269 temperatures in the high atmosphere temperature distribution is discussed in relation to rocket and radio observations on the assumption that heating of the ionosphere is due primarily to solar radiation and that temperature distribution is controlled by thermal conduction a model is presented which indicates a very rapid temperature rise between and km this would produce a density distribution in agreement with observations 2270 the temperature in the atmospheric region emitting the night glow line and in regions above faint auroral arcs 2271 effect of vertical drifts on the nocturnal ionization of the lower ionosphere vertical ionic drifts present in quiet conditions and enhanced during a magnetic storm result in a vertical redistribution of ionization and thus change the apparent recombination coefficient at a given height the resulting n profiles are calculated and shown to explain the sudden cessation of night time echoes of lf radio waves at times of magnetic disturbance reported by linquist 2272 a survey of the present knowledge of sporadic e ionization discussion of the various techniques of observi g e and the classification of the phenomenon by geographical zones auroral temperate and equatorial and by type as evidenced by the trace recorded on an ionogram the diurnal and seasonal variations in the three zones are shown to be quite distinct various theories of the nature of the ionization formations and the agencies producing them are considered and the subjects requiring special experimental and theoretical attention are indicated over references 2273 lunar tides in the sporadic e layer at ibadan an analysis of the lunar semi diurnal tides in is made for ibadan the results are presented in the form of harmonic dials comparisons are made between these results and those of other stations 2274 ionospheric measurements made at halley bay graphs of the monthly median values of at halley bay for july winter september equinox and december summer are given a large diurnal variation of electron density occurs in winter the seasonal maximum of electron density during the day is found at the equinoxes 2275 the diurnal and annual variations of over the polar regions the variations have been studied for about stations over a three year period and the following results have been found the diurnal variation is largest in winter and smallest in summer the maximum values of occur at noon in the northern and at midnight in the southern hemisphere there is a regular annual variation for a given time of day in northern winter has deep minima in the morning and evening in summer the latitude differences in are small but become large in winter up to per degree the lines of equal critical frequency lie between circles of geographic and geomagnetic latitude 2276 ionospheric changes at singapore during the solar eclipse of december the eclipse occurred in the late afternoon and no simple interpretation of the changes in the e and f layers can be given the critical frequency of the f layer did not change but there were considerable eclipse effects in the lower part of the f layer 2277 an analysis of drifts of the signal pattern associated with ionospheric reflections a statistic treatment to determine the drift and random velocity components from the signals observed on three spaced receivers particular attention is given to the random motion in order to examine the detailed movement of the pattern the results suggest a ruled pattern undergoing fluctuations in contour spacing as the pattern drifts across the receiver site 2278 triple splitting of the f echoes polarization measurements of triple split echoes at banaras agree with measurements at high latitudes the process concerned in producing triple splitting at low latitudes is discussed 2279 arctic measurements of electron collision frequencies in the d region of the ionosphere simultaneous measurement of refractive indices and the difference in the absorption of the two magneto ionic components of a signal transmitted from a rocket allowed the electron collision frequency profile to be determined the results of two midday flights indicate that the frequencies are lower by a factor of three than the unpublished theoretical values calculated by nicolet 2280 electric field theory of aurorae a qualitative description of the development of a typical auroral display following the growth of an electric field in the ionosphere 2281 an artificial aurora the auroral display at apia reported by cullington of could not have been caused by direct radiation from the explosion of a nuclear bomb at johnston island which is approximately miles away but was probably due to charged particles from the explosion 2282 a bistatic radio investigation of auroral ionization 2283 ire standards on static magnetic storage definitions of terms 2284 magnetic head reads tape at zero speed design details of a system enabling recorded hf signals to be played back at speeds low enough for the output to be fed to a pen recorder without deterioration in signal noise ratio 2285 development of the transistor inverter at using power transistors 2286 physical and electrical properties of silicon rectifiers for communications applications small junction type diodes with a current carrying capacity of up to a are considered 2287 current integration with solion liquid diodes the construction and characteristics of electrochemical diodes using iodine potassium iodide solution are described see of these can be used as electrical current integrators and flow or pressure detectors 2288 a new concept in computing the phase of a sine wave signal is used as an information bearing medium which together with majority logic permits the realization of logic operations nonlinear reactances are employed computing can be carried out more rapidly than by present techniques if microwave frequencies are used 2289 a new high speed digital technique for computer use square loop ferrite cores and transistors are used operating at digit rates of only two low voltage dc supplies are required and the system is not critically dependent on voltage and component variations 2290 the automatic computing engine at the national physical laboratory 2291 digital memory system keeps circuits simple a magnetic disk memory of to words capacity using simple control and selection circuits 2292 a general approach for obtaining transient response by the use of a digital computer adaptation of digital computers to the inverse laplace transformation process and the fourier integral method is shown to have major advantage in determining the transient response of linear control systems 2293 the use of hall generators in analogue multipliers experimental equipment incorporating an inas crystal hall generator is described 2294 operating experience with a transistor digital computer a description of the performance of a small laboratory model digital computer over a period of a year with analysis of service ability and transistor failures the failure rate of point contact transistors was higher than expected but was of the same order as that quoted by other workers for standard thermionic valves in digital computers 2295 quadratic interpolation in tapped potentiometer function generators the quadratic variation of the resistance to ground from the slider of an auxiliary potentiometer interpolating between the tapping points on the function generating potentiometer is utilized to achieve quadratic interpolation 2296 verification of the logic structure of an experimental switching system on a digital computer the verification problem is concerned with the construction on a computer of a logical program which satisfies all the design specifications prescribed for an experimental switching system and with the process of putting calls though the computer simulation to evaluate the systems logical structure 2297 stable high speed digital to analogue conversion for storage tube deflection discussion of the design of access circuitry for a barrier grid tube temporary storage system which converts a bit binary address into the analogue voltage necessary to deflect the electron beam to a specific storage area defined by the address a special feedback circuit and raster reference tube control the size and centring of the array of storage s study of the impedance of capacitors as a function of frequency strip stacked and disk type capacitors have been studied the natural resonant frequency is almost entirely dependent on the capacitance value and the connections 2298 solid electrolyte tantalum capacitors the manufacturing process is described and the temperature characteristics and results of life tests are given 2299 elements of electronic circuits part clamping or dc restoration 2300 the physical realizability of a microwave junction the conditions are derived which must be satisfied by a matrix to represent the admittance impedance or scattering matrix of a junction at a given fixed frequency 2301 the ferroresonant circuit a theoretical and experimental treatment of the resonance obtained by varying the voltage applied to a circuit containing an iron cored inductance 2302 behaviour of the ferroresonant series circuit containing a square loop reactor 2303 the present state of crystal resonator techniques review of production techniques with details of performance obtained in recent applications of crystal resonators in frequency standards filters and delay lines references 2304 the expansions of electromagnetic fields in cavities 2305 travelling wave resonators 2306 gyrators and nonreciprocal systems discussion of the conditions necessary for a linear four terminal network containing only passive elements and gyrators to have different attenuations in either direction 2307 a new synthesis procedure for two terminal pair networks using the symmetrical lattice structure 2308 synthesis of lc networks a method is outlined for the synthesis of certain voltage transfer functions by means of asymmetrical balanced lc networks terminated at the load end by a resistance a simplified analysis of transients in linear circuits caused by the frequency modulation of an input signal a simplified method of investigation of transients is described with the introduction of the concept of the transmission frequency coefficient an explanation is provided for the mechanism of dependence of the time constant of the frequency transient on the frequency of modulation of the input signal the frequency coefficients of transmission for aperiodic and differentiating circuits are also considered 2309 wave matrices of a quadripole th use of scattering and transmission matrices for cm wave quadripoles is considered and the essential properties of these wave matrices are determined the method is illustrated by a practical example in which an examination is made of the modulus and phase of the reflection coefficient of a waveguide filter consisting of two equal inhomogeneities and separated by a section of waveguide propagating an wave 2310 interchange of infinite attenuation elements in ladder filter structures formulae are given for interchanging series antiresonant and shunt resonant circuits 2311 branched filters the theories of cauer and piloty relating to constant impedance branched networks are supplemented and applied using image attenuation functions instead of cauers insertion loss function an eight terminal network using two low pass and two high pass filters without a differential transformer is described 2312 the reactance transformation of low pass into band pass ladder networks the low pass network is subdivided into quadripole elements which are then combined to form the band pass network 2313 development of filter technique in france during the last ten years 2314 flexural vibrations in mechanical filters matrix methods are used for calculating the characteristics of flexural vibrations in rods and the results are compared with those measured by an experimental method described the design of mechanical filters with torsional and longitudinal vibrations and free from flexural waves is discussed 2315 mechanical filters for communications technique english summary the principle of operation and the design of filters consisting of magnetostrictive transducers and mechanical resonators are described details are given of a if band filter and a ssb filter for a carrier frequency of 2316 transistor active filters using twin t rejection networks 2317 a topological investigation of network determinants the main result gives the determinant of the nodal admittance matrix of a rlc network without mutual inductance or ideal transformers 2318 the practical design of two phase networks an example illustrating the theory given in of 2319 linear multitapped potentiometers with loaded outputs an analysis of multitapped linear potentiometers is given for the type in which shunt resistors are connected between adjacent tapping joints and in the presence of an output load resistance 2320 a simple very low frequency oscillator amplitude limitation is effected by a zener diode and a selective circuit filters out the resulting harmonics giving amplitude stabilization that is not frequency selective 2321 transistorized generator for pulse circuit design the generator produces pulses of duration at repetition frequencies from to the maximum amplitude is into a load type switching transistors are used 2322 transistor phase locked oscillators an analysis followed by detailed design data for two systems one operating at and the other at mcs 2323 greater gain bandwidth in trigger circuits a special series connection of two valves produces a gain bandwidth product per stage of up to three times that of a conventional amplifier without introducing the unwanted time delay associated with a distributed amplifier 2324 cathode follower for a dc reference level describes the use of a cathode follower to provide a variable reference voltage source with a low output impedance 2325 design criteria for low level second harmonic magnetic modulators detailed analysis of a device suitable for low level dc amplification 2326 how to design pulsed distributed amplifiers principles of operation are discussed and basic design equations are listed details of design procedure and performance of a power amplifier operating around are given 2327 the effect of reaction on the gain of nonlinear amplifiers an analysis in which it is shown that in certain conditions the nonlinear differential equation may be reduced to a linear equation of infinite order with constant coefficients 2328 performance of class b audio amplifiers with random noise signals two basic limitations on performance are considered average anode power dissipation is the same as that for sinusoidal modulation but the positive grid operation permitted is slightly different 2329 construction of a logarithmic wide band amplifier the equipment described has a gain of about amplification is linear for input voltages up to and proportional within db to the logarithm of the input voltage from to frequency response is linear from to 2330 construction of a logarithmic wide band amplifier the equipment described has a gain of about amplification is linear for input voltages up to and proportional within db to the logarithm of the input voltage from to frequency response is linear from to 2331 variable magnetic amplifier a method is described for varying the current gain by means of a variable impedance in parallel with the feedback rectifiers 2332 volt second transfer efficiency in fast response magnetic amplifiers part and control analysis for the case of finite control circuit resistance and non ideal core characteristics defined as the summation of the quotients of the square of the number of turns and the circuit resistance for all control circuits is shown to be a basic reactor parameter 2333 on feedback in magnetic amplifiers part single feedbacks feedback configurations associated with two core full wave self saturating amplifiers are analysed and compared 2334 magnetic amplifiers for servo systems tabulated comparison of seven different combinations of push pull magnetic amplifier units 2335 linear power amplifiers using dynistors or trinistors the use of two or three terminal semiconductor switching devices with a pulse network in series with the output of a magnetic amplifier transducer acting as an amplitude phase converter is described these amplifiers are much smaller than conventional magnetic amplifiers of comparable maximum output power resistive or inductive loads can be used 2336 transistor amplifier for magnetic tape and drum playback the amplifier operates from a input over the range and from to c rise time of the output pulse is less than s details are given of the design and full performance 2337 a stable direct coupled transistor servo preamplifier capable of dc operating point stability and high gain at 2338 the three level solid state travelling wave maser theoretical comparison is made between the characteristics of the travelling wave maser and those of the cavity maser and the general requirements for slow wave structures are discussed theoretical analysis and experimental results are presented for the comb in waveguide slow wave structure 2339 a uhf ruby maser the maser is tunable over the range and consists of a ruby crystal at the centre of a teflon loaded cavity which is excited in a te pump mode 2340 three level masers as heat engines 2341 calculation and measurement of the noise figure of a maser amplifier 2342 stimulated rf amplifiers working on hyperfine levels of paramagnetic atoms a note on the possibility of obtaining signal amplification in the frequency range using crystals of salts containing bivalent ions of the isotope with oersteds to and number of paramagnetic ions the stored energy for one pair of hyperfine levels will be of the order of to ergs for a pulse duration of sec the output power may reach w 2343 parametric devices tested for phase distortionless limiting tests on two devices are described one is a amplifier and the other an s band converter both use variable capacitance diodes 2344 directional bridge parametric amplifier a description is given of the operation and performance of a directional bridge system using variable reactance diodes 2345 gain measurements on a pulsed ferromagnetic microwave amplifier the amplifier operates in the quasi degenerate mode in which one cavity serves as the resonant circuit for both the signal and the idle frequency fields a second cavity is used for the pump signal which is pulsed 2346 low noise parametric amplifier a note of preliminary analytical and experimental results obtained with a cavity type amplifier for the s band in which through variable coupling the effect of diode losses on noise figure can be minimized at the expense of pump power 2347 a comparison of the transient response of amplitude modulated and frequency modulated signals the performance of rc and rl circuits filters and transmission lines is analysed 2348 the diode reactance modulator a detailed analysis of the control of current through a capacitor by one or more diodes 2349 a magnetic amplifier commutating and pulse width encoding circuit description of a circuit designed for telemetry applications 2350 acoustoelectric effect three general approaches to the theory of the effect are discussed and a development of the phenomenological approach is given in detail for metals and semiconductors see of 2351 a new determination of the freespace velocity of electromagnetic waves a full description of the experiments briefly described in of 2352 the theory of interference modulation for double beam interference infrared interferometry is discussed 2353 spectroscopy in the far infrared by means of interference modulation practical application of the principle discussed in above 2354 a simple method of calculating electrostatic capacity attention is drawn to a simple theorem for evaluating the capacitance of certain conductors in free space such as a system of two spheres in contact with each other or a ring without hole 2355 diamagnetism of conduction electrons in metals calculation made by using a reasonably simple form for the field independent part of the susceptibility 2356 a superconductor in a high frequency field an equation is derived which describes the behaviour of a superconductor in a high frequency field and the frequency and temperature dependence of the impedance of a bulk superconductor are evaluated 2357 electrical discharges report of a conference held by the physical society in swansea sept 2358 theoretical total energy distribution of field emitted electrons 2359 experimental measurement of the total energy distribution of field emitted electrons 2360 magnetic analysis with electron beams a device based on the lorentz effect is used to estimate remanent magnetism see also of 2361 an extension of townsends approximation formula for ionization in a homogeneous electric field the use of an additional parameter improves the approximation and extends the range of validity for lower field strengths a general approximation formula is proposed for ionization dependent simultaneously on both field strength and voltage 2362 on the damping of electromagnetic waves in a plasma situated in a magnetic field using expressions derived by sitenko and stepanov for the components of the permittivity tensor an expression for the damping coefficient is obtained 2363 conductivity of plasmas to microwaves plasma conductivities for electrons with a maxwellian energy distribution are evaluated for the cases in which the collision cross section independent of the velocity and inversely proportional to the velocity the corresponding distribution functions of relaxation times are discussed 2364 microwave investigation of disintegrating gaseous discharge plasmas the phenomenon of afterglow is investigated both theoretically and experimentally by considering the shift of the resonance frequency of a microwave cavity enclosing the plasma measurements using binary gas mixtures show the production of a considerable number of atomic ions of the admixture even at low concentrations the process concerned in helium neon is a charge transfer one between a ion and a neon atom the relevant cross section being cm in other mixtures the atomic ions are produced by the penning effect and possibly the charge transfer process 2365 guided propagation in a slowly varying medium formulae are derived for the propagation of elastic or em waves in a variable stratified medium with particular application to underwater sound transmission 2366 absorption of electromagnetic waves by means of lossy resonant slots very thin microwave absorbers can be constructed by using a sheet of resistive with tuned slots at a distance in front of a metal plate the bandwidth can be increased by the insertion of a grid of dipoles and the effects of polarization are minimized if circular slots are used see also of june 2367 phase object diffraction patterns in microscopes and microwave fields optical phase diffraction patterns are interpreted by analogy with patterns obtained by a microwave technique at cm 2368 velocity modulation of electromagnetic waves 2369 propagation of an electromagnetic impulse in a medium with dielectric losses 2370 high q stark cavity absorption cell for microwave spectrometers design description and performance data are given of a large pillbox shaped stark cavity absorption cell for the region the cavity can be used in any mode with ranging from about to 2371 theory of the anisotropy of the width of ferromagnetic resonance absorption lines the dependence of the width of a radio frequency resonance absorption line on the internal field is derived from the landau lifshits equation and examples of ferrites with single axis and cubic symmetry are examined 2372 microwave spectrometer tests electron resonance a method of measuring the absorption properties of paramagnetic materials in which a sample is immersed in a dc field whose strength is varied to determine the value at which rf energy is absorbed by the sample 2373 three level masers at heat engines it is shown that a three level maser can be regarded as a heat engine and its limiting efficiency is that of a carnot engine the possibility of treating masers as heat engines represents a fundamental difference between masers and parametric amplifiers 2374 absorption and refraction of ammonia as a function of pressure at wavelength description of measurements made using a resonant cavity technique 2375 exact foundations of the theory of spin waves the validity of equations of the type of blochs spin wave equations is proved for the multi electron problem disregarding spin interactions 2376 theory of electron phonon interactions the theory has been formulated for nonpolar crystals in terms of a new set of basic states whose wave functions are essentially bloch functions that deform with the lattice a result of this is a generalization of the deformation potential theorem 2377 possible mechanism by which terrestrial corpuscular radiation arises in response to the action of cosmic rays expressions are derived giving the total number of protons and electrons generated per second at the equator in a tube of cross section the dependence of the intensity of the earths corpuscular radiation on height and latitude is shown graphically experiments show that the intensity near the equator is approximately times less than that calculated which indicates the existence of supplementary leaks from magnetic traps especially noticeable at high latitudes 2378 possible explanation of the radiation observed by van allen at high altitudes in satellites the possibility is considered that the radiation is due to the decay electrons and protons from neutrons produced by cosmic rays and stored in the earths magnetic field 2379 radiation transfer and the possibility of negative absorption in radio astronomy conditions are discussed under which negative absorption can arise at radio wavelengths when the medium will behave like an amplifier to the incident radiations the necessary conditions can be met in cases where the dominant radiation process is due to the cherenkov effect gyro radiation or synchrotron type radiation 2380 radio interferometry at three kilometres altitude above the pacific ocean a lloyds mirror type of interferometer using the surface of the sea as a mirror is described whose effective spacing changes in a continuous manner from zero to km during about one half hour the fluctuations caused by the ionosphere are discussed and the measurements of the fine structure details of cassiopeia cygnus hydra the sun and jupiter are described 2381 a pencil beam survey of the galactic plane at m a survey has been made of the galactic plane region from through the galactic centre to between and using the cross type aerial beamwidth min of arc near sydney contour diagrams of brightness temperature have been prepared the preparation of contours is described in detail and a detailed discussion of the accuracy of the temperatures is given 2382 radio emission from the vela puppis region 2383 the radio emission from centaurus a and fornax a 2384 a search for radio emission at m from the local supergalaxy 2385 approximations for the electron density in meteor trails improved approximate expressions for describing conditions near the point of maximum electron density for both fast and slow meteors are compared with herlofsens exact solution see 2386 oblique echoes from over dense meteor trails ray paths are computed for waves refracted by meteor trails curves are derived showing how the echo duration depends on the trail orientation these curves show that the sec law applies for overdense trails only if the plane of propagation contains the trail axis if not the effective secant exponent may be as small as the theory is in agreement with duration measurements of mckinley and mcnamera and gives results similar to the more complex wave solutions of keitel see of 2387 investigation of the drifts of the effective point of radio reflection along a meteor train experimental evidence is given to support the postulate of the drift of the effective point of reflection along a meteor train towards the maximum echo duration level drift velocities tend to have higher values in the case of shorter echo durations and vice versa from theoretical considerations it is predicted that maximum echo durations always occur at about km below the height of maximum ionization the degree of turbulence is considered to be slightly greater than that suggested by manning but less than that by booker and cohen see also of rao 2388 the limitations of narrow beam radio equipments in the detection of weak meteor showers fluctuations in background activity diffuseness of shower radiants and the short interval over which some showers are active are the chief limitations a significance test for use as a search method for weak showers is developed 2389 first results on the lunar diurnal variation of the horizontal component of the geomagnetic field at tamanrasset 2390 an apparent relationship between geomagnetic disturbances and changes in atmospheric circulation at millibars contour length and trough indices are used as a measures of atmospheric disturbance over north america and the eastern pacific ocean these features were studied for periods following geomagnetic disturbances from to march there appears to be a significant relation between geomagnetic activity and the development some days later of wave phenomena at the level 2391 radio electronics and cosmic flight a brief description of the flight of the russian cosmic rocket launched on the january the scientific equipment carried in the last stage and the possibilities open to these rockets for interplanetary space investigation are also examined 2392 study of cosmic rays and terrestrial corpuscular radiation by cosmic rocket a preliminary examination of data obtained by the cosmic rocket at distances between and from the centre of the earth graphs show that a maximum intensity of terrestrial corpuscular radiation is found at a distance of and that at this intensity falls to zero the density of cosmic rays was found by geiger counter to be particles cm sec and by scintillation counter to be particles cm sec 2393 methods for predicting the orbits of near earth satellites methods are described for predicting the times and positions of the daily transits of a satellite and the geometry of its orbit the methods depend upon maintaining an accurate record of the period of revolution from which the other orbital elements are deduced theoretically 2394 the effect of the earths oblateness on the orbit of a near satellite the equations of motion of a satellite in an orbit over an oblate earth in vacuo are solved analytically by a perturbation method the solution applies primarily to orbits of eccentricity or less the accuracy of the solution for radial distance should then be about and the error in angular travel about per revolution a brief comparison is made between theory and observation for sputniks and 2395 earth oblateness in terms of satellite orbital periods an equation relating the earths oblateness to the anomalistic and nodical periods and orbit parameters of a satellite is given 2396 changes in the inclination of satellite orbits to the equator an extension of earlier investigations of march taking into account the spread of atmospheric resistance around perigee see also of 2397 vanguard measurements give pear shaped component of earths figure calculations indicate that the periodic variations in the eccentricity of orbit of satellite can be explained by the presence of a third zonal harmonic in the earths gravitational field 2398 radio observations at of the first russian earth satellites report on observations in germany of satellites and the various types of amplitude and bearing fluctuations are interpreted and the wave propagation mechanism is discussed 2399 radio observations with satellite the earlier discovery of the great radiation belt around the earth has been confirmed and extended by the use of improved detector equipment this preliminary report suggests that visible aurorae and other geophysical phenomena are closely related to the reservoir of charged particles trapped by the earths magnetic field 2400 space vehicles satellites and missiles a symposium verbatim report of a symposium sponsored by the feedback control systems committee of the american institute of electrical engineers buffalo new york june 2401 radio echoes from some invisible objects in the troposphere a regular scanning of the troposphere was carried out by the central aerology observatory of the ussr from to at using a parabolic reflector and a pulse transmitter during the investigation radio echoes at heights up to km were recorded film recordings show the distribution of echo sources as functions of height and time 2402 variations in ionospheric f region characteristics analysis of records obtained by macquarie island geomagnetic latitude since 2403 study of horizontal drifts in the f and f regions of the ionosphere at waltair mag the diurnal and seasonal changes of drifts in the f region are given in detail the reversal of direction relative to movements at high latitudes is consistent with martyns drift theory 2404 some measurements of horizontal movements in region f using widely spaced observing stations vertical incidence recordings at stations some km apart were compared the results show a correlation between velocity magnitude and the degree of magnetic activity and a positive height gradient of velocity 2405 investigation of the inhomogeneous structure of the f region of the ionosphere results of vertical incidence soundings at kharkov from june to may have shown that in of cases the reflection from the ionosphere has a static character and that the regular diurnal and seasonal variation of the degree of inhomogeneity of the f region does not arise 2406 geomagnetic influence on the f and f regions of the ionosphere effect of solar activity noon critical frequencies for the f and f layers are examined for different seasons and levels of solar activity it is found that the f layer exhibits a geomagnetic control at periods of high solar activity only whilst the equatorial trough in is most marked during periods of low solar activity 2407 geomagnetic distortion of region e an analysis of the behaviour of the normal e region suggests that departures from the classical chapman theory can be attributed to vertical drift of ionization resulting from the interaction of the geomagnetic field and the sq current system flowing in or near the e region perturbations of under magnetically disturbed conditions and near the auroral zone are also discussed 2408 on the seat of the l currents causing geomagnetic tides a note on some ionospheric and geomagnetic data which support the view that the seat of the l current system is situated in the f layer 2409 a study of the morphology of ionospheric storms a study of variations of the maximum electron density in the f layer for the period at stations between and geomagnetic latitude storm time variations and disturbance daily variations during each six hour period were obtained and the changes of these with latitude were examined 2410 a rapid method of obtaining accurate virtual heights from an ionogram the variation of apparent vertical height with the amplitude of the reflected signal depends on constants of the equipment these constants are used to construct a transparent slider which corrects for this variation and enables virtual heights to be obtained accurately 2411 the reflexion of radio waves from a stratified ionosphere modified by weak irregularities consideration is given to the scattered wave which accompanies reflexion from a stratified ionosphere in which there are weak irregularities by considering these irregularities to be confined to a thin layer near a given height the possibility is examined that they might produce considerably enhanced scattering if they were situated near the reflexion level calculated on the basis of geometrical optics it is found that they would not have a very much greater effect at this level it is also shown that if the electron collision frequency is of the order likely to be encountered in the real ionosphere there would be little enhancement by resonance effects of the kind suggested by herlofson 2412 irregularities in refraction of radio waves and large inhomogeneities in the ionosphere description of the method and results of measurements of the vertical refraction of radio waves at in the ionosphere the irregularities of refraction are produced by inhomogeneities of dimensions about km in the f region the diurnal variation of inhomogeneities is analysed and it is shown that their presence is related to solar activity 2413 ionospheric self demodulation and self distortion of radio waves demodulation was observed only at low modulation frequencies the magnitude of the effect agreed with that predicted by theory and was also what would have been expected from results obtained in cross modulation experiments 2414 preliminary results of an experiment to determine initial precedence of organized electrification and precipitation in thunderstorms it is shown that electrification of clouds begins before any radar echo is observed this raises doubts about the assumption that precipitation is the primary cause of charge generation 2415 determination of the angle of arrival of auroral echoes an interference method is used at kjeller to measure the angle of arrival of auroral echoes as varies from to the range increases from to and it is shown that the height of the reflection area must be km 2416 horizontal motions in radar echoes from aurora observations at saskatoon at show a sytematic motion of echoes towards the west before midnight and towards the east after midnight the mean velocity in either direction showing a statistical relation to variations in the earths magnetic field 2417 new power sources for space age electronics developments are described in chemical nuclear and solar energy sources which are expected to fulfil requirements for portable electrical power in space output characteristics of different types are summarized 2418 a method for testing and establishing the rating of semiconductor rectifiers under dynamic conditions 2419 regulated power supplies a brief review is made of various types of stabilized power supply leading to the closed loop series regulator for which design details are given 2420 dry cells containing various aromatic c nitroso compounds as cathode materials the cells have a mg anode and an aqueous solution as electrolyte performance characteristics compare favourably with those of commercial leclanche type cells 2421 self discharge reactions in lead acid batteries in a theoretical and experimental analysis the rates of seven different reactions which contribute to the self discharge process have been determined references 2422 random number generator using subharmonic oscillators the outputs of two oscillators driven from a common source are combined in a hybrid ring the generator can produce random binary digits at a maximum rate of digits sec 2423 pulsed analogue computer for simulation of aircraft a description is given of the logical design of a computer for solving the nonlinear differential equations encountered in the simulation of aircraft performance under various flight conditions 2424 summarized proceedings of a conference on solid state memory and switching devices london september some of the newer techniques are discussed with reference to ferrite ferroelectric and superconducting devices and magnetic thin films 2425 transistors and cores in counting circuits it is shown how square loop magnetic cores and transistors can be combined to form noncritical reliable counting circuits capable of handling input frequencies up to 2426 unifying design principle for the resistance network analogue a cell principle technique due to macneal is extended and generalized as an illustration poissons equation is integrated over the volume of a representative small cell in which form it is easier to appreciate the analogy with the resistance network and to arrive at the relevant design parameters 2427 use of an electronic analogue computer with resistance network analogues a method for solving partial differential equations of the elliptical type is described the method is iterative and adjustments are made automatically by means of electronic storage elements and a switching mechanism some results are given 2428 magnetic matrix stores review of computer storage systems based on ferrites with rectangular hysteresis loops 2429 lens designing by electronic digital computer different methods of designing optical lenses by digital computer are considered in the light of existing aberration theory 2430 the dofl microelectronics program some of the microminiaturizatio techniques used at the diamond ordnance fuze laboratories are described 2431 the micro module a logical approach to microminiaturizatio a review is given of the progress of miniaturization the advantages of the micro module system the assembly of microelement components into units with a specified electronic function are outlined 2432 micro module design progress details are given of the application of a modular technique in the construction of a complete prototype communication receiver and certain digital circuits for multiplex equipment 2433 test patterns for printed circuit materials 2434 printed circuits applied to broad band microwave links detailed review of the characteristics and advantages of typical printed circuits 2435 thermistors for linear temperature readings two circuits are described for deriving an error voltage which varies linearly with the difference between actual and desired temperature 2436 the performance of pyrolytic carbon resistors the major factors affecting performance are carbon film thickness moisture permeability and thickness of protective coating operating temperature and the quality of the ceramic substrate the effect of these factors is small if the carbon film has a thickness of at least a 2437 realistic temperature power derating requirements for carbon composition resistors two derating methods are described based on statistical analyses of load life data 2438 rectangular hysteresis loop magnetic cores as switching elements theoretical bases and experimental results are given for core switching with voltage and current pulses 2439 dielectric losses with periodic rectangular voltage pulses application of a different method to the solution of a capacitor loss problem dealt ith by eisenlohr 2440 elements of electronic circuits amplitude limiting 2441 a general network theorem the realization of the transmission factor of a four terminal network with lumped circuit elements by a passive symmetrical quadripole and a transformer is discussed 2442 network characteristics the common network transformation theorem of griffiths and mole see of is shown to lack generality 2443 matrix analysis of vacuum tube circuits the equivalent four terminal network for a feedback amplifier is derived and the criterion for oscillation is deduced 2444 tchebycheff approximation for loss free image parameter filters according to cauer 2445 passage of a nonlinear oscillatory system through resonance a mathematical analysis of a nonlinear oscillator with one degree of freedom which can be described by a hamiltonian 2446 improved low repetition rate millimicrosecond pulse generator a discharge line device using a vibrating reed type of mercury switch in a suitable coaxial mounting provides pulse repetition rates of up to cs 2447 half cycle resonant delay circuit a new circuit generating a rectangular pulse of duration equal to the natural half cycle of an lc circuit the principles are applicable to the generation of pulses 2448 series diode increases multivibrator sensitivity triggering sensitivity of monostable multivibrators may be greatly increased by using a semiconductor diode as a series nonlinear element in the feedback loop good stability can be achieved 2449 multivibrator circuit using pnp and npn junction transistors details of an improved circuit giving low output impedance and small power consumption 2450 analysis and design of a transistor blocking oscillator including inherent nonlinearities the nonlinear differential equations governing circuit performance are derived analogue and digital computer solutions yield pulse responses in agreement with experimental results 2451 ten pulse amplitude discriminator a pulse height discriminator has been developed which is capable of operating at repetition rates up to it accepts positive input pulses with a threshold adjustable from to the output signal is of constant shape and amplitude the circuit is described and test results are given 2452 a new type of ring counter a system is described using separate eccles jordan circuits in which any number of stages may be employed advantages over other systems are indicated 2453 how ring counters work basic thyratron and thermionic valve circuits are described and reference is made to the use of the circuit as an electronic rotary switch 2454 dividing wide frequency bands a regenerative circuit is described which will divide a sinusoidal input frequency by two over a wide frequency range 2455 some properties of mathieu and related functions exemplified by the regenerative modulation process a frequency divider using regenerative modulation can be used as an analogue method for the solution of mathieu and meissner differential equations an experimental frequency divider is described and a number of waveforms obtained with it are reproduced 2456 the measurement of the time delay of ultrasonic delay lines 2457 quartz delay lines for radar systems two lines are briefly discussed the electromechanical type in which a silica or quartz bar is used in conjunction with one or two quartz crystal transducers and the rectangular or polygon plate type applicable to ultrasonic frequencies delay times from to are obtainable at low power levels 2458 band pass amplifiers their synthesis and gain bandwidth factor seven types of band pass amplifier are investigated and compared and their design formulae are given 2459 using cascading charts charts are given for determining the number of transitionally coupled double tuned amplifier stages needed to provide a required gain and bandwidth two cases are considered equal damping of primary and secondary windings one sided damping 2460 audio amplifier design cuts plate dissipation an auxiliary signal at ultrasonic frequency applied to the grid reduces anode dissipation at low signal levels 2461 overloading effects with cathode compensation further details on cathode compensation of a video stage with rc anode load including compensation for an rc load in the anode of the preceding stage 2462 application of magnetic amplifiers to engineering problems the various types of magnetic amplifier connection are discussed and a typical application of each is presented 2463 design of an emitter current controlled common emitter transistor if amplifier stage input and output impedances and their influence on the bandpass characteristics are studied the stage is suitable for broadcast receivers 2464 transistorized pulse amplifier instead of pulse transformers drift transistors with high cut off frequencies are used in diode logic circuits with input pulses the total rise and fall times are less than the delay between input and output pulses varying from to according to load conditions 2465 dc operational amplifier with transistor chopper description of a drift compensated dc amplifier with which an accuracy of can be achieved in airborne analogue computers vol 2466 weak field nuclear magnetic resonance maser 2467 study of a weak field maser type self oscillator characteristics of the maser described in below are discussed 2468 proposal for a staircase maser a proposal for obtaining amplification at approximately twice the pump frequency in which adiabatic fast passage is used to invert successively the and levels of a three level system 2469 tunable l band ruby maser the product of voltage gain and bandwidth was measured over the frequency range in a maser at temperatures of and 2470 low frequency prototype travelling wave reactance amplifier the circuit of an amplifier with special junction diode nonlinear capacitors in a semidistributed transmission line is described performance data at a signal frequency of show midband gains of with overall effective input noise temperatures of about 2471 vacuum diode microwave detection a new wide band discriminator a transmission line arrangement for frequency discrimination is described output is linear for frequency deviations up to two practical circuits are given with centre frequency and respectively 2472 surface charges produced on insulators by short and long time ionization 2473 note on the motion of electrons and holes in perturbed lattices a new set of orthogonal localized functions is discussed the functions bear the same relation to the functions of luttinger and kohn as the wannier functions bear to the bloch functions the new functions are used to give an alternative derivation of the effective mass equation 2474 thermoelectricity at very low temperatures review of theory and discussion of recent experimental work at temperatures below 2475 a possible mechanism of the potential variation of the joshi effect 2476 a method of studying the electrical recovery of a gas after a pulse discharge a method devised for a triggered discharge as in a thyratron 2477 on the temperature of electrons in a plasma in a variable electric field the investigation shows that the electron gas can exist in two stable states with different temperatures transition from one state to another occurs at certain critical values of the field and is followed by a considerable change in the electron temperature a particular type of hysteresis is noted in the dependence of the electron temperature on the field amplitude and frequency expressions for the complex conductivity of the plasma are also derived 2478 measurement of the attachment of slow electrons in oxygen drift tube measurements are extended into the termal energy range a three body attachment process is indicated 2479 theory of excited plasma waves the excitation of oscillations in a uniform plasma by an injected electron beam is considered and the frequency phase velocity and time rate of growth of the excited waves are derived as functions of the wave number 2480 nonlinear electron oscillations in a cold plasma 2481 production of two temperatures in an ionized gas in a magnetic field if the electrons radiate a considerable part of their energy in a time short compared to the relaxation time of the gas the electronic temperature will differ considerably from the ionic temperature 2482 a consistency condition for electron wave functions 2483 geometrical theory of diffraction in inhomogeneous media the theory developed by an extension of fermats principle and considering smooth convex bodies is applied to the calculation of the field of diffracted rays 2484 asymptotic theory of diffraction in inhomogeneous media problems discussed in above are treated here as boundary value problems they are solved exactly and the solutions are expanded asymptotically for high frequencies 2485 a note on the scattering of a plane electromagnetic wave by a small thin walled cylindrical dielectric tube 2486 nonreciprocal electromagnetic wave propagation in ionized gaseous media 2487 investigation of relaxation in magnetic resonance by the method of forced transient precession a method is described for measuring directly the relaxation time in liquids 2488 radiation damping in nuclear magnetic resonance observations on a nuclear two level maser have demonstrated the effect of radiation damping obtained by flipping the magnetization through about 2489 wide rf level rf unit for an nmr spectrometer this unit makes use of a crystal controlled oscillator for frequency stability and positive feedback to increase the effective q of the sample rf coil the circuit is well suited to saturation studies and relaxation time measurements in nuclear magnetic resonance investigations 2490 effective ferrimagnetic resonance parameters with gilbert type relaxation terms 2491 observation of the overhauser effect in a gas in the presence of a solid paramagnetic material note of nuclear magnetic resonance measurements made on propane gas in diphenyl picryl hydrazyl 2492 the influence of the saturation of paramagnetic resonance absorption on the faraday effect experimental investigations on a crystal of nd and discussion of results 2493 weak field nuclear magnetic resonance maser description of an instrument for nuclear magnetic resonance investigations based on proton spin resonance in circulating benzene 2494 method of treating zeeman splittings of paramagnetic ions in crystalline fields 2495 the royal greenwich observatory reference is made to the national time service associated equipment and land line links with other standards 2496 low energy corpuscular radiation at high latitude an explanation based on an acceleration mechanism 2497 origin of the radiation near the earth discovered by means of satellites 2498 radiation around the earth to a radial distance of km radiation measurements made during the flight of pioneer on december are discussed and a brief description is given of the two geiger muller detector tubes used and the associated telemetry equipment 2499 anomalous night time reception of a major solar radio burst a report of a noise burst received on five different arrays operating on frequencies between and at march in florida possible modes of propagation are discussed 2500 time relationship of metre wave and cm wave bursts metre wave bursts have an average delay of min the delay being less for bursts of small apparent diameter 2501 radar echoes from venus report on tests made on and february using specially coded pulse trains at and a maser type amplifier for reception 2502 cosmic ray increases associated with solar flares data from a neutron monitor for the years have been studied 2503 characteristics of solar outbursts to excite geomagnetic storms for major outbursts a pronounced first part before the time of maximum flare is related to short wave fade out while a large second part will cause a geomagnetic storm it is concluded that the second part of the outburst provides evidence of a corpuscular cloud 2504 fluctuations of temperature accompanying the solar eclipse during the eclipse there was a depression of the rms value of the fluctuations which was accompanied by a temperature inversion with a steep gradient as the eclipse passed the maximum blackout period the rms value of the temperature fluctuations between two points vertically separated was found to increase with diminishing inversion and to continue to increase as the gradients changed from positive to negative values 2505 some remarks on the interaction of solar plasma and the geomagnetic field an explanation of the small scale of magnetic disturbances on the earths surface is that currents flow in plasma sheets and move along the curved magnetic lines of force these sheets are distant less than one earths radius from the surface and would produce perturbation fields consistent with the size and direction necessary to explain storm time geomagnetic variations 2506 preliminary report on the effect of the solar eclipse on april on the geomagnetic field the changes in the d and h components are consistent with the decrease in e layer conductivity z component changes are influenced by earth currents 2507 effect of the solar eclipse on the geomagnetic fld and earth currents 2508 the suns artificial planet general scientific information based on a russian report of the space rocket launched on january 2509 two atmospheric effects in the orbital acceleration of artificial satellites a discussion of oscillations in orbital acceleration and the variations of orbital acceleration with angular distance of the perigee from the sub solar point 2510 atmospheric tides and earth satellite observations harmonic tidal waves are suggested as the cause of the major anomalies in orbital observations this explanation differs from that of groves of may who comments in reply 2511 the igy optical satellite tracking program as a source of geodetic information a note on the visual and photographic tracking program and the subsequent computations 2512 a new value for the earths flattening derived from measurements of satellite orbits data obtained from observations of and have been combined and give a value for the earths flattening of see also of march 2513 determination of satellite orbits from radio tracking data a computer program has been developed which permits an approximate determination of a satellite orbit from a minimal amount of tracking data 2514 observations of sputnik radio observations of satellite for the period july are tabulated 2515 recordings of transmissions from the satellite at the antenna laboratory the ohio state university irregularities in signals are attributed to polarization effects caused by variations in magnetic field near the observing point some periodic fading may be caused by a defect in the satellite aerial 2516 irregularities in the density of the upper atmosphere results from satellites results of observations of earth satellite orbits indicate that irregularities in air density especially at heights between and tend to recur at intervals of about days 2517 deduction of ionospheric electron content from the faraday fading of signals from artificial earth satellites a method is described for determining horizontal variations in the ionosphere both above and below maximum ionization results are compared with values of electron content deduced from ionograms 2518 recording radio signals from earth satellites a method is described for presenting simultaneously on moving film the information necessary for doppler frequency shift measurements for frequency sampling and for the study of signal intensity variations 2519 models of the atmospheric radio refractive index 2520 geophysical effects associated with high altitude explosions effects likely to be associated with high altitude explosions are discussed and related to observations of a nuclear and a chemical explosion 2521 observations of intense ionization of long duration below km altitude after some strong solar flares 2522 turbulence in the upper atmosphere ionospheric irregularities are studied in terms of turbulence theory the calculated scales of the irregularities and their random velocities are compared with experimental observations 2523 sporadic e and the f layer a comparison of curves of e percentage time with curves giving seasonal fluctuations of f layer ionization for four stations in both hermispheres indicates that sporadic e may be caused by a downward drift of f ionization 2524 a theoretical consideration of the electron and ion density distributions in the lower portion of the f region assuming that the photoionization processes in the ionosphere are the physics of the lower f region can be explained fairly well the appearance and disappearance of the f layer with solar zenith angle and solar activity can be understood no values of reaction coefficients can be found which are consistent with both the ion density distribution in the ionosphere and laboratory estimates of the coefficients 2525 occurrence of giant travelling ionospheric disturbances at night disturbances previously thought to be confined to winter daylight hours have been observed on night ionosonde records characteristics of the phenomenon are discussed 2526 structure and movement of large inhomogeneities in the ionospheric f layer simultaneous measurements have been made using three receivers km apart of the phase and angle of arrival of waves reflected from the f layer the size and shape of inhomogeneities and drift velocities have been calculated 2527 a new ionospheric phenomenon report of an isolated event recorded at jodrell bank at about on march by five separate receivers each monitoring various sectors of the sky on slightly different frequencies near a large increase of the noise level was recorded by three receivers a small increase by another and a decrease by another 2528 radio reflexions from the moon and solar corona the formula for the rotation of the plane of polarization given by daniels and bauer of is revised for the case when with low solar activity the electron density in the ionosphere has decreased and the electrons in the space around the earth cannot be neglected 2529 a study of noon f ionization in relation to geomagnetic coordinates earlier work of bhar of has been extended to cover data collected between and an analysis of which indicates that for constant the noon ionization varies with magnetic dip and geomagnetic latitude the shape of the curve is related to the sunspot cycle and shows two maxima spaced asymmetrically on each side of the geomagnetic equator 2530 ionospheric heating by hydromagnetic waves the dissipation of hydromagnetic waves in the ionosphere causes heating this heating is greatest between heights of and km it appears that the heating only becomes important during magnetic storms it may explain the lifting of the f region and the decrease in critical frequency during these periods hydromagnetic heating cannot however explain the variations in the horizontal component of the earths field during the main phase of magnetic storms 2531 effect of magnetic activity on drifts of the f region an analysis of observations made at waltair shows an approximately linear decrease of mean drift speed with increase of magnetic activity in the range 2532 sporadic e at vhf in the usa the occurrence of sporadic e propagation in the years on the cedar rapids sterling path at frequencies near and has been analysed the dependence of the received power on time of day season of year sunspot cycle and frequency has been studied a relation between oblique signal intensity and vertical incidence data has been found 2533 on the swf phenomenon dellinger effect and in the world wide distribution assuming a chapman distribution of ionization for the d region it is shown that is a function of solar zenith angle and magnetic latitude while the increase of during a sudden ionospheric disturbance depends on solar zenith angle only observational results are analysed and the effective factor by which solar radiation is increased during a sid is estimated 2534 ionospheric reflection coefficients at vlf from sferics measurements the magnitude of the ionospheric reflection coefficient as a function of ff frequency is calculated from individual spectral analysis of the ground wave and the once reflected sky wave results are compared with those obtained using an ionospheric model the success of the method depends upon the accurate location of the source and the correct selection of strokes which contain only appreciable vertical currents in the discharge column 2535 diurnal change of ionospheric heights deduced from phase velocity measurements at vlf 2536 igy observations of f layer scatter in the far east 2537 auroral activity at low latitudes spectroscopic observations made in southern france and at tamanrasset during are described 2538 movement of auroral echoes and the magnetic disturbance current system a brief review of the findings of other investigators and a report of observations made at invercargill new zealand on a preliminary analysis indicates that the ionization giving rise to vhf radar echoes occurs in the most intense portion of the disturbance current system and that the observed movements of electrons can account for the magnitude of the disturbance vector 2539 whistler mode echoes remote from the conjugate point 2540 scientific uses of earth satellites 2541 the american miniature nuclear generator snap a note on a power supply system for telemetry apparatus in a space rocket the decay energy of a radioactive po capsule is converted directly to electrical energy by means of thermocouples giving an output of with efficiency 2542 a transistor stabilized supply to feed an electromagnet used for nuclear resonance studies a circuit is described for a supply with current stabilized to parts in 2543 zener diodes stabilize tube heater voltages typical applications of zener power diodes to the regulation of ac and dc heater supplies are described 2544 internal resistance of dry cells a description of a simple nondestructive pulse technique for investigating the effect of a momentary or continuous discharge on internal resistance for a more detailed account see 2545 the design of a standard block for a digital computing system logical theory design considerations and practical circuit of a block based on alloy junction transistors operating at frequencies up to 2546 binary multiplication in digital computers shows how many steps can be eliminated from the usual process of multiplication by computer 2547 computation of sin n cos n and using an electronic computer 2548 rotating disk function generator for analogue computers a variable radius revolving lamina modulates the light incident upon the cathode of a photomultiplier tube to produce a required voltage time function 2549 a design for an automatic graph plotter transistors and printed circuits are used in equipment based on digital techniques points may be plotted at a rate of three per second with an accuracy within 2550 magnetic core matrices for logical functions some applications of cores having a square hysteresis loop 2551 the design of biased diode function generators relations between the number and spacing of diode sections to give minimum error are derived 2552 recent advances in potted and printed circuits the various potting resins are described in relation to the variation of properties with different proportions of hardener and the effects on the parameters of the potted components the causes of failure of potted circuits are discussed design problems in the use of printed circuits are examined with particular reference to questions of conductor thickness and spacing a method of sealing printed circuits by a thin polysulphide rubber layer which is sprayed or brushed on is described 2553 thermionic integrated micro modules the construction and application of microminiature heaterless valves resistors and capacitors using titanium and ceramic materials are described 2554 the transpolarizer an electrostatically controlled circuit impedance with stored setting the device operates by the controlled transfer of polarization through two or more ferroelectric dielectric sections in series 2555 an electronic timer with voltage control of setting a new grid controlled bootstrap circuit with common cathode trigger provides accurately controlled time delays up to about seconds 2556 microwave switching by crystal diodes 2557 tantalum printed capacitors description of the structural features and characteristics of capacitors using sputtered ta films as the base for the anodized oxide film with evaporated metal counter electrodes 2558 the surface enlargement of aluminium for electrolytic capacitors various chemical and electrochemical methods are described and compared and details are given of a method of measuring the increase in surface area achieved 2559 general solution of the symmetric iterative analysis of asymmetric passive linear quadripoles the asymmetric quadripole is divided into two symmetric quadripole sections which can be treated by iterative matrix methods 2560 investigation of an apparatus for recording atmospherics an analysis of an integrating circuit with a long time constant and its response to a series of pulses 2561 a topological nonreciprocal network element the element is a three terminal device which may be used with physical elements immittances to model the more complex nonreciprocal devices 2562 traditors a new class of nonenergic nonlinear network elements from an analysis based on the lagrangian dynamical equations a class of nonlinear multiport elements is defined which are characterized by the property of neither dissipating nor storing but only transferring energy 2563 transmitting frequency converter in which gold or silver bonded diode is used 2564 one aspect of minimum noise figure microwave mixer design 2565 a cryogenic oscillator a relaxation process based on the transition between the superconducting and conducting phases of a film is described oscillations at frequencies around have been obtained 2566 a sine wave generator with periods of hours an inverse function generator based on the difference amplifier is examined and examples of its use are considered in a logarithmic voltmeter and for sine triangle waveform transformation triangle sine transformation can be achieved by negative feed back a vlf triangular waveform obtained from a cr circuit and relay is thus converted to an accurate sine wave without transients 2567 tube transistor hybrids provide design economy a bistable cathode follower and four stage ring counter are described the transistors appear in the cathode circuits of the valves 2568 physical principles of avalanche transistor pulse circuits a model for the transistor is defined in terms of charge variables and the physical parameters of the device the transient performance of the model is calculated by focusing attention on the minority carrier charge stored in the base region and the influence of base width modulation upon this stored charge in the charge formulation of the problem the physical details of the avalanche multiplication process need not be considered multiplication is accounted for by the boundary conditions which it imposes upon the stored charge good agreement has been obtained between calculated and experimentally observed data for a simple avalanche transistor relaxation oscillator 2569 time to pulse height converter a circuit is described for deriving pulses the amplitudes of which decrease linearly with time 2570 linear gate of duration diodes with a recovery time are used in a coincidence circuit 2571 a torsional magnetostrictive delay line an application of the wiedemann effect using toroidal coil transducers 2572 pulse amplification using impact ionization in germanium some aspects of the phenomena of impact ionization in an impurity doped semiconductor at are described control of the breakdown process is used to obtain pulse amplification in the millimicrosecond range using two and three terminal devices 2573 reducing distortion in class b amplifiers linearization is accomplished by a nonlinear compensation network containing diodes the calculations for an af amplifier with distortion are described 2574 grounded grid power amplifier design a graphical design procedure is described using a disk seal valve type as an example 2575 single ended amplifiers for class b operation a transistorized high fidelity push pull amplifier is described in detail 2576 single ended amplifiers for class b operation a transistorized high fidelity push pull amplifier is described in detail 2577 designing high quality af transistor amplifiers a seven stage amplifier is described one transistor push pull an af output stage in which the biasing condition is controlled by the rectified output 2578 molecular oscillators and amplifiers the principle and operation of molecular beam oscillators and amplifiers are described with reference to the ammonia beam maser molecular amplifiers based on paramagnetic crystals give a wider pass band and a higher output power than the molecular beam type the frequency stability achieved is within one part in 2579 zero field masers solid state three level masers operating with zero magnetic field are shown to be feasible and to have advantages over magnetic field masers in many applications the requirements of the working substance are discussed and it is found that compounds of cr fe ni and gd should be suitable diagrams and tables of maser properties of selected compounds are given on the basis of present knowledge a number of amplifying frequencies between and should be available the range of suitable compounds which has been studied is very small and should be extended 2580 role of double quantum transitions in masers conditions are found in which the operation of a three level maser is governed by the double quantum process and does nor require a true pumping stage such a case although realizable in practice may be of doubtful technical applicability 2581 travelling wave solid state masers 2582 a maser amplifier for radio astronomy at x band the design and operating characteristics of a maser radio meter for use in radio astronomy at wavelength are discussed the operating system which is described has a bandwidth of and an input noise temperature including background radiation into the antenna of about k an rms fluctuation level of about is attained using an averaging time of seconds a discussion of the factors determining the sensitivity of such devices is presented 2583 two level maser materials 2584 theory of three level paramagnetic masers quantum theory amplification and oscillation output noise power spectrum noise figure discussion 2585 parametric amplifier receives space signals signal amplification was in la band and pump frequency in x band giving a noise factor of db and bandwidth using a paraboloid diameter feet the fraction of a watt radiated by pioneer was received at miles 2586 microwave parametric amplifiers and convertors the inherent gain noise and bandwidth characteristics of basic circuits are discussed and a brief description is given of a ladder network converter in which the output frequency is higher than the pumping frequency 2587 circuit conditions for parametric amplification correction of an error in valdes paper 2588 simplified product detector design a circuit is described for a pentagrid converter which may be self excited or separately excited and which has an inter modulation balance adjustment to reduce rectification effects 2589 the modulator as a phase detector a note on the error due to a finite switching voltage applied to a shunt modulator 2590 solution of maxwells equations in terms of a spinor notation the direct and inverse problem the use of spinor notation enables the solution to be obtained in more compact form than does vector notation 2591 the quantum mechanical theory of the dielectric orientation polarization of gases part the static orientation polarization of a dipole gas consisting of symmetric spin molecules 2592 noise theory for hot electrons nyquists theorem is extended to the case in which the distribution of electrons is disturbed by a steady electric field 2593 transient behaviour of the ohmic contact the behaviour of ohmic injecting contacts is analysed for transient currents at a fixed voltage these occur when the free carrier density in the solid is changed by some exciting agent as in photoconductivity or bombardment induced conductivity 2594 the calculation of the field in a homogeneous conductor with a wavy interface analysis showing that the perturbation of an em field in the conductor due to the ripples is proportional to their amplitude 2595 penetration of transient electromagnetic fields into a conductor theory for a uniform electric field abruptly applied to a plane boundary 2596 on the theory of the peltier heat pump the figure of merit for a single stage pump is optimized in the region of partial fermi degeneracy 2597 the space charge field emission hypothesis applied to hayashi data on discharges through gases 2598 concerning the nature of the aberrations in electron sheet beams a power series expansion is used to derive expressions for the aberrations up to the third order in electron sheet beams subject to purely electrostatic focusing four purely geometric aberrations and four aberrations due to chromatic effects are found 2599 new hollow cathode glow discharge current densities of can be obtained with a cathode consisting of a refractory metal with a spherical cavity in neon stable characteristics at a few milliamperes are obtained 2600 new experimental results for plasma electron oscillations study of oscillations in low pressure mercury vapour discharges with plane oxide coated cathodes 2601 a lagrangian formulation of the boltzmann vlasov equation for plasmas a variational principle is found which leads to a new formulation of the problem of small oscillations about equilibrium 2602 wave mechanical correction of the richardson dushman emission formula an attempt is made to overcome the discrepancies between the spin corrected theory of thermionic electron emission and empirical results 2603 rose einstein lattice gases equivalent to the heisenberg model of ferro antiferro and ferri magnetism a hamiltonian is presented that has the form of a finite series of bose operators and is equivalent to the heisenberg model 2604 formation of discontinuities in classical nonlinear electrodynamics 2605 polarization and angle dependence of the reflection factor of absorbers for centimetre electromagnetic waves the dependence of the reflection factor on the angle of incidence and plane of polarization of em waves is investigated for various types of absorbers and results are confirmed experimentally 2606 transients in conducting media the effect of incident wave fluctuations on the mean intensity distribution near the focal point of a lens an extension of chernovs analysis of to the case of fluctuations of arbitrary amplitude 2607 the kirchhoff young theory of the diffraction of electromagnetic waves a transformation is discussed which facilitates the evaluation of kirchhoffs double integrals 2608 on propagation of waves in slightly rough ducts mathematical treatment of acoustic and em wave propagation assuming that the heights of the roughness peaks are small compared to the average separation of the duct walls 2609 the propagation of a variable electromagnetic field in a stratified anisotropic medium computation of the field on the surface of an anisotropic conducting medium due to a dipole lying in the surface see also of 2610 on the propagation of electromagnetic waves in a medium with appreciable spatial dispersion brief description of a method more detailed then that of ginzburg of april in which expansions are obtained for direct and inverse dispersion it is shown that in cubic crystals inclusion of the spatial dispersion leads to a weak anisotropy of the index of refraction 2611 a general theory of magnetic double resonance the theory describes a system consisting of two interacting different species of spin one being saturated by a strong resonant radiation field and the other being detected by a weak field see also 2612 multiple quantum transitions in nuclear magnetic resonance 2613 the application of magnetic resonance to solid state electronics a description of the basic principles and techniques and an outline of some recent applications 2614 excitation of spin waves in an antiferromagnet by a uniform rf field it is possible to excite spin waves in an antiferromagnet by a uniform rf field provided that spins on the surface of the specimen experience anisotropy interactions different from those acting on spins in the interior 2615 exchange effects in ferromagnetic resonance a single dispersion law for transverse em waves and for spin waves is derived which takes account of both relativistic and exchange interactions 2616 paramagnetic electron resonance induction preliminary note on investigations of induced emission at paramagnetic resonance was used at room temperature and a wavelength of cm 2617 ferrimagnetic resonance modes in spheres the magnetostatic solutions of ferrimagnetic resonance in ferrite spheres are briefly derived some experimental results are compared with the theory 2618 role of double quantum transitions in masers 2619 form effect in linear magnetostriction 2620 electron interaction in solids characteristic energy loss spectrum the characteristic energy loss spectrum is analysed with the aid of the dielectric formulation of the many body problem 2621 improved measurements of the positions of intense radio stairs observations have been made at using the cambridge radio telescope as a crossed axis interferometer see also of edge et al 2622 the extension of solar radio spectroscopy to decametre wavelengths preliminary report on spectrographic investigations in the frequency range 2623 on short periodic variations in solar noise storms on days of enhanced solar radiation on in june july and august are investigated by an autocorrelation method in a search for short periodic variations with repetition times between and min results indicate that some noise storms are characterized by periodic variations with repetition times differing from day to day while other noise storms exhibit no periodic variations it is possible that a specific noise storm area retains its characteristics of short periodic variations in radio emission for a solar rotation or longer 2624 on the fine structure of solar bursts in the range and their drift in frequency high speed records have been obtained simultaneously on and with a twin channel receiver at the harestua solar observatory during the period february september an analysis of the records shows that of the bursts occur first on the lower frequency first first on the higher frequency and simultaneously the results are discussed and the receiving equipment is described 2625 a new high resolution interferometer for solar studies the device is essentially aa two element interferometer with the two aerials aligned equatorially which permits use far from the median plane and gives a resolving power of the order of alon et al 2626 a high resolution survey of the andromeda nebula at a report of observations made with the jodrell bank radio telescope 2627 a high resolution survey of the coma cluster of galaxies at 2628 the scattering of radio waves in the solar corona an account is given of measurements carried out each june during the period of the radio emission from the crab nebula at wavelengths of and m results indicate a pronounced sunspot cycle variation in certain regions of the corona a scatter anisotropy and the presence of refraction effects in addition to scattering see also of 2629 theory of the radio echo meteor height distribution in a non isothermal atmosphere the height distribution of echoing points of shower and sporadic meteors belonging to a homogeneous velocity group is calculated for a model atmosphere whose scale height is a linear function of height experimental cut off and the theoretical approximations involved limit the accuracy with which actual scale height and density may be found from observed meteor trails 2630 elevation height and electron density of echoing points of meteor trails these parameters may be evaluated by the continuous operation of cw equipment on mcs at least of all echoes are found to be distorted the electron density distributions are in qualitative agreement with known meteor mass distributions and trail shapes 2631 solar activity and transient decreases in cosmic ray intensity 2632 a new theory of the solar corona it is proposed that the solar corona consists of trapped charged particles moving in the magnetic fields of the sun experimental data are discussed in terms of this model 2633 disturbances of the earths magnetic field considered as relaxation variations records of the horizontal magnetic component at elisabethville and elsewhere show relaxation processes analogous to post disturbances of magnetic storms and subject to the day recurrence tendency 2634 possible causes of geomagnetic fluctuations having a sec period comment on of may daniels short and long period oscillations sometimes preceding but more often accompanying a main train of magnetic activity are described they are considered to be associated and of electromagnetic origin 2635 geographical variations in geomagnetic micropulsations significant differences consistently occur in simultaneous data obtained at stations miles apart 2636 on a possible auroral origin of certain geomagnetic pulsations 2637 the relation between the sudden disappearance of filaments and magnetic storms an analysis of records shows a correlation between the sudden disappearance of filaments close to the suns central meridian and magnetic disturbances 2638 green coronal line intensity and geomagnetism statistical analysis indicates a minimum in geomagnetic activity following the central meridian passage of regions of high green line intensity 2639 laws of motion of an earth satellite the principles of multistage rocket flight are considered and formulae for rocket velocity are derived tables give the satellite velocity and duration of flight for heights up to km 2640 a discussion on observations of the russian artificial earth satellites and their analysis the he text is given of fifteen papers discussed at a meeting in london november these include results obtained using radio telescopes and interferometers doppler recorders and direction finding and field strength measuring equipment applications are made to the computation of orbit parameters see also of for a similar discussion 2641 observations on the ussr earth satellites and the study of radio wave propagation measurements of bearing angle of elevation and doppler frequency shift were made at and the observed phenomena could be explained in terms of existing knowledge of ionospheric propagation the derivation of orbital parameters from the observations is discussed 2642 a type of variation of the signal strength from fluctuations of signal strength relative to the satellite position in orbit indicate that the satellite produces heavily ionized tracks of very long lifetime observations have been made to test this hypothesis and results are given 2643 diurnal lapse of signals from sputnik a brief note dated april states that systematic observations have established that pulse modulation is present only when the satellite is in sunlight on very close transits the cw signal can be detected with sufficient strength to record the doppler shift 2644 density of the atmosphere at heights between km and km from analysis of artificial satellite orbits 2645 fluctuations in the brightness of the second artificial earth satellite these brightness fluctuations are explained by the rotation of the satellite on its axis its maximum brightness corresponding to its greatest cross section as seen by the observer a graph shows these brightness variations as recorded by the odessa observatory 2646 the antipodal reception of sputnik the mechanism of the propagation of waves around the earth within the ionospheric layers is discussed and the best conditions for antipodal reception are deduced it is concluded that at stanford calif the best conditions for frequent reception occur from the south east during summer afternoons this is in agreement with observations 2647 satellite measured radiation the relevance of atomic change exchange processes to the nature of the radiation belt is noted 2648 some results of investigations on cosmic rays using artificial earth satellites the intensity variations of cosmic rays as recorded during the flight of the second sputnik are shown there were no appreciable corresponding variations at ground level 2649 corpuscular radiation and the acceleration of artificial satellites observations of satellites and more accurate values of acceleration have been calculated at twice the original resolution of august correlation with cm solar radiation is higher for than probably due to greater observational accuracy an increased acceleration of at the time of two major geomagnetic disturbances following flares indicates the effect of corpuscular radiation on atmospheric density at the km level 2650 on the existence of a strong magneto ionic effect topside of the f maximum of the kennelly heaviside layer observations of the faraday effect in signals from artificial satellites showed noticeable magneto ionic effects at altitudes up to km 2651 parametric amplifier receives space signals 2652 radio reflections from satellite produced ionization observations have been made on frequencies of and two very different effects obtained on both and are described 2653 cosmic ray instrumentation in the first us earth satellite the instrumentation was designed for conservation of electrical power and for stable and reliable operation over a wide range of temperatures 2654 some results of investigations of the upper atmosphere vertical rocket investigations carried out in ussr between and showed that contrary to established opinion above the e layer there is only a very shallow minimum in electron density the electron density increases up to with a maximum at km and then slowly decreases so that at km the density is electrons cm 2655 a theoretical study of the dynamical structure of the ionosphere a comprehensive survey of the modification to chapman theory which are necessary to explain the actual behaviour of the ionosphere both the large f layer anomalies and the smaller ones for the e and f layers are discussed over references 2656 conditions in the outer ionosphere it is found that the electron concentration in the outer ionosphere decreases with the height considerably less rapidly than it increases at lower levels the values obtained show that at the concentrations of electrons and neutral particles are of the order of and per cm respectively 2657 investigation of the equatorial electrojet by rocket magnetometer two layers of electrical current were detected one existing near an altitude of and the other about higher 2658 geophysical effects of high altitude nuclear explosions a report of observations made at hiraiso observatory on and august fade outs on frequencies between and an enhancement of atmospheric noise at have been recorded these effects are attributed to an increase in d layer ionization extending over much greater distances than had previously been envisaged 2659 sporadic e region ionization spread f and the twinkling of radio stairs kinematic instability in the ionization gradient of a medium drifting across a magnetic field is considered to be responsible for the three phenomena 2660 the effect of sudden ionospheric disturbances sids on pulse reflections from the lower ionosphere during a typical large sid associated with a class or class flare the increase in ionization might vary from at km through at km to unity at km the amplitude recovery of the e layer echo lagged about min behind the recovery of the lower echoes around km at all heights below km echo recovery occurred simultaneously 2661 rocket measurements of absorption in the lower ionosphere results are given of measurements of the field strength of one long wave and two medium wave transmitters the d layer minimum height is about km and medium wave observations indicate maximum absorption at km the attenuation being km for normal incidence 2662 refraction of extraterrestrial radio waves in the ionosphere expressions are derived for estimating ionospheric refraction at low frequencies horizontal gradients of electron density are considered positions of a discrete source obtained from observation at after applying corrections for refraction are within a few minutes of arc of the observed position at mcs 2663 simultaneous occurrence of subvisual aurorae and radio noise bursts on records show that there is a correlation between aurorae and noise bursts but anomalies exist which cannot be explained satisfactorily 2664 auroral isochasms observed isochasms and projections of circles in the equational plane along the geomagnetic lines of force are compared 2665 investigation of an apparatus for recording atmospherics 2666 an experimental proof of the mode theory of vlf ionospheric propagation 2667 a multiple channel dc recording system describes an am system with tape noise cancellation enabling up to twelve channels to be recorded on a conventional single track recorder together with speech and timing signals 2668 the thermal behaviour of semi conductor rectifiers measurements are described which were made on heavy current ge diodes to determine the thermal inertia the effect of cooling on the overload characteristic is discussed 2669 using silicon diodes in radar modulators a peak power of kw is developed using si diodes for charging the artificial line and for clipping reverse voltage swtings the diodes dissipate instantaneous powers up to kw 2670 selenium rectifiers with artificial layers of selenides of cadmium tin bismuth and lead the action of various selenides as barrier layers has been investigated by measurement of the rectifier dc and ac characteristics cdse and snse layers play an important role in rectification but the selenides of bi and pb seem to be unsuitable in general the layer material should have a resistivity cm 2671 current time relationship in the forward direction of electrolytic rectifiers qualitative explanation of the effects observed on applying alternating rectangular and sinusoidal voltages 2672 use of operational amplifiers in precision current regulators low drift high gain dc amplifiers in a control loop can reduce steady state error 2673 study of a digital analogue converter a technique is described using bistable multivibrator circuits for generating a current proportional to the numbers on a binary scale 2674 an analogue computer for the prediction of acoustic propagation in the atmosphere ray patterns are presented on a cr tube when air temperature and wind velocity data are fed into the computer 2675 new horizons in computing a report of some of the computer engineering techniques which were described in papers read at the international conference on information processing held in paris 2676 superconducting computer elements switching elements working at and storage elements of the persistent current type with a transition time of have been developed under laboratory conditions their successful commercial possibilities depend mainly on the development of thin metallic films of consistent quality used in the construction of these elements 2677 flux controlling type adder experimental circuits using magnetic cores to control switching are described 2678 the cryosar a new low temperature computer component the cryosar is a high speed component whose operation at about is based on impact ionization of impurities in ge two types using compensated and uncompensated ge can be used as bistable and normal diodes respectively turn on time is about sec they are very small and present results suggest excellent reliability 2679 thin magnetic films for digital computer memories characteristics of magnetic films and ferrite cores are tabulated 2680 semiconductor devices for microminiaturizatio integrated semiconductor devices are illustrated in which active and passive components are incorporated in a single piece of semiconductor material with no interconnecting metallic leads their application to logic circuits is explained 2681 design of random noise transformers the design is developed from basic principles and verified by experiment 2682 representation of switching circuits by binary decision programs 2683 the total excursion resistor the design of resistors that will remain within a guaranteed tolerance range throughout their life is discussed 2684 behaviour of square loop magnetic cores in circuits the switching time with a loaded secondary winding is derived the behaviour of ferrite cores under various conditions of loading and drive is shown to agree with theory 2685 high speed multiplexing with closed ring counters the action of a channel electronic switch which consists of semiconductor diode gates each controlled by a flip flop circuit is explained the switch can sample from to voltage sources at rates as high as 2686 probable life of paper capacitors a study based on statistical laws of probability experimental results are in good agreement with theory 2687 study of the transfer properties of a linear system based on the concept of rate of growth of spectral energy 2688 elements of electronic circuits part use of short time constant circuits with diodes and triodes august 2689 network transformations for wave filter design calculations are simplified by charts which enable the configuration of two terminal networks to be altered while retaining their impedance characteristic and also to alter the element values without changing the configuration or impedance characteristics 2690 band pass ladder filter half sections considering purely reactive half sections general formulae for branch and image impedances and reflectionless interconnections are examined 2691 generalization of zobel type ladder filters a new and simplified method of design in which the the filter is considered as an indivisible unit rather than a combination of elementary structures as in the zobel method 2692 physical theory and technique of electromechanical wave filters equivalent circuits are derived and the design of some practical filters is described with details of their performance 2693 constant s equalizers equations are derived for high medium and low frequency equalizers based on a bridged t configuration as equalization is varied from step to step the point of maximum equalization changes and the insertion loss s of unequalized frequencies remains constant 2694 tunnel diodes as high frequency devices 2695 transistor applications in pulse techniques details are included of high speed divider circuits and a stabilized dc power unit 2696 transistor circuits for a digital computer the requirements of amplifiers used for pulse regeneration are considered and blocking oscillators and regenerative amplifiers employing transistors suitable for reshaping and retiming pulses in a digital computer with a digit rate are described some details of their practical application are given 2697 simplified coincidence circuits using transistor and diodes a simple coincidence circuit is described which is as fast as a standard valve circuit the measured threshold and resolving time characteristics are given 2698 transistor circuitry for radiation counting four instruments are described a pulse amplifier a pulse height analyser a scaler and a linear count rate meter 2699 using divider vernier to synchronize pulses the vernier adds or deletes pulses at the input of frequency dividers thus enabling the output to be precisely synchronized eg to the wwv second pulses 2700 present applications of semiconductors description of semiconductor applications with particular reference to dc amplification for analogue computers 2701 wide band amplification at high frequencies a transmitter incorporating a wide band amplifier covering is described distributed amplification is used with artificial transmission lines in which the shunt capacitances are provided by the interelectrode capacitances of the values 2702 the design of cathode follower circuits a detailed summary of design principles and operating characteristics with a description of several circuit applications 2703 the fundamentals of a low noise hf preamplifier for to the circuit described uses a disk seal triode in grounded grid connection and is intended for radio astronomy applications at a wavelength of cm and with if bandwidth the input noise figure is 2704 contribution to the study of the operation of magnetic amplifiers the operation of a basic magnetic amplifier circuit is analysed assuming a square wave input and z rectangular hysteresis loop the area of which is increased due to eddy currents an equivalent circuit is derived that is applicable for the case of a periodic or continuous control signal 2705 volt second transfer efficiency in fast response magnetic amplifiers part as a design parameter the relation between volt seconds and ampere turns is confirmed by measurements on a specially designed magnetic amplifier part of july 2706 some aspects of feedback in transistor amplifiers the design of an amplifier with high input impedance is described and problems peculiar to the use of feedback in transistor circuits are discussed 2707 parametric energy conversion in distributed systems analysis of most types of travelling wave parametric amplifier with little or no dispersion shows that no exponential amplification at the fundamental frequency of an applied signal is possible although the total n energy increases with distance it is spread among a large number of frequency cross products for the beam type system amplification of the fundamental component may become possible as dispersion increases but a more detailed analysis is required 2708 the grain boundary amplifier the construction and characteristics of an amplifier are described which is based on modulation of the sheet conductance of a grain boundary in n type ge at k a power amplification of db was obtained at a frequency of which approached zero at 2709 a new class of materials for bloembergen type masers a class of substances exists which have four levels degenerate in zero field these levels show a linear zeeman effect but are not necessarily equally spaced when a magnetic field is applied and there are allowed transitions which are not limited to those between adjacent energy levels 2710 superregenerative reactance amplifier the method of operation of an l band variable reactance amplifier as a superregenerative amplifier is described the results indicate the feasibility of a single stage low noise microwave receiver 2711 parametric amplifiers and cancellation of ferromagnetic hysteresis by orthogonal polarization measurements have been made on tubular samples of ni zn ferrites showing the effect of a uniform magnetic field parallel to the axis on the magnetization due to alternating current in a toroidal winding for a sufficiently high field intensity hysteresis becomes negligible and the magnetization curve tends to become linear this principle has been applied in the design of a variable inductance parametric amplifier operating at with a gain of 2712 parametric amplifiers as superregenerative detectors the details of superregenerative operation are described and effects permitting self quenching are explained two cavity type parametric amplifiers using semiconductor diodes are investigated one in the l band near and the other in the s band near 2713 low noise tunnel diode amplifier an amplifier consisting of a tuned circuit shunted by a negative conductance tunnel diode is described and experimental gains bandwidths and noise figures obtained at are quoted greatly improved noise figures and microwave operation should be possible ultimately see below 2714 ferroelectric capacitors a vfo is described which incorporates a ferroelectric capacitor as a frequency modulating element 2715 the deflection of waves by movement of the media of propagation optical observations of aberrations of fixed stars are held to be inconsistent with the hypothesis that light waves are affected by movements of the ether this disproves datzeffs theory of which has already been criticised see of 2716 related experiments with sound waves and electromagnetic waves analogous situations in the propagation of sound and em waves are described and demonstrated experimentally these include cut off effects polarization rotation and external guiding superdirective arrays are also examined 2717 stable orbits of charged particles in an oscillating electromagnetic field in the field of a cylindrical waveguide driven in the mode the particle moves around the axis of the guide sufficient conditions for stable orbits are derived 2718 charge penetration into a conductor in equilibrium statistical mechanics is used to show that the electric charge on a conductor in equilibrium is not restricted to its surface but penetrates into the interior in the form of a space charge density the effective penetration depth being of the order of a few atomic distances similarly the electric potential in a charged conductor is not strictly constant but varies in space which results in a small but finite potential difference between the interior and the surface layers 2719 the determination of a criterion for the surface conduction of insulating solids an electrode system is described for determining a curve of the variation of specific resistance of a specimen as a function of distance between electrodes a criterion of surface conduction may be deducted by extrapolation 2720 electron temperature and electron noise in high frequency torch discharges the noise temperature of an electron torch in air and nitrogen at atmospheric pressure is measured at and found to be of which about is due to electron temperature and to shot noise these results and the measurements of other plasma characteristics are interpreted with reference to the findings of other authors references 2721 nature and role of ionizing potential space waves in glow to arc transitions westberg 2722 influence of the diffusion angle on the energy spectrum of an electron beam after passing through a thin film measurements have been made with a magnetic spectrograph on films of al ge and mn 2723 the three dimensional intensity distribution near the focus of waves diffracted by l slit and rectangular apertures 2724 theory of secondary electron emission of metals 2725 electron emission from the surface of pure molybdenum after bombardment by electrons after low energy electron bombardment for a period of sec pure mo surface at room temperature in the dark was found to emit electrons at energies up to the electron current decreased from to after 2726 the excitation of molecular vibration and rotation by impact of slow electrons a new approximate formula is derived for the cross sections for excitation of molecular vibration and rotation by impact of slow electrons account is taken of the fact that in such impacts the incident electron is moving much faster than the nuclei in the molecule while its wave function suffers considerable distortion by the molecular field 2727 electron energy distributions in plasmas part report of a method of carrying out a druyvesteyn analysis electronically the results show very wide deviations from the maxwellian distribution in striated discharges and suggest that a high anomalous rate of energy exchange between the electrons of a low pressure discharge is a much rarer phenomenon than might be supposed 2728 langevin equation and the ac conductivity of non maxwellian plasmas 2729 microwave investigations of plasma the basic theory and the experimental details of three methods are described resonator method waveguide method and cross modulation method the ambipolar diffusion and recombination coefficients and the electron collision frequency are determined and experimental results are reported 2730 excluded volume problem and the ising model of ferromagnetism 2731 stimulated emission of radiation by relativistic electrons in a ma gnetic field an expression is derived for the transfer of energy between an alternating electric field and electrons moving at right angles to a magnetic field it is shown that for relativistic electrons a net stimulated emission is possible 2732 diffraction by a smooth object a geometrical theory of diffraction a theory of wave propagation based on aan extension of geometrical optics is explained and applied to diffraction problems associated with smooth convex opaque objects 2733 diffraction of a skew plane electromagnetic wave by an absorbing right angled wedge 2734 growth of electric space charge and radio waves in moving ion streams in a medium comprising two identical interpenetrating ion streams four different space charge phenomena may occur two of these are discussed an instability described as a growing ion cloud this is thought to be the basic mechanism of a two stream amplifier and to be important in solar rf emission an evanescent wave sometimes wrongly interpreted as a spatially growing wave see of and back references 2735 thin absorbent films the problem of optimum thickness in connection with a classification of these films theoretical note on determining the film thickness for which the absorption of an incident plane em wave is a maximum 2736 aan electronic paramegnetic resonance spectrometer influence of the amplitude of modulation of the magnetic field on the line shape obtained by synchronous detection 2737 cross relaxation in spin systems analysis of the transition region of nearly equally spaced levels 2738 galvanomagnetic properties of cylindrical fermi surfaces 2739 on highly ionized regions of interstellar matter a parallel is established between the properties of heavily ionized regions and the superconducting properties of metals at very low temperatures this analogy leads to a new description of certain regions of the interstellar medium 2740 principles and present results of radio astronomy 2741 the nature of the cosmic radio sources a detailed review of observational data and discussion of theory references 2742 radio emission of the sun and planets a description of the suns radio emissions during periods of low and high activity on and radio bursts are considered and the thermal and sporadic theories are discussed radio emissions from jupiter venus and mars are also examined references 2743 radio emission following the flare of august two types of emission appear to have occurred a burst at and decreasing in intensity with decreasing frequency and a long lasting continuum on frequencies below delayed with respect to 2744 measurement of the cosmic ray intensity in the stratosphere at various heights and latitudes investigation of the altitude dependence of particles of the cosmic ray soft component in the latitude range to results indicate that at a latitude or the majority of particles of soft components are electrons generated by mesons at latitude an excess of electrons is found possessing energies vekiw cn expressions are derived for the primary particle energy spectrum at latitude the primary cosmic ray particle flux has been found equal to particles min cm sterad 2745 on recurrent variations in the intensity of primary cosmic radiation in a period of maximum solar activity recordings of variation in the intensity of cosmic radiations made during the period october to july show a cyclic variation with a stable period of mean solar days the maximum amplitude being reached in october 2746 flux and energy spectrum of cosmic ray particles during solar maximum fluxes measured over minnesota and texas in are significantly lower than those observed at solar minimum a mechanism is proposed to explain the changes 2747 cosmic ray cut off rigidities and the earths magnetic field 2748 some indices of solar activity based on ionospheric and radio noise measurements methods are described for producing indices of solar activity based on the ionization of the e and f layers and monthly mean figures thus derived are tabulated the two indices are compared with each other and with solar noise flux at and the correlation is high practical applications of the indices are discussed briefly 2749 prediction of sunspot numbers until the end of the present cycle a modified equation derived from recent data has been used for the determination of sunspot numbers for the period 2750 relation between type iv emissions and other forms of solar activity observations indicate a correlation between optical centres associated with type radio emissions see eg of and radio storm centres 2751 geomagnetic activity following large solar flares there is a marked tendency for magnetic disturbance to follow the largest solar flares no association was shown in the period near sunspot minimum this confirms the negative result found by watson of for roughly the same period 2752 the propagation of world wide sudden commencements of magnetic storms analysis of differences in the recorded time of the first impulse at ten widely separated observatories suggests that the position of the sun determines the hemisphere in which the sudden commencement first occurs 2753 circuits for space probes brief description of instrumentation in the payload stage of the pioneer vehicle and at tracking stations 2754 theory of the effect of drag on the orbital inclination of an earth satellite it is assumed that the drag is in the direction of the air velocity relative to the satellite and that its magnitude diminishes so rapidly with altitude that it is appreciable only near perigee in an elliptic orbit results are deduced for the secular changes in inclination up to but not including the final ballistic stage 2755 optical observations of artificial earth satellites observations are made visually using telescopes and are also recorded photographically an oscillographic method is described for recording the exact instant of the opening and closing of the camera shutter these observations are valuable in the determination of the exact shape of the earth 2756 radio observations of the first two artificial earth satellites review of some of the early measurements made by stations in west germany 2757 radar observations of the second russian earth satellite sputnik an analysis of observations made with the steerable radio telescope at jodrell bank at frequencies of and results suggest that the observed fading characteristics were due mainly to rotation of the satellite and from a study of the scattering area it is concluded that the satellite was a long object having a reradiation polar diagram with one major and many minor lobes there was no evidence that the satellite produced any ionization 2758 recording of sputnik on field strength recordings taken at breisach west germany of day time transits during the period november are discussed 2759 radio astronomical investigations by means of artificial earth satellites the ionosphere cuts off extraterrestrial radio emissions over a wide range of frequencies thus observations which would not be possible on the ground could be made from satellites 2760 investigation of sola r corpuscular radiation using artificial earth satellites 2761 discovery of electrons in the upper atmosphere by means of the third soviet earth satellite note of electron energies recorded between and above sea level the maximum electron energy registered was v 2762 investigations of the ionosphere by means of an artificial earth satellite a description of methods based on the doppler effect in which correct results depend on the appropriate choice of the two frequencies used 2763 some deductions of ionospheric information from the observations of emissions from satellite the theory of the analysis the effect of the ionosphere on the doppler shift frequency and on the frequency of faraday fading is expressed theoretically in terms of the difference in phase path of the waves for two positions of the satellite 2764 some deductions of ionospheric information from the observations of emissions from satellite experimental procedure and results the application of the approximate analysis to the small number of suitable observations suggest that the ionization density decreases slowly with height above the maximum of at night 2765 some results of the determination of the electron concentration of the outer regions of the ionosphere by observations of the radio signals from the first earth satellite the method of calculating the path of the radio waves in the outer ionosphere is described the electron concentrations determined for heights between and which vary between and are tabulated 2766 the indian program for the international geophysical year some results of the program on ionosphere a report of some ionospheric effects particularly those observed in equatorial regions 2767 a preliminary model atmosphere based on rocket and satellite data a model atmosphere is described for the height range km and values of density pressure and scale height are tabulated as functions of altitude discrepancies between data from various sources are examined and it is estimated that they are within the limits to be expected from latitude variations and the uncertainties of experimental observations 2768 chapman behaviour in the lower ionosphere it is shown that chapmans relations for the variation of critical frequency and height of a layer with solar zenith angle can be applied to any point on that layer and that it is not necessary to assume monochromatic radiation these results are then applied to electron density height profiles and it is shown that chapman behaviour can be detected to a height of being consistent with a scale height of or km 2769 some wind determinations in the upper atmosphere using artificially generated sodium clouds results for the height range km are reported 2770 coefficients for the rapid reduction of records to profiles without computing aids the tables of coefficients can be used for the ordinary ray at any station having aa magnetic dip less than the sensitivity of the coefficients to dip angle and gyrofrequency is discussed and comparisons are made with the profiles produced using the budden matrix method 2771 spiral occurrence of sporadic e intense sporadic e ionization at high latitudes in the northern hemisphere is distributed along a curve similar to a stormer precipitation spiral for negative particles 2772 an additional lunar influence on equatorial e at huancayo the time of first appearance of equatorial e during the period may april is shown to vary with lunar age this supports matsushitas hypothesis on the relation between s currents and equatorial 2773 some further analyses of e layer measurements in south africa during the solar eclipse of december a re examination of data see of szendrei and mcelhinny for preliminary results suggests that the measurements could be accounted for by assuming that of the solar radiation comes from outside the visible disk at the same time it is necessary to postulate an effective recombination coefficient of cm sec 2774 the electron density distribution in the outer ionosphere derived from whistler data a method of successive approximations is developed to determine the electron density distribution with height in the outer ionosphere when the variation of whistler dispersion with geomagnetic latitude is known the method is applied to specific whistler data and the results infer that the electron density distribution decreases exponentially with height in the range km an equation is derived for the distribution in this height range during january may 2775 some possible effects caused by strong gyro waves in the ionosphere a theory is developed for the effect of an extremely powerful pulse of extra ordinary gyro waves on the nocturnal e region near km and the day time d region near km the changes in collisional frequency and electron density at these levels are derived with their consequent effects on the propagation characteristics of a transverse ordinary wave at kcs it is shown that with radio pulses of sufficient power observable changes may be produced in air glow meteor trails fast particle tracks and local magnetic elements it would also be possible to use such a pulse to determine the coefficient of attachment at the km and km levels 2776 auroral x rays cosmic rays and related phenomena during the storm of february balloon observations of x ray bursts coincided with magnetic bays radio noise absorption and auroral luminosity 2777 photoelectric measurements of hydrogen emissions in aurorae and airglow 2778 theory of the origin of the very low frequency radio emissions from the earths exosphere the gyro rotation of solar protons about the earths magnetic field corrected for doppler shift is used to derive a general equation of the theory see of 2779 interpretation of smooth type atmospheric waveforms accurate waveguide or pulse reflection analysis of the regular type of smooth waveform reveals a subdivision termed pseudo regular this type can be satisfactorily explained using waveguide or pulse reflection theory of propagation when complicated source conditions are considered and the discharge in the lightning channel is not assumed to be effectively instantaneous 2780 very low frequency spectra of atmospherics propagated through the ionosphere a report of experimental results which support the mode theory suggested by budden 2781 transistor rectifier gives dc of either polarity a diagonally symmetric power transistor circuit which permits smooth load current variation over a range of several amperes 2782 transistorized three phase power supplies a description of the circuits required to convert a dc supply to a phase supply 2783 transistor invertors and rectifier filter units details are given of a symmetrical push pull circuit with improved output waveform and a bridge connection for very high output power both operate from a supply 2784 measuring load characteristics of silicon cells a simple test circuit is described which can be inserted in any type of rectifier circuit 2785 pn junctions in germanium the improvement of the physical characteristics of junctions is discussed with particular reference to power rectifiers 2786 switching vhf power with silicon diodes a coaxial type of switch designed for aircraft aerial systems 2787 ball relays a relay is described in which a ball or a number of balls of a permeable material attracted to an energized core simultaneously completes both the magnetic and the output circuits various forms of the basic design and their applications are given the advantages are long contract life low control power and simple construction 2788 testing high speed digital computer circuits a word generator providing bit serial binary words at a rate of is described any one of words can be selected manually high tetrodes are used to obtain high speed operation 2789 automatic input equipment for commercial data processing systems magnetic equipment for reading documents with characters and symbols printed in magnetic ink is described with a high speed transportation arrangement characters can be read and documents handled per second 2790 a fast method of reading magnetic core memories description of a word bit storage system using a method of core threading suggested by renwick of the system includes a circuit which prevents parasitic pulses from blocking the output amplifiers reducing the cycling time to 2791 the parametron a digital computing element which utilizes parametric oscillation japanese research and applications of parametric oscillation are described a parametron element is essentially a resonant circuit with a nonlinear reactance oscillating at haalf the driving frequency a binary digit is represented by either of two stationary phases radians apart 2792 a negative resistance for dc computers 2793 microwave parametric subharmonic oscillators for digital computing a variable capacitance oscillator with output frequency is described and its use for amplifying scaling and performing logic functions is discussed the advantages of carrier over base band systems for high speed computing are mentioned see above 2794 dynamic testing of computer building blocks a variable frequency pulse source with repetition frequency up to is described 2795 transistorizing electronic equipment a general discussion of semiconductor devices giving tabulated data on ge and si diodes and transistors specifications of associatted thermistors capacitors and batteries and a note on the construction of solid circuits 2796 some broad band transformers describes the construction theory and performance of transmission line transformers which take the form of twisted pairs having distributed interwinding capacitance bandwidth ratios as high as in the range can be obtained with transformation ratios of unity or 2797 some notes on the optimum design of stepped transmission line transformers 2798 double tuned transformers steady state and transient response a general analysis applicable to both wide and narrow band cases all degrees of coupling are examined and expressions are derived for insertion loss phase shift envelope delay rise time and overshoot 2799 current noise and nonlinearity in pyrolytic carbon films a high correlation exists between noise and nonlinearity when the variations in film dimensions are taken into account a balanced bridge method for measuring nonlinearity is described 2800 microwave semiconductor switching techniques 2801 switching circuits for missile count downs a transistor circuit is described which produces a switching pulse if its input differs by more than a predetermined amount from a given reference level the use of nonlinear negative feedback ensures stable operation over a wide temperature range 2802 voltage variable capacitor selection guide tabulated information is presented to facilitate the choice of the best component for the circuit requirements 2803 elements of electronic circuits amplitude selection and amplitude comparison october 2804 signal flow graphs an article in three parts covering basic theory topological relations for network synthesis and applications to feedback theory 2805 signal flow graphs a discussion of the application of masons technique of circuit analysis of and of 2806 dissipation loss in multiple coupled resonator filters a simple approximate formula enables centre frequency loss to be computed and elsewhere loss may be computed from the prototype low pass filter after suitable circuit modification unsymmetrical and symmetrical designs are considered 2807 miniature resonators for uhf an investigation of the extent of miniaturization possible in coaxial resonators 2808 a negative resistance for dc computers a nomogram is presented for the design of a circuit using transistors and resistors to give any required value of negative resistance 2809 some applications of non euclidean geometry in quadripole theory a survey of literature and an attempt to correlate the work of various authors the treatment of impedance and noise transformations by means of the poincare and cayley klein models of non euclidean hyperbolic space is discussed references 2810 novel expression for the relationship between the real and imaginary parts of the transfer function of a linear filter lipkin 2811 theory a nd design data for the synthesis of tchebycheff parameter filters 2812 microwave parametric subharmonic oscillators for digital computing 2813 experiment indicating generation of submillimetre waves by an avalanching semiconductor 2814 curves obtained by van der pols method for an oscillator with cubic nonlinearity 2815 frequency control of magnetic multivibrators a basic circuit is developed allowing output frequency to be controlled continuously or in steps over a wide frequency range variations of the circuit provide similar controls of output amplitude 2816 designing transistor circuits sequential circuits parts bistable flip flop a stable and monostable multivibrator blocking oscillator and negative resistance circuits and transistor reactor combinations are discussed 2817 stepping up frequency with counter circuits precise frequency multiplication is achieved with digital feedback counter divider circuits and a phase comparator the circuit described multiplies frequencies between and by a factor of with an error of 2818 reducing errors caused by power supply variations differential amplifiers in cascade cancel the errors 2819 concertina phase splitter the performance of the circuit is analysed with particular regard to the frequency range of operation 2820 graphical determination of the operating characteristic of a magnetic amplifier a method of constructing a performance characteristic for a magnetic amplifier is described based on the equivalent circuit derived earlier of october bernard and pio taking account of the nonlinearity of the associated rectifier and expressing output current as a function of current in the control circuit 2821 q multiplication with transistors two transistor circuits are described with negative impedance stable to within over a temperature range 2822 feedback design for transistor amplifier stages equations are given for realizing a specific input impedance or maximum feedback for a given gain 2823 avalanche controlled semiconductor amplifier the theory of a particular avalanche controlled semiconductor amplifier is given its hf operation should be good 2824 three level spin refrigeration and maser action at 2825 method for calculating simultaneous resonance conditions in a three level ruby maser 2826 multilevel pulsed field maser for generation of high frequencies the maser has been operated at as an oscillator at both and with a pumping frequency of principles of operation and characteristics are discussed 2827 low field x band ruby maser the signal frequency used was and the pump frequency the low pump frequency and low magnetic field requirements are attractive although the achievable gain bandwidth product is lower than with other masers 2828 a surface wave parametric amplifier the proposed amplifier takes the form of a slab of ferroelectric material between two conducting planes the slab is pumped with high power useful gain would be achieved at x band frequencies even with present ferroelectric materials with new materials the amplifier could be used at mm 2829 relaxation phenomena in diode parametric amplifiers oscillations have been observed in parametric amplifiers under certain conditions with cw pump sources the effect varies with pump power being a relaxation oscillation at lower pump power and a stable oscillation when this is increased 2830 lumistors amplifiers of the future 2831 criterion of uniqueness for the solutions of maxwells equations a linear medium characterized by the absence of dielectric or magnetic hysteresis is considered 2832 two coordinate colour a short discussion of the subjective and objective characteristics of a colour and their relation to colour vision the two colour experiments of land are summarized and their bearing on goethes two colour theory of and granits recent experiments is indicated 2833 grapho analytical plotting of trajectories of charged particles in variable electric and constant magnetic fields two techniques are described based on addition of velocities and radius of curvature examples of plotting using these two methods are shown errors and means of correcting them are indicated 2834 the phenomenon of depolarization in small conducting bodies in an extensive electromagnetic high frequency field continuation of earlier investigations current density and internal field are calculated as a function of the external field the results are discussed with reference to measurements on ge in the temperature range at 2835 role of negative effective mass in negative resistance a theoretical investigation of the relations between negative effective mass carrier distribution and negative resistance 2836 impurity scattering in super conductors perturbation theory is used to determine the reduction in super conducting transition temperature due to scattering by impurities dissolved in the superconductor 2837 the radiation from a charged particle passing through a plate expressions are derived for the fourier components of the radiation field in the space in front of and behind a dielectric plate in vacuum 2838 motion of a charged particle in an anisotropic medium expressions are derived for the em field components and the total energy losses are determined for a charged particle moving in an anisotropic gyroelectric and gyromagnetic medium 2839 magnetic perturbation of cathode rays the splitting of an electron beam when it penetrates a magnet was observed with electron diffraction apparatus an explanation is given in terms of polarization of free electrons 2840 ion drag pressure generation a theory of pressure build up under unipolar ion conduction is presented and verified experimentally constriction of the current flow leads to sizable pressures in insulating liquids 2841 on acoustic electrical phenomena in a degenerate electron ion plasma a calculation of the absorption coefficient for ultrasonic waves travelling in a plasma 2842 low frequency oscillations of plasma in a magnetic field mathematical analysis of small oscillations of a plasma consisting of electrons and singly charged ions some limiting cases are discussed for which a solution of the dispersion equation can be found 2843 on the behaviour of a conducting gaseous sphere in a quasistationary electromagnetic field investigation by the perturbation method of the stability of a homogeneous plasma sphere with an external field 2844 statistical derivation of the dispersion formula of a lorentz plasma of finite temperature 2845 an investigation on plasmas in external magnetic fields steady state varying fields in english 2846 dependence of electron mobility on magnetic field in a fully ionized gas analysis with tables and illustrative graphs of the variations of drift and hall mobilities with magnetic field 2847 a system of magnetic moments in a weak variable magnetic field a mathematical analysis of a system of magnetic moments which possesses electric exchange and weak magnetic dipole dipole interactions and which is located in an external magnetic field the equation of motion of the magnetization vector is derived and the limits of its applicability are discussed 2848 on magnetic permeability for the case of magnetization under the action of a circular alternating field in the presence of a dc longitudinal field a method is described for measuring the permeability of a torsion free iron wire results are given for various values of the circular alternating field the longitudinal field and the wire tension 2849 ferromagnetic resonance in a circularly polarized electromagnetic field of arbitrary amplitude the exact solution of the magnetization equations of motion is examined the dependence of the magnetization components on the amplitudes of the magnetizing field and rf field is determined 2850 cherenkov radiation from dipoles mathematical analysis of the cherenkov radiation from electric and magnetic dipoles moving in a continuous medium in a channel or a slit 2851 on the cherenkov radiation of an electron moving in a medium with spatial dispersion an examination of the cherenkov radiation in an isotropic medium including a consideration of spatial dispersion the angular distribution of the radiation intensity and the escape of the radiation through the surface of the medium are discussed 2852 radio emission from an atomic explosion in an atomic explosion which is accompanied by asymmetric emission of quanta radio waves are emitted due to the presence of a current in the ionized air the duration of the oscillation in each halfwave is of the order of for a given asymmetry in emission of the rays the amplitude of the oscillations depends weakly on the total number of quanta 2853 emission of radio waves from detonations transient em waves giving a field strength of about close to an explosion of high explosive were recorded using a receiver tuned to they are attributed to ionic rather than thermal effects see of 2854 discussion of the influence of frequency in the problem of the investigation of the optimum absorption thickness for a thin metallic film the absorption of em waves by films so thick as to be equivalent to the solid material and by very thin films is considered 2855 spectral diffusion phonons and paramagnetic spin lattice relaxation discussion of paramagnetic relaxation phenomena at low temperatures by analogy with holsteins theory of trapping of resonance radiation in gases 2856 on the overhauser stationary effect in paramagnetic salts and semiconductors discussion of the problem of obtaining stationary nuclear polarization in nonmetals by means of a complete or partial saturation of one or more components of the paramagnetic resonance hyperfine structure 2857 three level spin refrigeration and maser action at positive and negative signal spin temperatures both small compared to the ambient temperature can be realized through three level excitation 2858 optical maser design excitation by electron impact is suggested for a maser working in the visible region see of june 2859 possibility of production of negative temperature in gas discharges the production of negative temperature by the excitation of atomic levels is suggested and the difficulties of obtaining sufficient excited atoms for maser action are considered 2860 handbuch der physik encyclopedia of physics vol electric fields and waves the volume comprises the following five parts static fields and stationary currents g wendt in german quasi stationary a nd nonstationary currents in electric circuits r king in english electromagnetic waveguides and resonators in english propagation of electromagnetic waves the dispersion and absorption of electromagnetic waves 2861 angular diameter measurements of the radio sources cygnus and cassiopeia on a wavelength of cm results given in each case for two directions at right angles show that cassiopeia is circularly symmetrical and approximately the same size at metre wavelengths while cygnus is markedly asymmetrical with a major axis which may be slightly larger at the shorter wavelength the position angle of this major axis is is measurement equipment is described 2862 aerial array operating at an array of mirrors in diameter mounted at equal intervals on a beam long has been erected at nancay from for the study of rf solar radiation by interferometry centres of rf emission are found closely associated with optical centres 2863 the radio emission from the direction of the supergalaxy an analysis of observations made at suggests that the band of radio emission running perpendicular to the galactic plane at about is not associated with the local supergalaxy 2864 theory of the cosmic ray equator the westward shift of the cosmic ray equator from the geomagnetic equator is explained by assuming that there exist ionized atmospheric layers which rotate more slowly than the earth the resultant magnetic field beyond the layers is then a dipole field whose magnetic north pole is west of the geomagnetic north pole 2865 effect of magnetic anomaly on particle radiation trapped in geomagnetic field july 2866 investigation of variations in cosmic radiation the phenomena which can be investigated by an artificial earth satellite and the measuring instruments which can be installed in it are described 2867 investigation of ultraviolet solar radiation 2868 on the structure and mechanism of sunspots 2869 on a possible mechanism of solar nonstable processes leading to neutron eruptions the hypothesis is proposed that the formation within the sun of a nucleus with increased lithium concentration may be the initial cause of nonstable processes of all kinds and in particular the formation of sunspots 2870 the geometry of the earths magnetic field at ionospheric heights 2871 induced electromagnetic fields in the earth a general theoretical study of the effect of geomagnetic variations in the earth 2872 geomagnetic effects of nuclear explosions report of an analysis of changes in the earths magnetic field which occurred when two bombs were exploded at night at a high altitude over johnston island and august results indicate that the upper atmosphere at a distance of km was ionized to near daytime intensity field changes were detected up to km away for a shorter account see electronics vol 2873 geomagnetic disturbances due to nuclear explosion possible reasons for the observed effects at honolulu on and august are discussed 2874 magnetic effects resulting from two high altitude nuclear explosions an examination of vector diagrams of geomagnetic variations in a horizontal plane due to explosions on and august indicates that the effects may be classified into four phases initial second main and final 2875 some geomagnetic phenomena associated with nuclear explosions magnetograms recorded at three station in the immediate area of the explosion on show no disturbance of the h component of the earths field at the time of major disturbances in z and d components vector diagrams of the disturbance in the vertical plane at the three stations are compared with those for the explosion on and are found to be markedly similar despite the different geographical positions and altitudes of the two events in the latter event changes in the h component were comparable with those in z and d 2876 geomagnetic pulsations and the earths outer atmosphere hydromagnetic oscillations of the ionized outer atmosphere are considered as a possible cause of geomagnetic pulsations observational results are applied to this model and the distribution of ionic density is determined 2877 important contribution to international scientific collaboration a brief report on the fifth assembly of the special igy committee which took place in moscow august delegates from countries were present and some preliminary results were discussed 2878 some dynamic problems of flight to the moon trajectories for reaching the moon or for flying round the moon and returning to the earth are considered the initial rocket velocities and the distances from the earth and moon of four different orbits are tabulated a periodic orbit passing near the moon and earth seems to be impractical because an error in the initial velocity of mm sec would be enough to allow the rocket to escape into space after only four revolutions for a shorter account see 2879 the launching of a cosmic rocket towards the moon a short account of the day to day progress of the cosmic rocket from to january in the first hours it travelled to a distance of passing the moon and entering an orbit round the sun see below 2880 the launching of cosmic rockets and astronomical problems march 2881 soviet cosmic rocket a description of the kg rocket which was fired on the and which passed within a distance of of the moon the orbit round the sun lies between the earth and mars and has a period of months the minimum and maximum distances from the sun will be and km signals were emitted from the rocket on and the eccentricity of the orbit is as compared with for the earth a photograph of the sodium cloud released at a distance of km is shown 2882 satellites and space probes launched in us and ussr a tabulated summary of launching dates instrumentation and results 2883 some variational problems connected with the launching of an artificial earth satellite a mathematical analysis of the best angle of elevation for a rocket which is required to put a satellite into an orbit with minimum fuel consumption and allowing for a variable gravitational field and the rotation of the earth 2884 determination of the lifetime of an artificial earth satellite and study of the secular perturbations of its orbit a general mathematical method is described which is valid for any satellite and which takes account of the distribution of atmospheric density with altitude this method is based on single parameter series of integral curves of a first order equation from graphs and tables the satellite lifetime and the variation of the orbital parameters with time are rapidly calculated the effect of atmospheric rotation on the secular variations of the satellites orbit are found to be small 2885 the motion of an artificial satellite in the noncentral field of terrestrial gravitation in the presence of atmospheric resistance the orbit of a fictitious satellite of weight kg and diameter has been calculated in four hours using an electronic computer the perigee revolves around the earth times in days the ascending node regresses in the direction opposite to the earths rotation at a rate of about per day 2886 effect of geophysical factors on the motion of a satellite the orbital calculations based on the use of differential equations in terms of elliptical osculating elements depend on the accurate estimation of geophysical factors such as air resistance and gravitational anomalies the determination of these factors from satellite observations is considered 2887 the use of artificial earth satellites for the verification of the general theory of relativity three main points could be examined the rotation of the perigee of mercury which according to theory should revolve in a century the deflection by of light rays in passing near the sun the gravitational shift of spectral lines 2888 an experimental and indirect method for determining the high atmospheres density an approximate method is described for calculating the density of the atmosphere above km using as data observed life times of artificial satellites no longer in orbit calculated densities are compared with those measured by means of rocket probes 2889 new approach in the theory of satellite orbits a proposed co ordinate system is useful for investigating the motion of an earth satellite 2890 short time measurement of time dilation in an earth satellite a method for measuring the gravitational red shift based on the variation of the frequency difference between two oscillators as a function of altitude 2891 air density in the upper atmosphere from satellite orbit observations the results given agree with those of king hele of 2892 investigation of cosmic rays by means of artificial earth satellites these investigations led to the discovery of a belt of charged particles round the earth which at a height of passed at the rate of particles per sec through an area cm this radiation would be very dangerous to unprotected living beings 2893 ionizing radiation at altitudes of to kilometres pioneer the total ionizing component of cosmic radiation was measured on october by means of an ionization chamber mounted on the pioneer lunar probe vehicle data were taken over an altitude range of to and a latitude range of to the calibration procedure and the analysis of the telemetered data are described 2894 satellite observations of solar cosmic rays on three occasions during august large increases in the intensity of charged particles outside the van allen radiation zones were detected by at high magnetic latitudes and low satellite altitudes it is suggested that these increases are due to solar protons associated with large solar flares 2895 investigation of the earths magnetic field using an artificial earth satellite an investigation by means of magnetometers located on the satellite of the space distribution of the earths magnetic field at great heights and of inhomogeneities in the ionosphere the effect of the magnetic field on the polarization of radio waves reflected from the ionosphere the latitude effect of cosmic rays and auroral phenomena are considered 2896 problems of measurement of the pressure and density of the high layers of the atmosphere by means of artificial earth satellites temperature pressure density and composition between and are tabulated the concentrations of oxygen and nitrogen between and km are also shown 2897 the density of the earths outer atmosphere according to satellite observations orbital data of satellites and are used to determine atmospheric density above km results agree closely with those obtained from observations of satellites and retardation effects are also discussed measurement of the concentration of positive ions along the orbit of an artificial earth satellite the surface potential of a satellite and the distribution of charged particles around it are discussed instruments for measuring the ion concentration and the transmission of results to earth by radio telemetry are described graphs of the air temperature a t different heights are also shown references 2898 preliminary results of measurements on doppler shift of satellite emissions measurements of transmissions from and on and have been analysed to investigate the influence of the propagation path on observed data results indicate that the wave travels about slower than the wave 2899 refraction of very high frequency radio signals at ionospheric heights calculations relevant to the radio tracking of space vehicles show that refractive errors due to the troposphere rapidly decrease with increasing elevation angle while those due to the ionosphere initially increase the with elevation angle and then decrease gradually the elevation angle error is plotted for realistic models of the ionosphere and troposphere 2900 work carried out under the auspices of the indian national committee for the igy the following papers and data are included a preliminary report on the nature and origin of atmospherics atmospheric electricity observations in india during the igy radiosonde techniques for measuring potential gradient and conductivity geomagnetic work at alibag annamalainagar and trivandrum during the igy atomic nitrogen in the thermosphere ionospheric disturbances at low latitudes studies of cosmic radio noise on at ahmedabad meteors and ionization rates of fading of reflected pulses of vertically incident electromagnetic waves at ahmedabad on and observations on galactic radiation at diurnal variation of ionospheric absorption on at waltair during the igy effect of enhanced solar activity on the f region drifts at waltair a new continuous wave radio method for the study of ionospheric drifts program of igy solar observations in india solar control of some unusually remarkable geophysical events radio emission from the sun at the radio patrol of solar flares optical tracking of artificial satellites table solar flares during july to september table sudden enhancement of atmospherics sea during july to august table sudden cosmic absorption sca during july table solar flare effects recorded during july to june 2901 investigation by rockets of the composition of the atmosphere at great heights a description of containers designed to collect samples of the atmosphere is given and results obtained between and are tabulated 2902 measurements of the pressure in the upper atmosphere a description is given of a container with recording instruments which after release from a rocket record the pressure of the upper atmosphere a comparison is made between pressure measurements obtained in usa and ussr at pressure and temperature variations at different heights are shown graphically 2903 investigation of ionic composition of the ionized layers of the atmosphere rockets and artificial satellites equipped with mass spectrometers of the type described by bennett automatically sending results to the earth are considered the ionization of the atmosphere by a fast moving satellite vehicle and the effect of the vacuum created behind it are also examined 2904 results obtained with rocket borne ion spectrometers a description of the instrumentation used and an analysis of the results obtained from the three flights in which both positive and negative ion spectrometers were flown 2905 some studies of the upper atmosphere in the auroral zone observations show close correlation between blackouts complete blanketing of f by e slant and geomagnetic ba y disturbances the height of the absorbing region responsible for the daytime polar blackout appeared to be lower than when the event occurred at night to explain these results the effect on the ionosphere of x rays generated by solar particles is discussed 2906 model of the ionosphere electron density data obtained by a russian rocket can be correctly interpreted by the f layer model proposed in the 2907 the worldwide distribution of the f layer electron density seasonal and nonseasonal variations and correlations with solar activity seasonal and nonseasonal variations of the maximum electron density in the f layer at noon are largely asymmetrical in the two hemispheres at midnight they are symmetrical a general circulation of the upper atmosphere is suggested as an explanation for these and other anomalies discussed 2908 the diurnal development of the anomalous equatorial belt in the f region of the ionosphere a study is made of the latitudinal distribution of for each hour of the day for the equinoctial months at sunspot minimum and also of the diurnal variation of at a number of low latitude stations the observed behaviour of in both cases is suggested to be due not only to vertical drift of ionization but also to horizontal movement between the poles and the equator during the day 2909 time and height variations in the daytime processes in the ionosphere part an extension of earlier work of variations of the decay of electron density with height are discussed for the height range km an expression is developed for the loss coefficients over this range for northern middle latitudes at noon 2910 geomagnetic and ionospheric phenomena associated with nuclear explosions magnetograms and ionograms recorded at stations in the central pacific ocean have been analysed for the periods covering the explosions on and august some geomagnetic variation could be explained by a dynamo effect associated with wind velocities of miles sec and a ten fold increase in electrical conductivity 2911 some effects of nuclear explosions on ionospheric vertical incidence soundings an analysis of observations made at tahiti maui and rarotonga at the time of an explosion on abnormal absorption which lasted three hours was recorded at maui and tahiti for auroral effect see of may the on the august the date of another explosion the onset of abnormal absorption at maui and rarotonga appeared to be delayed by five hours 2912 sudden ionospheric disturbances caused by an atomic explosion a note on recordings of atmospherics and solar rf bursts made at toyokawa japan 2913 disturbance in the ionospheric region following the johnston island nuclear explosion from a study of time delay at various observatories in the vicinity it is assumed that the ionospheric disturbance due to the explosion on the august is a by product of a gaseous shock wave propagated at a velocity considerably greater than that of sound anomalies in this assumption are discussed 2914 measurement of electrostatic fields in the upper layers of the earths atmosphere the charge acquired by a body located in a plasma is examined an instrument measuring the field potential in the ionosphere is described electrostatic field variations due to moving rockets or satellites are considered 2915 ionosphere electron densities and differential absorption a review of daytime ionosphere measurements made over new mexico using a rocket to ground cw radio propagation method and a preliminary report of similar measurements made in the arctic ionosphere during polar blackouts 2916 on the measurement of virtual height 2917 interpretation of the variation of ionospheric absorption as a function of frequency errors in nondeviative absorption calculations are attributed to the presence in the e layer of a thin densely ionized e layer the expression used earlier has been revised results obtained using the new expression indicate that it allows a more detailed study of the absorption process 2918 ionospheric conditions in the circumpolar region a preliminary analysis of ionospheric and magnetic field measurements made from a drifting observatory in the arctic ocean during the period may april values of were obtained for during the arctic night 2919 investigation of the solid component of interplanetary matter by means of rockets and artificial earth satellites the kinetic energy of micrometeorites is measured by an acoustic method or by a new type of sensitive photomultiplier results of collisions of these particles with polished plates located on rockets are shown tables giving values of brightness mass radius and estimated fall out on the earth in hours are included particles ejected from the sun and charged cosmic dust are also considered 2920 a preliminary meteorological study of the origin of whistlers a possible unique source of whistling atmospherics is found to be the presence of large cyclonic disturbances at the geomagnetic conjugate point for the whistler receiving station the possible role of these cyclonic disturbances in producing narrow magneto ionic duct propagating conditions is also discussed 2921 control techniques annual review covering investigations of control problems methods of control and regulating equipment references 2922 silicon solar batteries as a source of electrical supply in artificial earth satellites experiments using si pn junctions to convert solar radiation into electrical energy are described photo elements having a surface area of cm and a thickness of mm were used at sea level with the suns rays incident normally an efficiency of was recorded corresponding to for an area of m with a solar constant of a si plate exposed to the sun showed a temperature of 2923 breakdown of silicon power rectifiers a description of a type of breakdown which can occur when si junction rectifiers are used in series to rectify a high frequency hv supply the cause was traced to minority carrier storage effects and methods of overcoming it are described 2924 elimination of the effect of thermal delay of the cathode on a valve with grid compensation the circuit described earlier of may is adapted for the compensation of transient fluctuations by means of an rc network which delays the application of the compensating voltage to the grid 2925 magnesium bismuth oxide dry cells the cell construction and its performance characteristics are described after an initial voltage drop cells have a flat voltage discharge curve slightly above 2926 zinc mercuric dioxysulphate dry cell a cell is described which has the desirable characteristics of the mercuric oxide alkaline cell the conventional construction of the dry cell and a relatively flat discharge characteristic at for loads within the rated current density 2927 controlling the digital computer a non mathematical discussion of the programming and application of computers for scientific purposes 2928 an experimental arithmetic unit detailed description of a unit which performs a repetitive multiplication program and checks the results for errors 2929 the design of the ferranti pegasus computer the detailed engineering aspects of the design problem are discussed part 2930 a word magnetic core memory the storage matrix consists of ferrite cores and has a read write cycle of its construction is described together with the driver and sense amplifier circuits 2931 a positive integer arithmetic for data processing 2932 irredundant disjunctive and conjunctive forms of a boolean function a thorough algebraic method is described for determining the complete set of irredundant normal and conjunctive forms the procedure is mechanical and the method can be applied for programming computers 2933 electronic computers the application of analogue computers to the solution of control system problems 2934 approximating nonlinear functions by shunt loading tapped potentiometers in analogue computing machines 2935 the multipurpose bias device part the commutator transistor a study of the application of the rutz commutator transistor to three input one output logical problems for handling by automatic computer systems the rutz commutator is a single emitter amplitude sensitive device with three separate input wires applied to the emitter its design will be detailed in a subsequent paper 2936 two collector transistor for binary full addition 2937 a mathematical model for determining the probabilities of undetected errors in magnetic tape systems 2938 the magnetic tape store for pegasus 2939 the recording of digital information on magnetic drums methods of representing binary digital information on magnetic drums are discussed with regard to their reliability cost and technical merits 2940 international components symposium summary of papers read at the royal radar establishment malvern in september reliability efficient use of space liquid cooling techniques and optimum component shapes for automatic assembly are discussed 2941 calculation of inductance of toroids with rectangular cross section and few turns 2942 solid circuits discussion of the international symposium on electronic components held at malvern england a solid circuit forming the equivalent of several transistors connected by resistors and capacitors is obtained by depositing films of conductive resistive and dielectric materials on a small block of semiconductor material the solution of problems regarding the operation of components at high temperatures is mentioned 2943 printed circuits in receiver construction outline of development of the printed circuit and description of modern production techniques 2944 pro and con on seven different methods of printed wiring the basic techniques for each method are described and compared a table of relevant us patents is included 2945 a circuit theorem on rectification nonlinear capacitors and inductors cannot effect rectification unless nonlinear resistance is present in the circuit 2946 new method of evaluating ferro inductors formulae for calculating the insertion loss and the resistance increase due to the iron core are derived the practical factors governing optimum coil design are investigated 2947 cold cathode voltage transfer circuits practical techniques used in the application of cold cathode triodes are given in detail a number of circuit diagrams is included 2948 charge and discharge of a nonlinear condenser through a linear nondissipative inductance has shown that for a capacitor with a semiconductor as dielectric the capacitance is proportional to where is the voltage across the capacitor and is the voltage across the capacitor and is a constant a circuit is analysed in which such a capacitor is connected in series with a lossless inductance and a direct voltage source and a comparison is made with an exponential capacitor exp applications to the generation of rectangular and triangular waveforms are indicated see also of evaluating base materials for printed capacitors definition of terms specifying the losses of base materials used for printed circuits which affect the size and q factor of printed capacitors 2949 a vacuum plant for the frequency calibration of quartz vibrators see also of 2950 a network theorem the impedance level of half a symmetrical network can be changed without altering the frequency response the use of this theorem for the solution of network problems is discussed and illustrated by an example 2951 noise and noise free two port networks treated by the isometric circle method see 2952 on the design of four terminal interstages for pulse applications the limits set by the input and output capacitance on the time response and the conditions for no overshoot are determined methods for achieving the necessary pole distributions are described and circuit networks suggested 2953 the mathematical treatment of transistor feedback circuits formulae are tabulated giving in convenient form the parameters of transistor networks for four types of feedback circuit 2954 design and development of strip line filters 2955 concentric shear mode electromechanical filter an experimental filter of simplified design is described which consists of four magnetostrictive ferrite disk resonators 2956 a broad band variable group delay equalizer the equalizer has been developed for use in fm microwave systems it is inserted in the signal path in long radio relay systems the performance is adequate for the transmission of frequency division multiplex telephony of at least channels or subcarrier colour television transmission 2957 comments on frequency pulling of maser oscillators the physical origin is illustrated of the theoretically predicted reduction in frequency pulling with increasing number of beam molecules and reasons are given for its failure to occur in practice 2958 a solid state microwave amplifier and oscillator using ferrites experimental results obtained with an oscillator based on the proposal by suhl the active element is a piece of magnetized ferrite at room temperature 2959 sensitivity of a self excited oscillator theoretical and experimental investigation of the characteristics of a valve feedback oscillator suitable for nuclear resonance detection 2960 crystal oscillators in communication receivers 2961 unijunction transistor forms flip flop the construction and performance are described of a multivibrator circuit for a stable or monostable operation see also its active element is the double base diode a terminal pn junction device 2962 pulse generator uses junction transistors a transistor circuit is described giving pulses of duration at repetition rates of pulses with internal delays of of 2963 distortion in transistor amplifiers an analysis of the distortion in low level grounded emitter stages due to input circuit nonlinearity and to variations of collector to base current gain 2964 low frequency transistor oscillators theoretical treatment of a junction transistor oscillator for frequencies of a few frequency and amplitude stability conversion efficiency and the conditions governing starting are considered a practical circuit design is derived and experimental results are given 2965 build up of large signals with elimination of reflections in magneto strictive storage lines greater reliability and increased storage capacity are obtained by substituting twelve energizing coils for the usual one with this arrangement a steel wire delay line can be used see also of 2966 a transistor gating matrix for a simulated warfare computer brief description of a circuit devised in which used a matrix of point contact transistors amplification of signals was also achieved 2967 signal enhanced delay line to maintain pulse shape the high frequency response of the delay line described is improved by selective amplification 2968 pulse compression a method is described for compressing frequency modulated rf pulses ie shortening them and increasing their amplitude by passing them through a delay distortion network consisting of a chain of lattice quadripoles the theory outlined is based on work by caucer published posthumously its practical application in the field of radar should result in higher resolving power for a given signal noise ratio 2969 minimizing mismatch loss simple formulae and curves are given 2970 upper limits of output power in vacuum tube and transistor ac amplifiers simple analysis and comparison based on idealized characteristics 2971 stacked valve circuits an analysis by means of feedback theorems and modified equivalent circuits application of the method to the cascade amplifier and the cathode follower circuits is given in detail 2972 single ended push pull output stages the development of low dc resistance pentodes and high resistance moving coil loudspeakers has made possible the construction of transformerless output stages several types of which are described the paper is based on the work of w aschermann and j rodrigues de miranda see of 2973 a low frequency selective amplifier the frequency is variable in steps from to the selectivity can be set up to the amplifier is dc coupled a twin t network shunted by a capacitor acts as a selective network in the negative feedback line 2974 pt pa unit description of a band switching rf amplifier for and which uses a pair of valves type pt in parallel 2975 a broad band intermediate frequency amplifier for use in frequency modulation microwave radio relay systems a amplifier is described which is suitable for the transmission of channel frequency division multiplex telephony or subcarrier colour television signals in fm microwave radio relay systems a test tone noise ratio of is not significantly degraded after transmission through five amplifiers in tandem 2976 watt audio amplifier the circuit described includes small output valves in parallel push pull connection 2977 self balancing magnetic amplifiers of the differential feedback type a magnetic amplifier for extending the range of aa moving coil ink recorder is described 2978 the use of transistors in airborne audio equipment 2979 negative feedback transistor amplifiers design data are given for high fidelity af amplifiers 2980 microwave amplification by maser techniques elementary analysis of maser operation including its application to wide band short transit time amplification 2981 demodulator limiter for control system signals description of transistor circuit for automatic control systems which acts as limiter during modulation or demodulation 2982 magnetically keyed phase sensitive demodulators the operation and performance of a pulse shaping circuit using magnetic reactors is described the properties of three types of phase sensitive demodulator are compared diode demodulators have linear characteristics magnetic amplifier demodulators have high input impedance and transistor demodulators combine good linearity with low noise level 2983 transistorized phase discriminators half wave and full wave phase discriminators are described with two or three terminal dc outputs an analysis of the operating characteristics of transistors in discriminator circuits is given temperature stability and power limitations are discussed 2984 interferometry for the far infrared 2985 infrared radiation and its detection a comparison of the sensitivity and time constant of available detectors of infrared radiation thermal detectors of thermocouple bolometer and pneumatic type and photoelectric detectors are discussed 2986 the lorenz number the theory of the lorenz number of a conducting crystal is developed for the band and one electron models of the electron assembly with certain approximations the lorenz number is found to be equal to the mean square fluctuation of the thermoelectric power 2987 some scattering problems in conduction theory an expression derived for the scattering of electrons by inhomogeneous slowly varying strain fields is applied to scattering by dislocations and stacking faults 2988 free path formulae for the coefficient of diffusion and velocity of drift of electrons in gases 2989 free path formulae for the electronic conductivity of a weakly ionized gas in the presence of a uniform and constant magnetic field and a sinusoidal electric field a general free path formula is given for the drift velocity of electrons in a weakly ionized gas in a sinusoidal electric field most special cases of interest including the magnetic deflection of an electron stream in a gas are readily derivable from the general formula the results find application in microwave and ionospheric studies of the motion of electrons in gases as well as in experiments on the magnetic deflection of an electron stream see also above 2990 radio star ridges the distinctive amplitude variations known as ridges can probably be explained in terms of divergent lens effects in the e region see also of 2991 oscillations in direct current glow discharges experimental results are given concerning the stable oscillations with the same period which occur in the current and in the light emitted by the positive column 2992 mechanization in the presence of magnetic viscosity in a mathematical expression is derived for solving problems of magnetization of magnetically viscous samples in particular those of cylindrical shape see also of 2993 diffraction of electromagnetic waves by ribbon and slit rigorous solutions are presented for a wave incident on a plane normal to the edge of the ribbon or slit but with arbitrary angles of incidence and polarization for diffraction by circular plate and hole see of 2994 diffraction of a spherical wave pulse by a half f plane screen fourier integral treatment for a point source 2995 distortions of magnetic resonances by additional and excessive oscillatory fields a theoretical explanation is given of the shift of the resonance frequency which occurs as a result of the presence of an extraneous rf electric field see also 2996 the dependence of the amplitude of the first harmonic of nuclear magnetic resonance absorption on the amount of detuning 2997 equivalence between the line width and the rate of energy relaxation in the inversion spectrum of ammonia 2998 on the equilibrium configurations of oblate fluid spheroids under the influence of a magnetic field 2999 toroidal oscillations of a spherical mass of viscous conducting fluid in a uniform magnetic field 3000 theoretical treatment of the kinetics of diffusion limited reactions the diffusion limited reaction has been solved for a random initial distribution of a and b particles 3001 a consideration of radio star scintillations as caused by interstellar particles entering the ionosphere part daily and seasonal variations of the scintillation of a radio star part the accretion of interstellar particles as a cause of radio star scintillations an analysis is made of measurements of scintillations of the rf source in cassiopeia recorded at ottawa during at a frequency of the data show certain daily maxima occurring at solar times dependent on the date of the year and grouped unsymmetrically in a way which suggests that they are due to the infall of interstellar particles from outside the solar system the velocities of certain of these particles are derived by simple applications of vector addition employing the known velocity of the earth see also of 3002 the mullard radio astronomy observatory cambridge the observatory was formally opened in two instruments then under construction were a radio star interferometer for and a pencil beam system for investigating continuous galactic radiation at the aperture synthesis technique applied in the two systems is described see also of 3003 worlds largest radio telescope an illustrated description of the design and construction of the fully steerable paraboloid of the jodrell bank instrument with details of the driving system and drive control equipment 3004 the distribution of the orbits of sporadic meteors radio observations at adelaide during are analysed a distribution of orbits is derived which is consistent with radar and visual observations in the northern hemisphere 3005 variations in the intrinsic strength of the quadrantid meteor shower analysis of the occurrence rate of meteoric signals detected on a vhf forward scatter east west path in canada see also of 3006 a theory of long duration meteor echoes based on atmospheric turbulence with experimental confirmation the experimental evidence is examined with the conclusion that the theory does not accurately represent the properties of meteoric echoes 3007 meteor activity in the southern hemisphere activity and radiants of meteor showers are discussed and compared with similar data for the northern hemisphere see also above and of 3008 ionospheric indices of solar activity it is suggested that a simple index based on e layer measurements at a single station is adequate and that the additional effort required to provide the index based on f layer measurements at three stations is not justified see also of minnis 3009 observation of a new type of flare a mass of very bright material was ejected from a flare about from the suns limb except for the velocity the mass possessed all the properties of a small flare 3010 the effective electrical constants of soil at low frequencies a possible explanation is presented for the large appa rent dielectric constants which occur at frequencies of the order of 3011 igy rocket program an outline of the work of the igy subcommittee of the us technical panel for rocketry a table is given listing organizations participating and their objectives 3012 a possible troposphere ionosphere relationship a relation is suggested between f layer characteristics and the passage of meteorological fronts through the troposphere a hypothesis for dynamical coupling between the two regions is outlined 3013 electric field measurements in the stratosphere above the exchange layer the field decreases monotonically up to the limit of measurements made in and the measured and calculated values are in good agreement 3014 electric field measurements above thunderstorms in measurements at heights of to above central florida a positive upward flowing current of about was found 3015 models of the lower ionosphere as may be inferred from absorption results values of deviative and nondeviative absorption and their variations with cos are calculated for the d region models of nertney of piggott unpublished and mitra and for the e region model of jones of satisfactory agreement with experimental results is found for mitras model of the d region but not for jones model of the e region 3016 a study of spread f ionospheric echoes at night at brisbane frequency spreading diurnal and seasonal variations in spreading of the penetration frequency are compared with similar world wide data the observations are interpreted in terms of scattering from clouds of enhanced ionization near the f layer maximum and a seasonal vertical movement of these clouds is suggested the extent of which increases with latitude parts 3017 severe ionospheric storm notes on the disturbances of august september 3018 disturbances in the lower ionosphere observed at vhf following the solar flare of february with particular reference to auroral zone absorption the effects of the flare on ionospheric scatter links in the band at high latitudes are reported an abrupt increase in oblique incidence signal intensity occurring almost simultaneously with the arrival of cosmic rays was following during during the next three days by abnormally high levels at night and low levels during the day background cosmic noise measurements showed increased absorption at night and greatly increased absorption during day light the penetration into the d region of moderately heavy solar atomic ions is suggested as an explanation of the absorption phenomena 3019 solar eclipse of june and its effect upon the ionosphere the investigations at delhi reported include vertical incidence ionospheric measurements the recording of variations of sw and mf signals and the recording of solar noise on evidence of three distinct corpuscular eclipses was obtained both on the ionization density of the f layer and on the absorption in the nondeviating region these were found to occur and before the optical eclipse theoretical arguments and past observations indicate that these corpuscular emissions may have originated from the so called m region of the sun 3020 ionospheric research note on signal strength changes during the annular solar eclipse on and the control days for transmitters both in south africa and in other countries 3021 disturbances in the f and e regions of the ionosphere associated with geomagnetic storms the e and f layer variations which occur during geomagnetic disturbances are examined for different phases of the solar cycle and for a number of latitudes the data are discussed in relation to the electron drifts associated with geomagnetic disturbances see also below 3022 disturbances in the ionospheric f region associated with geomagnetic storms middle latitudes disturbances at middle latitudes are divided into negative and positive types characteristic of high and low latitudes respectively these results are discussed in terms of vertical drift of electrons and the disturbance daily variations in the geomagnetic field the bearing of the dynamo current on seasonal and latitude variations of disturbances is discussed part of 3023 ionospheric irregularities causing random fading of very low frequencies ionospheric studies by the lunar technique equipment operating near ottawa comprises a transmitter keyed on for sec and off for sec feeding a paraboloid via a horn and orthogonal dipoles with a similar reflector feeding a dual conversion receiver and synchronous detection is used to give an af output signal equal in frequency to the doppler shift of the signal reflected from the moon preliminary results indicate the presence of fading due to libration long and short period faraday rotation and long term fading without faraday rotation 3024 the electrification of precipitation and thunderstorms a review article cosmic rays radioactivity and other agencies produce ion pairs which are transferred to cloud droplets or ice crystals and establish a droplet charge distribution greatly influenced by differences in conductivity for positive and negative ions rain formed from these droplets may be electrified usually both positive and negative drops being present processes are considered which charge this rain and and may eventually lead to a lightning stroke the conditions necessary to establish gross free charge distributions by regeneration are specified and shown to be met under frequently occurring meteorological situations references 3025 rotational temperatures measured in aurorae at churchill manitoba the measurements indicate there is no latitude effect a vertical temperature gradient of is deduced see also of 3026 a study of the audio frequency radio phenomenon known as dawn chorus experimental evidence supports the hypothesis that dawn chorus signals are generated by the entry into the ionosphere of clouds of positively charged particles of solar origin propagation appears to take place in the extraordinary magneto ionic mode along the earths magnetic lines of force 3027 removal of heat from sealed miniature equipment experimental investigation has shown that the most satisfactory way of dissipating the heat generated internally is by providing thermal conduction paths from the heat sources to the front panel 3028 utilizing the suns energy report on progress in the development of solar batteries of the si p n junction type with description of experimental installations in england 3029 a stabilized dc power supply using transistors a mains operated unit is described which provides an output voltage variable from to at currents of up to 3030 germanium rectifiers as electronic components discussion of advantages and applications cooling methods and overload characteristics are considered 3031 a low voltage stabilizer employing junction transistors and a silicon junction reference diode 3032 voltage regulator uses multi vibrators voltage changes vary the frequency of an astable transistor multivibrator and the average value of the load voltage is thus kept constant 3033 multichannel drives for transmitters and receivers in the hf band methods of tuning accurately to a prescribed frequency are described as applied to a diversity oscillator with manual tuning an automatically tuned airboard received transmitter drive 3034 monitoring the modulator a circuit for monitoring the output of a high power modulator on a pair of headphones 3035 odd binary asynchronous counters 3036 a one microsecond adder using one megacycle circuitry 3037 high speed computer stores megabits design and performance details of the lincoln computer are given 3038 an iterative analogue computer for use with resistance network analogues 3039 circuitry and characteristics of a repeating electronic analogue computer description of a computer for solving engineering problems a hyperbolic field tube is used as multiplier 3040 the error effect of the operation amplifier in analogue computers the various errors and their sources are discussed and some methods of automatic correction are described 3041 a multiplier based on the two parabola method the method of operation is described and the accuracy obtainable is shown by some examples of calculations 3042 the utilization of domain wall viscosity in data handling devices 3043 transistors in current analogue computing a comparison of variable current and variable voltage analogue computing techniques shows that transistors are particularly suitable for the former low power low frequency transistors in direct coupled amplifiers which may be used in computers are described 3044 electric correlators typical applications of electric correlating devices are discussed and the operation of various types of these is described details are given of a static type translator using transistors and crystal diodes as nonlinear switching elements 3045 a time division multiplier 3046 analogue multipliers and squarers using a multigrid modulator 3047 a small coincident current magnetic memory 3048 the role of printed wiring in high fidelity the advantages of printed wiring techniques are summarized 3049 a design method for wide band balanced and screened transformers in the range leakages and winding capacitances are accurately and independently controlled and a high degree of winding balance is attained with an insertion loss of about db 3050 simplified pulse transformer design an outline of design techniques for low and high power pulse transformers 3051 the frequency lock afc circuit noise free operation of the system is analysed and its performance at low signal noise ratios is considered a theory of the system operation under the latter conditions is developed from an examination of the tracking errors resulting from noise and changes in signal frequency practical results obtained are in agreement with this theory 3052 a novel electronic transmit receive switch a type valve capable of withstanding between grid and cathode isolates the receiver from the transmitter tank circuit 3053 stabilization of current operated transistor switching circuits a method is given for calculating the parameters of simple compensating circuits 3054 the transistor as a speech path switch the suitability of transistors is discussed and some methods of using them for this purpose in telephone systems are described 3055 complexity in electronic switching circuits 3056 future circuit aspects of solid state phenomena several phenomena such as superconductivity molecular amplification magnetic effects in semiconductors and the nonlinear capacitance of pn junctions are discussed from the point of view of the circuit designer new devices will to an increasing extent be based on controlled inhomogeneity 3057 the influence of electromagnetically coupled systems compound systems consisting of a primary electromagnetically coupled to a secondary system are considered the equations obtained are applied to examples of magnetic coupling and a conducting diode 3058 a new technique in ferrite phase shifting for beam scanning of microwave antennas in the device described a longitudinal magnetic field is applied to a ferrite rod in a rectangular waveguide excited in the te mode phase shifts of over and variations in transmitted power of less than have been obtained with aa field of oersteds see also of 3059 computation of crystal admittance the results of a digital computer program designed to calculate the admittance of a coaxial crystal for various values of video resistance spreading resistance and barrier capacitance over the range are given comparisons with available measurements are made 3060 method of obtaining pressure and temperature insensitive microwave cavity resonators methods using invar walls with steel or brass end plates for te cavities are unsatisfactory due to hysteresis effects improved techniques are described for fixed frequency resonators which have temperature coefficients less than per the pressure coefficient is less than in per millibar 3061 retardation effects caused by ferrite sample size on the frequency shift of a resonant cavity expressions are derived using perturbation theory for the frequency shift of a circularly polarized resonant microwave cavity due to insertion of a small ferrite sample 3062 simplified design of impedance matching networks a step by step method of impedance transformation is described the formation of and networks from the basic l section and some complex matching networks for particular applications are discussed 3063 super selectivity with crystals constructional details of a lattice type if filter with two crystals the response curve is symmetrical 3064 a frequency independent microwave attenuator with largely constant phase shift a waveguide attenuator of the rotary vane type is described and calibration and error curves are given close agreement of measured attenuation with theoretical values was obtained in attenuators for the range of 3065 the transactor the two terminal constant current and constant voltage generators used in equivalent circuits of active networks are replaced by transmission type active elements called transactors the relations between variants of this element are established 3066 theory of two phase networks phase splitting networks as used in ssb modulation systems are discussed and calculations by approximation methods are described 3067 phase shift oscillator indicates radar range firing range information is conveyed by a variable af note 3068 high order harmonics for x band oscillator stabilization a simplified phase locking stabilization technique for microwave oscillators harmonic orders up to about are used 3069 the simultaneous generation of two oscillations in one oscillator and the stability of the difference frequency the operating conditions are determined which are required for the simultaneous generation of two different frequencies in a valve feedback oscillator see experimental results are discussed 3070 grid diode sawtooth generator description of a simple timebase circuit with wide frequency range 3071 experimental and theoretical investigation of semiconductor hall effect generators 3072 silicon transistor crystal oscillators have high temperature stability outline of circuit design considerations and discussion of experimental results 3073 difference counters two examples are given with maximum counting rates pulses and pulses the design of a decimal difference counter is outline 3074 direct coupled amplifiers a method is described of artificially matching valves to obtain improved mutual compensation for the effects of normal heater supply voltage changes adjustment is easier than selecting naturally matched pairs of valves and considerably better balance is obtained 3075 a if amplifier for wide band microwave links 3076 direct coupled amplifiers with junction transistors a balanced dc amplifier circuit is analysed and the theory of its operation is developed on the basis of the work by abers and moll the problem of balancing the circuit with ideal and with commercial type transistors is considered and practical design formulae are derived 3077 masers and reactance amplifiers basic power relations an alternative derivation based on circuit theory of the expressions of manley and rowe the power relations involve only the source and load frequencies and are independent of the specific characteristics of the nonlinear device 3078 maser noise measurement 3079 new ferrite microwave amplifier an experimental solid state amplifier using a ferrite material as the active element is described the device is suitable as an amplifier of very weak microwave signals see also of 3080 the reaction field and its use in some solid state amplifiers the theory of the maser is presented in terms of the radiation reaction field produced in a cavity or waveguide by the presence of the electromagnetic moment of the sample being investigated two amplifiers are discussed which use the reaction field in different ways from the usual solid state maser 3081 the pn junction on a variable reactance device for fm production a transistor modulator for a carrier frequency is described which gives good fm with negligible am change in modulating signal produces a deviation of 3082 the influence of a strong magnetic field on the dielectric constant of a diamagnetic fluid 3083 formulae for dielectric constant of mixtures formulae are tabulated with references and shown to be special cases of a general fundamental formula an exception is the lichtenecker type of formula possibly owing to incorrect assumptions 3084 the second order effect of free electrons on lattice conduction second order perturbation theory in conjunction with the usual treatment of electron phonon interaction allows us to calculate the correction to the first order result for the scattering of phonons by electrons it is shown that the second order term is much smaller and therefore negligible this justifies the use of the first order theory in the treatment of the interaction in metals and semiconductors 3085 a method of calculation of electrical conductivity using relaxation theory a general solution is obtained for the electric current density irreversibility is then introduced so that practical cases may be considered a perturbation approximation gives the same result as that based on the bloch theory 3086 a note on the energy gap model of superconductivity 3087 gauge invariance and the energy gap model of superconductivity on the elementary theory of thermoelectric phenomena all the relations between the thermoelectric parameters are deduced from physical properties rather than by means of mathematical transformations the sources of the heat and emf developed are indicated 3088 the plasma resonator the interaction between an ionized gas column and an electromagnetic wave in a waveguide is studied at cm effects examined include the influence of the discharge current gas collisions decay times of electron density and modulation of the rf power 3089 new effects of an anxiliary electrode on a discharge at low pressure an auxiliary electrode close to the cathode provides a means of sensitive control of the discharge optimum operational conditions were found for a range of discharge parameters low frequency noise may be suppressed by an electrode of wire gauze 3090 theory of secondary emission the elementary theory of secondary electron emission has been generalized and modified to incorporate results of recent measurements of the range energy relation and the dissipation of energy by slow electrons iin solids these modifications give considerably improved agreement between the theoretical and experimental universal reduced yield curves 3091 satellite electron theory of ferromagnetism antiferromagnetism and related phenomena a theory based on classical concepts is developed to show the electronic nature of ferromagnetism magnetic properties of transition metal oxides are briefly discussed 3092 a note on the ground state of antiferromagnetism kasteleijns method of obtaining the lowest energy state is generalized for the cases of two and three dimensional lattices 3093 on the reflection and refraction of magnetohydrodynamic waves 3094 asymptotic formulas for diffraction by parabolic surfaces asymptotic solutions to the wave equation are found at a boundary consisting of a paraboloid of revolution or a parabolic cylinder the results are applied to the reflection at such surfaces of incoming plane waves or divergent waves from a point or line on the axis of the surface 3095 double modulation system for narrowing electron resonance absorption lines a method for observing electron resonance absorption on an oscilloscope screen by modulating both the magnetic field and the klystron frequency the apparent line width can be reduced by a factor of relative to the true line width 3096 microwave studies of the internal motion and the structure of methyl amine 3097 potential barrier and molecular structure of methyl mercaptan from its microwave spectra 3098 microwave spectrum of and dependence of quadrupole coupling constant on the vibrational state 3099 proposal for a nuclear quadrupole maser it is suggested that certain substances exhibiting pure quadrupole transitions have the requisite properties for maser operation the differences between masers based on these substances and on paramagnetic solids are discussed 3100 fluctuations in amplification of quanta with application to maser amplifiers expressions for the probability distribution of quanta for the average values and for the fractional fluctuation are developed and applied to maser type amplifiers 3101 the reaction field and its use in some solid state amplifiers 3102 radio frequency zeeman effect in o by the molecular beam magnetic resonance method the ratio of the value of the rotational magnetic moment to that of the electron spin moment is found to be the ratio of the g value of the unpaired electron spin moments in to that of the free electron spin moment is 3103 the cloud chamber the theory and application of the wilson cloud chamber are outlined and its m modification by gabor and hampton is briefly described 3104 sources of radio noise on the planet jupiter daily records made from december to march at gainesville florida at suggest that there are two localized sources on jupiter and that jupiter is surrounded by an ionosphere of electron density ie comparable with that of the earths ionosphere 3105 radio emission from the comet report of observations carried out at the radio observatory stockert 3106 a consideration of radio star scintillations as caused by interstellar particles entering the ionosphere part the kind number and apparent radient of the incoming particles discussion of results given earlier indicates that the interstellar particles must be hydrogen atoms 3107 the proportion of umbra in large sunspots the ratio of umbral area to whole spot area is evaluated and shown to vary significantly with the position of the sunspot in the solar cycle 3108 detection of submillimetre solar radiation preliminary results are presented which indicate regions of transmission in the wavelength range 3109 short time transients in solar noise histograms have been made from observations at dwingeloo holland rebers theory that there is a linear relation between wavelength and duration of pips is not confirmed at this frequency 3110 a review of recent investigations into sunspot cycles summaries of and comments on selected published papers and ccir documents relating to predictions of solar activity for use in ionospheric work 3111 occultation of a radio source by the solar corona measurements of radio noise flux from taurus a when its angular separation from the sun is very small suggest that partial wide angle scattering has occurred due to electron density irregularities in the solar corona 3112 a solar flare on november visual and radio observations during the flare are presented anomalies in the radio observa tions are accounted for by small regions of the flare remaining enhanced for several hours after the main effect had subsided 3113 centimetre wave observations of the solar eclipse of june radiation measurements at disclose an ellipticity in the brightness distribution of the suns disk with the greatest extent in the equatorial plane 3114 proper and improper use of statistics in geophysics a discussion of some of the peculiarities of the geophysical sciences together with their implications for statistical methods particularly for the correlation coefficient is given the discussion is illustrated by an analysis of a recently published paper in conclusion some advice e on the use of correlations is offered 3115 hydromagnetics and the earths inner core it is suggested that the terrestrial magnetic field is produced in an inner liquid core permeated by a magnetic field of secondary motions partly hydromagnetic occur in an outer surrounding liquid region and the field emerging from the complete core is the small field measured at the earths surface 3116 method of magnetic storm forecasting from the activities of flares accompanied by the solar radio noise outbursts a statistical examination has been made of the occurrence of magnetic storms solar flares and radio noise outbursts on the correlations discovered are applied to the problem of forecasting magnetic storms during the igy 3117 ionospheric studies in india during the international geophysical year 3118 propagation and the international geophysical year summary of phenomena which affect hf and vhf propagation some methods of observation are suggested to the radio amateur 3119 artificial satellites of the earth extracts are given from radio published before the launching of the ussr satellites see eg of and results of observations made at various stations in the uk are summarized 3120 tracking the man made satellite an outline of the preparations for launching and observing the us satellite including the use of an electronic computer for calculating the orbit from observational data 3121 the use of surface weather observations to predict the total atmospheric bending of radio rays at small elevation angles 3122 the detection and measurement of water droplets a method of obtaining a permanent record of drop size is described it can be used for droplets of less than diameter 3123 the threefold structure of the atmosphere and the characteristics of the tropopause the atmosphere in the northern hemisphere is divisible into three regions north of the polar front jet south of the sub tropical jet and the region between the jets each region has a typical vertical temperature structure in the stratosphere and troposphere and a characteristic tropopause height 3124 the effect of the equatorial electro jet on the ionospheric e and f layers the occurrence of low values of at ibadan is correlated with variations in the horizontal and vertical components of the earths field and with f layer parameters an immediate relation is indicated between the electrojet the production of equatorial e and vertical drifts in the f layer 3125 dynamical structure of the ionospheric f layer formulae giving diffusion velocity and its divergence are derived for the electron ion gas in the ionosphere on the assumption of a linear temperature gradient the change in electron density distribution is then calculated using these formulae for different models of the ionosphere comparisons of the calculated and observed changes in the f layer show that bradburys rather than chapmans theory is more appropriate 3126 on the occurrence of the f layer in japan part a statistical analysis based on vertical incidence soundings over a sunspot cycle shows annual seasonal and diurnal variations good correlation is demonstrated between frequency of occurrence and sunspot number 3127 some further observations from aircraft of frost point and temperature up to measurements at various altitudes taken in flights over southern england in are tabulated good general agreement is obtained with measurements 3128 variation with height of rainfall below the melting level radar measurements in warm front conditions suggest that there is uniformity of drop size distribution and rate of rainfall with height once meeting is complete and terminal velocity has been attained 3129 on a special aspect of the condensation process and its importance in the treatment of cloud particle growth the distribution of water vapour around a droplet depends upon the ratio of droplet size to a factor determined by the equilibrium rate of exchange of molecules between the water surface and the water vapour 3130 electric charge separation in subfreezing cumuli a theory of the electrification of thunderclouds on charge separation occurring when supercooled droplets impinge on ice particles the theory can explain observed charge separations without assuming the presence of large hailstones 3131 the measurement of world wide thunderstorm activity at a single locality counts of atmospheric impulses received in england in the band are found to be similar to records of integrated noise in california in the band see it is inferred that world wide thunderstorm activity was recorded in both experiments 3132 preliminary discharge processes in lightning flashes to ground the first return stroke is usually preceded by three successive and distinct discharge processes lasting several hundred milliseconds the characteristics of the field changes in these preliminary stages are analysed in terms of the distance of the source probable mechanisms are discussed 3133 the accuracy of the determination of reflection heights and distances of atmospherics on the basis of their waveform the errors in calculating reflection height h and distance d of atmospherics are investigated as a function of the ratio hd and of the reflection modes a recorded waveform is analysed and results are tabulated see also 3134 diurnal variation in the occurrence of dawn chorus a histogram of observations made at frequencies between and on days between january and july at college alaska shows a maximum at local time which appears to be related to geomagnetic latitude 3135 choke or capacitor input basic differences of operation and application of the two systems of power supplies are explained 3136 design of transistor regulated power supplies two applications of the circuit are described one giving at and the other at output resistance is about and ripple on full load is less than it 3137 germanium and silicon power rectifiers 3138 a multipurpose electronic switch for analogue computer simulation and autocorrelation applications abstract 3139 an error analysis of electronic analogue computers abstract 3140 a wide band multiplier using crystal diodes the quarter square multiplication is used the squaring being performed by networks of biased ge diodes in the feed back paths of standard computing amplifiers these networks have phase shifts of less than at and the errors of the multiplier are less than of maximum output 3141 a new storage element suitable for large sized memory arrays the twistor use is made of the wiedemann effect whereby a torsion applied to a magnetic wire shifts the preferred direction of magnetization into a helical path there three modes are suggested in using the effect for storage cells the coincidence of circular and longitudinal magnetic fields inserts information into the wire as a polarized helical magnetization operation similar to the coincident current toroid with the wire acting as its own sensing winding the wire is not twisted but the screw sense of the flux path is related to the current polarities equations relating to the switching performance of a twistor are derived and a description of an experimental bit array is given 3142 the ibm edpm memory system 3143 a new type of ferroelectric shift register ferroresonant circuits for digital computers an analysis of bistability in ferroresonant circuits and the practical application to high frequency operation present limit circuits are shown for a shift register stage binary counter and input logical adder 3144 logic circuits for a transistor digital computer 3145 junction transistor switching circuits for high speed digital computer applications 3146 an electrolytic tank as an analogue computing machine for factorizing high degree polynomials by means of simple measurements all the roots of a polynomial as high as the degree can be located to within about 3147 pulse generator and high speed memory circuit 3148 the development of a new method of circuit analysis in ladder networks the method outlined is applied to networks consisting of tandem connected l sections calculations are simpler than in conventional methods 3149 explicit formulas for tschebyscheff and butterworth ladder networks a new set of simple formulae has been found for the element values in a tchebycheff or butterworth ladder network which apply when the degree of the denominator of the transfer function is odd and the reflection coefficient has zeros alternating in the left and right half planes 3150 rc filters and oscillators using junction transistors 3151 the distortion of frequency modulated oscillations caused by rc networks general remarks on distortion factors of filters not accurately tuned to the carrier which have a skew symmetric phase characteristic and a mirror symmetric amplitude characteristic 3152 mutual correlation of fluctuation type interference at the output of frequency filters the method is discussed of determining the interference correlation function for two filters forming the loads of a two frequency channel receiving system with or without detector 3153 proposal for a solid state radio frequency maser a brief comment on conditions which are necessary to construct a maser using zeeman levels of the pure quadrupole spectrum 3154 characteristics of the beam type maser velocity distribution of molecules in a beam type maser is analysed by an approximate method the average velocity of the molecules is much less than the most probable velocity when the power level and focusing voltage are low the relations between amplitude focuser voltage and frequency agree well with experimental results to be detailed in part 3155 solid state oscillator for microwave frequencies an experimental solid state device using gadolinium ethyl sulphate an ionically bound paramagnetic salt as the active element is described see of scovil et al 3156 the influence of a high frequency gas discharge on the frequency of a self excited short wave oscillator stage continuing earlier investigations further tests were made with a oscillator under various conditions of discharge coupling and magnetic field characteristic curves indicating a linear relation between frequency and anode voltage are obtainable the interpretation of the observations is discussed 3157 polyphase oscillators the frequency stability and freedom from harmonics is greater for single phase than for symmetrical polyphase oscillators 3158 phase generator has resistive shifter the generator operates over a frequency range and supplies a pair of sinusoidal voltages with an accurately known phase relation that is continuously adjustable over 3159 designing oscillators for greater stability methods of improving the frequency stability of an oscillator which can be divided into an amplifier and a feedback network are described and examples are given 3160 simultaneous pulled oscillations in a triode oscillator incorporating two oscillatory circuits simultaneous oscillation at two frequencies is possible and owing to mutual pulling both frequency and amplitude modulation occur a physical explanation of the pulling of a nonlinear oscillator by an external input signal is given 3161 second order nonlinear systems in these systems where time is not explicitly shown the four space is split into a displacement subspace and a velocity subspace the two being related by a hypercone in a transformation singularities of integral curves and certain shock phenomena are discussed and the analysis is applied to two types of multivibrator 3162 pulse generator and high speed memory circuit 3163 cathode coupled flip flop a reliable design procedure 3164 analysis of cathode coupled free running multivibrator a quantitative equivalent circuit analysis valid for frequencies where the interelectrode capacities can be neglected gives results in good agreement with experiment 3165 high speed flip flops for the millimicrosecond region 3166 transient analysis of second order flip flops a mathematical analysis of the trigger sensitivity and switching speed of flip flop circuits whose action can be represented by a second order differential equation the method is applied to a point contact emitter input transistor flip flop 3167 a sawtooth crystal calibrator circuit and construction details of a sawtooth generator triggered from a crystal and giving detectable harmonics up to 3168 feedback coupling in circuits with crystal triodes circuit design methods are described and the formulae derived are tabulated 3169 binary decimal counter operates at mcs a design of counter which produces one output pulse for every ten input pulses is described it uses logical and gates in a feedback loop 3170 statistical fluctuations and optimum transfer functions of a counting rate meter equations are derived to obtain the optimum response conditions and suitable circuits are described 3171 an amplifier for ac bridges the requirements of an amplifier for ac bridges working to an accuracy of one part in ten thousand or better from power frequencies to audio frequencies are discussed an amplifier to meet in part these requirements is described and figures are given for its performance 3172 a uhf wide band amplifier description of the design of a amplifier with bandwidth about for program distribution 3173 a feedback circuit equivalence transfer network representations and their transformations are used to show that the feedback in a bootstrap amplifier with shunt feedback may be considered either positive or negative without inconsistency 3174 a simple shaft digitizer and store a shaft position encoder of simple construction for analogue to digital conversion is described 3175 some applications of square loop ferrite cores to telecommunication switching 3176 high speed gating circuit using the beam deflection tube 3177 the approximation of special frequency laws by means of tables of frequency functions an approximation method facilitating the synthesis of two pole and quadripole networks is described 3178 admittance impedance and scattering matrices the concepts and their interrelation are defined 3179 analysis and synthesis of electrical circuits by means of an electrolyte tank experimental procedure for solving network problems is described 3180 effects of x ray irradiation on the frequency temperature behaviour of at cut quartz resonators results for resonators fabricated from natural quartz synthetic quartz grown on several different cuts of seed plates and synthetic quartz containing al or ge impurity are reported 3181 tolerances of quartz crystals for filters and their measurement methods for measuring series resonance and crystal inductance are indicated 3182 negative impedances and gyrators survey of characteristics and classification of the various types of impedance inverter and gyrator their realization in the form of transistor circuits is discussed see of 3183 stability criteria for linear systems and realizability criteria for rc networks a new set of stability criteria in linear systems is drived about half of the hurwitz criteria can be neglected when certain of the coefficients of the characteristic equation are positive the conditions for realizability of rc networks are closely related to the stability and aperiodic criteria and are given in the form of polynomial coefficients 3184 basic properties and characteristics of a synchronous filter the operation of integrating devices used for improving signal noise ratio is discussed a simple circuit with a long open circuited line as store is analysed 3185 dynamic core behaviour and magnetic amplifier performance discrepancies between theoretical analyses and measurements of magnetic amplifier performance are attributed to excessively simplified representations of core behaviour experimentally acquired knowledge of core flux characteristics is used to predict the operation of amplifier systems 3186 reduction of the distortion of pulse fronts in transistor video amplifiers methods are described for reducing the distortion of leading edges caused by diffusion and other effects in the transistor base region compensating circuits are analysed and phase and amplitude response curves are given 3187 compensation for changes in base to emitter voltage with temperature an economical method of compensating power transistor circuits consists including in the emitter circuit metallic resistors having small positive temperature coefficients 3188 dc amplifier using transistors and a silicon bridge modulator matched si junction diodes are used in a bridge modulator to convert the input to ac which is then amplified by transistors and detected the design is suitable for measuring dc inputs of mv and or more 3189 transistor class b push pull stages the relative merits of single ended and symmetrical output stages are discussed in general the single ended circuit offers considerable advantages 3190 feedback arrangements in transformerless push pull output stages different methods of applying negative feedback to single ended and symmetrical class b circuits are discussed 3191 measurement of noise in a maser amplifier measurements on an beam maser whose cavity and input and output loads were cooled to near liquid nitrogen temperature yielded a noise figure of based on room temperature as compared with a theoretical figure of 3192 computation of noise figure for quantum mechanical amplifiers an expression is derived in terms of the physical quantities of the electromagnetic structure and of the paramagnetic salt used 3193 theory of a three level maser 3194 gain bandwidth and noise in maser amplifiers a theoretical study reveals that the optimum gain bandwidth product of the two port maser is only half that of the circulator maser for the same basic cavity the optimum noise figure is the same if some bandwidth is sacrificed in the two port maser practical considerations may however make the latter competitive 3195 experimental determination of the noise figure of an ammonia maser an outline of the technique of measurement is given 3196 modified wkb approximation for bothes differential equation in diffusion theory 3197 equipartition of energy and local isotropy in turbulent flows homogeneous turbulence was produced experimentally and experiments showed that the turbulence became isotropic at a faster rate than equipartition of energy occurred other experiments where approximately isotropic turbulence was subjected to deformation indicated that even at high reynolds number the deformation in a shear flow can cause anisotropy the connection of the investigation with turbulent flows in general is discussed 3198 barrier layer photo emf of photo electric elements with dyestuffs tests were made on photo elements consisting of dye stuffs deposited on a quartz plate clamped between semi transparent electrodes of pt au or rh three different types of assembly were transversely illuminated in most cases a positive photo emf was obtained 3199 on the nature of the electron in this paper the concept of the electron as a fundamental particle of modern physics is discussed in relation to paulis exclusion principle wave mechanics the uncertainty principle and relativity 3200 the charge density near a sharp point on a conductor the idea that surface charge tends to infinity at convex sharp points on conductors and to zero at convace points is investigated on electrostatic principles it is found that the problem has not been solved a new attempt is made using potential theory methods from which a fairly general solution is obtained 3201 evaluation of transport integrals for mixed scattering and application to galvanomagnetic effect the johnson whitesall evaluations of the conductivity integrals for mixed scattering have been extended to allow their application to the high mobility semiconductors applications in the analysis of hall effect corbino magnetoresistance and thermomagnetic phenomena as functions of magnetic field are illustrated 3202 interaction between waves and electrons with some remarks on superconductivity discussion of interactions occurring between elastic waves and free electrons in metal particularly below the debye temperature 3203 silent electric discharge at low frequency in air using insulating electrodes note on the joshi effect and the variation or discharge current as a function of applied voltage using beeswax electrodes in dry air irradiated by light 3204 three dimensional potential well the possibility of generating potential wells having depths of the order of thousands of electron volts is discussed 3205 variation of inductance by dielectrics in particular plasmas a qualitative interpretation of the frequency changes in oscillatory circuits which are coupled to electrodeless gas discharges see eg above 3206 analysis of multivelocity electron beams by the density function method mathematical techniques useful in the solution and interpretation of the density function equations as applied to multivelocity electron beam problems are presented with some conclusions about the nonconservative nature of signal or noise propagation along a multivelocity beam the paper serves as a background for a detailed calculation of noise propagation through the gun region of an electron beam 3207 density function calculations of noise propagation on an accelerated multivelocity electron beam the propagation of noise fluctuations through the low voltage multivelocity region immediately in front of the potential minimum of a diode or electron beam has been computed despite the absence of any conventional loss elements two noise parameters or measures of the noise fluctuations when the beam is passed through a multivelocity region are significantly different at the output from those at the input changes are such as to lower significantly the minimum noise figure of a microwave valve 3208 the elastic scattering of electrons an examination of basic theory in particular the rutherford formula with reference to experimental results 3209 theory of secondary electron emission by high speed ions a new theoretical treatment shows that the yield of secondaries is proportional to the rate of energy loss of the incident particles and is independent of work function conductivity and other bulk properties of the metal the theory explains the experimental observations and its application to general problems of electron escape and capture is discussed 3210 estimate of the time constant of secondary emission energy considerations allow a simple estimate to be made of the time constant of secondary emission 3211 ionization by positive ions a method of measuring the ionization cross section of atoms is described in which electrons are collected from single collisions of an ion beam passing through a gas at low pressures measurements are given for twenty three cases over energy ranges approximately and to 3212 plasma oscillations in a steady magnetic field circularly polarized electromagnetic modes the propagation of em waves in the direction of the field is considered by taking account of the thermal motion of electrons results are derived which differ markedly from those of the appleton hartree electromagnetoionic theory near the cyclotron resonance frequency 3213 notes on the ground state of anti ferromagnetism the conclusions reached by earlier investigators are compared with those which result from the spin wave theory see the discrepancies are briefly discussed 3214 general solutions of equations of a classical nonconservative electromagnetism 3215 electromagnetic potentials in a heterogeneous nonconducting medium for em fields in a stationary nonconducting medium isotropic or anisotropic the dielectric constant and permeability of which are given point functions the general theory of representations in terms of scalar and vector potentials and of hertzian potentials is developed 3216 tensor theory of gyromagnetic power general linear relations for non absorbing media are derived the influence of symmetry upon tensor equations and the effect of magnetic anisotropy on em wave propagation is examined 3217 electromagnetic waves in nearly periodic structures the theory of simple harmonic electromagnetic waves in a nearly periodic structure of the type used in linear accelerators is discussed by an expansion in a series of appropriately defined transmission modes of the field in a unit cell of the structure the possibility of the expansion being assumed it is shown that the coefficients can be expressed as integrals of the field over the input or output apertures of the cell the modification to the corresponding solution in the strictly periodic structure can be calculated by perturbation theory in the first approximation the structure can be represented by a series of four terminal networks and the voltages and currents in these can be defined in such a way that the relevant parameters vary smoothly in the neighbourhood of resonance 3218 optical detection of magnetic resonance in alkali metal vapour the apparatus is described together with experimental conditions under which signals have been observed a possible application of the technique is the measurement of weak magnetic fields 3219 heterodyne detection of free precession in nuclear magnetic resonance details of a method applied to proton resonance in solutions 3220 narrowing effect of dipole forces on inhomogeneously broadened lines observations of the effect in mn ferrite and yttrium iron garnet are described the theory for cases in which the spatial period of the inhomogeneity is large compared to atomic distances and is either short or comparable to sample size is discussed and its applications are considered 3221 dielectric rod waveguide cells for microwave spectroscopy the calculation of the distribution of microwave power around a quartz rod excited in the dipole mode enabled rod sizes to be selected for cells covering the range teflon windows were found to be satisfactory see also of the 3222 theory of a three level maser a complete theory is discussed for a gaseous system with an extension to paramagnetic solids 3223 an attempt to detect linearly polarized radio emission from the galaxy a paraboloidal reflector was used at a frequency of with receiver bandwidth of plots of position angle of the plane of polarization against time are given for regions near and show that its variation is in the direction to be expected from the ionospheric data 3224 relative intensities of the four principal rf sources observed at a wavelength of cm note on rf source sagittarius a some rf sources have been located during observations of the milky way region made by means of the new radio telescope at dwingeloo netherlands special studies have been made of five of these in class a cygn a taur a virg a and sgtr a and the equivalent temperatures have been determined 3225 the effects of incomplete resolution on surface distributions derived from strip scanning observations with particular reference to an application in radio astronomy the limitations of one dimensional scanning methods for measuring surface distribution particularly that of radio brightness over the suns disk are discussed 3226 tests on a model of an aerial for use in radio astronomy 3227 radio emission from the remnants of the supernovae of and measurements at are compared with previous radio and optical observations see of 3228 the cosmic radiation and solar terrestrial relationships paper presented at the assembly of the union geodesique et geophysique internationale rome september reviewing the properties of cosmic radiation and its association with solar and geophysical processes and including a description of experimental methods developed to study low energy cosmic ray particles 3229 the incidence of meteor particles upon the earth radio echo rates for both shower and sporadic meteors measured at adelaide with cw equipment are applied to the calculation of the incident flux above limiting brightnesses in the region of dependence of ionizing probability on velocity is discussed and the fluxes and densities agree reasonably well with independent evaluations from visual meteor rates 3230 a prediction of a meteor orbital period the probable orbital period of a meteor shower observed on is predicted from examination of snowfall records in japan assuming the suggested correlation between precipitation and occurrence of meteor showers to be real 3231 analysis of the sinusoidal variation of magnetic declination of april and analysis of magnetograms of european stations suggests the development of a counter clockwise vortex like perturbation in the ionosphere bordering on the southern limits of the auroral zone and lasting less than 3232 radar in the rain an outline of radar investigations into cloud structure 3233 radiosonde trials at payerne report of trials in switzerland in may and june in which types of radiosonde from various countries were compared 3234 investigation of the upper layers of the atmosphere measurements of composition pressure density and temperature up to a height of miles were made by means of containers which collected samples of air after being automatically released from rockets experimental data are tabulated and some results obtained in the usa and ussr compared references 3235 ionospheric drifts at brisbane measurements over a year period show that speeds are less than those observed at higher altitudes the e region and solar harmonics show large seasonal phase changes in the northward component the phase for the northward component in summer is in fair agreement with higher latitudes the f region harmonic seasonal change is greater in the eastward than in the northward component 3236 measurement of ionospheric winds experiments made at domont france by the three receiver method are described the electron displacements deduced from observations correspond to some extent with those necessary to account for the daily variations in the earths magnetic field 3237 some possible relations between the nightglow and the ionosphere ionospheric data from stanford california are compared with nightglow data from cactus peak california the nocturnal variation of the brightness of the green line of is found to be similar to the variation of height of thd f region the nocturnal variation of the brightness of the red lines of is found to be similar to that of the electron density of the f region the possibility that the red lines are produced by radiation following dissociative recombination of electrons with o ions is discussed paper presented at the assembly of the union geodesique et geophysique internationale rome september 3238 the reflection coefficient of ionospheric layers experiments made at and show that the reflection coefficient which is nearly unity for the f layer falls to a very low value for the e layer and that loss of energy due to reflection from the latter is of the same order as the nondeviative absorption 3239 the scattering of radio waves of very high frequency in the ionosphere 3240 radar echoes from inter stroke processes in lightning radar echoes at were used to investigate interstroke lightning processes the most intense activity of junction streamers is between heights of these junction streamers may sometimes grow in height up to although their activity decreases with height the lowest level at which they occur remains constant throughout flashes and their horizontal extent is about to km echoes from these junctions always decrease before the onset of a flash 3241 theory of the auroral spectrum paper presented at the assembly of the union geodesique et geophysique internationale rome september the main luminescence observed is due to inelastic collisions made by the incident particles and by the ejected electrons degradation of the ultraviolet radiation emitted and scattering of solar radiation thermal processes such as dissociative recombination 3242 the work of soviet scientists on the luminescence of the night sky and aurorae a review of the research carried out in the last years with particular reference to the igy in a network of stations all over the ussr references 3243 a method for interpreting the dispersion curves of whistlers an analytical solution to the problem of determining the dispersion of a whistler from a known electron density in the outer atmosphere is formulated the results are then applied to the inverse problem of deducing the variation in electron density from the dispersion curve a numerical example is given 3244 calibration of narrow sector radiogoniometers for atmospherics 3245 the balanced transistor dc convertor a theoretical analysis of operation is given 3246 current capacitance characteristics of metal rectifiers report of measurements and discussion of the reverse current voltage and capacitance voltage characteristics of metal rectifiers at room and liquid air temperatures 3247 silicon rectifiers the characteristics are given of an experimental rectifier unit rated at and peak inverse voltage it is hermetically sealed in a metal case of mm diameter 3248 the influence of the copper raw material on the properties of copper oxide rectifiers the characteristics of rectifiers were investigated as a function of manufacturing conditions and degree of purity of the copper used results are tabulated and show that rectifier characteristics are considerably affected by the oxygen content of the copper 3249 logical design of a computer for business use paper presented at the convention on electronics in automation cambridge england june describing an emi serial machine operating at a clock rate of with magnetic drum storage 3250 torsional waves in wires disk loading increases computer memory note on the characteristics of a disk loaded delay line machined from a solid brass rod 3251 digital analogue converter provides storage a transistorized converter changes eight binary bits received in parallel from a shift register to steps in amplitude of a sine wave one binary bit is used to obtain phase information operation operation is performed within a sampling period occurring at an average rate of 3252 analogue and digital computers in nuclear engineering a group of articles outlining the principles of operation and giving a survey of application in the usa 3253 ada a transistor decimal digital differential analyser circuit techniques and assembly and construction methods are discussed the specification of the machine is summarized and some typical problems are considered 3254 signals from switched ferroelectric memory capacitors 3255 electric nonlinear computation performed by linear elements 3256 application of junction transistors to carrier frequency computing amplifiers a discussion of the properties required by a transistorized summing amplifier in a carrier frequency analogue computer details are given of a practical amplifier using standard commercial transistors 3257 moulding moves in on printed circuits the moulding process described permits the use of heavy gauge conductor material in circuits of high current carrying capacity 3258 an automatic gain control system for microwaves 3259 wide band balun transformer description of a balun transformer developed for use with a cro deflection amplifier bandwidth extends from below to above input impedance data and pulse response characteristics are shown one balun coil can be used alone as a passive wide band pulse inverter 3260 design of wide band rf transformers utilizing a synthesized equivalent network 3261 signals from switched ferroelectric memory capacitors the equivalent circuit for a bistable storage capacitor is a current generator with a resistance in parallel the properties of the output signals from switched and unswitched stores are discussed using this model 3262 high speed microwave switching of semiconductors a microwave switch using an n type ge diode has been shown to give pulse rise and decay times as low as 3263 transistor nor circuit design a nor circuit gives a signal output only when no input signal is present in examination of transistor characteristics gives a stable design for an arbitrary number of inputs and outputs on a single type transistor crosstalk factor and speed of operation are considered 3264 a new family of transistor switching circuits two pairs of output levels are obtained from the dual range circuits described which incorporate both npn and pnp transistors the possibility of lower stand by power dissipation and greater switching speed than the dctl circuits see of is offered 3265 transistor terminal switches discussion showing how the blocking voltage concept may be applied to obtain negative resistance characteristics using a junction transistor a point contact transistor a modified double base diode or a modified tetrode a few applications mainly in telephone systems are indicated 3266 a note on noise temperature expressions are given for the effective noise temperature of a lossy passive network with internal noise sources their application in different receiving systems is discussed 3267 recent advances in finline circuits 3268 equivalent admittance impedance and scattering matrices 3269 electric nonlinear computation performed by linear elements simple linear circuits are shown for performing multiplication division and inversion and forming powers positive and negative roots logarithms antilogarithms and hyperbolic functions 3270 interpretation of network theorems in terms of laplace transforms 3271 greater selectivity with the cw clipper filter a two stage amplifier with variable bandwidth 3272 charts simplify passive lc filter design universal design data permit design of butterworth and tchebycheff filters of prescribed steady state insertion loss characteristics design of band pass prototypes of lumped element configuration is given 3273 a travelling wave directional filter 3274 design and manufacture of practical filter circuits discusses the effects of distributed capacitance component proximity encapsulating material and impedance mismatch 3275 travelling wave tube limiters 3276 a phasor method of nonlinear network analysis the network is represented by the sum of a finite number of simple sinusoidal functions with time chosen from a knowledge of the network experiment and preliminary analysis an appendix illustrates stability tests and an application of the method to a typical problem 3277 fine structure of response curves of frequency entrained oscillations jump and hysteresis phenomena suggested by cartwright see of together with a dependence of entrainment range on forcing amplitude have been observed in an electromechanical analogue of a forced self excited system 3278 a low frequency random signal generator the and noise components each in an overall bandwidth of are selected from the noise output of an argon filled thyratron operating in a magnetic field after peak rectification the resulting noise signals are added so that their dc components cancel the amplitude distribution of the resultant output then approximates very closely to a gaussian distribution the output noise spectrum is flat from zero frequency up to a full circuit diagram is given 3279 measurements of the quality of very low frequency rc oscillators a figure of merit is calculated for a number of different rc networks and the experimental determination of this coefficient is described 3280 double excitation in decimetre wave oscillators with coaxial lines the simultaneous oscillation at a frequency corresponding to a setting of about in a disk seal triode oscillator tuned to is investigated and the calculations are verified by experiment 3281 monovibrator has fast recovery time use of complementary transistors decreases recovery time of monostable multivibrator this prevents erratic operation when circuit is used in a television sync generator since both transistors are off during timing cycle circuit is relatively insensitive to transistor variations and operates reliably from to for input frequencies from to 3282 a simple rectangular pulse generator the cathode coupled multivibrator circuit discussed produces pulses of up to amplitude with rise times from to 3283 method of obtaining integral mark space ratios of high accuracy with a continuously variable control frequency a pulse generator circuit is described in which the mark space ratio can be adjusted to within over the range to for control frequencies from to 3284 increasing quartz oscillator stability brief description of a quartz servo oscillator forming part of frequency standard equipment type a frequency error of less than in occurs for a change in supply voltage or change in temperature 3285 fast gray wedge analyser for high input rates a full description is given of the circuits and operation of a pulse height analyser designed for positive input pulses at rates up to with less than distortion of the spectrum the resolution is approximately 3286 pulse compression part description of an experimental realization of the method discussed in of january 3287 the time behaviour of logarithmic amplifier input circuits the nonlinear nature of the logarithmic amplifier input circuit causes the time constant to vary with current and three definitions of effective time constant are examined based on an analysis of the time behaviour of the input circuit to a step change of input current 3288 new types of dc amplifier the cascade balance system owen prinz method of zero drift correction is applied to the first of two identical amplifier stages the residual drift is then balanced against that of the second stage the overall drift is reduced times as compared with the parallel balance system a practical design is fully discussed 3289 new types of dc amplifier the reflex monitor system a correcting amplifier or monitor identical to the input stage of the main amplifier corrects alternately its own drift and that of the main amplifier a differential input is used which rejects in phase drift components and residual drifts are balanced between the two amplifiers full details are given of a practical circuit which has certain advantages over the simpler cascade balance system described in part above 3290 push pull amplifier design a method of designing class ab push pull amplifiers which eliminates the need to plot composite characteristics is discussed and some examples are given which compare favourably with practical results 3291 total differential feedback a device for squaring the effective possible feedback in a feedback amplifier 3292 the simple reactor circuit its operation and mode transition 3293 the series magnetic amplifier a theoretical analysis is given of the steady state operation of the amplifier for saturation states of the cores the control circuit impedance and control voltage relations determining the mode of operation are established and the gain characteristic and time constant are considered 3294 analysis of the full wave magnetic amplifier circuits considering the change of the width of the dynamic hysteresis loop 3295 the operation of the current type self balancing magnetic amplifier a theoretical analysis giving the voltage gain and time constant in terms of the circuit parameters within the range of ideal components the input impedance is zero 3296 high frequency amplification using junction transistors the maximum possible stage gain of a unilateralized grounded emitter narrow band amplifier stage is calculated and the design of interstage coupling transformers is described a typical if amplifier stage is designed and its stability factor calculated 3297 an analysis of transient response of junction transistor amplifiers an exact solution of the one dimensional diffusion equation is obtained by the method of laplaces transform the short circuited output collector current is calculated for a step input forcing function experimental results agree with the theory and for ordinary conditions the physical process underlying transistor transistor action must be diffusion of minority carriers across the base region 3298 how transistors operate under atomic radiation results of tests on an amplifier detector system show that degrading effects of irradiation can be controlled to some degree by negative feedback measurements were also made on a single separate transistor and a coaxial cable 3299 internal noise of transistor amplifiers the internal noise levels of two commercial transistor amplifiers were measured for various input impedances and the results are shown graphically 3300 transistors in speech equipment the use of transistors in af circuits is described and constructional details are given of a speech amplifier 3301 theory of the ferromagnetic microwave amplifier all three possible types of operation using respectively two electromagnetic cavity modes two sample modes and one sample and one cavity mode are discussed one especially simple case that of a sphere in the first type of operation is treated separately thereafter all three cases are discussed in terms of scalar and vector potentials an appendix deals with the gain bandwidth problem and gives an expression for the equivalent negative q of the sample 3302 twin cavity for nh masers a system of two coupled cavities is described replacing the single cavity of an nh maser using this system the curve of the oscillation frequency against cavity temperature presents a plateau thus reducing considerably the pulling effects of the cavity 3303 maser noise considerations a discussion of the effect of the saturation rf field on the noise figure of a three level maser for the conditions considered the effect is small the spontaneous emission equivalent temperature for a free electron vacuum tube amplifier is one half that of a maser in principle more general quantum mechanical amplifiers can be constructed which will not have spontaneous emission noise 3304 compact microwave single sideband modulator using ferrites see also of 3305 foster seeley discriminator a detailed analysis is given of the circuit and the use of the design formulae is illustrated with the circuit arrangement described a sensitivity of af signal per can be obtained with less than second harmonic distortion at modulation 3306 statistical properties of an isotropic random surface 3307 possibility of luminescent quantum yields greater than unity it is shown that an excited sensitizer can transfer its energy simultaneously to two activators under suitable conditions leading to two emitted photons per incident higher energy photon the probability of this transfer process is computed and the process is shown to be experimentally feasible 3308 physics and the new electronics vacuum electronics and the new crystalline solid electronics are compared a brief account of recent work on semiconductors and maser amplifiers is given and the effect of these new developments on the training of electronic engineers is discussed 3309 some remarks about electron correlation a comparison is made between theories representing different approaches to the inclusion of correlation in the wave mechanics treatment of a free electron gas 3310 correlation energy of an electron gas at high density plasma oscillations an analysis of the contribution made by zero point oscillations to the correlation energy of an electron gas at high density this contribution is expressed in terms of that from the scattering states by using the analytic properties of the scattering amplitudes the results are compared with those of bohm pines of 3311 correlation energy of a high density gas plasma coordinates the model hamiltonian of sawada which describes electron correlation at high density is examined it is shown that the set of scattering modes for momentum transfers below a certain is not complete it is completed by the plasma mode is the natural debye length of the theory 3312 characteristic energy loss of electrons passing through metal foils momentum exciton model of plasma oscillations previous work is extended to obtain a unified theory of collective and individual electron effects in the excitation of a degenerate electron gas by fast incident electrons the theory is equivalent to the screening out by the incident electrons 3313 quantum theory of electrical transport phenomena using a simple model a technique is developed which gives the entire density matrix of the system of charge carriers in the steady state the model consists of noninteracting free or bloch electrons scattered by random rigid impurity centres the density matrix is developed in ascending powers of the strength of the scattering potential the boltzmann transport equation represents an approximation valid in the limiting cases of very weak or very dilute scatterers higher order corrections are given 3314 the specific heat of the electrons of metals a new approximation method is used to calculate the specific heat for low temperatures taking account of electron interaction results are compared with those obtained by other methods 3315 exact nonlinear plasma oscillations a solution is given for the problem of a one dimensional stationary nonlinear electrostatic wave in a plasma free from inter particle collisions in the limiting case of small amplitude waves the linearized theory can still be applied by using singular first order distribution functions 3316 contribution to the diffusion oscillations in gas discharge plasma 3317 quenching of the negative glow by microwaves in cold cathode gaseous discharges a discussion of results obtained in he at a pressure of mm hg using pulse at enhanced emission was observed in ne a and xe discharges at mm hg 3318 the theory of the surface effect of secondary emission for primary energies of about of the secondary electron yield in light metals can be ascribed to surface effects for higher energies and heavier metals surface effects can be neglected 3319 effective electron electron and electron ion cross sections in plasmas cross sections for elastic scattering are infinite for strictly coulomb interaction but finite values are found by using debyes theory of electrolytes 3320 report on the course of the international school of physics of the italian physical society varenna july august report of the proceedings of the course on magnetic properties held at the villa monastero varenna the text is given of lectures and communications including the following paramagnetism in crystals magnetic properties of metals paramagnetic relaxation ferromagnetism metamagnetics or critical field antiferromagnetic materials nuclear magnetism and nuclear relaxation line breadths and the theory of magnetism the influence of electrons on nuclear spin resonance in diamagnetic materials chemical displacement and indirect interaction stochastic theory of magnetic resonance the concept of temperature in magnetism magnetism at very low temperatures and nuclear orientation cyclotron resonance in crystals optical methods for radio frequency resonance magnetic properties of super conductors hall effect in ferromagnetics critical scattering of neutrons from ferromagnets the van vleck model of ferromagnetism influence of the apparatus on nuclear magnetic resonance paramagnetic resonance of impurities in a semiconductor the electric analogue to antiferromagnetism antiferroelectricity magnetic susceptibility of electrons in periodic fields 3321 equivalence theorems for electromagnetic fields theorems are considered with reference to electric and magnetic surface currents 3322 forces and stresses in an electromagnetic field the theories of faraday larmor and livens and the energy method are compared and applied to some illustrative examples the three theories may lead to different results for nonrigid magnetic materials and the larmor and livens theory may not be applicable to magnetostriction a discussion by r m lichtenstein giving a further thermodynamic method is included 3323 coils for the production of high intensity pulsed magnetic fields the design performance and applications of a pulsed field system for are described it consists of a capacitor bank charged to which is discharged through a be cu helix of in internal diameter and long detailed design data are also given for a range of coils giving increased volume and field uniformity at lower field intensities and include a coil providing transverse access to the field 3324 production and use of high transient magnetic fields par the mechanical and thermal limitations of solid metal coils are discussed and illustrated by experiment these limitations can be removed by force free coil designs part of 3325 variable and reversible magnetic fields obtained from a permanent magnet a permanent magnet forms the core of a cylinder whose surface is made of two armco iron shoes and two brass shoes rotation of the cylinder directs the flux either to a shunt or across the gap of the magnet for deflection of an atomic beam 3326 oscillations of electron cloud in external fields the density fluctuations are analysed in a pure electron gas not neutralized by positive ions and under the influence of an external magnetic field 3327 a semi infinite array of parallel metallic plates of finite thickness for microwave systems 3328 on the line width in ferromagnetic resonance it is suggested that the line width is modified by a nonuniformity of the demagnetization field throughout the specimen it is shown that the broadening is greater for a disk magnetized normal to its plane than for one magnetized in its plane and also that the effect would be greater for ferrites than metals both results are in agreement with experiment 3329 theory of the ferromagnetic microwave amplifier 3330 high temperature molecular beam microwave spectrometer a description of measurements at on the rotational transition of kcl 3331 effective magnetic anisotropy and magnetostriction of monocrystals a nine constant expression is derived which describes empirically the spontaneous magnetostriction to the sixth order in the direction cosines of the magnetization the relation between the effective anisotropy in domains and domain walls is also studied 3332 diffusion of charged particles in a homogeneous electromagnetic field an approximate solution is considered 3333 the elastic impurity centre model an approximation between two extraneous atoms in a crystal lattice 3334 radio astronomy the main part of this issue is devoted to a group of papers dealing with practical and theoretical aspects of radio astronomy abstracts of some of the papers are given individually titles of others are as follows introduction to radio astronomy the discovery and identification by karl guthe jansky of electromagnetic radiation of extraterrestrial origin in the radio spectrum early radio astronomy at wheaton illinois the telescope program for the national radio astronomy observatory at green bank west virginia noise levels at the national radio astronomy observatory radio astronomy at the meudon observatory a high resolution radio telescope for use at the sydney radio telescope measurements of solar radiation and atmospheric attenuation at millimetres wavelength scanning the sun with a highly directional array a wide band antenna system for solar noise studies the radio spectrum of solar activity a swept frequency interferometer for the study of high intensity solar radiation at metre wavelengths the cornell radio polarimeter a time sharing polarimeter at a polarimeter in the microwave region radio sources and the milky way at flux measurements of cassiopeia a and cygnus a between and it the distribution of cosmic radiation background radiation a galactic model for production of cosmic and radio noise hydrogen line study of stellar associations and clusters extragalactic line studies measurements of planetary radiation at centimetre wavelengths planetary and solar radio emission at metres wavelength radio emission from comet on lunar thermal radiation at lunar radio echoes radar echoes from the moon at a wavelength of cm a phase tracking interferometer radio astronomy measurements at vhf and microwaves cosmical electrodynamics 3335 spectral lines in radio astronomy a review of atomic and molecular resonance lines occurring in the radio spectrum it is shown how radiation from the galaxy is modified by interstellar gas 3336 radio astronomy polarization measurements a survey of possible techniques for measuring polarization and for studying the faraday effect shows which components should be measured methods for deducing the electron density along the path are discussed and applied to data on radiation from the sun and the crab nebula 3337 absorption techniques as a tool for cm research absorption lines in the spectra of radio stars are used to study the distribution of interstellar gas minimum distances to radio stars and problems related to cosmology 3338 excitation of the hydrogen line the influences of certain mechanisms on the spin temperature such as electron collision and interaction with light are considered and their importance to radio observations is discussed the deuterium line at is also considered 3339 restoration in the presence of errors a discussion of the relationship between observed aerial temperatures and the true distribution of a celestial source techniques for allowing for certain errors are described 3340 a broad band microwave source comparison radiometer for advanced research in radio astronomy 3341 a method of calibrating centimetric radiometers using a standard noise source 3342 a radio telescope 3343 an antenna array for studies in meteor and radio astronomy at metres 3344 radio telescope antennas of large aperture 3345 mark minitrack base line components 3346 the large scale structure of the galaxy observations at are being made at sydney australia using an aerial of diameter and beam width and a receiver with bandwidth of a composite diagram of the galaxy is shown based on these observations and similar observations at leyden netherlands 3347 radio observations of the comet arend roland observations made at cambridge between march and may at and using different instruments gave negative results emission at and has previously been reported elsewhere 3348 duration of transients in solar radio noise histograms of observations made at oslo are given rebers theory see of is confirmed for this frequency see also of february please note change of number 3349 frequency drift of short time transients in solar radio noise an analysis of records made at oslo on a two channel receiver is being made to give a detailed study of solar noise storm bursts channels are centred on and bandwidth is time constant and noise factor about it is suggested that the transients in most cases have a frequency drift in either direction ranging from about to higher values 3350 discussion of solar radio flux measurements and an estimation of the accuracy of observations revision of previously published data is recommended 3351 critical frequency refractive index and cone of escape in the solar corona nomograms give refractive index governing radio propagation in the solar corona and the semivertical angle of the cone of escape 3352 studies at the mc math hulbert observatory of radio frequency radiation at the time of solar flares records of radiation at and during several hundred flares are compared with associated data obtained from spectroheliograms 3353 a dynamic spectrum analyzer for solar studies the range is swept three times a second in three overlapping bands results appear as a frequency intensity display on film 3354 radio interferometry of discrete sources salient features of the theory and practice of radio interferometry are presented with special attention to assumptions and to the specifically two dimensional aspects of the subject a theorem is proved according to which only certain discrete stations on a rectangular lattice need be occupied for full determination of a discrete source distribution procedures in interferometry are discussed in the light of this result and an optimum procedure is deduced current practice is considered over conservative eg independent data in the case of the sun are obtainable only at station spacings of about wavelengths on the ground a fact which has not hitherto been taken into account 3355 preliminary report of geomagnetic observations at prince harald coast antarctica the results of geomagnetic observations during the first japanese antarctic research expedition are briefly summarized the geomagnetic total intensity was found to be less than the value in vestines world map correlations between geomagnetic and ionospheric phenomena are discussed 3356 apsidal motion of an igy satellite orbit an error in previous work is corrected concerning the movement of the line of apsides relative to a node please note change of udc number 3357 winds and temperatures between a review the results of measurements by various methods of temperature and wind velocity in the northern hemisphere and briefly outlined the results are used to obtain consistent systems of zonal wind and temperature for the winter and summer seasons a standard atmosphere is suggested for northern latitudes to a height of km extended to km for latitudes to for both seasons 3358 the use of radio stairs to study irregular refraction of radio waves in the ionosphere information from various sources on the amplitude and phase scintillation of radio star radiation is reviewed and the experimental data compared with theory there is general agreement on most but not all of the characteristics of the scintillation and its variation with time and zenith angle the rate of scintillation increases under magnetically disturbed conditions there is good correlation with spread f ionospheric reflections and some with sporadic e reflections the scale of the irregularities causing the scintillation is of the order of a kilometre the most puzzling problem is the cause of the night time maximum in scintillation references 3359 some measurements of high latitude ionospheric a theory of absorption and a technique of measurement are described observations at have shown that marked differences can occur in disturbed periods between stations km apart most of the absorption occurs below the e region and it correlates well with the geomagnetic k index 3360 ionosphere review sunspot activity has reached unprecedented high values average f layer critical frequencies have increased by a factor of just over two since monthly mean values for noon and midnight were considerably higher that at last sunspot maximum muf as high as have been reported and examples of long distance reception at and are noted though sunspot maximum may have occurred before the end of little change in propagation conditions is expected over various paths in as compared with those during similar months of quasi maximum conditions may well prevail throughout and 3361 transistor relays have low idling current two transistor circuits for remote control are shown which operate a or electromechanical relay from the output signal of a receiver this may be a carrier modulated at or a pulsed microwave signal using si transistors the idling current is a few microamps 3362 magnetic regulation transistor power supply the method uses saturable reactors in the input and load circuit of the supply for close regulation a silicon diode reference voltage may be used 3363 compact supplies have wide range regulation use of solid state rectifiers and high current regulator tubes eliminates power transformer and reduces size and cost of power supplies units have regulation better than ripple of and stacking factor of about capacity per inch of rack space 3364 a method of designing small power transformers for communication equipment 3365 the effect of capacitance on power supply filter bounce a discussion on the design of power supply filters 3366 regulated supply for transistor amplifiers 3367 semiconductor rectifiers summary of characteristics and review of industrial applications of si ge se and copper oxide rectifiers 3368 a new coltage divider circuit for semiconductor rectifiers auxiliary transformers divide the inverse voltage across high power rectifiers 3369 the fused silicon rectifier a comprehensive review dealing with rectification theory basic fabrication techniques and the properties of si the counter electrode alloy solder the base solder and the base electrode encapsulation and heat dissipation theoretical and experimental properties of si rectifiers 3370 rating and application of germanium and silicon rectifiers a discussion of the factors limiting the life and rating of semiconductor rectifiers practical design criteria are considered including fusing surge voltage protection and parallel and series operation 3371 direct water cooled germanium power rectifier a description of the development performance and operation of various types of water cooled unit 3372 a unique approach to computer versatility the need for a computer which can perform specialized computations as well as general data processing is met by the integration of a general purpose computer with a digital differential analyzer the design involves shared storage system and special input output facilities 3373 description of a large electronic computer description of the ibm type computer which comprises storage units of magnetic tape core and drum type 3374 cycle and delay time considerations in a real time digital computer considerable improvement in a computer program can be obtained by careful selection of cycle and delay times the criterion of information handling efficiency provides a basis for comparing the quality of various programs 3375 recording and read out circuits for binary numbers in a magnetic drum storage system details of the storage system used in the computer type at the milan polytechnic see also of 3376 a swiss analogue computer an electromechanical system is described in which quantities are represented by ac voltage amplitudes and by the angle of rotation of shafts in a servo system 3377 trapped flux superconducting memory a memory cell based on trapped flux in superconductors has been built and tested the cell is constructed entirely by vacuum evaporation of thin films and can be selected by coincident current or by other techniques with drive current requirements less than the short transition time of the trapped flux cell indicates its possible use in high speed memories the superconductive film memory does not exhibit the problems of delta noise in core memories resulting from the difference in half select pulse outputs 3378 an analysis of a persistent super current memory cell a theoretical model of a storage cell based on thin films of superconductors is discussed an experimental device built to resemble the model was found to have the predicted behaviour 3379 a binary weighted current decoder a method for driving cr rubes from digital equipment is described in which the deflection yoke is fed directly from binary weighted constant current sources design considerations are outlined and a comparison is made with other methods 3380 radio interference control as applied to business machines 3381 negative impedances transistors and feedback circuits and their interrelations the use of transistors in negative impedance feedback circuits is investigated and the influence of transistor characteristics on the network parameters is determined theoretically and by measurement some practical difficulties are discussed 3382 mechanics of electronics some suggestions for layout and mechanical design of equipment 3383 the influence of the coefficients of the transfer function of a transmission system on the output characteristics as a function of time the input considered is in the form of a step function 3384 on the use of ferrites in wide band hf transformers design problems encountered using ferrite cores in hf power transformers are discussed including methods of heat dissipation characteristics of two commercially available designs are given 3385 electronic switch doubles as cathode follower basic two way electronic switch may be expanded to multiway unit by adding input selector circuits or may be used as a precision cathode follower by eliminating the selector circuit has near infinite input impedance and near zero output impedance comparator compensation permits accuracy of over 3386 an electronic transmitter receiver antenna switch description of a twin triode circuit for instantaneous break in operation 3387 miniaturized tantalum solid electrolytic capacitors the replacement of an aqueous electrolyte by an oxide film results in an improvement in the low temperature characteristics and an extension of the frequency range these capacitors also have the advantage of storing more charge per unit volume than previous types 3388 theory of electrical networks with nonlinear elements mathematical treatment making use of almost periodic functions 3389 the occurrence of abnormal states in certain ferroresonant circuits two identical parallel resonance circuits incorporating coils with iron cores are connected in series conditions are examined under which an applied alternating voltage is not equally distributed between the circuits see also of 3390 the problem of increasing the frequency stability of crystal oscillators by means of compensation herzogs method of improving the pierce oscillator by including a compensating resistance is investigated the dependence of the oscillator frequency on the circuit parameters with or without compensation is calculated the advantages of compensation are offset by serious drawbacks especially in crystal clock applications 3391 the calculation of linear circuits circuit components which may include valves transistors and transformers are set up in the form of a multipole admittance matrix from this five determinants are obtained 3392 theory of networks of linearly variable resistances a network of fixed resistances and linear rheostats driven by a common shaft can replace nonlinear elements such networks are amendable to good design techniques and can be described in a mathematical form analogous to that of fixed rl networks 3393 theoretical and experimental investigation of distortion in low frequency junction transistor quadripoles expressions are derived for calculating distortion by differentiating the quasilinear hybrid parameters of the quadripole methods are described of measuring distortion in junction transistor quadripoles in earthed base earthed emitter and earthed collector circuits calculated and measured results are compared for the earthed emitter circuits close agreement is found the application of the results of the investigation to the design of transistor amplifiers is discussed see also of 3394 high frequency crystal filter design techniques and applications commercially available hf crystal filters exhibit performance characteristics previously attainable only at lower frequencies filters normally consist of from two to eight quartz resonators in a lattice or bridge network and are characterized by high q and stability under extreme environmental conditions normal values of q for filter components in the range are from to in certain filters element qs exceed by eliminating the need for multiple frequency conversions the small rugged filters are useful in many am ssb and fm receivers as well as single sideband generators 3395 low pass filters for mobile use constructional details are given of simple compact filters for the suppression of radiation at television frequencies from mobile transmitters operating at frequencies below and in the range 3396 transmission line low pass filters the networks consist of sections of line with suitably constructed lumped shunt capacitance design curves are given and practical models are illustrated 3397 design of three resonator dissipative band pass filters having minimum insertion loss comment on of and authors reply 3398 band pass filter design technique universal curves provide design information for butterworth and tchebycheff stagger tuned filter networks for band pass amplifiers required number of stages centre frequency cut off frequencies and stage gain requirements can be determined 3399 galvanomagnetic oscillators the type of hall effect oscillator described has an efficiency of 3400 an ultrastable keyed vfo high stability is achieved by constructing the variable tuned circuit which has a high q and is of rigid construction as a single unit separate from the remainder of the oscillator clickless keying is obtained by a relatively small change in screen grid potential 3401 self oscillatory systems with two degrees of freedom at multiple frequencies mathematical analysis of the operation of an oscillator using two coupled tuned circuits resonating at frequencies one of which is an approximate multiple of the other expressions are derived for the oscillator frequencies and their instability as a function of the instability of the tuned circuits and the supply voltages 3402 idealized treatment of relaxation oscillator circuits topological analysis of idealized circuits with the introduction of critical point notation a correct solution can only be obtained if the system oscillates 3403 transistor oscillator supplies stable signal colpitts circuit employing one germanium transistor and one zener diode operates from a laboratory regulated power supply to maintain a sine wave voltage of precise amplitude 3404 determination of the frequency of a transistor multivibrator between and to experimental and theoretical results supplement those of mc duffie of for the pulse duration and repetition rate of astable transistor multivibrator circuit 3405 pulse height selector with constant analysis time a single channel pulse height selector with a analysis time constant to within independent of the pulse height is described 3406 unusual transistor circuits the main features of design and a physical explanation of the action are given for voltage catching transistor pump emitter squared follower and transistor gating circuits 3407 millimicrosecond pulses in the millimetre wave region a technique is described for the generation amplification and detection of pulses in the mm region the pulses are wide at the base with a peak power of a few milliwatts 3408 forty megacycle scaler the scaler has a scale of eight and uses a fast flip flop as a basic element the latter can be triggered at a rate higher than and has a double pulse resolution of 3409 decade decimal counter speeds printed read out high speed circuit uses magnetron beam switching tubes to sample store and provide multi output functions without stopping the original count or losing input information during read out 3410 amplifier low frequency compensation general expressions are deduced for the indicial response ie response to unit step input and gain frequency and phase frequency response leading to conditions for maximal flatness compensation is then considered together with the effects of negative feedback multistage amplifiers are also discussed 3411 pulse method for the amplification of af oscillations the advantages and efficiency of a pwm method are discussed 3412 dynamic range of negative feed back pulse amplifiers analysis of the limiting conditions for grid current in two or three stage amplifiers 3413 more transformerless amplifiers a review of recent work published since an earlier article of single input series connected and petersen sinclair output stages of are discussed 3414 practical circuits of video amplifiers using junction transistors practical circuits with two two types of russian transistor are described complex feedback is used in order to reduce the distortion of the leading edges of the pulses 3415 noise temperature measurement on a solid state maser noise measurements have been made on a three level maser operating at with sufficient accuracy to establish that its noise temperature does not exceed it 3416 a parametric electron beam amplifier 3417 the optimum design of a tunable multiplier for frequency modulated oscillations the design of tunable frequency multipliers containing simple one or two stage filters in the individual multiplier stages is investigated adjacent channel attenuation and distortion can be achieved if the multiplication per stage does not exceed the fundamental frequency should not be less than about 3418 combined limiter and discriminator the limiter incorporates a harmonic rejector in series with the diode distortion less than of any harmonic is easily obtained and stray capacitances are small leading to high sensitivity and output 3419 pulse detector with an inductance capacitance filter an ideal detector with an lcr filter is considered taking into account the internal impedance of the current source a method is proposed for calculating the voltage at the load when detecting pulses of arbitrary shape and the necessary formulae are derived 3420 the ether and the special theory of relativity an ether which is immobile in its immediate surroundings but capable of a movement of translation is suggested it is hoped that this hypothesis will provide a physical explanation of electrodynamic and other phenomena and will not be inconsistent with the results of the special theory of relativity 3421 polarimetry in the infrared 3422 connection between electron temperature determination by means of the langmuir probe method and the two probe method 3423 the lamb shift an elementary account of present day knowledge concerning the electron and a discussion of lamb and rutherfords experiment see egin relation to the anomalous magnetic moment of the electron 3424 use of complex conductivity in the representation of dielectric phenomena a representation for complex conductivity is proposed in which a simple debye mechanism results in a semicircular locus a non zero value of dc conductivity does not cause this plot to lose its unique shape in the low frequency range 3425 theory of superconductivity 3426 temperature rise of solid junctions under pulse load the magnitude and duration of current pulses are correlated with temperature rise in the junction use of successive approximations assuming that various parts of a body are not yet subjected to a temperature increase or have already reached a temperature differential corresponding to the steady state reduces the problem to a simple case of heat diffusion 3427 charged particles in a nonuniform radio frequency field under certain conditions particles of either sign will experience an acceleration towards the position of least field strength such an acceleration is demonstrated in a slotted magnetron having no magnetic field and a cold cathode 3428 theory of ferromagnetic anisotropy by means of a virial theorem and perturbation theory the anisotropy energy of a ferromagnetic crystal is expressed in terms of the coulomb energy alone this is approximated by a multipole expansion and the anisotropy constants are given in terms of electric multipole moments and crystalline potential constants the multipole moments which arise from the orbital angular momentum induced by spin orbit coupling have been estimated from the known values of angular momentum 3429 effect of crystalline electric fields on ferromagnetic anisotropy the effect of the electrostatic crystalline field has been considered for a magnetic crystal in which the ions are strongly coupled by ferromagnetic exchange on the basis of the one ion approximation that the exchange can be represented by a weiss molecular field expressions for the anisotropy constants have been derived the treatment assumes that the magnetic electrons can be considered as localized on the individual ions and thus applies primarily to nonmetallic substances such as ferrites 3430 the time sequence and amplitude distribution of barkhausen jumps report on discussion of results obtained in investigations of the magnetization of fe ni alloy wire specimens to determine the dependence of barkhausen jump characteristics on field strength and specimen shape 3431 some new aspects of the reflection of electromagnetic waves on a rough surface the roughness is represented by electromagnetically interacting hemispherical bosses whose radii and mutual distances are small relative to the wavelength the effects of such a surface on both vertically and horizontally polarized radiations are considered as functions of the angle of incidence 3432 apparatus for the experimental study of the diffraction of centimetre waves apparatus operating at is described for determining the phase and intensity at any point of the em field two versions are presented one for the investigation of diffraction near the axis and the other for the distant diffraction field the effect of diffracting bodies less than in size can be detected 3433 diffraction of cm electromagnetic waves by dielectric rods part lucite diameter semicylinder fields very close to surface the diffraction field is examined very close to the surface of a lucite semicylindrical rod with its plane surface at various orientations relative to the axis of propagation of the incident wave parts of 3434 the microwave spectrum of and in the cm and bands 3435 the characteristic frequencies of negative molecular ions of oxygen between and observed in ionized air discharge tubes absorption frequencies are determined from the current variations in a coil round a discharge tube containing pure air supplemented in some cases by at pressures of absorption frequencies above give rise to strong absorption at pressures below mm hg 3436 noise temperature measurement on a solid state maser 3437 radio pictures of the sun a radioheliograph erected at sydney australia combines the principles of the multi element or grating interferometer and the mills cross it consists of two rows of parabolic aerials of diameter arranged in the form rm of a cross each row being long diagrams of the lower corona have been prepared from observations of radiation 3438 investigation of scintillation of the sun observed at a wavelength of cm results of observations including simultaneous measurements at and cm indicate that scintillations are of atmospheric origin and are related to zenithal height solar activity and wavelength the apparent diameter of the sun also fluctuates 3439 investigation of the scintillation of the sun observed using several aerials on a wavelength of results of measurements of scintillation made with three receivers at variable distances show that the average dimension of the ground shadows is their velocities are compared with those of winds at the altitude of the tropopause 3440 polarization of solar radio outbursts changes in the polarization of rf emission at were recorded at tokyo on july during a solar flare 3441 the scattering of radio waves by the moon measurements of the rapid fading of echoes at a frequency of show that the effective scattering region has a radius of about one third of the lunar radius and is located at the centre of the visible disk range measurements indicate that the echo is returned from the front edge with a power reflection coefficient of see also of browne et al 3442 sweets mechanism for merging magnetic fields in conducting fluids the mechanism is investigated in a semi quantitative manner if two oppositely directed sunspot fields having scales of about km were brought together sweets mechanism would allow them to merge in about two weeks the mechanism gives a means of altering quickly the configuration of magnetic fields in ionized gases and converting magnetic energy into kinetic energy of the fluid 3443 the solar flare of february its cosmic and geophysical effects records of the intensity of cosmic rays and of atmospherics show that a sudden large increase in the former at was accompanied by a sudden decrease in vlf atmospherics particularly as observed at bagneux at km 3444 the earth and its magnetic field review of modern theory which attempts to explain the presence and properties of the observed magnetic field in terms fully compatible with the structure of the earth determined independently references 3445 the effect of solar flares on the the geomagnetic field the dynamo equation is solved for a conductivity produced by solar flare ultraviolet radiations from the sun the crochet amplitudes in horizontal field components are then computed and compared with observed results it is found that fair agreement exists between the theoretical and experimental values only if the seat of the crochet current system is within a few kilometers of the current system producing the quiet day solar variation 3446 sudden commencements of magnetic storms and atmospheric dynamo action statistical analysis of world wide magnetic data discloses an appreciable diurnal change in the amplitude of scs the average electric current system for the disturbance diurnal variation shows marked concentrations in polar regions and suggests that the system exists within the earths atmosphere while the current system of the storm time variation would appear more likely to be of extra terrestrial origin a dynamo theory is applied to explain the atmospheric part of magnetic disturbances and a consistent wind system is obtained to produce current systems for magnetically quiet and disturbed days this system contains diurnal and semi diurnal terms and its order of magnitude agrees with recent ionospheric wind observations 3447 the geophysical year and the ionosphere discussion of the organization and program of the igy with particular reference to ionospheric measurements and techniques 3448 radio observations of the russian earth satellite observations were made at and at the mull rd radio observatory cambridge using interferometer and doppler techniques details of the calculation of the orbit are given and possible new methods of finding the distribution of electron density with height are suggested 3449 observations on the orbit of the first russian earth satellite report of calculations carried out at the royal aircraft establishment farnborough hants to determine orbit constants from interferometer and doppler measurements observations of signal amplitude and fading indicate that the ray path of long distance transmission from the satellite to a receiving station is complicated 3450 radar observations of the first russian earth satellite and carrier rocket a note of instruments used and observations made at jodrell bank at frequencies of and with pulse durations of and respectively 3451 further radio observations of the first satellite reports of interferometer measurements at made at urbana illinois and doppler measurements at made at chelmsford 3452 charge transfer reactions an improved method for determining charge transfer cross sections is applied to symmetric and unsymmetric reactions for a large number of gases and gives higher values than originally reported a comparison of the rates of collisional processes in the d e and f region shows that the charge transfer rate is much larger than that for any other collisional process in the upper atmosphere see of 3453 an appraisal of photon counter measurements of upper atmosphere parameters a model atmosphere has been computed from measurements of density and o concentration using rocket borne photon counters near km inconsistencies have appeared and it is concluded that the density at km is higher than that found using photon counters 3454 calculation of group indices and group heights at low frequencies a formula is derived from which the group index designated for normal incidence including collision effects can be easily computed as a function of the real and imaginary parts of the refractive index for frequencies below a set of curves can then be prepared from which the group height to be expected from a given electron density profile can be quickly determined by graphical methods 3455 the movements of sporadic e layer clouds the drift speed of isolated clouds was measured by observing the beat between a ground wave signal from a cw transmitter and the sky wave reflected from the moving cloud comparison of these observations made at night with other evidence suggests that scattering is greater than in the day a method for determining the direction of drift is suggested 3456 relation between virtual and actual heights in the ionosphere a mathematical discussion of the various methods of determining the distribution of electron density with height in the ionosphere and a treatment of the comparison and integral methods an annotated bibliography with references is given 3457 the coefficient of diffusion of ions in the f regions the application of sutherlands molecular model to the f region gives too large a coefficient of diffusion if recent rocket estimates of f layer molecular density are correct if langevins formula for the diffusion coefficient is used instead the discrepancy is less but for an f region in which diffusion is in inappreciable calculated values of the coefficient are still about times too large possible influencing factors are discussed 3458 the origin of the ionospheric irregularities responsible for radio star scintillations and spread f part the present state of knowledge about the irregularities responsible for radio star scintillations is summarized and the existing theories of the origin of these irregularities are discussed all of the suggestions are shown to be inadequate to explain the observed features of scintillations and spread f it is shown that any i nizing agent from outside the earths atmosphere is unlikely to be responsible for the ionospheric irregularities that cause radio star scintillations and that the mechanism for their production must be sought in the terrestrial atmosphere 3459 the origin of the ionospheric irregularities responsible for radio star scintillations and spread f part a theory is presented which attributes the occurrence of ionospheric irregularities in the f region to turbulent wind motion in the dynamo region at a height of km the resulting turbulent component of the electric potential field produced is communicated to the f region as suggested by martyn where magneto electric forces then cause the ionization to form eddies it is suggested that the absence of daytime scintillations is due to the inhibition of turbulent flow by large temperature gradients during the day the theory is then shown to explain the major features of radio star scintillations together with the long term correlation of scintillation amplitude with magnetic activity and the variation of spread f and scintillations at different parts of the earth over the sunspot cycle 3460 diurnal absorption in the d region an analysis of the diurnal variation of cosmic noise at from which are derived the d region electron density and an exponential approximation to the vertical distribution of nitric oxide 3461 the electron content of the ionosphere report of an investigation noted earlier using radio echoes from the moon to determine the electron content the apparatus and the methods of analysis are described results for seven periods between october and september are given an almost constant ratio is found between observed electron content and that expected in a parabolic layer there is some evidence for tidal effects 3462 a critical discussion about special ionospheric characteristics twelve month running means of f and r are compared for locations and linear relations between the two are apparent for limited regions deviations from linearity may be genuine at some locations and due to magnetic effects but may arise from observational errors and inconsistencies at others present data are inadequate for examination of m factors on a world wide basis 3463 the sunspot cycle and radio communications 3464 some problems of the physics of the ionosphere part fluctuation of the electron density and scattering of radio waves electron density usw scattering and turbulence of the ionosphere are discussed and experimental results are analysed references 3465 curvature induced error in the analysis of fading records curvature of lines of maximum amplitude in a radio field strength pattern drifting cross an array of three receivers can introduce an error into the estimate of the drift velocity but the error is expected to be large only infrequently the mean error is sm ller for an array of receivers at the corners of an equilateral triangle than for one at the corners of a right n angled triangle 3466 radar observations of lightning on metres the echo cross section was approximately m the visually estimated echo duration approximately and the horizontal extent several miles the associated atmospherics are described 3467 me surements of the absolute intensity of the aurora and night airglow in the region 3468 ra io reflections from aurorae a further study o fradio echoes at following earlier work by bullough and kaiser good correlation is found between the daily frequency distribution of echoes and the mean daily variation in magnetic disturbance at eskdalemuir results and conclusions conflict with the chapman ferraro martyn theory 3469 uhf radar observations of aurora radar echoes have been obtained on a frequency of at south dartmouth mass the diurnal and seasonal variations in the occurrence of echoes is discussed and also the conditions required to obtain echoes 3470 the waveforms of atmospherics and the propagation of very low frequency radio waves 3471 vh radar echoes associated with atmospheric phenomena during observations with radar equipment at echoes were obtained which could not be attributed either to aurorae or to meteors the characteristics of these echoes suggest that they may be due to upward discharges from the troposphere to the ionosphere which may be triggered off by meteors 3472 semiconductors shrink servo system size a velocity type servo system in which the network design is based on the constant current driving source and low impedance load conditions imposed by transistor operation output impedance is reduced considerably by using a double common collector power stage with inverse feedback 3473 th effects of dust and force upon certain very li ht electrical contacts a quantitative relation is established between dust concentration and contact failure an examination of contact loading shows that contact resistance may rise rapidly at loadings less than mg unless surface films can be permanently removed 3474 progress report on semiconductor rectifiers findings indicate that silicon and germanium rectifiers are more desirable in high temperature areas while selenium retains its superiority in high c rrent uses 3475 de ign of magnetic circuits for miniature relays the polarized type of relay with a rotary armatur is suggested as the most suitable type for miniaturization 3476 the solion an electrochemical transducer the operation of this device is based on concentration polarization where an electric current passing through an electrochemical system is limited by dif usion and convection variables such as fluid f ow the solion consists of a small cylinder of p astic material containing a potassium iodide solution in which two or more electrodes are immersed polarization is effected by a battery when the unit is stimulated by light heat sound pressure or movement the resultant hydraulic flow within the cell produces a current output these r actions are reversible 3477 wa xelectrolyte batteries two types of punched cell battery have been developed they are long and respectively and in diameter with short ci cuit current and a cell is stamped from a three layer sandwich consisting of a zn sheet a conductive vinyl film and between the two layers a separator impregnated with a zncl polythylene glycol mixture 3478 self setting servo gate simple circuit used in ionospheric pulse experiments picks out pulses transmitted at a fixed repetition frequency in the pres ce of random noise and improves reliability of synchronizing link by factor of 3479 basic magnetic logic circuits in computers classification of fundamental circuits which can be realized by means of square loop ferromagnetic cores 3480 the design of the control unit of an electronic digital computer the design of the control or sequencing unit is discussed in one system the order code is determined by the arrangement of the diodes in a diode matrix and in another by the threading of wires through a matrix of ferrite cores 3481 analogue multiplier based on the hall effect discussion of the application of the hall effect for electronic multiplication of voltages an investigation of semiconductors shows si to be the best for accurate multiplication the choice of crystal dimensions is discussed with reference to the solution of a potential problem with skew boundary conditions which determines the hall voltage 3482 an accurate electroluminescent graphical output unit for a digital computer the unit is fabricated from a uniform layer of electro luminescent phosphor with parallel conducting strips on either side these sets of strips being at right angles to form a matrix of conductors a changing electric field between selected strips of both sets causes fluorescence at their intersection intersections are selected in turn and the pattern is recorded photographically details of some prototype matrices are given 3483 the design of function generators using silicon carbide nonlinear resistors the effective current vol ge characteristics of sic resistors are modified by linear resistors placed in series and parallel such modified resistors are then used as input or feedback components in amplifiers to give nonlinear functions design details are given of squie law and sine function generators using this device 3484 magnetic switching circuits for the representation of logical relations a design method is derived for obtaining the number of cores and the number of turns required on each core for a given sw itcing function results of a systematic investigation are given for switching functions with two and three variables 3485 a bista able element suitable for use in digital computers parts the development of a trigger c ircui using pnp and npn transistors is described switch on and switch off times of are achieved with a high current carrying capacity enabling several other circuits to be driven from it th transient response of the circuit to a voltage rap input at either the turn on or turn off terminals is analysed mathematically the results thus obtained assuming certain operating conditions show good agreement with experimental observations a decimal adder using a stored additional table a description of a serial decimal adder which accepts numbers in binary coded form the binary digits are decoded into a set of pulses which actuate a built in addition table storing all the po sible sums 3486 word generator for digital testing a beam switching tube supplies arbitrary nine bit words at pulse rates from a few to for testing and evaluating digita systems pulse shape can be varied from spike to square wave by changing plug in capacitors 3487 the reactance valve at audio frequencies the reactance valve circuit is analysed to derive circuits producing an inductive impedance at af with pa ticular reference to obtaining a a large q fac tr 3488 approximate relations between transien and frequency response an existing graphical method for deriving the transient response of a linear netwo k from the sinusoidal frequency response and vic eversa is extended to cover certain difficult cases typical examples are illustrated 3489 the application of printed circuit techniques to the design of microwave components 3490 developments in printed microwave components 3491 the locking band for the automatic phase control of frequency formulae are derived relating the locking band to the filter parameters and the delay time of the circuits 3492 des gning transformers for blocking oscillators design procedure based on four common circuits is given the pulse shape is calculable and a size reduction over previous units is obtained with a type core 3493 an extened general network theorem on rectification extension of gewartowskis theorem 3494 a new type of construction for high grade transductor cores improvements of laminated core design and assembly are discussed which permit a better utilization of the qualities of the material 3495 calculation of the duration of a quasi equilibrium state in a phantastron circuit a formula is derived and typical operating conditions of phantastron circuits are considered 3496 transistor circuits for use with gas filled multicathode counter valves transistors are used in conjunction with dekatrons to provide a logical circuit the combination is run off a low voltage supply the hv to the dekatrons being supplied by a transistor dc converter a block of these circuits is made to function successfully in a telephone exchange register 3497 ceramic capacitors a complete substitute for paper and mica capacitors the electrical characteristics of paper mica and ceramic capacitors are compared performance tests on receivers before and after substituting ceramic for paper capacitors show no significant difference 3498 the sense of rotation and curvature of the impedance loci of real and ideal two poles the impedance of a two terminal network as represented on thegauss number sphere describes a closed curve revolving completely at least once in a clockwise direction for a frequency variation from a method is given for synthesizing two poles which h ve impedance loci turning anticlockwise in places 3499 design of complex resonators an investigation of resonators consisting of several uniform coaxial line sections with different characteristic impedances 3500 microwave high power simulator by periodically injecting energy from a directional coupler into a waveguide cavity made in the form of a closed loop much higher power levels can be achieved than are available from microwave power generators energy is stored in a circulating or travelling wave see also of 3501 the scattering matrix in network theory 3502 frequency transformations in filter design 3503 optimum filters with monotonic response the amplitude characteristic has no ripple in the pass band and a high rate of attenuation in the stop band and combines the desirable features of the butterworth and tchebycheff response 3504 a twin t variable slope filter by suitable modification a twin t notch filter is converted into a low pass filter in which the rate of attenuation up to a specified upper frequency is controlled by a single potentiometer design data are given and a detailed circuit is described 3505 filters built from coaxial conductors zobels method of filter design is applied to coaxial line filters considering the impedance of the line as a function of frequency characteristics can therefore bermined for the entire frequency range design data are shown in a series of tables and four types of filter section are discussed in detail 3506 a filter with characteristics approximating to those of an ideal low pass filter the design and construction of a filter are described whose characteristics conform closely to those of the idea l lw pass filter specified by kupfmuller the variations of its amplitude response up to cut of at are less than at cut off the response is of its maximum value and the fluctuations of grou delay are less than 3507 rc and lc resonant filters and their application i selective amplifiers the design of a narrow b nd amplifier with a centre frequency of about is discussed following a comparison of circuits with different types of filter elements a two stage circuit with negative feedback and incorporating a rc band stop filter was the design adopt d or use in the measurement of the solar magnetic field 3508 an approach to the design of constant resistance amplitude equalizer networks a method of designi g constant resistance amplitude equalizers to give a desired frequency response characteristic over a given range is suggested a typical example illustrates the method of adjusting the response of a velocity type pick up over part of the af spectrum 3509 a treatment of cascaded active four terminal networks and with application to transistor circuits 3510 self oscillator with large circuit attenuation the optimum operating conditions for power transfer to the load and the efficiency of the oscillator are discussed equations are derived and graphs show the grid voltage variations for different values of attenuation 3511 amplitude stabilized low frequency oscillator the performance of a vlf oscillator for the range with the output stabilized by biased diodes or lamps is analysed formulae for the harmonic content with different initial damping are deduced and means of reducing it are indicated a circuit for measuring the harmonic content is described 3512 double tetrode oscillator the oscillator covers a frequency range of and can be anode modulated with pulses repeated at a rate of about constructional details are given 3513 crystal oscillator has variable frequency a maximum frequency deviation of is obtained from a two stage crystal feedback amplifier operating at with a long term frequency stability within a few parts per million 3514 frequency stabilization of usw oscillators by using harmonics for the excitation of the quartz crystal modern methods of direct stabilization of d rect stabilization of usw oscillators by quartz crystals are reviewed circuits are described in which the static capacitance of the crystal is compenated by inductance simple bridge circuits for operation over a range of frequencies are also described in which the crystal is excited by high order harmonics uncompensated circuits are also considered and comparison is made between the various types of circuit 3515 a three phase three valve multivibrator a three valve circuit in which each amode is capacity coupled to the other two grids is described frequencies up to are obtained using miniature rf pentodes 3516 generation of bell shaped pulses a pulse generating circuit is described for producing pulses to long at a repetition frequency of 3517 transients in pulse circuits with point contact transistors analysis based on the dynamic characteristics of transistors transient processes in relaxation oscillators and triggering circuits are examined 3518 a carrier energized bistable circuit using variable capacitance diodes a variable capacitance junction diode when used in a simple circuit driven from a high frequency source can cause that circuit to have a bistable characteristic suitable for dynamic storage or to have a sensitive output input characteristic suitable for control or detection purposes 3519 adjustable electronic delay circuit for the microsecond range a modification of a pulse discriminator circuit of a type described by moody et al using secondary emission pentodes is described by means of an adjustable capacitance coupling dynode and grid the time interval between successive negative and positive pulses derived in the circuit can be adjusted between and for an application of the method in a delayed coincidence circuit see 3520 binary frequency divider with unction transistors 3521 limited gain operational amplifiers the effect of finite gain can be allowed for by assuming infinite amplifier gain and then adding fictitious elements to the feedback network to reduce the gain to its actual value this leads to a more convenient equivalent network of which simple examples are given 3522 parallel t rc selective amplifiers the operation of a less familiar form of selective amplifier with low impedance input is analysed in which the signal is injected at the null point of the parallel t network in the feedback loop design equations are derived and applied as an example to a fixed tuned amplifier with a square wave input 3523 electronic equalizer description of an af amplifier with variable boost or attenuation at both the low and high frequency ends of the response characteristic typical response curves of the amplifier are shown 3524 hum in audio stages a design procedure based on measurements on typical valve types for reducing hum in the audio stages of ac dc equipment 3525 design of feedback amplifiers for prescribed closed loop characteristics 3526 modified rice neutralization the theory of rice and modified rice neutralization are discussed an formulae are derived for maximum stability with no feedback voltage on the grid the conditions for positive and negative feedback are also derived 3527 subminiature magnetic amplifiers a description of circuits using a new ferristor fast saturable reactor which may be used as a magnetic amplifier or as a bistable ferroresonant element 3528 transistor bias circuits a detailed comparison of four bias circuits with reference to performance and the operating point stability a practical stability factor is derived together with general design formulae for bias components the 3529 the use of universal curves in the design of transistor amplifier stages design curves are derived from the principal transistor parameters for linear operation at low frequencies 3530 dc transistor amplifier for high impedance input a short discussion and circuit diagram of an amplifier using a double emitter follower and grounded emitter voltage amplifier temperature compensation gives short term drift stability the input impedance is and the current gain 3531 theory of parametric amplification using nonlinear reactances the parametric amplifier is analysed phenomenologically in terms of an equivalent circuit model the model consists of a signal circuit resonant at an idling circuit at and a pumping circuit at these three circuits being coupled across a nonlinear inductance the analysis is general enough to delineate the conditions on the signal level and circuit parameters which lead to distortionless amplification expressions are derived for power gain bandwidth and noise factor for the case in which the signal and idling frequencies are well separated and for the degenerate case in which these two frequencies are equal 3532 solid state maser amplifier the operation of a solid state maser amplifier at is described a dual frequency cavity containing paramagnetic potassium chromicyanide in an isomorphous cobalt diluent is used at k the upper three of the four energy levels of the cr ion are used spin state populations are inverted by saturating the resonance absorption at the experimental observations of the maser both as an amplifier and as an oscillator are compared with theory 3533 new approaches to the amplification of microwaves the basic principles governing the operation of two new types of molecular microwave amplifier the maser and the parametric amplifier are described both types of amplifier have relatively narrow bandwidths but excellent noise properties 3534 ferrite microwave detector it is shown theoretically that second order terms in one component of the magnetization of a ferrite under the action of a rf field may be used to produce magnetostriction in the ferrite and so to detect an am microwave signal an experimental technique is described in which the detector consists of a long thin ferrite rod in a waveguide magnetostriction vibrations are observed by means of a polarized ceramic rod bonded to the ferrite the qualitative results agree with theory and factors which are expected to improve performance are discussed 3535 noise output of balanced frequency discriminator a mathematical analysis for gaussian noise input assuming no limiter action 3536 a conductivity storage transistor pulse width modulator transistors of both point contact and junction types exhibit in certain pulse applications prolonged conduction generally ascribed to hhole storage this can be controlled in a circuit to provide a simple means of pulse width modulation for time division multiplex the technique is described for use with selected point contact transistors 3537 thermoelectric effects the basic principles of thermoelectricity are reviewed recent achievements are outlined in terms of specific practical applications n and the present status of the more detailed theoretical treatments is discussed in a nonmathematical fashion useful equations describing important parameters are tabulated over references 3538 optical theory of thermal velocity effects in cylindrical electron beams the present theory is based on a nonlaminar optical model which treats thermal velocities as an integral part of the motion a maxwellian distribution of initial transverse velocities is assumed at the cathode and a first order focusing theory is applied in order to calculate trajectories at any point in the beam it is shown that whenever a long beam is confined by a focusing field images of the cathode are formed repeatedly along the axis when applied to uniform magnetic focusing fields the theory predicts the periodic formation along the axis of cathode images and crossovers and a relative rotation of successive images such effects have been reported 3539 effect of variation of dc current in a modulated electron beam experiments indicate that existing theory needs correction an empirical formula satisfying all experimental observations is difficult to obtain 3540 oscillations in plasma part a sensitive super regenerative detector was used to study oscillations in a looney brown tube without auxiliary electron beams oscillations were detected by a small external aerial 3541 nonlinear effects in electron plasmas a mathematical study of three groups of effects namely the excitation of harmonics coherent interaction and incoherent interaction complications of finite boundaries external fields non zero temperature multistream flow and collisions are ignored the main interest is in the incoherent interaction which results in spectral decay and damping effects are compared with experimental data 3542 waves in a plasma in a magnetic field an analysis of the small amplitude oscillations of a fully ionized quasi neutral plasma in a uniform externally produced magnetic field no self excitation of waves around thermal equilibrium is predicted in contrast to the results of gordeyev for longitudinal electron oscillations propagated perpendicularly to the constant magnetic field there are gaps in the spectrum of allowed frequencies at multiples of the electron gyration frequency but zero landau damping when the ion dynamics are included two classes of low frequency oscillations are found and the results for the propagation of em waves in an ionized atmosphere are also derived 3543 conductivity of plasmas to microwaves the complex conductivity is calculated for a neutral plasma with electrons having a distribution in space and velocity which does not change over a time interval long compared with the period of the microwave field the conductivity is derived for velocity distributions given by the dirac function a step function and a maxwellian distribution 3544 plasma diffusion in a magnetic field the equations governing the diffusion of a fully ionized plasma across a magnetic field are derived it is assumed that macroscopic quantities vary slowly across an ion radius of gyration and that the interparticle collision frequency is much less than the gyration frequency the relevant transport coefficients electrical resistivity thermal conductivity and thermoelectric coefficient are derived some similarity solutions of the equations are found 3545 nonlinear electromagnetism and photons in the functional theory of particles 3546 new tables of total mie scattering coefficients for spherical particles of real refractive indexes k the total mie scattering coefficient is defined as the total flux scattered by the particle divided by the flux incident on its cross section the size parameter the theory applies only to a very dilute aerosol of randomly arranged spheres and does not allow for coherence in the field or for multiple scattering has been calculated on an electronic computer for in steps of and for and 3547 scattering of electromagnetic waves by lo g cylinders the field scattered by a metal or dielectric cylinder when excited by a wave propagated in a direction normal to the cylinder axis is discussed theoretically for plane and cylindrical waves the radius of the cylinder is comparable with the wave length the dielectric cylinder is a resonant structure 3548 propagation through a dielectric slab propagation from a point source through an infinite slab is considered theoretically with particular reference to the apparent source and its modified polar diagram an appreciable change in polar diagram can be produced by even a thin sheet of dielectric 3549 the microwave spectrum and structure of trichloracetonitril the microwave spectrum of as been studied in the range using a stark modulation microwave spectrometer 3550 nuclear magnetic resonance the phenomenon is briefly discussed and the pound system for its detection is described for high resolution work the bloch spectrometer is particularly suitable 3551 audio frequency nuclear resonance echoes a spin e ho technique for determining nuclear magnetic resonance by experiments in the earths magnetic field is described it is possible to derive the true spin spin relaxation time even if the field is not homogeneous 3552 the radio telescope at the royal radar establishment malvern 3553 radio noise from planets a comparison is made of hf radio noise from jupiter and venus and from terrestrial lightning the hypothesis that radio noise from the two planets is due to electrical discharges analogous to terrestrial lightning requires modification 3554 the distribution of radio brightness over the solar disk at a wavelength of centimetres part the s owly varying component the emitting regions were studied individually using a element interferometer producing fringes of arc in width during the radio sources were found to lie about above and to have the same size as plages faculaires the angular distribution of radio flux follows approximately a cosine law suggesting that thet the source is a thin shell parallel to the suns surface the correlation between radio flux and sunspot areas is discussed part 3555 meteor radiant determination from high echo rate observations a simplified analysis is given of the clegg method for delineating meteor radiants from radar observations see of a further analysis reveals a new and faster method of interpreting the data contained in meteor echo records this method is applicable when sensitive equipment is employed and the resulting echo rate is very high 3556 the association of solar radio bursts of spectral type with chromospheric flares simultaneous optical and radio observations were made for over flares of which were of class and of which are associated with type events of the bursts were recorded during the life of the flare usually near the beginning the probability of a burst accompanying a flare is greater for large flares and is the same for flares on the east limb as for those in the centre of the disk this implies a wide cone of escape for type radiation 3557 a new effect of chromospheric eruptions 3558 bureau of standards role in igy a short summary of the work undertaken 3559 radio research and the igy the objectives and organization of the igy are outlined the programs of observations which are of particular interest to radio engineers and the users of rockets and satellites are described 3560 artificial earth satellites 3561 radio observations on the russian satellites the following short contributions were presented at a meeting of the radio and telecommunication section of the iee london november observations at cambridge apparatus used at the royal aircraft establishment some direction finding observations on the signal observations of bearing and angle of elevation of satellite i estimating the height of the first satellite from radio interferometer records precise frequency measurements on first russian satellite analysis of doppler data from earth satellites radio observations of the signal characteristics of satellite radar observations of the russian earth satellites and carrier rocket observations at the royal radar establishment discussion 3562 ranging the satellite by doppler shift observation an experimental m thod using simple apparatus 3563 unusual propagation at from the ussr satellite interferometry recordings were obtained in washington on a few occasions during october when the satellite was on the opposite side of the earth near an antinodal point 3564 a note on some signal characteristics of sputnik 3565 detection of sputniks and by cw reflection the method described is based on the reception of the transmission of wwv at a distance of about miles 3566 the last days of sputnik deductions are based on radio reflection records using wwv transmissions on 3567 proceedings of the polar atmosphere symposium held at oslo july part ionospheric section the text is given with ensuing discussions of papers presented at the symposium abstracts of some of these are given individually titles of others are as follows results of ionospheric drift measurements in the united states results of ionospheric drift measurements in norway movements of ionospheric irregularities observed simultaneously by different methods turbulence in the ionosphere with applications to meteor trails radio star scintillations auroral radar echoes and other phenomena geographic distribution of geophysical stations on the polar cap a theory of long duration meteor echoes based on atmospheric turbulence with experimental confirmation 3568 theoretical views on drift measurements the conversion of the amplitude pattern drift at the ground as sampled by three closely spaced receivers to the true drift in the ionosphere requires the ionosphere requires the determination of auto and cross correlation functions problems in relating ground pattern drift to ionospheric drift are stated 3569 the drift of an ionized layer in the presence of the geomagnetic field the efficiency of air winds in causing ionization drift decreases with atmospheric pressure thus in the f region electric fields may be the main cause of drift in the region electric fields may contribute equally with air winds in the d region air winds would be the main cause the effect of winds and fields is causing drifting of cylindrical irregularities in each region is given 3570 the height variation of horizontal drift velocities in the e region the drift was measured on two adjacent frequencies corresponding to heights of reflection differing by about km the diurnal change in the ns and ew velocity components differs in phase at the two heights 3571 large scale movements of the layers moving wavelike disturbances with appear to travel with inclined wavefronts having both horizontal and vertical motions which are often of similar magnitudes and the with varying direction the effects are independent of magnetic activity and are probably not caused by atmospheric winds a travelling compressional wave is suggested as an alternative to motion caused by electric fields 3572 electron distribution in a new model of the ionosphere rocket measurements between and for pressure density and temperature are used to derive a new empirical model for temperature and electron density in the ionosphere this model agrees well with the theory of temperature variation and radio measurements of electron density 3573 some implications of slant e slant e is common in polar regions the virtual height of traces rising from up to a linear characteristic passing through the origin relates virtual height and frequency it is suggested that slant e is due to back scatter from e four modes of propagation are possible direct back scatter reflected back scatter single reflected scatter double scatter experiments are suggested which would distinguish between them 3574 an easily applied method for the reduction of hf records to nh profiles including the effects of the earths magnetic field the method depends on sampling h at fixed submultiples of the frequencies at which true heights are required the latt r are then obtained by averaging the values of h a complete computation is presented for washington dc and the results checked against an analysis of curves for known profiles 3575 the electron distribution in the ionosphere over slough part quiet days the distribution of elect on density with height is calculated from records using an electronic computer the method assumes sumes that the curve increases monotonically and allows for the effect of the earths magnetic field the height of maximum electron density in the f layer is found to be considerably lower than previously supposed particularly in the summer and equinox months 3576 the height variation of drift in the e region simultaneous observations at and of drift velocities show significant differences and it is deduced that they refer to different heights the velocities rotated through at a nonuniform rate during daylight hours the nonuniformity is due to the variation of reflection height in the winter months the rotation at the smaller height lagged with respect to that at the larger rapid changes in drift were observed during september and october the results agree with those deduced by greenhow and neufeld of from meteor trail observations if allowance is made for the height differences 3577 solar tidal effects in the f region of ionosphere over delhi harmonic analysis of and shows the existence of semi diurnal and seasonal solar tidal effects in the f layer at delhi vertical drifts of in summer in winter and at the equinoxes are calculated from ionization density variations attachment coefficients including these tidal effects worked out for different seasons are in agreement with those obtained by ratcliffe et al 3578 a study of the ionospheric irregularities which cause spread f echoes and scintillations of radio stars a discussion of the correlation between the occurrence of spread f echoes at slough inverness and oslo the irregularities responsible for the spreading occur in bands which lie along parallels of latitude and have a width of the order of km it is suggested that the irregularities occur at heights near km 3579 ionospheric records of solar eclipses the horizontal gradients of ionization produced during an eclipse introduce curvature into the isoinic contours so that the ionosonde soundings are effectively oblique the resultant errors in the deduced ion distributions assuming vertical soundings give rise to many of the apparent abnormalities in c eclipse records 3580 travelling disturbances in the ionosphere changes in diurnal variation the mean diurnal variation in the direction of horizontal movement of travelling ionospheric disturbances is plotted for january and for january in the years of the main feature of the former is an unusually large change of direction about midday possibly associated with high sunspot activity 3581 progress in the field of ionospheric research and tropospheric wave propagation report based on papers presented at a conference held at kleinheubach germany october and organised by the german ursi committee and the nachrichtentechnisch gesellschaft 3582 ionospheric true height and muf calculations mufs calculated from the more accurate determinations of the electron density distribution see above are consistently higher than the slough bulletin values 3583 the spectrum of the electron density fluctuations in the ionosphere the fluctuations are assumed to arise from the vertical transport of small pockets of air in the presence of a non adiabatic temperature gradient and vertical gradients o mean electron density a preliminary account of the theory of the spectrum o the fluctuations is given with references to the application of the results to ionospheric and tropospheric scattering of radio waves see also of 3584 polar disturbances disturbances in the ionosphere and geomagnetic field and also auroral behaviour are usually treated statistically in this paper an attempt is made to investigate what occurred in a few specific cases there is some evidence for a spiral auroral zone 3585 statistical results and their short comings concerning the ionosphere within the auroral zone the difficulties of obtaining significant data from high latitude curves are discussed together with the statistical treatment of such data these difficulties could be minimized by the adoption of the recommendations of the ursi high latitude committee 3586 measurements of irregularities and drifts in the arctic ionosphere using airborne techniques special supplement part an ionospheric recorder was installed in an aircraft and flights were made in north polar regions the interpretation of the experimental data in terms of ionospheric structure is discussed some drift measurements were made at the north pole see also of and 3587 quantitative measurements of absorption in the auroral zone the various alternative methods of measuring ionospheric absorption are discussed and the results compared with particular reference to the north polar region 3588 echoes from the lower ionosphere during polar blackouts 3589 polar blackout occurrence patterns a brief survey of the geographical distribution of the probability of the occurrence of black outs in north polar regions difficulties in interpretation of the data are discussed 3590 classification of atmospheric waveforms the desirability and requirements of a systematic classification of atmospheric waveforms are discussed an observational scheme is suggested and interpreted in terms of known properties of the discharge and propagation mechanisms these data are reviewed to clarify application of the scheme to individual waveforms the relation between the classification and previous inadequate groupings is indicated 3591 heat transfer in power transistors a general discussion of thermal problems in operating power transistors between and 3592 power supply and suppression in portable mobile working practical details of the use of car batteries or petrol electric sets for power supply 3593 stabilized the unit design of a compact equipment for anode supplies of 3594 improved control circuit for regulated power supplies a cathode follower is inserted between the control valve and the regulator valve in an electronic voltage regulator to increase the current range over which regulation may be maintained 3595 digital codes in data processing systems the design of digital coding systems including error detecting and error correcting codes is discussed 3596 a new cycle counting instruction for a three address electronic digital computer 3597 an electrical apparatus for solving polynomial equations the analogue equipment described can be used for solving equations of up to degree with real coefficients 3598 computation of arc tan n for using an electronic computer 3599 the application of square hysteresis loop materials in digital computer circuits theories and the practical design of shifting registers are explained core matrix storage systems are reviewed a description is given of a store in which a shifting register is used to convert the parallel output into serial form this register is also used during the writing process 3600 a decimal product accumulator dekatrons enable the correlation between two series of numbers to be found if all terms are positive given pairs of numbers of two decimal digits each the machine accumulates products per minute 3601 british built computers a review of digital and analogue computers with details of specifications special features and applications 3602 analysis of current pulses an approximate method of analysis used earlier is extended to include nonlinear characteristics and its application to a class c amplifier circuit is described 3603 printed circuits and high quality amplifiers printed circuits are suited to equipment where standardization is essential inherent in this type of circuitry is improved performance special production methods are needed to ensure reliability 3604 etched if amplifier pares colour tv cost 3605 simple variable voltage power supply design details of a circuit giving an output of at currents up to 3606 electromagnetic fields in a ferromagnetic medium with particular reference to harmonic distortion due to hysteresis the frequency dependence of the third order distortion factor of an inductor at low flux densities is studied theoretically an analogue method is described which enables the study to be extended experimentally to large flux densities and complex input waveforms 3607 a numerical graphical method for synthesizing switching circuits economical circuit arrangements can be rapidly developed by systematic application of three simple rules to a numerical representation of a boolean function simple examples ar egiven 3608 minimum energy triggering signals the optimum signat is defined as that which produces a given current through or a voltage across a resistive output element at a given time while requiring a minimum of energy from the generator the solution of this problem is discussed and illustrated by a simple case 3609 controlled saturation in transistors and its application in trigger circuit design carrier storage of charge in transistors has a maximum which is defined as controlled saturation this depends only on the base current this idea is used to develop a trigger circuit of good resolving time whose output terminal is able to handle heavy currents and presents a low impedance 3610 fast transistor relay describes a push pull switching circuit incorporating zener diodes having a rise time of and capable of handling currents up to 3611 ge eralized operators for the approximate steady state analysis of linear and nonlinear circuits the method is a periodic analogue of the time series technique by which waveforms are represented by an component operator giving values at each of ordinates a shift operator translates any waveform by of the appropriate sample period for linear circuits the method is advantageous wher ethe periodic input is known and a similar description of the output is required without recourse to fourier analysis for nonlinear circuits the output is obtained by a series of approximations applied to the steady state condition 3612 signal theory 3613 system theory as an extension of circuit theory 3614 derivation of the phase characteristic from the attenuation curve in minimum phase systems the graphical method described is illustrated by numerical examples 3615 stable crystal filter is parallel resonant a high q unbalanced crystal circuit is similar to a parallel tuned circuit with a low lc ratio over an appreciable frequency range it is readily adaptable for use in fm oscillators signal generators and variable bandwidth filters 3616 the concept of heterogeneous surface impedance and its application to cylindrical cavity resonators formulae are developed relating the q factor and the resonant frequency of a cavity to its dimensions and the fourier components of the surface impedance function the cases of circumferential and axial heterogeneity are analysed in detail in general a unique value of surface impedance cannot apply to an unbounded periodic sheet unless the period is small compared with 3617 synthesis of tchebycheff impedance matching netwg networks filters and interstages 3618 two theorems concerning group delay with practical application to delay correction two theorems a e stated which enable properties of group delay to be expressed directly in terms of the transfer function of a linear transmission system examples are given to show how the results might be usefully applied to certain problems of delay correction 3619 linear pulse forming circuits synthesis of delay line networks description of synthesis procedure for delay systems used in processing continuous trace radar information 3620 the network synthesis on the insertion loss basis methods of synthesis of most important network functions are derived in terms of the steady state network performance realization procedures are explained and expressed in explicit formulae for direct application to the design of conventional ladder structures with an arbitrary number of branches the symmetrical and the inverse impedance low pass networks are solved in detail 3621 exact ladder network design using low q coils 3622 conditions for the impedance and admittance matrices of n ports without ideal transformers 3623 equivalent circuits of noisy networks equivalent circuits for a combination of amplifiers attenuators and terminations are presented and a new method for the precision measurement of noise figure is described 3624 small signal heterodyne mixers with excessive injection amplitudes the theory of small signal heterodyne mixers operating with very large injection potentials is described the mixer properties investigated are the conversion transconductance the relative amplitudes of the difference freq ency and injection frequency components in the output and the amplitude of the injection modulation frequency component in the output in the case where the injection potential is amplitude modulated to a small degree a set of universal performance curves is obtained for mixers of a particular class chosen to illustrate the method 3625 vxo a variable crystal oscillator description of a stable oscillator which covers the range and uses six crystals 3626 flip flop stability modifications to the circuit described earlier including the use of a different type of valve do not affect its stability in respect of pulse duration 3627 transient processes in a trigger circuit with a transistor transient processes in a common base circuit using a point contact transistor are considered expressions for the currents are derived and the speed of operation of the circuit is estimated requirements are formulated for point contact transistors to be used in high speed trigger circuits see also of 3628 high sensitivity transistor pulse trigger circuit a ge diode and a differential negative resistance of high stability consisting of a transistor amplifier with positive feedback u is used 3629 transistorized rc phase shift power oscillator data on the performance of a phase shift circuit operating at frequencies around are given 3630 a theorem concerning noise figures see 3631 stagger tuned band pass amplifiers a procedure is given for designing narrow band amplifiers with either bandwidth or rise time are specified data are included for single tuned cascades with up to five stages see also of 3632 stability and the effects of valve input conductance in wide band if amplifiers an analysis of the effects of small variations of circuit parameters and of valve input conductance on amplitude and group delay response of double tuned interstage amplifiers see also of 3633 some studies on delayed feedback circuits by inserting delayed signals along with the main signal to be observed an improvement in signal noise ratio can be achieved other applications of this circuit are for producing artificial reverberation as a narrow band filter and as a short time storage circuit 3634 bootstrapped differential amplifier with reduced common mode effects a common mode signal of changes the differential gain of the circuit by or less full scale deflection can be obtained on a recorder with input 3635 push pull audio amplifier theory a mathematical analysis is given applicable to all classes of th epush pull amplifier assuming nonlinear valve characteristics 3636 two valve pre amplifier the performance of the amplifier is discussed when used with magnetic and crystal pickups tape recorder play back heads and microphone and radio inputs 3637 straight pa for centimetres design and operating details for a rf amplifier on using a double tet ode 3638 a nonlinear low frequency instability phenomenon in audio amplifiers under certain conditions af amplifiers with feedback may show instability at low frequencies which is not predictable by conventional linear analysis the problem is analyzed theoretically with supporting experimental results and a technique given for reducing the nonlinear effect 3639 some augmented cathode follower circuits direct coupled cathode follower circuits with very high input and low output impedance are described suitable for driver stages see of buffer stages and frequency selective amplifiers 3640 magnetic amplifiers basic principles and applications a basic qualitative description of the prin iples of operation 3641 transistor high gain tuned amplifier particular attention has been paid to stability of gain and bandwidth against transistor variations over a period of months the maximum gain of about db has changed by only with no measurable change in bandwidth the amplifier has been designed principally for use as a bridge detector and general purpose amplifier but provision has also been made for transistor noise figure measurements by the addition of a stage at the input in which the transistor under test provides sufficient gain to make the effective noise figure of the amplifier negligible for most purposes 3642 a stable gain transformer coupled transistor af amplifier the amplifier is designed primarily for use with dc choppers giving a square wave output at cs circuit diagrams are given and the performance is illustrated by graphs changes in the transformer design for use at other frequencies are discussed 3643 a transistorized decade amplifier for low level audio frequency applications national electronics conference paper 3644 a generalized theory of transistor bias circuits a general method of analysing bias circuits is presented almost all three terminal bias circuits can be reduced to the same standard form for which the analysis is given an example from current practice shows the unifying concepts resulting from the general theory 3645 transistor amplifier stages operating from and a description of low level stages using a type transistor which can be used to build rc coupled amplifiers operating in ambient temperatures up to 3646 direct coupled transistor audio amplifier description of a design procedure for a three stage amplifier in which the collector of one stage is di ectly connected to the base of the following stage see of february 3647 parametric amplification using low frequency pumping describes how low frequency pumping is possible if two pumping sources are used in conjunction with a nonlinear reactance having an odd order nonlinearity an analysis of the equivalent circuit is given 3648 a travelling wave ferromagnetic amplifier amplification of signal power can be obtained in a propagating structure which is partially or totally embedded in a ferromagnetic medium it is shown that one form of the structure possesses two propagating modes and can also support a travelling wave supplied by a local oscillator which provi es through the magnetic changes a time varying coupling between the two propagating modes the principle of operation is illustrated by a simple transmission line model 3649 contribution to the theory of the molecular generator the resonance interaction between an electromagnetic field and a molecular beam and self oscillatory processes in a molecular oscillator are investigated for the case of a single velocity beam results obtained taking account of nonmonochromatic molecules in the beam are considered qualitatively 3650 operation of three level solid state maser at a three level paramagnetic solid state maser has been operated both as an amplifier and as an oscillator at a single crystal of about of containing as active element is used 3651 parametric amplification of space charge waves 3652 the magnetic ring modulator and demodulator advantages and disadvantages are outlined with reference to the equivalent circuit and to a practical modulator for use with a carrier frequency 3653 multiplication of frequency modulated oscillations over an extremely wide frequency range the problem of multiplying in a ratio with a fundamental frequency of is discussed with reference to the performance of a serrasoid modulator see also of may 3654 frequency modulation by inductance variation a frequency modulation by inductance variation a magnetically stable ferrite modulator the operation of modulators incorporating a reactance valve or a variable inductance is summarized the losses in the magnetic core of the inductance modulator are considerably reduced by using magnetic ferrites and details of this type of modulator are given it can be used in simple variable frequency circuits up to 3655 simple circuit stabilizes ferrite fm modulator stabilization over a range of frequencies is achieved by the use of an auxiliary fixed frequency oscillator and associated feedback control circuit 3656 multichannel pulse height analysers proceedings of an informal conference held at gatlinburg tennessee september 3657 transistor af amplifiers 3658 a variational principle for classical field theories 3659 the definition of current charge and electric force in the unified field theory 3660 on the deduction of the lorentz einstein transformation from maxwells electromagnetic field equations 3661 precision determination of the velocity of electromagnetic waves using an interferometer of improved performance operating at a value has been obtained 3662 investigations by microscope and oscillograph of the electroluminescence of nonconducting diamonds the electroluminescence is investigated at fields strengths above cm with very strong fields and high current densities graphite whiskers form in the diamond at the electrodes and the electroluminescence is thereby enhanced oscillograms indicate that recombination processes are a contributory cause of electroluminescence 3663 magnetic interaction of electrons and anomalous diamagnetism 3664 on the theory of skin effect in metals the coefficient of em wave transmission through a sufficiently thick film is calculated taking into account a small slowly damped addition derived from the evaluation of the spin magnetic moment 3665 critical current for superconducting films mathematical analysis of critical currents for superconducting films thick 3666 emission mechanism of cold cathode arcs a new theory is proposed in which excited atoms play a predominant role as a source for ion generation in the vicinity of the cathode surface the processes of resonance ionization and of ionization in the strong electric field at the cathode surface are considered 3667 a general theorem for dense electron beams a sufficient condition for the existence of any particular set of trajectories is derived for pierce type dense electron beams 3668 energy loss by a charged particle passing through a laminar dielectric part a general expression has been obtained for losses of a particle moving in an unbounded laminar medium or a waveguide filled with a dielectric polarization losses are examined and an expression for the spectral distribution of parametric cherenkov radiation is derived 3669 electron electron interaction and heat conduction in gaseous plasmas the thermal conductivity in low gas pressure ne and xe plasmas has been shown experimentally to be determined chiefly by heat flow in the electron gas of the plasma the experimentally determined values of the thermal conductivity are in agreement within less than one order of magnitude with those given by the theory of spitzer n harm 3670 energy exchange between electron and ion gases through coulomb collisions in plasmas the general aspects of energy exchange between the electron ion and molecular constituent gases and their energy transfer to the boundary have been examined experimentally for a partially ionized gas coulomb collisions between electrons and ions are shown to contribute significantly to thermal energy transfer from the electron gas even in weakly ionized gases in a plasma produced in ne gas at hg at the characteristic time for equipartition of excess mean electron energy with the ion gas varies from to as the ion concentration increases from to cm 3671 theory of electric waves in inhomogeneous plasmas dispersion functions are derived for longitudinal waves in plasmas of variable electron density the special case of a quasi neutral electron beam of spatially variable density is discussed 3672 simplification of equations for the distribution function of electrons in a plasma an analysis based on the boltzmann kinetic equation considering initially a spatially homogeneous plasma located in electric and magnetic fields 3673 contribution to the theory of transport processes in a plasma located in a magnetic field the mean statistical characteristics such as velocity heat flow and stress tensor are determined 3674 space charge field emission and the ionic condenser high es fields measured at the electrodes during gas discharge experiments in h indicate that the mechanism initiating a flash of intermittent glow is field emission from the cathode or from the negative space charge the hypothesis is applied to the experimental results of other workers and is confirmed it is shown to provide simple explanations for many gas discharge phenomena it is suggested that the measured high fields are due to concentrated space charges forming ionic condensers with the electrodes or within the gas itself in the form of stationary striations 3675 statistical broadening of spectral lines emitted by ions in a plasma 3676 ponderomotive force in localized plasma in the electromagnetic field of a plane wave a sphere of uniformly ionized gas is considered as a rough model of localized plasma the radius of this sphere is smaller than the wavelength of the field in vacuum or in plasma expressions for the internal and surface intensities of the ponderomotive force are derived 3677 excitation of plasma oscillations and growing plasma waves report of preliminary results of a new experiment in which the beam is modulated by a microwave signal before it interacts with the plasma a very strong interaction is observed which shows essentially the theoretically predicted form of behaviour 3678 movements of rarefied plasma in an alternating magnetic field an expression is derived showing that even with constant current the energy of rotation of plasma particles can increase many times in consequence of the decrease of the radius 3679 contribution to the theory of anisotropy of ferromagnetic single crystals a mathematical analysis based on dysons theory of spin wave interaction is applied to the investigation of anisotropic ferromagnets of hexagonal symmetry 3680 paramagnetic resonance and polarization of nuciei in metals a theory of paramagnetic resonance is proposed based on simultaneous solutions of maxwells equations and the kinetic equation for the density operator it is shown that the polarization varies with depth and also that the paramagnetic resonance gives rise to selective transparency in metallic films 3681 basic features of neels theory of impurity atom after effects exposition in simple terms of neels theory of magnetic diffusion after effects of the equivalent circuit of a bloch wall is derived which allows for the influence of impurity atoms 3682 two dimensional problems of the decay of magnetic fields in magnetohydrodynamic the normal modes of decay of magnetic fields in conducting fluids are studied for different classes of steady motion see of and 3683 on a macroscopic measurement of the spin of electromagnetic radiation the spin of em radiation may be deduced from the torque exerted at microwave frequencies by a circularly polarized wave upon a screen which can conduct current only parallel to a given direction see of calculations are made of the angular momentum and scattering cross sections of the screen and the feasibility of an accurate experiment is discussed 3684 the cherenkov effect in composite isotropic media a theoretical investigation based on the invariance of maxwells equations the case of two coaxial dielectrics and permeable cylinders with a common cylindrical interface and a charged particle moving along their common axis is considered results are discussed with particular reference to cherenkov radiation at radio and microwave frequencies the effect of coherence on the output of the emitted radiation is outlined 3685 radiation from a point charge moving uniformly along the surface of an isotropic medium energy emitted per unit of time by a particle moving along a surface in a nondispersive is calculated relativistic conditions and for magnetic and fe expressions are derived for relativistic and norrite type media see also 3686 diffraction by cylindrical reflectors measurements of the near zone diffracted field of a cylindrical reflector with a line source at the centre agree with calculations using geometrical optics current the equivalent line currents give slightly better agreement 3687 the propagation of slow electromagnetic waves along inhomogeneous plasma layers on the basis of schumanns work the special case of surface waves of the plasma and the adjoining layers of air is considered 3688 molecular beam resonances in oscillatory fields of nonuniform amplitudes and phases the transition probability equations are reduced to forms which are suitable for digital computer calculations a computer program for the calculation of the shapes of the resonances is described 3689 quantum theory of galvanomagnetic effects a study is made of the effect of the quantization of the electron orbits in a magnetic field on the galvanomagnetic properties of an isotropic semiconductor or semimetal in the phonon scattering range the conductivity tensor is calculated using the quantum mechanical density operator the hall coefficient and transverse resistivity are studied for a number of different sets of conditions for electron density magnetic field and temperature 3690 theoretical investigation of the electronic energy band structure of solids a review including sections dealing with the elements of energy band theory the uses of group theory and perturbation theory a survey or numerical methods for solving the crystal wave equation examples illustrating complex energy band structures a representative list of about references is given experimental techniques are discussed by lax below 3691 experimental investigations of the electronic band structure of solids experiments are discussed which have been of value in contributing to current knowledge of the band structure of many materials of importance at present the experiments mentioned including those involving the de haasvan alphen effect cyclotron resonance the galvanomagnetic effect and infrared absorption 3692 electron interaction in solids general formulation a general hamiltonian formalism is developed to treat from first principles the motion of electrons in solids including their mutual coulomb interaction it is shown that under suitable circumstances plasmons the quanta of the plasma oscillations represent a well defined elementary excitation of the solid the existence criterion for plasmons is found to be a high electronic polarizability after the plasmon modes are separated out the remaining electron interaction is found to be screened with a range of the order of the interelectron spacing the usefulness of this effective hamiltonian for the calculation of the electronic energy levels and cohesive energy in solids is discussed briefly 3693 electron interaction in solids collective approach to the dielectric constant a quantum theory of the dielectric constant for solids of both low and high polarizability is developed from first principles in the latter case the approach used is collective in that the long range part of the electron interaction is described by the plasmon field both the static and frequency dependent dielectric constant are derived it is shown that the interaction between electrons may be described in terms of the dielectric constant of the solid provided the electrons in question form a small minority group which can be isolated from the much larger majority electron group 3694 electron interaction in solids the nature of elementary excitations possible elementary excitations in solids are studied with the aid of the general theoretical approach developed in the preceding papers of this series and above particular attention is paid to the basic theoretical justification for the individual particle like elementary excitation effective electrons it is concluded that good qualitative arguments could now be given for the existence of effective electrons in solids the presence of an energy gap is shown to be a necessary condition for the existence of strong spatial correlations between minority carriers in solids and the nature of such correlated minority electron excitations is discussed 3695 approximate theory of ferrimagnetic spin waves the wave functions and the energy spectrum for the spin wave problem in a normal spinel are found by means of a straightforward extension of andersons approach to antiferromagnetism on only ab exchange is assumed to exist and the calculation is carried to second order in the magnitude of the propagation vector k five distinct energy surfaces are found two of which are identical in the classical limit to the ones previously reported by h kaplan 3696 propagation of radio waves from cosmical sources a formula is given for the refraction of radio waves reaching the earths atmosphere from outside the formula may be applied to waves from artificial earth satellites 3697 a new spectral characteristic in solar radio emission equipment at frot davis texas covers the band and comprises a diameter parabolic aerial with three broadband primary arrays coaxially mounted at its focus see of april et al a new type of last burst having a frequency time graph in form of an inverted u and for duration is reported and the possible origin of these bursts is discussed 3698 effective magnetic meridian for cosmic rays observations of the cosmic ray meridian made with neutron intensity monitors at melbourne australia are reported doubts are expressed about the equivalent dipole theory of the earths magnetic field see of 3699 scientific observations of the artificial earth satellites and their analysis report of a discussion held by the royal society on 3700 lifetime of an artificial russian satellite a simple formula for the calculation of lifetime from data on the initial orbit is given it was applied to observations made at johannesburg of the doppler effect on signals received at from the first russian satellite 3701 interception of radio signals transmitted by the satellite sputnik i brief outline of apparatus and methods used some recordings of the and transmissions obtained in florence are reproduced 3702 observations in australia of radio transmissions from the first artificial earth satellite observations of the strength of and signals were made at bringelly near sydney australia the rate of fading appears to be a minimum when the direction of propagation of the wave is nearly perpendicular to the earths magnetic field 3703 ionospheric drift in the f region near the magnetic equator graphs of the diurnal variations of drift in the f layer based on observations made at singapore from september to august suggest that the drift is predominantly in an ew direction and has a maximum value of about 3704 artificial aurora the luxembourg effect is explained and the possibility of using it to produce a luminous discharge in the e layer is discussed 3705 determination of auroral height by radar preliminary report of observations made during the igy at a radar station erected at above sea level at bluff in the south island of new zealand echoes have been recorded at from heights of about km and ranges up to about km to the south 3706 atmospheric radio noise 3707 a note on the evaluation of the response of a nonlinear element to sinusoidal and random signals a method is developed based upon a mathematical technique described by lewis which is particularly useful for the analysis of nonlinear control systems simple cursors may be constructed to determine the effective gain of the nonlinear unit the application to hysteretic nonlinearities and the response to random signals is illustrated 3708 statistical design theory for strictly digital sampled data systems present design theories are based on system response to inputs of known shape and little attention is given to situations in which only the statistical properties of the inputs are known the basis of a statistical design theory is presented and applied to the optimum design of a strictly digital system the new theory forms a close parallel to wieners theory of optimum filtering and prediction and its various manifestations in applications to continuous feedback control systems 3709 a correlation between the transient and frequency responses in servomechanisms statistical evidence is used to relate time and frequency response parameters these empirical relations together with a new theoretical relation for the delay time enable the step response to be sketched given the open loop response some nontypical closed loop responses may be broken down into two subtransient step responses which are separately determinable 3710 fundamental equations for the application of statistical techniques to feedback control systems 3711 direct drive amplifier for two speed servos a five transistor servo amplifier drives a standard motor without using an output transformer for a two speed system the amplifier contains a switching circuit incorporating zener diodes and a three stage feedback network 3712 automatic power plant for telecommunications installations the development of multichannel radio telephone services capable of unattended operation for long periods has led to the need for automatic generators of electric power some of the factors in the design of diesel power plants are considered both mains standby and dual alternator systems are discussed 3713 hot transformers brief note on two experimental types of transformer designed for operation at c one housed in an evacuated stainless steel case is rated at the other is of open construction with a nominal rating of at 3714 magnetic inverter uses tubes or transistors a means of producing ac from dc the collector and emitter coil windings of the on transistor of a multivibrator are differentially connected across the input voltage so that the drive winding partially determines the frequency of oscillation 3715 simulation of nonlinear field problems some three dimensional problems can be solved by using a resistance network in conjunction with a single ac amplifier a function generator a scanning switch and a number of simple analogue storage units 3716 matrix analysis of logical networks a novel method of matrix algebra is derived for the analysis of networks representing logical systems too complex for conventional approaches using boolean algebra it is shown that truth tables of system blocks may be treated as matrices and that logical operations on such matrices can be performed efficiently 3717 an analogue computer for fourier transforms 3718 analogue computers in the nuclear power programme 3719 new applications of impedance networks as analogue computers for electronic space charge and for semiconductor diffusion problems the general second order partial differential equation is transformed to the equivalent equation of finite differences and hence relations for analogue impedance networks are derived resistance chains are applied to the case of one dimensional high vacuum diodes yielding results within about of the exact solutions rc networks are applied to semiconductor diffusion with space and surface recombination giving some new results for pn diodes a plane resistance network applied to a triode with space charge gices the anode current grid voltage curve within a few per cent of the published value see also of may 3720 a basic transistor circuit for the construction of digital computing systems a circuit comprising one transistor one capacitor and three resistors forms the basis of a complete digital computing system for use where high operation speed is not essential the construction of well known computer circuits from the basic circuit is described and a complete logical computing system using circuits is developed to demonstrate their application 3721 printed wiring an assessment and detailed description of processes in the production of photo etched circuits the properties of the copper foil used are examined and particular attention is paid to the photographic and enamelling techniques and to dip soldering 3722 small transformers with low magnetic leakage the external field characteristics of various types of laminated and c core transformers are examined to determine the form of construction with lowest leakage 3723 wide band transformer characteristics a parameter is defined for wide band transformers which represents the series resonance of the leakage inductance and the primary and secondary stray capacitances it is shown that this parameter may be determined from the low frequency requirements on the transformer and then used as a guide to the attainable high frequency response 3724 terminal properties of magnetic cores the terminal properties of the cores can be obtained from their dynamic step response it is shown that for thick mils or more thin mil and intermediate sized cores there is a unique relation between the flux in the core and the applied coulomb turns the analysis is verified by experiment 3725 new techniques for winding subminiature coils details of a method for winding self supporting coils of adhesive coated wire 3726 solid state thyratron switches kilowatts the opation of a controlled silicon rectifier and its application in various switching circuits and converters are described 3727 broad band balanced duplexers 3728 research of condensers and its results voltage temperature and frequency characteristics are given for a number of types of capacitor particularly the batio and silvered mica types 3729 accelerated life testing of capacitors 3730 precision variable capacitors for high grade electronic equipment two types of small variable capacitor are described which were designed to meet stability and accuracy specifications comparable with larger types one gives a linear frequency variation over of shaft rotation the other gives a sinusoidal variation of frequency about a mean value as the rotor shaft is turned continuously 3731 excitation of higher order modes in spherical cavities 3732 some general properties of nonlinear elements part small signal theory the analysis of nonlinear capacitor modulators demodulators and negative conductance amplifiers with only two signal frequencies present gives results that agree with the general energy relations of part of in addition the gain bandwidth terminal admittances and sensitivity to changes in terminal admittances or in local oscillator drive are given together with their dependence upon the amount of nonlinearity generally the bandwidth of these devices approaches zero as the nonlinearity approaches zero 3733 general properties of frequency converting networks a generalized analysis of frequency converting systems consisting of networks containing nonlinear inductors capacitors and resistors and including also nonlinear l c and r coupling elements the mesh and nodal equations for a general nonlinear network are given and it is assumed that a certain high voltage and current distribution the so called fundamental state results from the presence of carrier current and voltage sources first order perturbational equations are then derived corresponding to the disturbance of the disturbance of the fundamental state by small signal voltage or current sources linear differential equations with time dependent coefficients are obtained which yield for a periodic fundamental state equations in matrix form methods of simplifying the matrices are shown and the method is used to examine stability conversion gain and loss an example a polyphase magnetic modulator is analysed 3734 parallel four terminal networks a simple relation exists between the output input voltage ratio for any number of four terminal networks in parallel and their parameters of output admittance and short circuit transfer admittance the relation enables the voltage ratio to be stated without solving the networks 3735 a wide band multiplier unit capacitive coupling leads to easily adjustable wide band couplers a practical design of a wide band frequency multiplier unit incorporating these and covering all bands from to is given 3736 ceremic if filters match transistors resonant filters can replace if transformers with improvement in size cost ruggedness and insertion loss their input and output impedances are compatible with those of transistors 3737 transient phenomena in band filters analysis of a filter consisting of two coupled circuits 3738 simultaneous asynchronous oscillations in class c oscillators it is shown theoretically and practically that self starting asynchronous oscillations are possible in a class c pentode oscillator transient and steady state solutions are obtained for such an oscillator with one and two degrees of freedom 3739 shf frequency standard uses double conversion 3740 simultaneous oscillations at two frequencies in a self oscillatory system with automatic bias an investigation of the self biasing by grid current in an oscillator confirms that oscillations at two different frequencies may occur see also of may 3741 an atomic reference oscillator 3742 frequency stabilization of a microwave oscillator with an external cavity 3743 multivibrator circuit for millimicrosecond pulses pulse rise times of about and a repetition frequency of several can be achieved with the value circuit described pulse width can be adjusted continuously without affecting the rise time 3744 precision pulse generator 3745 dekatrons and electromechnical registers operated by transistors transistor circuits are described for driving cold cathode decade tubes and electromechanical counters in both cases the transistor circuit combines the waveform shaping properties of the thermionic valve with the economy of power achieved with the cold cathode valve high reliability of performance is also attained 3746 magnetic core dividers for itv sync generators an accurate and stable digital divider can be made with a pair of magnetic cores having rectangular hysteresis loops division by factors up to has been obtained in a single stage in the frequency range 3747 on the problem of synthesis of amplifier circuits a new mathematical method is described for the analysis of transients in amplifiers and a means of synthesis is suggested for multistage systems considering different types of distortion 3748 design of conditionally stable feedback systems conditionally stable systems are shown to have a greater feedback than that obtainable from unconditionally stable feedback circuits the design of such systems is analysed mathematically and a practical method for automatically preventing oscillation occurring in them is suggested experimental results obtained with a suitable circuit are presented 3749 some aspects of half wave magnetic amplifiers the performance of half wave magnetic amplifiers is analysed and a theory presented which allows for a finite control circuit resistance or rectifier reverse conductance and imperfect core properties experimental results obtained with amplifiers using different cores show good agreement with theory various methods of bias are reviewed and a conductance controlled amplifier is described 3750 a fast response full wave magnetic amplifier 3751 the effective feedback factor of self balancing magnetic amplifiers 3752 three output immittance theorems a discussion of various theorems having practical application in the analysis of transistor circuits 3753 nonlinear distortion in transistor amplifiers following an analysis of the causes of distortion in common emitter circuits the distortion factor is derived from the static characteristics the dependence of distortion on temperature collector bias input signal level and load resistance is determined and calculated values are compared with results of measurements 3754 some transistor input stages for high gain dc amplifiers several types of input stage are investigated and methods of reducing drift are suggested it is shown that drift of operating point in transistor dc amplifiers depends on the type of circuit the lowest drift being obtained using the transistor as a chopper 3755 a transistor high gain chopper type dc amplifier a modulated system is employed consisting of a transistor input chopper a high gain transistor ac amplifier and an output chopper the system has an open loop gain of with a band extending from direct current to peak output is and current drift referred to input is in the range the voltage drift at the input is less than 3756 designing transistor af power amplifiers the amplifier described delivers to a load it contains a driver stage a phase splitter using a transistor pair and a push pull output stage 3757 operation of a solid state quantum mechanical amplifier the operation of an s band solid state quantum mechanical amplifier operated at with a computed noise temperature of less than is compared with similar devices and is used as proof of the condition of discrete phonon saturation which has been previously postulated see also of june 3758 the solid state maser a supercooled amplifier a review of maser techniques with descriptions of two level molecular beam and three level solid state devices amplifier and oscillator characteristics noise measurements and future developments are discussed 3759 a uhf solid state maser maser action at a frequency of has been obtained by using a cavity mode at the pumping frequency and a lumped resonant circuit at the amplifying frequency 3760 design considerations for circulator maser systems a general expression for effective maser system noise temperature is calculated and a working approximation is derived the noise and stability requirements for a low noise circulator maser system are given in terms of maser gain and of dissipative losses and swr in various parts of the system 3761 system noise measurement of a solid state maser a complete amplifier system with an effective input noise temperature of is described the sources of noise are analysed and it is shown that the noise temperature of the maser proper is close to the theoretical value 3762 electron spin and phonon equilibrium in masers 3763 a travelling wave parametric amplifier a lossless transmission line with periodically varying distributed inductance and a constant distributed capacitance will support a growing current wave for maximum amplification the oscillator used for providing the periodic variation of inductance must be synchronized with the incoming signal the noise figure of such an amplifier should be very favourable an experimental investigation is in progress and related schemes are being studied in which precise frequency and phase relations are not demanded 3764 proposed negative mass microwave amplifier it is pointed out that negative masses occur in semiconductors at energies close to the band edge if the energy contours are reentrant there it is suggested that such a semiconductor might be used as the active element in a microwave amplifier although preliminary experiments with germanium did not show the effect see also of 3765 on chandrasekhars theory of turbulence the theory has been generalized to the case of axisymmetric turbulence and eight differential equations in eight defining scalars of double and triple correlation tensors deduced two of these equations replace that of de karman and howarth in the theory of isotropic turbulence 3766 on decay of energy spectrum of isotropic turbulence 3767 electric field distribution in polarized photoconductors the distribution is determined from changes which occur in the persistent polarization see of under various polarizing conditions 3768 the fundamental state of an electron gas detailed discussion with reference to mayers treatment of electron correlation energy 3769 force densities in dielectrics a new approach to the theory of electrical conductivity of solids since the electrical conductance of a body is a measure of the fluctuations of charge in a state of thermodynamic equilibrium an analysis of these fluctuations gives the value of the conductivity the value derived agrees with that of drude but is found to be half that for the lorentz sommerfeld model 3770 the boltzmann equation in the theory of electrical conduction in metals the boltzmann equation for electrical conduction in metals is derived assuming where is the collision time an expression independent of this assumption is considered but not evaluated 3771 theory of electrical conductivity of anisotropic inhomogeneous media 3772 quantum theory of the electrical conductivity of metals in a magnetic field the kinetic equation for the density matrix is derived and the asymptotic values of the kinetic coefficients in a strong magnetic field are analysed 3773 on the theory of spectral line broadening in plasma 3774 structure of shock waves in a plasma investigation of a shock wave in a plasma taking account of the difference in electron and ion temperatures three cases are examined nonstationary shock wave stationary shock wave in a strong magnetic field 3775 electrodynamical acceleration of plasma bunches a method is described of generating a gas discharge plasma by the electric explosion of a mm diameter copper wire in a discharge chamber evacuated to mm hg a capacitor is used with initial voltage 3776 quantum kinetic equation for plasma taking account of correlation a quantum kinetic equation for a system of particles with coulomb interaction is derived taking into account the correlation of the mutual position of the charged particles 3777 on the effective field in a plasma equations for the partial distribution functions are used to compute the effective field acting on charged particles in a plasma the effective field differs from the mean field by a small quantity of the order of where n is the number of particles within a sphere of radius equal to the debye radius 3778 the dispersion equation for plasma waves the validity of different formulae is discussed when collisions are infrequent no dispersion equation exists except in special cases see also of 3779 on the dynamics of a bounded plasma in an external field an investigation of the dynamics of a quasi neutral plasma formation located in the field of a plane em wave the method of successive approximations is used within the limits of the assumptions of the analysis a plasma bunch tends to spread out 3780 an energy principle for hydromagnetic stability problems the problem of the stability of static highly conducting fully ionized plasmas is investigated by means of an energy principle developed from one introduced by lundquist of the method is applied to the general axisymmetric system and to plasmas which are completely separated from the magnetic field by an interface 3781 radiation of plasma in a magnetic field mathematical analysis of em radiation in plasma taking account of electron spin in a uniform magnetic field 3782 coherent scattering and radiation of electromagnetic waves by plasma in an inhomogeneous magnetic field the propagation of quasi plane waves in a waveguide filled with plasma in a longitudinal magnetic field and the radiation in an electron plasma of a bunch which travels through a spatially periodic axially symmetric magnetic field are discussed the plasma tends to focus the bunches and a longitudinal focusing effect results from the attraction between the induced currents flowing in the same direction 3783 models demonstrating the phenomena of ferromagnetic hysteresis extension and refinement of the preisach model see also of 3784 contribution to the phenomenological theory of paramagnetic relaxation in parallel fields the role of spin lattice interaction is examined and the applicability of the results of this analysis to paramagnetic absorption at high frequencies and temperatures of the order of is considered 3785 the classical electromagnetic equations expressed as complex four dimensional quantities it is possible to compress the classical em equations into three complex four dimensional quantities representing respectively em field currents and charges and vector and scalar potentials this notation is useful in problems relating to waveguides cavities and aerials for microwaves 3786 theory of magnetohydrodynamic waves using the energy pulse tensor of abraham 3787 dynamo effect in magnetohydrodynamic theory 3788 surface currents induced by short wavelength radiation the integral equation given by fock of for the surface currents induced in a perfectly conducting convex object by short wave length plane electromagnetic waves is solved directly by the method of fourier transforms the result agrees with focks indirect approach some general properties of the equation are also discussed 3789 the cherenkov effect produced by single particles in gases the application of photo multipliers for detecting cherenkov radiation is discussed and successful experimental work is reported 3790 a new formulation of scalar diffraction theory for restricted aperture 3791 radiation of charged particles in flight past ideally conducting bodies the problem is discussed in the nonrelativistic approximation and the induced charge and currents are calculated initially without considering retardation the radiation due to the current system determined is then estimated the dipole approximation is used to derive expressions for the rate at which energy is radiated the radiation resistance for a waveguide system is calculated and its dependence on the particle velocity and on the radius wavelength ratio is shown graphically 3792 stark effect at and millimetres wavelength nitric oxide stark effect measurements have been made for the first time in the mm wave region results of stark effect measurements on the and transitions of the ground state of falling at and mm respectively are reported and are shown to fit closely existing theory the electric dipole moment of no in the ground state is found to be debye unit 3793 electric susceptibility of ethyl chloride in the centimetre region results of measurements at over a pressure range and a temperature range are discussed see also of and 3794 electron spin and phonon equilibrium in masers it is pointed out that the successful operation of in three level steady state masers is incompatible regardless of the operating frequencies of the maser with the assumption that the relaxation rates are determined by the interaction between the lattice vibrations and the helium bath 3795 identity of spin temperature and thermodynamic temperature 3796 generalized mobility theory a formal theory of mobility is presented that does not depend on the existence of a transport equation in particular the hamiltonian describing the electron plus the scattering system is not decomposed into an unperturbed part plus a perturbation only the applied field is treated as small the result is shown to reduce to the usual transport result when the scattering perturbation is weak without assuming the existence of a relaxation time the relation between a many electron treatment and the one electron treatment is demonstrated for the case of fermi as well as boltzmann statistics 3797 the band theory of metals brief report of a conference held at the physical society at imperial college london december some papers are noted 3798 a lunar radio interferometer in a two aerial interferometer used in radio astronomy one of the aerials can be replaced by the surface of the sea in the instrument described the ionosphere of the moon is used in place of the second aerial with metre wavelengths the minimum angle of refraction of the lunar ionosphere is found to be of the order of 3799 radio interference phenomena due to the ionosphere of the moon an attempt to explain the increase of solar radio emission observed before and after a solar eclipse by interference effects due to refraction of radio waves in the lunar ionosphere 3800 a remarkable solar radio event increased solar radio noise at a frequency of was recorded at nera observatory netherlands from on november the maximum value was approximately times the noise level of the quiet sun fluctuations with a period of occurred and are attributed to solar phenomena 3801 a radio image of the sun on wavelength in june at a station of the physical institute in the crimea a new stationary radio telescope with a parabolic reflector of diameter was put into commission isophotes of the sun obtained at and are shown 3802 energy spectrum of cosmic radiation a theory is given for the observed spectrum const where for a wide range of values of momentum 3803 diurnal variations in the number of shower meteors detected by the forward scattering of radio waves ellipsoidal theory the ellipsoidal geometry inherent in the forward scatter process is developed fully the more rigorous results obtained are compared at various stages in the analysis with those given by the simplifying cylindrical approximation developed in part the potentially observable trails are first located and their distribution determined the fraction of these providing a signal exceeding some given level is found and the total number of these observable trails as a function of trail orientation is determined by integrating over the spatial distribution part 3804 resonance effects in the theory of meteor observability the observability theory for forward scattering and revised to cover the resonance that occurs when there is a component of the incident electric vector transverse to the axis of the meteor trail normalized contours are given 3805 solar activity and cosmic radiation experimental observations of cosmic radiation during intense solar activity are presented and examined with particular attention to the period around the solar flare of february the results obtained are discussed in relation to models of solar activity involving corpuscular streams 3806 on the asymmetry of the heliographic distribution of the storm producing probability of flares the probability is greatest for flares near the centre of the disk and for those in the ne and sw quadrants the greater probability for flares in the western hemisphere is not statistically significant 3807 the distribution over the emitting area of x radiation from the solar corona and the residual intensity during total solar eclipses the e layer is assumed to be ionized by xrays of approximate wavelength a the intensity of coronal radiation in this waveband is calculated and the results lead to a considerable degree of limb brightening and to emission of radiation at radii greater than that of the visible disk the intensity of the residual radiation during total eclipses can be calculated and is estimated to have been about in and and about in 3808 magnetic activity following a solar flare the conclusions reached by watson of that solar flares and increases of magnetic activity are not correlated is not correct when the magnitude of the flare and its position on the disk are taken into account there is a positive correlation as was shown by newton see eg of and 3809 international geophysical year a report on the us program with a brief account of some of the activities during the first five months 3810 estimating the life of a satellite 3811 lifetime of an artificial earth satellite the approximate formulae given by fejer and scott are compared with those given by a more exact method and found to be accurate provided the eccentricity is not large 3812 british radio observation of the satellite brief reports of the observations made on the first russian satellite at the bbc station tatsfield the radio research station slough and ministry of supply establishments are given these include measurements of the signal characteristics field strength doppler frequency shift and bearing and elevation of the satellite 3813 the effect of diffusion on the vertical distribution of ionization in a quiet f region electrons are assumed to disappear by attachment to neutral molecules and by diffusion the coefficient of attachment is assumed to be constant while the diffusion constant is calculated according to classical theory using rocket measurements of air density and temperature the vertical distribution of electrons can be calculated the results are at variance with those actually observed possibly because the diffusion constant is much less than that assumed 3814 ambipolar diffusion in the f layer diffusion in the f layer probably depends on the diffusion of in the coefficient is estimated to be about one quarter of the value normally assumed to be applicable in the f layer 3815 horizontal wind systems in the ionospheric e region deduced from the dynamo theory of the geomagnetic variation wind systems are deduced from sq data for the solstice seasons in both northern and southern hemispheres and the diurnal and semi diurnal components are examined a comparison of the theoretical system with observed winds is made wind velocities are calculated taking account of coriolis forces and assuming the electron density at night to be that at noon parts 3816 non chapman like variations in the ionospheric e and f layers effect of the sq current system part variations in e and f are examined in various months in addition to those of march which have already been discussed see of and it is shown that in non equinoctial months e is larger in the winter hemisphere than in the summer hemisphere for the same solar zenith distance this unsymmetrical distribution is interpreted as being due to the sq current system effect in the e layer the sq current system developing more strongly in summer than in winter somewhat similar results are observed for the f layer but detailed examination shows that they can be explained by the temperature difference between the summer and winter hemispheres 3817 radio star scintillations at an equatorial station scintillation of radio stars has been measured at in ghana for four years it is unusually intense occurs only at night and is correlated with spread echoes from the f layer and with equatorial scatter of radio signals near sunspot maximum 3818 the diurnal and seasonal variations of spread f ionospheric echoes and the scintillations of a radio star the degree of spreading is greater at inverness than at slough but the diurnal and seasonal variations are similar and can be correlated with the scintillations of the radio star in cassiopeia provided an allowance is made for the zenith angle of the star see also of june 3819 a method of determining the correlation between f and sunspot number the monthly median critical frequency and the smoothed sunspot number r can be represented for a month m and time of day by the continuous periodic functions a and b are examined using data obtained at six places in japan 3820 solar activity and the ionosphere observations at slough showed that the intensity of the ultraviolet and x radiation responsible for the existence of the e layer of the ionosphere was higher in september october and november than ever before recorded and that on individual days in november the critical frequency of the f layer at noon was above see also of april 3821 disturbances of the ionospheric f region associated with geomagnetic storms part auroral latitudes results of a statistical treatment show that the deviation of f on a disturbed day is similar to the negative disturbance in middle latitudes see part of january the deviation of is different main features of the f disturbances can be accounted for by vertical electron drift 3822 electron density fluctuations and scattering of radio waves in the ionosphere discussion of theoretical and experimental determinations of electron density fluctuations and of energy scattered at vhf indicates that in vertical incidence soundings at frequencies below the critical frequency the scattered field is chiefly due to waves first scattered in the forward direction and then reflected from higher levels in the ionosphere 3823 control of the ionosphere by means of radio waves a note on the possibility of using radio waves near the gyrofrequency of electrons in the ionosphere to control the electron temperature and hence the rates of diffusion attachment and recombination 3824 an artificial ionosphere the release from rockets of potassium into the high atmosphere produces an ionized cloud lasting for about an hour suitable for returning microwave signals 3825 waveform studies of electric field changes during cloud to cloud lightning discharges assuming that cloud to cloud discharges may be identified from the sign of the field change and the time separation of the individual strokes such discharges exhibit all the features known to be associated with ground discharges they include precursors multiple strokes return strokes slow field changes and hook components junction field changes between strokes 3826 auroral display observed from unusually low geomagnetic latitudes observations of the aurora display of september are reported with brief details of some related effects 3827 horizontal movements of aurora the drift of auroral forms has been measured at three stations in canada south of the auroral zone no evidence is found of a motion due to the earths rotation relative to a fixed point in space the distribution and magnitude of the drift speeds parallel and normal to the geomagnetic meridians are similar to those found for ionospheric drifts the drifts speeds increase with geomagnetic activity particularly in an ew direction 3828 a continuously recording automatic auroral radar a low power system with fixed aerials is used to give a continuous photographic record the echo intensity is also integrated electronically to give a chart record which is immediately available 3829 abnormal polarization of the atmospheric pulses reflected successively from the ionosphere elliptic patterns of gradually decreasing eccentricity and tilt angle have been observed in cathode ray direction finders used to record atmospherics due to lightning discharges at a distance of about 3830 electromagnetic radiation from lightning strokes a theory is given of the spectral distribution and the amount of vlf radiation emitted from a vertical lightning stroke from cloud to ground the radiated energy has a maximum intensity at about and a total width at half maximum of the total energy radiated in one leader and return stroke is estimated to be about joules 3831 atmospheric radio noise at frequencies between and the results are described in terms of a voltage envelope at the output of a narrow band receiver between points the rms voltage deduced by integrating the measured amplitude distributions varies between four and eight times the average voltage the noise is always much more impulsive than fluctuation noise the structure of the voltage envelope is considered in two ways the amplitude distribution of pulse peaks and the amplitude distribution of voltage see also of 3832 variable output mains transformer a design using eight windings giving voltages produces any integral output voltage between and by simple switching auto transformer operation above extends the range to v 3833 voltage conversion with transistor switches the conversion of a dc voltage to ac at high audio frequencies at powers of is achieved using a circuit containing transistors and modern magnetic core components 3834 failure rate studies on silicon rectifiers a study of the failure rate of rectifiers rated at peak inverse volts under various conditions average failure rates for the type are approximately three times those for the type under identical conditions 3835 transistor filters ripple in a low voltage dc power supply a capacitance of is effectively multiplied by by the addition of a junction transistor operating as an impedance transformer 3836 magnetic voltage stabilizers the use of saturation effects in a number of basic designs is described brief details of a valve controlled automatic stabilizer circuit are given 3837 a survey of delay lines for digital pattern storage a review of em and ultrasonic delay lines for use over a wide range of delay times wire type acoustic delay lines using magnetostrictive transducers acoustic lines using liquids or solids as delay media and both the continuous and lumped parameter types of em delay line are examined 3838 modern trends in analogue computation 3839 a special analogue computer for calculating the oscillations of diaphragms 3840 passive components for submarine telephone cable repeaters the design and inspection of inductors and transformers are briefly described details of the inspection of silvered mica capacitors are given as an example of the procedure adopted 3841 nomogram for air gap design a nomogram is given for determining the relation between the actual air gap in a choke or transformer and its effective value for normal types of laminations thermistors a review is given of the various types of thermistor their method of manufacture and the physical theory of their operation some typical applications are outlined 3842 saturable reactors fire radar magnetrons magnetic modulator uses saturable reactors to convert input sine wave into narrow high peak power output pulses basic action of current pulse compression with magnetic modulators is explained polarizating and differentiating circuits delay line wave shaping pulse permeability measurements cancellation effects and related features leading to improved design are discussed 3843 a multichannel dekatron scaling unit equipment is described for counting simultaneously in up to six channels a variety of counting rates can be obtained 3844 the duroplast capacitor a tubular paper capacitor impregnated with epoxy resin which eliminates the need of a sealed metal can constructional and electrical data are given 3845 thermal fluctuations in a nonlinear system an electric circuit containing a voltage dependent resistance and a capacitance is studied a general method is given for finding the spectral density of current fluctuations and explicit results are obtained for two special forms of rv 3846 a numerical method for the determination of a two pole function which approximates a given complex function in a band of real frequencies 3847 on the theory of anisotropic obstacles in cavities variational expressions are derived for the resonance frequencies of a cavity containing a material with tensor electromagnetic properties 3848 circularly polarized microwave cavity filters 3849 synthesis of driving point and transfer functions by continued fraction expansion a method of synthesis of driving point functions has been developed in which more than one network element may be included in each branch of the ladder network the method is first applied to rl and lc two element type networks and then extended to the general rlc network four terminal networks having prescribed driving point and transfer impedances are synthesized in a similar manner 3850 the unbalanced symmetrical parallel t network taking account of condenser loss the network is analysed without adopting the usual approximations and its application to wave analyser and oscillator circuits is discussed see of 3851 synthesis of a class of microwave filters 3852 bifilar t trap details are given of a circuit with a bifilar t trap designed for rejecting the second harmonic of a signal in an infrared detector amplifier other applications of the bifilar t trap are considered eg a tuned af amplifier having a bandwidth of a few hundred cycles with a narrow band of high attenuation at the centre and a narrow band feedback amplifier 3853 production of millimetre waves by a spark generator a brief account of experiments which suggest that the spark generator does not offer a practical means of extending the radio spectrum to wavelengths less than mm 3854 circuits for forming pulses from a sinusoidal voltage using a relatively low supply voltage circuits are considered which have a number of advantages over multivibrator and trigger circuits valve transistor or hybrid circuits can be used 3855 the schmitt multivibrator a detailed design procedure is given and applications of the circuit are outlined 3856 a method for sharpening the output waveform of junction transistor multivibrator circuits a method of designing the circuit to reduce the recharging time of the coupling capacitor is given an improvement in waveform at the collector of one transistor is achieved with an accompanying deterioration of the other output 3857 design of a dual pulse code train generator description of a pulse train generator developed for delay line testing which provides a double train of pulses of variable separation 3858 transistor oscillators and their load independent properties the equivalence of the internal and the external feedback in a transistor oscillator circuit is established two types of load independent oscillator are considered one with a load impedance in parallel with the equivalent passive quadripole and the other with the impedance in series the conditions for obtaining an oscillator with two load independent impedances and a load independent oscillator in the form of a six terminal network are examined see also of 3859 experimental and theoretical investigation of a frequency stabilized transistor oscillator for the condition for oscillation of a feedback oscillator is derived the amplifier its load and the feedback network are treated as a single cascaded quadripole output voltage and frequency variations as a function of temperature load and supply voltage were measured on a practical circuit containing a quartz crystal resonator a general rule for adjusting the emitter series resistance so that the input parameters remain constant during variations of temperature could not be established 3860 designing transistor circuits sinusoidal transistor oscillators a criterion for the generation of a single sinusoidal waveform is developed from linear network theory and applied to basic transistor oscillator circuits practical problems of distortion are discussed 3861 designing transistor circuits small signal parameters and equivalent circuits the merits of various equivalent circuits for transistors are discussed with emphasis on the common base derived y h and t arrangements 3862 performance of three millimetre harmonic generators and crystal detectors 3863 a method for investigating amplifying circuits with characteristic equations of the third degree for short build up times a method is proposed in which a number of difficulties in design are eliminated as an example results are given of an investigation of a correction circuit using an inductance in the grid circuit 3864 squelch circuit mutes magnetic tape echoes a biased diode type of avc is described which eliminates echoes due to print through effect by rejecting outputs lower than below peak signal level 3865 the cathoguard a method of reducing the input and output capacitances of a wide band pulse amplifier is described 3866 the asymmetry of two circuit tuned and coupled filters due to feedback via the grid anode capacitance the asymmetry due to feedback in the characteristics of an if amplifier is calculated for a circuit with tuned filters and for coupled filters the limiting conditions for instability are also determined see also below 3867 transistor q multiplier for audio frequencies the use of positive feedback to increase the selectivity of a tuned circuit is discussed the performance of a practical circuit giving for example a q of at is described 3868 transistor ac amplifier uses multiple feedback the use of shunt and series negative feedback loops simultaneously in each stage is considered 3869 a sensitive superconducting chopper amplifier an amplifier based on a magnetically modulated wire and similar in principle to that due to templeton is described it is designed for the study of thermoelectricity at liquid he temperatures 3870 centimetre solid state maser a three level solid state maser using doped with has been operated as an amplifier at the design is somewhat different from that previously reported of july which operates in the same frequency range 3871 two level solid state maser microwave amplification and oscillation have been observed at using two level electron spin systems the materials used were single crystals of quartz and of magnesium oxide each containing paramagnetic defects 3872 maser oscillator with one beam through two cavities the behaviour is investigated using a geometrical representation of the schrodinger equation and a qualitative explanation is given of the ability of the maser to oscillate simultaneously at two frequencies 3873 a low noise wide band reactance amplifier 3874 circuit analogues of suhl type masers a tuned circuit in which inductance varies with time and two coupled tuned circuits in which mutual inductance varies with time are analysed and shown to act as amplifiers under certain conditions these considerations are preliminary steps to the final problem leading to the suhl type maser see also of 3875 amplification using a precessing magnetic moment an account is given of the analysis of an arrangement in which two tuned circuits are coupled to a precessing magnetic moment it is shown that with where and are the resonance frequencies of the circuits and the precession frequency useful amplification can be obtained in the course of the analysis the bloch equations are solved to a higher order in approximation than is usual parametric amplification of the fast electron wave 3876 experimental characteristics of a microwave parametric amplifier using a semiconductor diode a rectangular cavity simultaneously resonant at and is used with a ge junction diode having a zero bias capacitance of and a spreading resistance of with a pumping signal applied at amplification can be obtained at either of the lower frequencies at gain preliminary measurements show a noise figure less than db 3877 noise figure measurements on two types of variable reactance amplifiers using semiconductor diodes the use of semiconductor diodes in an up converter and in a negative resistance amplifier at is described a bandwidth of was obtained with the latter at a maximum gain of and a noise figure as low as has been achieved 3878 an experimental investigation of the method for obtaining an optimum amplitude phase modulation a report on experiments confirming the main premises of the theory of the method proposed by tetelbaum see 3879 balanced modulators based on the hall effect in semiconductors balanced modulators based on the hall effect in and n type ge are investigated sensitivities are too low for practical use 3880 a phase sensitive detector a detailed circuit is given of a system for measuring the voltage swr in a waveguide by detecting a modulated carrier by using a very narrow effective bandwidth detection is possible at signals levels as low as 3881 analysis of transient processes in diode detection by a method based on the use of low frequency equivalent circuits a method is proposed for analysing the transient processes in a system consisting of a hf amplifier and a diode detector the method is based on the linear approximation of the processes occurring during detection and on the replacement of the detector and of the amplifier circuits by equivalent lf circuits various types of circuits and various shapes of the envelopes of the input signal are considered 3882 the distortion of frequency modulated oscillations due to asymmetry in two circuit filter networks second and third order distortion factors for quasi static and dynamic distortion conditions are calculated using formulae derived from a series expansion of the filter phase and attenuation characteristics 3883 quantum theory of the refractive index a perturbation theory is used to obtain a unitary transformation which approximately diagonalizes the total hamiltonian for a system made up of a radiation field in interaction with gas molecules 3884 a model of phosphors on the basis of quantum mechanics part kinetics of electron and phonon reactions the optical behaviour of a phosphor is discussed assuming that two types of defect centre exist in the crystal 3885 a property of dielectric constants of dielectrics in thermal equilibrium theoretical discussion of dielectrics with or without internal sources of energy a lumped circuit model of a molecular amplifier with lorentz shaped bandpass characteristic is derived 3886 irreversible thermodynamics and carrier density fluctuations in semi conductors the formalism of irreversible thermodynamics is applied to the kinetics of carrier transitions in semiconductors the thermodynamic forces the generalized resistors and admittance functions are introduced it is shown that the thermodynamic forces which establish the regression of a perturbed state to equilibrium are the differences of the quasi fermi levels that have to be assigned to each group of carriers the generalized resistances are simply related to the transition rates the kinetic equations for the rate of change of the various carrier concentrations are then written in a unified form the spectral density matrix of the spontaneous carrier fluctuations being found from the admittance matrix the results are then expressed in a closed form which is valid for nondegenerate as well as for degenerate semiconductors the theory is applied explicitly to electronic noise in extrinsic and near intrinsic crystals with and without recombination centres 3887 the theory of the anomalous k skin effect in metals for obliquely incident radiation the effective surface impedance of a metal varies with the direction of polarization of incident radiation in the upper visible and ultraviolet ranges formulae for refractive indices reflectivities and principal angles at oblique incidence are derived in terms of two surface impedances experimental results are in good agreement with the theory 3888 the microfield in assemblies with coulomb interaction critical assessment of holtsmarks theory in the light of the results of recent investigations see also of 3889 investigation of the transverse motion of ions in a discharge in a strong longitudinal magnetic field the influence of the gas pressure on the average transverse velocity of ions was investigated using a rotating probe in an argon discharge it was found that for pressures and in spite of a strong magnetic field of about oersteds a considerable quantity of ions reached the side walls of the discharge chamber so that an estimate could be made of the energy acquired by the ions in the radial electric field 3890 the demonstration of single electron avalanches and their secondary processes in gases continuation of earlier experimental investigations on electron avalanches in oxygen nitrogen and air an interpretation of the observed delay in the formation of avalanches in nitrogen and air is given 3891 electrical discharges between coaxial electrodes luminous corona discharges occur when transient voltages are applied between a wire and a small coaxially mounted ring in air photographs show that the shapes of the discharges differ according to the polarity of the electrodes 3892 the initiation of a vhf pulse discharge in neon an investigation carried out at with pulses of duration sec is described the distribution function of the electron velocities the kinetic coefficient of the electron interaction with the gas molecules the hf conductivity and the onset of discharge induced by a rectangular hf pulse are examined the results are presented graphically 3893 pulse ionization chamber as a device for simultaneous investigation of the energy and angular distributions of charged particles 3894 small oscillations in an electron beam the stability conditions for the propagation of small amplitude em oscillations in noncompensated electron streams are examined and solutions for some particular cases are obtained 3895 on the space charge divergence of an axially symmetric beam the usual assumptions made in estimating the space charge effect are consistent with a coaxial cylindrical conducting boundary for small amounts of divergence a hyperbola solution is suggested this may in some cases be as good as or better than the usual solution even when divergence is not small 3896 small signal power conservation theorem for irrotational electron beams the theorem describes the balance between the rf kinetic and rf electromagnetic powers in a laminar beam the thermal velocity distribution at the cathode is neglected the kinetic power flow is expressed in terms of the chu potential the longitudinal component of the rf beam current and the equivalent longitudinal surface current on the beam boundary see 3897 variation of secondary emission with primary electron energy a simple formula is given relating secondary emission to primary electron energy which is more in agreement with experimental results for and than previous theoretical formulae 3898 effective cross sections of electrostatic interaction in plasmas definitions 3899 effects of electron electron interactions on cyclotron resonances in gaseous plasmas from the boltzmann fokker planck equation a set of equations is derived and solved numerically the results indicate that the real part of the electrical conductivity of the plasma power absorption is reduced by electron electron interaction at the peak of resonance and the width of resonance is increased 3900 nonlinear phenomenological theory of plasma oscillations damped oscillations are shown to arise under certain conditions the intensity of the standing waves being augmented by collisions with a loss of efficiency in general increasing current and plasma temperature tend to promote oscillations while the role of plasma density is more complex the influence of a magnetic field in the limiting case of no damping is also investigated 3901 completely integrable singular electromagnetic field derivation of expressions for the components of the completely integrable singular electromagnetic tensor with reference to maxwells equations 3902 induction by an oscillating magnetic dipole over a two layer ground expressions for the mutual electromagnetic coupling between two small loops and for the self impedance of a loop over a two layer earth are derived 3903 effect of a gravitational field due to a rotating body on the plane of polarization of an electromagnetic wave it is shown that for electromagnetic waves the gravitational field of a rotating body acts as an optically active medium thus the plane of polarization of the wave rotates while it passes through this field the effect is small the angle of rotation due to the gravitational field of the sun is about radian 3904 approximate calculations of the diffraction of plane electromagnetic waves by some metallic bodies part a new approximate method of calculation is described which is applicable to the diffraction of em waves by wedges or strips the method applies to wavelengths much smaller than the linear dimensions of the diffracting body 3905 basic microwave properties of hot magnetoplasmas the usual conductivity tensor of a uniform plasma in a uniform static magnetic field is generalized to include four effects of random motion of plasma electrons the results are applied to the evaluation of the index of refraction for microwave signals 3906 investigations of the paramagnetic nuclear resonance absorption in a capacitor field the advantages and disadvantages of using a capacitor field for high resolution nuclear induction spectroscopy are briefly outlined 3907 theory of saturation in nuclear magnetic resonance 3908 energy band splitting and inter band terms in the dislocation of lattice atoms in a solid 3909 on the theory of a fast polaron expressions for the dependence of the polaron energy on its initial velocity are obtained in connection with polarons the breakdown voltages for ionic dielectrics are also examined results of investigations on alkali halide crystals are tabulated 3910 spin lattice relaxation it is pointed out that phonon relaxation times can be the dominant quantity measured in the usual saturation spin lattice relaxation measurements the analysis indicates how pulse measurements may be used to evaluate the actual spin lattice relaxation time independently of the phonon relaxation time 3911 one dimensional impurity bands the density of states of one dimensional crystals consisting of functions randomly distributed has been calculated on the ibm computer the chains contained impurity atoms and the most probable error in the integrated density of states at various energies was estimated to be at most calculations were performed for various values of the parameter where is the density of atoms and the attenuation constant appropriate to the isolated bound state the results at different densities are compared with those obtained from various physical models 3912 the spur method in the problem of the exciton the excitons in ionic crystals are examined the interaction of electrons and holes with lattice vibrations is considered it is shown that the change of energy at low temperatures is primarily determined by the weakening of the interaction of charged particles with the field of polarized vibrations when the temperature rises without increase of kinetic energy the effective mass of the exciton is calculated see also of 3913 the initial radius of meteoric ionization trails kinetic theory is applied to the formation of regions of ionized and neutral atoms of meteoric material about the path of a meteor it is found that the high initial velocity of the diffusing particles causes the trail to reach an initial radius quickly and normal diffusion then ensues a reflected signal may be computed as if the initial radius mean free paths were reached instantaneously 3914 the random occurrence of meteors in the upper atmosphere the distribution of time intervals between bursts of signals over a path was studied statistically using data obtained in two periods of two hours and bursts respectively results were consistent with forward scattering from meteor trails produced by random entry of meteors into the atmosphere 3915 identification of m regions on the sun 3916 the duration of emission and the slope of the pulse spectrum of solar ultraradiation during the chromospheric eruption of and recordings made at various stations are analysed and discussed in relation to various theoretical models references 3917 the calculation of the centre limb variations and the one dimensional intensity profiles at and cm for a rotationally symmetric corona model at constant temperature the calculated results are compared with those obtained from measurements by christiansen warburton and was 3918 geomagnetic disturbances associated with solar flares with major premaximum bursts at radio frequencies mc a close association is found between solar flares in the early phase of which radio noise at frequencies is received and sudden commencement ionospheric storms on the earth it is suggested that this rf emission may be from the suns outer atmosphere and corona and thus may indicate which solar flares are accompanied by the ejection of storm producing particles although flare data are incomplete the proportion of flares having major early bursts is estimated at and the number of flares is comparable to the number of ionospheric storms not identifiable with well established day recurrent series an average time delay of days occurs between flare and geomagnetic disturbance and the intensity of the disturbance is related to the position of the flare on the suns disk 3919 progress of sputnik estimates of the orbital period semi major axis now and eccentricity on and two intermediate dates are given these are based on observational data from different sources 3920 determination of orbital characteristics of an earth satellite from single station radio transit observations meridian observations of the satellite have been made by means of an interferometer located at cleland ohio because of the generally low altitude of the satellite at this station horizontal dipoles were replaced by commercial yagis 3921 the mesopause region of the ionosphere observations have been made at with pulse sounding apparatus at christchurch new zealand since early in initial results see of are confirmed extended observations indicate the continuous existence of ionization throughout a range of heights from about to km 3922 new rocket measurement of ionospheric currents near the geomagnetic equator rocket borne magnetometer measurements indicating current sheets at heights of and are described comparison with other data indicate that at km only half the total current system had been penetrated 3923 ionosphere electron density measurements with the navy aerobee hi rocket electron densities were measured at heights between km and above new mexico by the doppler shift method in which the beat note between a signal and a reference signal at was recorded the results corrected for obliquity effects confirm the general structure of the ionosphere previously measured and are consistent with simultaneous records the ionosphere remains dense between e and f regions sporadic e was associated with a sharp spike in the distribution at approximately km thick 3924 differential absorption in the d and lower e regions a method of measuring electron densities in the d region is described in which use is made of the faraday effect in rocket flights at white sands new mexico at noon on a day of high absorption a value of electrons cm was obtained for an altitude of km 3925 concerning ionospheric turbulence at the meteoric level a discussion on the application of fluid mechanics to meteoric phenomena is continued with particular reference to a rough trail paradox which concerns the relative turbulent velocities of large and small eddies the paper is mainly concerned with the relative merits of work by booker and cohen and by manning eshleman regarding the explanation of radar echo fading 3926 solar flare effect in the f layer of the ionosphere is plotted as a function of local mean time where is the difference between the measured critical frequency and the normal value based on that measured one hour previously the plot for the period of the intense solar flare of february shows a positive pulse of amplitude followed by a second smaller pulse later an analysis of the statistics of the fluctuations in has been made 3927 medium frequency observations of the lower ionosphere during sudden disturbances records obtained during sid by pulse sounding at are analysed in detail the observed behaviour gives support to the theory of friedman and chubb that soft x rays and not lyman radiation are responsible for sids 3928 variations in the height of ionospheric layers during magnetic storms statistical work carried out on washington ionospheric data for and magnetic planetary figures from crpl publications shows that the e layer remains unchanged in height while the f layer rises during storms application to parkers theory of gives as the height where storm associated solar energy is absorbed 3929 an apparent ionospheric response to the passage of hurricanes evidence is given for the association of the passage of a hurricane with a departure of the critical frequency of the f layer from its monthly mean value the four hurricanes discussed resulted in rises in critical frequency of up to a possible mechanism is suggested 3930 radio noise from lightning discharges records obtained at slough during two local thunderstorms in july and august are reproduced including simultaneous recordings on and with bandwidths and respectively 3931 between the atmospherics an examination is made of the background cosmic radiation between atmospherics at a frequency of records are explained in terms of an ionospheric shutter operated by two mechanisms d region absorption by day and shift of coupling level between ordinary and extraordinary modes relative to the gyro level at night observations of precipitation static and local atmospherics are also described 3932 annals of the international geophysical year vol the first volume to be published of a series of instruction manuals titles of the parts of ionospheric vertical soundings measurements of ionospheric absorption the measurement of ionospheric drifts and miscellaneous radio measurements 3933 the reflection and screening effects of metallic enclosures in a plane electromagnetic wave three cases of reflection and screening action are investigations for wavelengths of the order of the dimensions of the enclosure a hollow cylinder with axis parallel to the electric field a hollow cylinder with axis parallel to the magnetic field and a hollow sphere the increase of the reflection coefficient with rising frequencies screen attenuation and resonance effects are discussed 3934 nuclear batteries outline of principles of operation and applications 3935 radio waves power transistor circuits 3936 voltage current characteristics of semiconductor power rectifiers the distribution of the concentration of carriers of pin and pnn types is examined monomolecular and bimolecular recombinations are considered the dependence of the injection coefficient on the current and the characteristics is calculated and the voltage drop in the bulk of the semiconductor is investigated 3937 medium power silicon rectifiers the construction manufacturing techniques and electrical characteristics of the diode type mn of pin structure are described 3938 stabilized power supplies using transistors the operation of simple stabilizing circuits is analysed and methods of improvement by preamplification or compensation are discussed practical circuits which have low temperature coefficients are described 3939 the logical design of a simple general purpose computer the logical design described here is used in minac partially constructed at the california institute of technology and lgp manufactured by librascope inc these serial binary digital computers make use of magnetic drum bulk storage and use three circulating registers and fifteen flip flops 3940 digital computer adding and complementing circuits various direct coupled transistor circuits are described suitable for use with double gate shifting registers the performance of these circuits operating with a digit spacing of is illustrated with waveform photographs 3941 an algorithm for determining minimal representations of a logic function 3942 computing techniques for the sampling parametric computer 3943 dynamic accuracy as a design criterion of linear electronic analogue differential analyzers 3944 fine graduation of the timing pulse generator disk of an electronic computer the construction is described of a disk providing the synchronizing pulses for the storage system of a digital computer the nonferromagnetic disk of about diameter carries a thin layer of nickel near the rim the layer is cut by radial grooves of width and there are five concentric tracks with differing numbers of grooves the outer track thus consists of ferromagnetic teeth which at rev min generate pulses at a repetition frequency of about details of the dividing and engraving machinery are given 3945 nondestructive memory employing a domain oriented steel wire a magnetic storage system using a steel wire under tension is described a small solenoid is used to magnetize the wire locally and for observing the flux change produced by an interrogative current pulsed through the wire itself 3946 an electronic analogue multiplier using carriers an electronic analogue multiplier is described which is based on a modulation technique no dc amplifiers are used which makes the output entirely free of drifts all distortions up to the fourth order are eliminated the experimental model that has been built handles inputs from dc to and gives an output from dc to the amplitude range of the output is 3947 trigonometric resolution in analogue computers by means of multiplier elements abstract 3948 stability and convergence limitations on the use of analogue computers with resistance network analogues it is shown that the solution of equations such as breaks down if the gradient of is negative and sufficiently large to cause the correct solution to be wavelike see also of and 3949 electronic integrator with immediate digital output details are given of a technique for obtaining an instantaneous numerical value proportional to the area of a recurring voltage transient the basic principle is to summate the pulses from a generator whose repetition rate is a linear function of the instantaneous input voltage the system has a high order of linearity approximately and is used for roughly triangular pulses of duration 3950 an improved electromagnetic integrator description of a permanent magnet moving coil system for integrating an electrical signal of varying polarity over integration times as long as one day 3951 symposium on computers the text is given of seven papers read at a symposium held at mt eliza victoria december 3952 magnetostrictive delay line equivalent electromechanical circuit for a magnetostrictive nickel delay line is given the optimum matching at the input and output end is discussed 3953 magnetic core memory cell with nondestructive read out outline of a method of using different values of incremental permeability of a dc biased magnetic core to obtain a binary storage cell one of the possible applications is for visible indication of binary states in magnetic shift registers 3954 a transistor driven magnetic core memory description of a storage system with a capacity of words designed for a transistor airborne digital computer tradic at bell telephone laboratories both the read and write operations are based on a coincident current technique 3955 current steering in magnetic circuits magnetic switches are described in which the current from an energizing source is guided or steered through one out of many possible parallel branches the conducting branch being selected by the presetting of appropriate magnetic elements 3956 the logic of bidirectional binary counters 3957 a new diode function generator 3958 a cathode ray tube analogue to serial digital converter small fluctuations of the cr tube screen equilibrium potential cause proportionate fluctuations in the steady secondary emission current arriving at a collector anode the parameters affecting changes in this current are investigated using an external electrode on the cr tube face to modulate the screen potential experiments are described to determine minimum electrode width and spacing consistent with the production of a discrete pulse output from each electrode when a pattern is scanned 3959 printed circuits a review of printed circuit techniques suitable for modular equipment 3960 divided output transformers to overcome self capacity in the primary winding of an af output transformer at high frequencies the output from the final stage may be fed to two transformers one for the low frequency and the other for the high frequency range this overcomes the necessity for a single high quality transformer and the output can be fed directly to two separate loudspeakers 3961 contribution to the study of a rectifier in series with an inductive resistance different hypotheses are considered for expressing the voltage drop across the rectifier at low frequencies values of mean and maximum current are calculated according to each hypothesis and compared with vith values measured using a coil of inductance and resistance in series with a valve rectifier a circuit for measuring low peak voltages using a gas filled tetrode is described 3962 capacitive phase shifters the design is described of a continuous phase shifter consisting of a variable capacitor with four groups of stator plates and one group of kidney shaped rotor plates 3963 a field effect varistor a two terminal passive semiconductor is described in which the current can be held constant within in the voltage range v currents from to can be handled the ac dc resistance ratio in this region is of the order of 3964 elementary proof of an extended reactance theorem for two terminal networks a proof is derived for fosters reactance theorem which is also applicable to its extended form covering loss free circuit elements and transmission lines 3965 high q quartz crystals at low temperatures q measurements in the range to over for several modes of vibration are described in one case a value of was obtained 3966 elimination of unwanted modes of oscillation in cylindrical cavities the possible modes in high q cylindrical cavity resonators are analysed and the suppression of residual modes by special coupling systems or discontinuities inside the cavity is discussed measurements were made on ten tunable cavities of different size covering the frequency range a frequency modulated source was used to determine the permissible limits of the cavity tuning range and the dimensions of the discontinuities for obtaining the desired attenuation of unwanted modes without reducing q by more than the modes and their amplitudes are tabulated 3967 q factors of a transmission line cavity 3968 exponential transmission lines as resonators and transformers 3969 general method of analyzing bilateral two port networks from three arbitrary impedance measurements the method consists in mapping stereographically on the surface of the riemann unit sphere three given output quantities and their corresponding measured input quantities the fixed points and the multiplier of the normal canonic form of the linear fractional transformation representing the network can be obtained by using kleins three dimensional generalization of the pascal theorem the different constructions of the geometric part can also be performed analytically simple numerical examples are worked out 3970 transformation quadripoles according to the insertion loss theory the design of filter networks with prescribed attenuation characteristics and impedance transformation in the pass band is discussed see also of 3971 graphical determination of matching sections a description of graphical methods using the smith chart for matching impedances by means of l or t sections 3972 degenerate solutions and an algebraic approach to the multiple input linear filter design problem 3973 optimum filters for independent measurements of two related perturbed messages 3974 antenna filters for a military radio system high q coaxial filters are described covering both transmission and reception over the range in only sub bands 3975 bandwidth limitations in equalizers and transistor output circuits 3976 temperature compensated crystal oscillators in the method described a passive network containing a thermistor is enclosed in the same envelope as the crystal 3977 the cathode coupled multivibrator considered as a coupled pair of two therminal networks the multivibrator is considered as an active two terminal network with negative differential resistance together with a passive two terminal network formulae derived on this basis for determining the multivibrator operating characteristics give results in close agreement with experimental values 3978 sawtooth generators with commercial type values for producing deflection voltages of high amplitude and extremely short duration the circuit of a special high speed oscillograph with a time base resolution of is described which was used for examining the waveforms produced by various pulse generators investigated pulse amplitudes of with rise time and have been obtained 3979 transistorized photomultiplier has resolution description of high sensitivity photomultiplier circuit for use in a scintillation counter 3980 secondary emission tubes in coincidence circuits switching waveforms of a trigger circuit based on a valve type efp are analysed and switching speed and operating conditions are discussed 3981 harmonic amplifier for x band local oscillator the final frequency tripler in a harmonic amplifier cascade uses an uhf triode with coaxial cathode input resonator and a wave guide output resonator giving about output 3982 a one valve dc amplifier with high impedance input a simple one valve high impedance probe circuit intended for direct connection to a dc amplifier is described drift is about in the first half hour of use a simple method of reducing the input time constant is also given 3983 low noise amplifier circuit details are given of a cascade amplifier using disk seal triodes designed for the study of semiconductor noise at low temperatures the theoretical noise figure of the amplifier is calculated and compared with the value obtained from radiometer measurements 3984 temperature stability of transistor class b amplifiers this is discussed generally and in relation to three types of circuit commonly used graphical design methods for achieving optimum stability are developed and comparative practical results are given 3985 the maser a review of development describing the principles of molecular beam negative temperature optically pumped and solid state masers 3986 maser amplifier characteristics for transmission and reflection cavities the noise temperature bandwidth and gain modulation for transmission and reflection type masers are compared the latter type is superior in most respects although the same noise temperature may be obtained with the transmission type with some sacrifice in bandwidth and gain modulation a figure of merit for both types is given 3987 a ferromagnetic resonance frequency converter an experimental and theoretical study of a converter using a magnetized disk of single crystal yttrium iron garnet inputs at and are used to produce an output at in a cavity resonant at all three frequencies the output power agrees with that expected theoretically within experimental error see also of 3988 a parametric amplifier using lower frequency pumping experimental verification of the principle of parametric amplification using a pumping frequency lower than the signal frequency is described variable inductance ferrite core and variable capacitance semiconductor diode elements have both been used the former at with pumping at and the latter at with pumping at bandwidth and noise have been measured as functions of gain for the diode amplifier and the results compared with theory see also of june and 3989 linear frequency discriminator for subcarrier frequencies the discriminator uses a heptode valve with out of phase signals on its two control grids it is suitable for low frequency fm signals having large deviations 3990 the electrodielectric induction an analogy between magnetic and dielectric quantities discussed earlier is developed with special reference to dynamic phenomena 3991 the method of secondary quantization in phase space a statistical analysis of systems of interacting particles in which use is made of the number of particles in various points of coordinate momentum phase space which at every point of phase space are random functions of time this method can be used for considering particles and fields in electromagnetic interaction 3992 dimensions for a unified theory of electromechanics a dimensional relation between voltage and mechanical force is derived and a set of three dimensions length time and the square root of force is proposed for a unified theory 3993 interaction of charged particles in a dielectric analytical results may be summarized by the statement that if sufficiently distant external charges in a dielectric interact with each other and with the charge of an extra electron or hole as if all charges were renormalized according to the expression 3994 absorption in a dielectric slab energy incident on a parallel slab of high loss material with high dielectric constant is considered at angles of incidence greater than the reflected energy is smaller the more lossy the material the absorbed energy is a maximum at certain angles of incidence depending on the polarization and dielectric constant 3995 magnetic forces and relativistic speeds in stationary electron beams in nonrelativistic electron beams magnetic forces may have to be considered they are still more important in relativistic beams care must be taken in using the results of calculations in which these forces are neglected 3996 note on positive ion effects in pulsed electron beams experimental results are given for electron beams of duration under conditions normally encountered in high power microwave valves 3997 energy spectrum of an electron beam after passing through a thin metallic film the energy loss is determined for films of al cr bi au ag and cu 3998 very high voltage electron diffraction description of a diffractograph operating at voltages up to 3999 the use of electron diffraction for magnetic analysis brief note on a method of evaluating magnetic field strength from the eccentricity of superposed diffraction rings 4000 electron scattering phenomena new methods of investigations are reviewed 4001 diffusion and elastic collision losses of the fast electrons in plasmas when the energy spectrum in ne at mm hg pressure can be separated into a primary high energy and a secondary low energy maxwellian group then the mean free path of the fast electrons can be evaluated by use of the diffusion law is found to be independent of the plasma density it is remarkable that there is little interaction between fast and slow groups even when the density of the slow one becomes comparable to or even higher than that of the fast group 4002 electron energy distributions in uniform electric fields and the townsend ionization coefficient the second order differential equation which expresses the equilibrium conditions of an electron swarm in a uniform electric field in a gas the electrons suffering both elastic and inelastic collisions with the gas molecules is solved using the jeffreys or wkb method of approximation the theory is illustrated by a comparison of calculated and observed results for hydrogen 4003 experimental examination of holtsmarks theory of line broadening 4004 deviation from the holtsmark shape of the balmer lines in plasma 4005 scattering of electromagnetic waves in a plasma the intensity of combination scattering due to plasma density oscillations is determined with and without a constant uniform magnetic field 4006 suppression of plasma oscillations in a hot cathode discharge tube containing gas at low pressure oscillations of frequency can be generated the oscillations can be suppressed by mounting a plane anode and cathode sufficiently close together the discharge can still be maintained 4007 on the propagation of hydromagnetic waves in compressible ionized fluid mathematical treatment based on a method of characteristics 4008 the behaviour of a completely ionized plasma in a strong magnetic field 4009 mass spectroscopy investigations of photoionization in gases experimental equipment is described and references are given 4010 the theory of ferromagnetic resonance at high signal powers it is shown that two anomalous effects in the microwave absorption of ferromagnets are connected with two kinds of instability of the uniform precessional motion of the total magnetization against certain spin wave disturbances the susceptibilities are calculated for the final state attained by the medium with high signal levels and are shown to agree with experiment 4011 reflection and refraction in magnetohydrodynamic fluids of finite conductivity are considered on the basis of the euler minkowski system for hydromagnetic waves propagated in a direction differing from that of the external magnetic field 4012 investigation of and compensation for the inhomogeneity of the magnetic field of an electromagnet 4013 stabilization and control of an electromagnet by means of magnetic proton resonance long term magnetic field stability of the order of is obtained by means of a proton resonance system incorporating a magnetic field discriminator circuit and a variable frequency transitron circuit 4014 on the reflection of electromagnetic waves on a rough surface 4015 propagation of plane electromagnetic waves in a directional conductor with variable direction of conductivity propagation through a series of directional screens is considered each screen being rotated by the same angle with respect to the adjacent screen 4016 the theory of electromagnetic waves in a crystal in which excitons are produced it is shown that in a crystal several waves of the same frequency polarization and propagation direction exist but with different indices of refraction this phenomenon differs from double refraction of light and occurs even in isotropically polarizing cubic crystals 4017 diffraction patterns at the plane of a slit in a reflecting screen measurements were made of the diffraction pattern in slits ranging in width from to microwave radiation of and was used ratios of intensity in the slit to intensity of the unperturbed beam were determined for plane polarized radiation incident on the conducting screen 4018 diffraction by a perfectly absorbing thin screen comparative measurements of the diffraction patterns in and near slits of perfectly absorbing and reflecting thin screens show that the reflected diffraction patterns of the slits are the same for distances greater than 4019 the edge conditions and field representation theorems in the theory of electromagnetic diffraction addendum to 4020 wavelength dependence of scattering coefficient for infrared radiation in natural haze a formula consistent with the mie scattering coefficient is given for see of june 4021 propagation in a gyrational medium 4022 cooperative phenomena in quantum theory of radiation cooperative effects in systems having dimensions small relative to the wavelength are investigated in relation to the quantum mechanical identity principle the application of this effect to a gas maser is mentioned 4023 the radio source in the direction of the galactic centre observations of radio flux densities at frequencies from to show that the radiation could originate from a nonthermal source lying behind ionized hydrogen 4024 radio observations of a lunar occultation of the crab nebula comparison of brightness distributions at and shows a difference in apparent size of the radio source details of the lunar atmosphere are also obtained see below 4025 radio observations of the lunar atmosphere the refraction occurring in the lunar atmosphere is estimated from observations at of the lunar occulation of the crab nebula on january the electron density at the moons surface is derived for an atmosphere in hydrostatic equilibrium and for a continuously escaping atmosphere 4026 the distribution of brightness at metre wavelengths across the suns disk 4027 apparent temperatures of some terrestrial materials and the sun at millimetre wavelengths report of measurements made using a dicke type radiometer the apparent temperature of the sun was between and at vertical angles the sky temperature was under clear conditions but cumulus nimbus cloud raised this to a value nearly equal to that for ground level air 4028 magnetohydrodynamic shock waves in the solar corona with applications to bursts of radio frequency radiation shock fronts ahead of corpuscular streams may account for type and type bursts detailed calculations are given based on a set of transport equations previously derived for an ionized gas of 4029 variation in the speed of rotation of the earth since june 4030 the general expression of the diurnal variation of the atmospheric electric field considering the influence of the eddy diffusion near the ground 4031 simultaneous measurement of air earth current and the atmospheric electric potential gradient 4032 oscillations of a system of disk dynamos the behaviour of two disk dynamos coupled to one another is examined in relation to the earths magnetic field it is found that reversals of electric current and magnetic field occur unlike the case of a single disk dynamo see also of 4033 the earths magnetic field above wspg new maxico from rocket measurements the absolute magnetic field was measured from ground level to km with a proton precessional magnetometer the typically quiet field differed significantly from that of a dipole but no ionospheric discontinuity was found 4034 some observations of geomagnetic micropulsations these new observations of diurnal variation direction and frequency spectrum are viewed in comparison with published data and it is suggested that they have a solar time dependence and may occur locally at two stations in longitude apart related signals are only occasionally observed however the phase relationship l of the few which are related together with differences in direction characteristics reported by other observatories are not in agreement with recent theories of the origin of micropulsations 4035 the propagation velocity of world wide sudden commencements f of magnetic storms a model is presented in which a longitudinal hydromagnetic wave generated by impact between a plasma cloud from the sun and the earths field travels east and west round the geomagnetic equator the wave will be stable at altitude and traeel at about 4036 the magnetic storm effects and the interplanetary electromagnetic state alvens theory that a beam of rarefied ionized gas is ejected from the sun can be applied to explain terrestrial cosmic ray observations and magnetic storm effects 4037 visual thresholds for detecting an earth satellite 4038 effect of length of observing time on the visual threshold for detecting a faint satellite may formula for inferring atmospheric density from the motion of artificial earth satellites 4039 effect of the earths equatorial bulge on the lifetime of artificial satellites and its use in determining atmospheric scale heights 4040 calculation of the lifetime of a satellite 4041 explorer over africa records of visual observations made in south f africa 4042 determination of radio propagation elements due to an artificial earth satellite a simple formula is given expressing path length for determining the virtual position of a radiating source 4043 the international geophysical year indian programme 4044 high altitude infrared studies of the atmosphere a balloon flight with a littrow spectrometer gave spectra from ground level to ft water vapour bands had completely disappeared above 4045 calculation of true heights of electron density in the ionosphere by assuming that the electron density distribution can be approximated by taking linear sections of variable length records may be manually converted to true height electron density profiles the method takes into account the earths magnetic field and is similar to that used by jackson results are compared with actual electron density profiles derived from rocket observations 4046 the analysis of rocket experiments in terms of electron density distributions the relative delay o of a pulsed signal as a function of rocket position is used to deduce the electron density distribution to heights of about km the data are analysed for ascent and descent at frequencies of and peaks are shown at and and an intense irregularity on ascent at km good agreement with a simultaneous record is obtained 4047 solar activity and radio communication the monthly median value of the f critical frequency for noon during december was the highest december average value ever recorded at slough this gives a value close to for the demarcation frequency used for planning radio communication in temperate latitudes 4048 correlation of the initial electric field and the radar echo in thunderstorms precipitation as detected with radar is a necessary but not sufficient condition for significant cloud electrification the presence of detectable precipitation does not lead to thunderstorm electrification unless the precipitation echo shows rapid vertical development 4049 the development and masking of charges in thunderstorms 4050 auroral absorption of cosmic radio waves on february a relative absorption of approximately was recorded near troy ny during a spectacular auroral display 4051 the role of f layer tilts in detection of auroral ionization back scatter echoes received at stanford california from the auroral e region are shown to be propagated by way of a tilted f layer the rays returned from the e region scattering source proceed to the f layer without intermediate earth reflection the f layer is so tilted that the rays are then returned to the receiver a tilted mirror model of the f layer demonstrates the effect this explanation is shown to be more probable than that in which the echoes are presumed to be returned from auroral ionization at great heights although this latter explanation may occasionally be true 4052 natural electrical oscillations in the earth air ionosphere cavity excited by lightning discharges the theory underlying the experimentally observed resonance effects is discussed 4053 thermoelements and thermoelectric dc generators detailed theoretical investigation of thermodynamic efficiency taking account of the various thermoelectric effects and changes in resistivity and thermal conductivity higher efficiencies should be obtainable than those indicated by other authors problems of construction and mechanical strength are also considered 4054 low resistance earth electrodes their achievements and accurate measurement the electrical characteristics of various soils and the effects of moisture content temperature and additives as well as electrode shape and spacing are discussed electronic computer research a note on the research program of the national bureau of standards followed by ten short papers with titles as under a high speed multiplier for electronic digital computers processing pictorial information on digital computers low power plug in packages for electronic computer circuitry seac converted to applications research facility a function generator for two independent variables man machine simulation system problem solving on the high speed computer chemical structure searching with automatic computers magnetic amplifiers for digital computers diode amplifier shift register 4055 electronic computers a survey with tabulated data on german equipment references 4056 accuracy control in electronic business data processing systems 4057 digital codes in data processing systems simple digital correlator a description is given of a simple electronic correlator which employs punched tape input and visual digital readout code cathode counting tubes are used in the arithmetic unit several basic design considerations are briefly discussed and an outline is given of the recent application of the correlator to a problem in meteor physics 4058 an improved technique for fast multiplication on serial digital computers 4059 half adders drive simultaneous computer a combination of transistorized half and full adders emitter followers output amplifiers and multiplier gates provides simultaneous binary addition of digital inputs 4060 relay scanning design technique generates high accuracy and speed in analogue to digital transducer measurements the converter is designed to handle three decades of binary decimal pulses each decimal unit is equivalent to input the converter scans an internal voltage until it becomes equal to the unamplified input voltage and supplies a serial pulse output 4061 the design of function generators using short time memory devices and nonlinear elements the various types of function generator discussed have easily controllable output waveforms which can be made to approximate to any desired shape with a high degree of accuracy 4062 an electronic differential analyser equations are derived to show the effect of errors due to co circuit elements and some experimentally obtained solutions are compared with calculated values 4063 on the application of an electronic differential analyser for finding the roots of a polynomial a transfer function is used with the polynomial as numerator and another suitable function as denominator the roots are given by the zeros of the system 4064 digital field computers to eliminate the speed limitation of conventional digital techniques for field computations a nonuniversal unitary system is proposed based on the analogy between electron flow through a resistance network and the flow of pulses through a network of computer units an integral number n is represented by n pulses and a basic unit generates a train of synchronized pulses from two input pulse trains of n and n pulses the interconnection of a lattice of basic units gives a finite difference representation of the general field equation 4065 an automatic graph plotter the adaptation of an analogue plotting table for accepting input data in digital form is described 4066 the application of digital computers to nuclear reactor design the main computational problems are reviewed together with examples of the treatment of neutron transport problems an assessment is made of the performance requirements of future computers 4067 use of laguerre filters for realization of time functions and delay 4068 analogue multiplier and function generator with cathode ray tube a capacitive pick up device is mounted outside the cr tube in front of the screen it is easily replaced so that the same tube can be used as multiplier or for generating different types of functions 4069 an electronic computer for statistical analysis of radio propagation data 4070 printed circuits review of materials and manufacturing processes 4071 coils for magnetic fields a comparison between wire wound foil wound and coaxial cable wound solenoids considering the limitations of temperature rise and weight equations relating field power and internal temperature difference are obtained from which the performance of any coil can be calculated the relative advantages of al or cu windings are considered 4072 a note on the self resonance of ceramic capacitors details of changes in self resonant frequency with capacitor type length of connecting leads and method of mounting are given practical applications of the self resonance of these components in vhf circuits are suggested 4073 certain applications of matrices to circuit theory matrices can be constructed for circuits so that their eigenvalues and vectors relate to the circuit parameters propagation constants characteristic impedances and symmetrical components in polyphase systems are considered from this point of view 4074 synthesis of series parallel network switching functions from the switching functions of n variables those which correspond to networks are abstracted and called network functions properties of those network functions corresponding to series parallel networks are studied and a method for synthesis is developed 4075 high power radio frequency broad band transformers the design of wide band transformers composed of simple transmission line elements and capable of handling radio frequency power of the order of is discussed examples are given of devices matching ohm coaxial cable to balanced pair transmission lines with a standing wave ratio of less than over the band 4076 complex matching the conditions are investigated for obtaining maximum real power at the input of a complex load matched to a generator with complex internal impedance 4077 analysis and synthesis of delay line periodic filters 4078 pulse distortion by band filters the roots of the homogeneous differential equations for image parameter band pass filters with one to four stages are tabulated the integration constants are determined for the case of a square wave modulated carrier equal to the mid band frequency of the filter 4079 design of unsymmetrical band pass filters 4080 simplifying phase equalizer design a graphical method using bridged t and all pass lattice networks 4081 power amplification bandwidth figure of merit for transducers including transistors a figure of merit based on spot frequency maximum power amplification bandwidth is derived for a transducer which is unilateralized and conjugately matched the result being simplified by assuming a bell shaped frequency response specific formulae are given for valve and transistor circuits see eg of 4082 on the synthesis of three terminal networks composed of two kinds of elements a set of necessary and sufficient conditions and a method of realization of all sets of series parallel lc three terminal network functions from the zeroth to the sixth degree are given 4083 a low noise crystal controlled converter for construction details of a converter providing satisfactory reception of signals of about above noise level 4084 millimicrosecond pulse generator the generator uses a length of high frequency cable which is charged from a known dc potential the cable is then discharged into the load by a magnetically operated mercury switch at pulse repetition frequencies up to for pulses of rise time 4085 calculations for a capacitor with rotating armatures piloting a very low frequency generator 4086 fluctuations in quartz crystal oscillators results of an analysis using symbolic differential equations show that the noise and thermal fluctuations are not determining factors for stability see also of 4087 thermally compensated crystal oscillator frequency stabilization without the use of a temperature controlled oven is obtained by varying the effective shunt load of the crystal a thermistor bead being the temperature sensitive element transistor circuit varies reactance frequency control of a oscillator to within is achieved by means of a variable reactance circuit which produces an effective capacitance change of up to for a change in emitter current from zero to 4088 a neon pulser for the computer laboratory an output of peak positive or negative at pulse repetition frequencies from less than to is obtained 4089 high speed pulse amplitude discriminator a circuit is described for use in fast counting systems it handles pulses of amplitude generating a positive output pulse of constant amplitude whose length is determined by the length of the input pulse dead time is about and peaks apart are separated 4090 optimum noise performance of linear amplifiers a single quantitative measure of amplifier spot noise performance is established which removes difficulties associated with the effect of feedback on the noise figure as it is a function only of the amplifier noise and circuit parameters it determines the lowest noise figure obtainable at high gain with a given amplifier used alone or passively connected to other amplifiers of the same and it provides an index of the absolute quality of noise performance 4091 performance calculations for dc chopper amplifiers switched chopping and demodulating circuits are analysed and methods of calculating the essential parameters are described 4092 dc amplifier expands input voltage range a direct coupled dc amplifier with infinite input voltage range and infinite input impedance is described and details are given of its application in a differential valve voltmeter without input voltage dividers for measurements at mean levels between and 4093 the generation and amplification of millimetre waves a detailed survey of techniques and devices including the maser and the harmodotron references 4094 the design of primary and secondary radar if amplifiers the features of synchronous and stagger tuned circuit arrangements are discussed and design procedures outlined practical considerations such as feedback coil design and heat dissipation and the design of amplifiers having logarithmic characteristics are also covered 4095 direct or ac coupling for deflexion amplifiers a quasi dc coupling system using a vertical deflection amplifier input switch providing dc reference pulses for level clamping is described it is suitable for the range dc and the range of dc shift can be extended indefinitely as far as insulation permits 4096 a direct coupled phase splitter a precision cathode follower and inverter are described having an output resistance of about and a frequency response from dc to beyond and 4097 ringing amplifier a circuit for amplifying pulses by in a radar transponder is described damped oscillations produced by the transient response of a tuned circuit are amplified and the second half cycle selected to trigger the transponder the unit is of small size and has a low power consumption and a fixed internal delay of 4098 bootstrap circuit technique the normal amplifier the cathode follower and the anode follower are shown to comprise a set of four circuits related to one another by simple circuit transformations three methods of excitation are distinguished each circuit may be put into feedback form and the four basic feedback configurations applicable to bootstrap amplifiers are given a number of practical examples are described 4099 magnetic amplifiers the use of magnetic amplifiers at static switching devices is discussed switching action is obtained by biasing to saturated or unsaturated states a binary to quaternary decoder using this principle is described 4100 magnetic amplifier design commencing with the basic information of power supply frequency desired gain and time constant charts are developed to determine the core design with reference to load voltage and current with a specified core additional charts are presented to determine the design of the winding layout 4101 superconducting rectifier and amplifier to avoid heat losses due to heavy current leads in apparatus at liquid helium temperatures a high voltage ac supply is applied to a transformer which is coupled to the load through a coil of superconducting material by applying a magnetic field parallel to the axis of the coil a dc component is produced in the load a current amplification factor of is obtained at using coils of wire drawn from lead tin solder 4102 collector bias the transistor equivalent of cathode bias and some applications a self bias circuit for stabilizing the operating point of a transistor amplifier without unduly decreasing the gain at very low frequencies is discussed expressions for the frequency response stability and input impedance are derived and the application of the circuit to amplifiers oscillators and active filters is considered 4103 diode cuts transistor cut off current drift amplified thermal variations of cut off current in grounded emitter amplifiers can be compensated by compensated by connecting a diode experiencing the same thermal changes and having similar collector base junction saturation current characteristics across the transistor base emitter junction 4104 a stabilized dc differential transistor amplifier design details and performance characteristics of a circuit which is insensitive to temperature changes the method employed eliminates feedback and compensating circuits with their attendant complications and disadvantages 4105 designing multiple feedback loops design considerations applicable to transistors in the common cathode common base or common emitter connections are discussed theorems for determining the gain of any multiple loop circuit and a stability criterion are given 4106 the saturation effect in a system with three energy levels 4107 a three level solid state maser nonmathematical description of three level maser operation including a mechanical analogy some constructional details and operating characteristics of a particular model amplifying at are given 4108 low noise amplifier description of a parametric amplifier using a variable capacitance in the form of a diffused base si diode with an active area in diameter advantages and applications of such amplifiers are discussed 4109 ring modulator reads low level dc dc signals in the range are fed via a logarithmic si diode attenuator to a ring modulator and converted to ac which is amplified and serves as a measure of the dc input 4110 the forty eighth kelvin lecture infrared radiation historical survey with details of applications in the field of infrared spectroscopy 4111 importance of the faraday to elemental constants and electricity standards the ratio em can be determined with high accuracy and without uncertainties due to electrical standards and the acceleration of gravity using the value of the gyromagnetic ratio of the proton determined from precision measurements the cyclotron frequency of the faraday determined electrochemically 4112 anisotropic effects in geometrically isotropic lattices an analysis of the anisotropy produced by an arbitrary ratio of element spacing to wavelength in an artificial lattice dielectric the granularity which is important at high frequencies is considered in detail 4113 the electric properties of a dielectric with a variable number of relaxation centres expressions are derived for permittivity and of dielectric loss tangent it is shown that the number of ions and dipoles which give rise to relaxation polarization increases with temperature leading to an increase of permittivity 4114 plasma approach to metallic conduction normal and superconductive response in metals may be construed as limiting modes of metallic conduction using a theory of plasma interaction 4115 report on the course of the international school of physics of the italian physical society varenna report of the proceedings of the course on solid state physics held at the villa monastero varenna the text is given of lectures and discussions including the following optical properties of solids the transition from the metallic to the nonmetallic state electrons and plasmons transport properties of solids point imperfections in solids dislocations in germanium and silicon properties of semiconductors semiconducting compounds shallow impurity states in semiconductors recombination processes in semiconductors semiconductors with charge carriers of low apparent mass 4116 the theory of the anomalous skin effect in metals information concerning the fermi surface obtained from measurements of surface impedance in the region of the anomalous skin effect does not depend on whether the conduction electrons are considered as a gas or as a degenerate fluid 4117 skin effect with shock waves approximate formulae are given for the skin effect in a cylindrical conductor traversed by a shock wave 4118 the impulse breakdown characteristic of a point plane gap in air the influence of the duration of the impulse wave on the breakdown characteristics for both polarities was investigated for air at a pressure of cm hg and temperature c 4119 the complex formulation of the equations for two dimensional space charge flow the equations satisfied by an electron for congruent space charge flow are solved using a complex variable formulation for a constant magnetic field normal to the flow solutions are also obtained in the presence of magnetic fields and for flow along the level lines of a harmonic function 4120 containment of a fully ionized plasma by radio frequency fields a fully ionized plasma is treated as a compressible loss free dielectric in a rf field it is shown that there are steady forces which may be used to confine a body of dense plasma in a conducting cavity resonant in a suitable mode a particular solution the e cut off mode for which extensive numerical calculations have been made is discussed in some detail and interpreted in terms of possible physical experiments 4121 investigations on the occurrence of high frequency oscillations in an ion source with magnetic guiding field oscillations at about were observed in and and their amplitude and frequency were measured under various conditions the effect is interpreted as an acoustic type of plasma oscillation 4122 oscillations in a plasma with oriented dc magnetic field the angular dependence of the double resonances representing coupling of a low energy plasma and cyclotron oscillations is studied for all orientations of the dc electric and magnetic fields using a nonlinear phenomenological approach conditions favourable for manifestation of these modes are indicated 4123 statistics of the ising ferromagnet the ising model is treated by synthesizing a cluster treatment with the spherical model which is used to determine approximately the molecular field acting on the cluster and the effective interactions between dipoles of the cluster the method is applied to the square net and to the cubic lattice and the critical temperatures are obtained 4124 the use of the kerr effect for studying the magnetization of a reflecting surface if a domain wall moving in an alternating field crosses a small area illuminated with plane polarized light the change in intensity of the reflected light passing through a nearly crossed analyser can be detected by use of a photo multiplier cell and by amplification of the alternating component of its output signal experimental results agree well with theoretical predictions see also 4125 paramagnetic centres as detectors of ultrasonic radiation at microwave frequencies it may be possible to detect microwave phonons generated by an electromechanical or magnetomechanical transducer by observing their effect on the saturation of an electron spin resonance line the quantitative aspects of this are estimated 4126 the equations of electromagnetic induction the association of maxwells electromagnetic equations with einsteins space time equations is considered 4127 stark effect resonant cavity microwave spectrograph the construction and use of a cavity for a k band stark modulated spectrograph are described the cavity is a circular cylinder of variable length operating in the te modes see also of 4128 improvement in millimetre wave detection a modification of the detector used in mm spectroscopy of is described which facilitates the adjustment the cats whisker 4129 the saturation effect in a system with three energy levels mathematical analysis of the effect of a high frequency alternating field with given harmonics on a system with three energy levels expressions are derived for dielectric constant or permeability applicable to maser operation 4130 spin lattice relaxation resonances in solids preliminary experiments suggest the importance of a spin lattice relaxation mechanism in certain cases possible applications to spin echo storage devices and to masers are outlined 4131 some features of the motion of rapid current carriers in polar crystals investigation of the behaviour of polarons majority current carriers in crystals with increase of energy 4132 gain measurements of large aerials used in interferometer and cross type radio telescopes 4133 radio telescope sees billion light years details are given of the drive control system associated with the jodrell bank radio telescope see also of 4134 the computer and control for the telescope at jodrell bank the analogue computer and the drive and correction systems which it controls are described 4135 further observations of radio emission from the planet jupiter characteristics of radiation at are described in detail the radiation appears to be random noise varying rapidly in intensity and its short term characteristics can be affected markedly by the terrestrial ionosphere three main sources of noise are apparent but none can be identified with visual features the great variability and spectral concentration of the radiation suggests an origin in some form of plasma oscillation in an ionized region having a critical frequency of about see also of 4136 the variation of decimetre wave radiation with solar activity a statistical method is used to segregate the quiet component from the slowly varing component of solar decimetre wave radiation in the period for this purpose the radiations at frequencies and have been correlated with sunspot numbers sunspot areas and faculae the mean lives of the various radiations and activities have been estimated and compared there is an increase of life with decreasing radio frequency the life of radiation is about the same as sunspots but measurements of the latter show some anomalies the slowly varying radiation flux is proportional to frequency in the range studied the quiet sun flux has a small but significant variation with solar activity the relative change being greater for smaller frequencies the possibility that this variation may be associated with uncorrelated local sources such as prominences is not entirely excluded 4137 changes in amplitude of the day variation in cosmic ray intensity during the solar cycle of activity the amplitude variation is in general agreement with the changes in solar activity assessed by the sunspot number only for the years and the poor correlation for the years may be explained by the changes in the electromagnetic conditions in interplanetary space during the solar cycle 4138 on the increase in cosmic ray intensity and the electromagnetic state in interplanetary space during the solar flare of feb a detailed analysis of the onset times of the increase in intensity is used in the study of the electromagnetic state the existence of deflecting magnetic fields between the sun and the earth is demonstrated a probable mechanism is discussed whereby flare low energy cosmic ray particles could be trapped and guided by a solar beam which could also have caused the large magnetic storm observed two days after the flare 4139 geomagnetic latitude effect of the cosmic ray nucleon and meson components at sea level from japan to the antarctic preliminary report on results of measurements made on board the ice breaker soya from november to april the effects of a cosmic ray storm in the antarctic are described 4140 a theoretical rate amplitude relation in meteoric forward scattering 4141 observations of angle of arrival of meteor echoes in vhf forward scatter propagation 4142 the fading of long duration meteor bursts in forward scatter propagation 4143 the phoenicid meteor shower from radio observations at adelaide six hours before peak activity the radiant coordinates are estimated to be the radio rate of measured on high sensitivity equipment is much lower than that expected from visual rates of to reported to later see also of 4144 sunspot and magnetic activity unusual features of sunspot and magnetic activity in the years and their effects on the performance and frequency usage of some hf radio teletype circuits are examined 4145 the swedish radio scientific solar eclipse expedition to italy preliminary report on observations of the solar eclipse of february 4146 nonuniformity in the brightness of the suns disk during the eclipse of june the brightness distributions derived from british and norwegian ionospheric measurements are presented so as to show their underlying similarity quantitative data for the most probable distribution are given and a comparison is made with radio noise measurements at during the eclipse 4147 a survey of ground conductivity and dielectric constant in norway within the frequency range of and measurements were made using the wave tilt method and a ground conductivity map of southern norway has been prepared 4148 on the theory of magnetic storms and aurorae it is shown that the nonmagnetic beam of ionized gas assumed in the chapman ferraro theory is inconsistent with cosmic ray observations and that the main phase of the storm cannot be explained in terms of a nonmagnetic beam the arguments of chapman and cowling against the electric field theory are discussed and shown to be invalid 4149 statistical investigation of magnetic crochets at tamanrasset 4150 sub audible geomagnetic fluctuations the observations of duffus and shand have been extended to cover the frequency range of records obtained at a portable subsidiary station about miles from the main station near victoria bc in the same mame magnetic latitude showed no phase shift of the normal daytime oscillations 4151 large amplitude hydromagnetic waves above the ionosphere the hydromagnetic wave velocity is calculated as a function of altitude there are two regions where the wave velocity changes very rapidly with altitude and it is concluded that hydromagnetic waves above the ionosphere have an amplitude greater than the geomagnetic fluctuations they produce at the surface of the earth see also of october 4152 method of magnetic storm forecasting from the activities of flares accompanied by solar radio noise outbursts a statistical study indicates that solar flares accompanied by radio noise bursts have a close correlation with terrestrial magnetic storms see also of february 4153 on the magnetic clouds responsible for variations of cosmic ray and geomagnetic field discussion of the mechanism suggested by morrison by which large ionized gas clouds carrying tangled magnetic fields are emitted from the sun and modulate the galactic cosmic rays reaching the earth it is shown to be more probable that smaller magnetic clouds are intermittently ejected from the sun and slowed down by the interplanetary gas the velocity of accompanying unmagnetized streams is unaffected and the different velocities account for the observed initial and main phases of terrestrial magnetic storms the model also explains some solar cosmic ray phenomena 4154 radio studies during the international geophysical year studies are discussed under five headings vertical soundings ionospheric drift measurements backscatter radio noise and atmospheric studies and rockets and satellites the history program and organization of the igy are briefly outlined 4155 theoretical analysis of doppler radio signals from earth satellites the analysis is briefly described and its application to the calculation of the orbits of two satellites sputnik and explorer from isolated observations made at one station is given 4156 observations of the us satellites explorers and by cw reflection the passage of satellites explorer and may be detected by the increased signal strength of as a result of ionization from the satellite paths see also of 4157 continuous phase difference measurements of earth satellites two similar receivers are used operated from a common local oscillator the phase meter compares the af tones from the two receivers see also of 4158 on the interpretation of the doppler effect from senders in an artificial satellite the doppler effect is simply related to the angle of incidence of the transmitted signal if the geomagnetic field is ignored otherwise the relationship is complex and an investigation of the actual ray paths is necessary even for the deduction of approximate numerical values 4159 the effect of the ionosphere on the doppler shift of radio signals from an artificial satellite application of snells law to a ray passing through a spherically stratified ionosphere to a receiver on the ground leads to a relation between doppler shift and angle of incidence at the ground 4160 high atmosphere densities models of the upper atmosphere are modified to allow for diffusion and other factors in order to conform to the results obtained from satellite observations 4161 distortion of the magnetic field in the outer atmosphere due to the rotation of the earth assuming a cavity surrounding the earth caused by the earths revolution the equations of the fields imply a westward shift of the dip equator in the outer atmosphere in agreement with cosmic ray evidence 4162 anomalies in ionosonde records due to travelling ionospheric disturbances anomalies in ionosonde records of the f region during the passage of travelling disturbances are classified into four main types the diurnal and seasonal variation of their occurrence is discussed and it is suggested that the ion distribution at a height of governs the type of anomaly observed see also of 4163 travelling ionospheric disturbances in the f region data obtained from april to march on the horizontal movements of the disturbances are analysed for a single radio frequency the monthly means of direction show a seasonal change from in winter to in summer with a small change in mean speed from to km min respectively 4164 measurement of the ionospheric faraday effect by radio waves reflected from the moon continuous waves at were transmitted from belmar and received at urbana after reflection from the moon from to the change in total electron content deduced from measurements made during the night of january was about times the change computed for a parabolic layer from vertical incidence recordings at the transmitter site 4165 the effect of certain solar radiations on the lower ionosphere an electron density distribution in the d and e regions of the ionosphere is computed lyman alpha lyman beta the lyman continuum and x radiations are considered the resulting electron distribution is used to compute parameters which may then be compared with data from rocket and longwave radio experiments in general there is good agreement between experimental results and the values predicted by the model 4166 on the ionospheric current system of the geomagnetic solar flare effect the analysis of magnetograms obtained at niemegk near berlin between and shows that the sfe current system is independent of the system and situated at a lower level contributions to the geomagnetic sfe apparently come from both the d and e regions see also of taubenheim 4167 the interpretation of changes in the e and f layers during solar eclipses results obtained during a series of eclipses support an interpretation of ionospheric changes in terms of the response of a chapman layer to the obscuration of a solar disk where localized sources of ionizing radiation are superposed on a uniformly bright background an alternative hypothesis of a uniform disk and a complex layer with two different species of ion does not adequately explain observed characteristics experimental results indicate that errors due to layer tilts are probably not important see also above 4168 method of measuring ionospheric winds by fading at spaced receivers current statistical methods of measurement are critically reviewed and compared as a result a method is suggested that may be less laborious than the autocorrelation methods but of comparable accuracy see eg of 4169 on the bearing of ionospheric radio waves systematic measurements of bearings obtained by means of special df equipment of february et al are analysed and fluctuations are interpreted with regard to propagation modes and distance when the great circle muf exceeds the signal frequency the mean bearing coincides with the direction of the transmitter aerial but deviates considerably when the great circle muf falls below the signal frequency the changes are attributed to a major deviation from the great circle path combined with a final scatter hop from continental land masses deviation of anti podal signal bearings are explained assuming that the signals follow paths of low absorption night zones 4170 an automatic recorder for measuring ionospheric absorption ionospheric absorption is deduced from the ratio of the amplitudes of singly and doubly reflected vertical incidence pulses the two pulses are separated by adjustable gates and applied to two logarithmic amplifiers followed by a difference circuit operating a chart recorder in the absence of a second reflection a local reference pulse can be used the system being calibrated subsequently 4171 low frequency reflection in the ionosphere the transition from the ionosphere to interplanetary space report of a discussion held by the royal astronomical society in london february including five short talks concerning the solar corona zodiacal light radio echoes from the moon earth satellite observations and af atmospherics 4172 free air turbulence measurements of the altitude distribution between and of layers of turbulence made by means of a gustsonde incorporating a vhf transmitter are analysed 4173 thunderstorm charge separation laboratory experiments show that charge separation may arise from the collision between graupel pellets and ice crystals from friction between ice formations at different temperatures or with different amounts of contamination and from the re solidification of a liquid layer in contact with ice 4174 low latitude reflections from the aurora australis observations of radar reflections for the period march june are reported records of radar visual and geomagnetic observations for one day are compared 4175 velocity of propagation of electromagnetic waves at audio frequencies 4176 physical processes in contact erosion a general survey of erosion effects for relatively low voltages and currents 4177 transistor voltage and current stabilizers details are given of a current generator and a voltage generator using transistors and a zener diode coupled together the circuits provide a stabilized current supply of up to 4178 electrical protection for transistorized equipment semiconductor diodes are used to limit excessive voltages accidentally placed on telephone circuits 4179 new batteries for the space age a survey of short life electrochemical batteries developed for extreme reliability at high discharge rates under stringent operating conditions the main characteristics of recent types are given in tabulated form 4180 short cut multiplication and division in automatic binary digital computers a modified short cut process is proposed and the application of such procedures to restoring or non restoring division techniques is discussed 4181 a full binary adder employing two negative resistance diodes this adder provides outputs which are virtually in coincidence with the input signal a full adder is described using positive gap diodes of the type described by reeves and cooke of which operate with pulses 4182 tradic the first phase a general report is given of the equipment which was designed and built to test the feasibility of airborne digital compters using transistors 4183 an analogue computer study of the transient behaviour and stability characteristics of serial type digital data systems the transient characteristics of sampled data computer systems incorporating a holding circuit are examined with particular emphasis on the transient response to a standard input step function 4184 transistorized analogue digital converter the analogue digital converter described has a power consumption of less than and codes input signals up to at a maximum sampling rate of inputs with errors not exceeding the output is at the rate of digits the volume of the unit is in 4185 a direct reading printed circuit commutator for analogue to digital data conversion the disk type commutator described supplies the digital digital signal required for output equipment operation without the need for supplementary coding or additional translation circuitry to remove ambiguities 4186 function tables in digital control computers stored function tables with appropriate interpolation techniques can be used with advantage in digital control computers where there are limitations on space and computing time eg the control loop of servo systems 4187 a load sharing matrix switch a matrix switch winding pattern has been developed which allows the power from several pulse generators to be combined in a single high power pulse to drive a computer core type storage system this pulse may be directed into one of a group of outputs an example with outputs is given 4188 miniaturization design techniques the construction of an em relay is described as an example 4189 reliable printed wiring without hole pads a plated hole technique is described 4190 an electronic transformer the anode follower circuit is used as a transformer in a cable system where signals are distributed from a master generator to a number of separate displays the load on the source is negligible the voltage transformation is independent of the impedance transformation both being controllable the cable may be matched if necessary and the system bandwidth is inversely proportional to the cable length 4191 large signal behaviour of directly heated thermistors part of a study of thermistor circuits part 4192 temperature compensating networks a generalized analytical design procedure is proposed for the realization of two typical temperature compensating bias networks employing thermistors for class b push pull transistor amplifiers a set of simple relations is derived for evaluating the network component values and restrictions are indicated on the choice of appropriate thermistors 4193 the spherical coil as an inductor shield or antenna the coil is a single layer winding of constant axial pitch on a spherical surface its properties can be expressed by simple formulae and can be used to evaluate the shielding effect of a closed nonmagnetic metal shell resonance effects are studied 4194 applications of nonlinear magnetics it is shown how saturable core reactors may be used in such applications as counters timers voltage and current references frequency multipliers firing circuits for thyratrons and ignitrons pulse shaping circuits for magnetrons rectifying circuits bistable flip flops frequency detectors and square wave oscillators 4195 minimization of components in electronic switching circuits the details are given of a method using boolean functions for designing switching circuits using a minimum number of if diodes or transistors 4196 some comments on minimum triggering signals a theorem on the energy transfer characteristics of a linear network is proved see also of july 4197 the response of a network to a frequency modulated input voltage mathematical treatment illustrating the relative simplicity of the method of operational calculus 4198 an exact theory of n component steady state operators for linear circuits 4199 unstable linear systems and the minimum phase condition the relations between transfer functions for unstable systems and the class of minimum phase transfer functions are examined 4200 the limits of the regions of stability of the normal state in certain ferroresonant circuits the unequal voltage distribution between the two identical resonance circuits referred to in of may is explained by periodic variations in coil inductance 4201 multi gain representation for a single valued nonlinearity with several inputs and the evaluation of their equivalent gains by a cursor method 4202 radio engineering use of the cayley klein model of three dimensional hyperbolic space applications to the solution of network problems are outlined see also 4203 some optimum four terminal networks having given input and output shunt capacitances 4204 optimum network functions for the sampling of signals in noise transfer functions are calculated for networks which maximize the ratio between the average amplitude of n successive samples of the output signal and the rms output noise and a continuous sample of the output 4205 active band pass filter has sharp cut off an adjustable rc af filter having butterworth attenuation characteristics and octave cut off slope is described outputs of rms can be obtained without appreciable harmonic distortion the dynamic range exceeds db 4206 on the discrimination of a synchronized oscillator against interference accompanying the synchronizing signal the response of the oscillator to an interfering signal is investigated when the interference component of the oscillator output is small the response is found to be linear and the discrimination is expressed analytically the experimental results are in good agreement with theory 4207 simplified design of pulse forming networks the network consists of a five section capacitive circuit and a single layer continuously wound tapped solenoid 4208 designing transistor circuits switching dynamics equivalent circuit data for determining overall response time are tabulated for basic transistor switches with an applied input step for the underdriven condition the overdriven case is also considered 4209 transistor pulse generators for time division multiplex point contact transistor circuits to generate pulses in the microsecond range are described together with means of frequency dividing and interlacing pulse trains and their application to time division operation of telephone transmission and switching systems 4210 built up of large signals with elimination of reflections in magnetostrictive storage lines by means of multicoil transducers in german with english summary an ultrasonic storage delay line using transducer coils and a stainless steel wire long has a capacity of decimal places see of january 4211 amplifier delay charts the time delay in various types of amplifier due to the network phase shift can be determined from the series of charts given if the amplifier bandwidth and number of stages are known 4212 relating the nyquist plot to the root locus plot 4213 high efficiency push pull magnetic amplifiers with transistors as switched rectifiers various circuits are considered in which the efficiencies exceed and they are particularly suitable where the available power supply is limited 4214 a simple transistor amplifier for energizing a hall multiplier 4215 nonlinear distortion in transistor amplifiers at low signal levels and low frequencies 4216 transistor video amplifiers the principles of design of iterated video amplifiers using transistors are discussed in terms of a simplified hybrid equivalent circuit the design and performance of an experimental television video distribution amplifier are described 4217 polarization of a molecular beam by an alternating field with variable amplitude and phase 4218 nonlinear effects of the interaction of resonance fields in the molecular generator and amplifier analysis of a molecular oscillator with an auxiliary field based on the polarizability of a quantum system situated in two resonance fields such a system can operate at two frequencies which depend on the amplitude as well as the frequency of the anxiliary field 4219 susceptibility of the three level maser the susceptibility presented to a radiation field of frequency by the paramagnetic material is calculated the effect of the cavity reaction at the frequency is considered the line shape is shown to be drastically altered for large amplitude driving fields 4220 noise in maser amplifiers theory and experiment the theoretical treatment is based on an equivalent microwave circuit the effective input noise temperature of a reflection type beam maser was found experimentally to be which is in agreement with theory an upper limit of for the beam temperature was deduced 4221 quantum analogue of the ferromagnetic microwave amplifier certain resemblances between the modes of operation of the three level maser and the ferromagnetic microwave amplifier are shown to be superficial by constructing a quantum mechanical model of the latter device it is shown that while establishment of a negative temperature for two levels is essential in the three level maser it is inessential in the analogue of the ferromagnetic amplifier which in essence depends only on the time varying part of the density matrix 4222 phase dependence of a ferromagnetic microwave amplifier the phase dependent operation of an amplifier using polycrystalline yttrium garnet is shown experimentally 4223 minimum noise figure of a parametric amplifier with the aid of a circulator the noise figure may be made to approach the minimum value where is the pumping and the output frequency 4224 a low noise nonlinear reactance travelling wave amplifier results obtained with an experimental model for using nonlinear capacitances are given 4225 a rectifier modulator with stable low carrier leak the action of a constant current ring modulator in which the input transformer is replaced by high impedance valve circuits is analysed in detail the theoretical analysis is confirmed experimentally using a carrier frequency stable carrier leak levels more than below the carrier current from each source are possible 4226 pulse modulation transmitted through a linearly modulated transit time device a discussion of basic principles with reference to the serrodyne device and their application to frequency shifting computers pulse duplexing and a multiple reflex pulse amplifier 4227 new physical constants from dimensional analysis three quantities are formulated which represent constants of astronomy and classical mechanics and of submicroscopic physics and which correlate phenomena in electromagnetic quantum and classical physics 4228 the special theory of relativity and the ether datzeffs theory is held to be quite untenable 4229 theoretical problem posed by an extended model of the electron and the proton arguments about the stability and relativistic properties of elementary particles taken as extended sources of em fields are considered 4230 the physical interpretation of mean free path and the integral method an extension of previous theoretical work on electron transport in solids see of january 4231 generalization of the variation principle in theory of electrical conductivity 4232 theory of the anomalous skin effect in normal and superconducting metals the current density in a normal metal in which the electric field varies over a mean free path is derived from a quantum approach in which use is made of the density matrix in the presence of scattering centres but in the absence of the field the method is applied to superconductors 4233 anomalous skin effect in a magnetic field a classical and quantum mechanical derivation of cyclotron resonance in metals is given the quantum derivation yields the same result as the classical calculation except in the limit of low quantum numbers or high magnetic fields 4234 noise and electron temperatures of some cold cathode argon discharges noise temperatures at were compared with the corresponding electron temperatures for the positive columns of some cold cathode discharges in a they were found to be in close agreement the discharges gave reproducible results and are recommended for use as noise standards 4235 the townsend discharge in a coaxial diode with axial magnetic field an approximate theory of the striking characteristics of coaxial cylinders in an axial magnetic field taking into account the effects of elastic collisions of the electrons measurements in the pressure range mm hg are in general agreement with the theory 4236 the fresnel biprism in electron optics influence of the size of the source effect of a periodic voltage applied to the wire of the biprism 4237 contribution to the theory of transition radiation the transition radiation and cherenkov radiation produced when a charged particle moves in succession through two media of different dielectric and magnetic properties are considered the cases in which one medium is a vacuum are discussed in detail 4238 apparatus for producing plasma beams a brief account is given of simple apparatus and experiments conducted with it 4239 effect of electron exchange on the dispersion relation of plasma oscillations the dispersion relation is derived from a canonical transformation slightly different from that of bohm and pines a correction factor is introduced for electron exchange effects but agreement between theory and experiment is not thereby improved 4240 model for the surface potential barrier and the periodic deviations in the schottky effect the model is based on the quantum mechanical calculation by bardeen on the form of the potential at the surface of a sodium like metal and the analysis of sachs and dexter on the quantum limits of the image face theory the periodic deviations are recalculated and results compared with previous theory and experiment 4241 remarks on spin wave theory for the ferromagnetic exchange problem a theory is developed which is essentially equivalent to the bloch bethe van kranendonk formalism see thermodynamic properties below the curie point are fully treated 4242 the production of very homogeneous axially symmetric magnetic fields inhomogeneity in the magnetic field between two pole pieces is due to irregularity in the pole piece and to boundary effects which may be reduced by current shims in the form of compensating coils 4243 electromagnetic energy transfer methods of calculating and measuring the flow of electromagnetic energy are compared and contrasted the differences between the low frequency and high frequency approaches to energy flow problems are discussed and suggestions are made to ease the difficulties in the way of students and teachers faced with these apparently irreconcilable differences 4244 microwave zeeman effect and theory of complex spectra 4245 dispersion the effect is discussed in terms of group and phase velocities and applied to waveguides cables circuits and the ionosphere 4246 the effect of fluctuations on the diffraction patterns of a focusing system general formulae are derived for the average distribution of intensity and the distribution of fluctuations in a diffraction pattern when fluctuations are present in the incident wave limiting cases of large and small fluctuations are considered 4247 transmission characteristics of inclined wire gratings 4248 on resonance in infinite gratings of cylinders 4249 on scattering and reflection of electromagnetic waves by rough surfaces 4250 diffraction of microwaves by tandem slits 4251 induced and spontaneous emission in a coherent field the resonant interaction between a coherently oscillating radiation field and a number of similar atomic systems coupled to the field through their electric dipole moments is analysed quantum mechanically distinction is drawn between coherent and incoherent parts of the energy terms corresponding to induced and spontaneous emission are identified and it is shown that the latter includes both coherent and incoherent components special situations related to masers and to the coherence of spontaneous radiation are discussed 4252 theory of cyclotron resonance treatment of cyclotron resonance in a metal in an inclined magnetic field and in a parallel magnetic field with arbitrary electron reflection 4253 theory of cyclotron resonance in metals an investigation of the influence of field strength and temperature on the surface impedance of a metal in rf and constant magnetic fields parallel to the surface 4254 the skin effect and ferromagnetic resonance mathematical analysis of normal and anomalous skin effect in metals under conditions of ferromagnetic resonance 4255 polarization of a molecular beam by an alternating field with variable amplitude and phase equations are derived and an exact solution is given for the case when the frequency of the applied field is the same as that of the molecular transition approximate solutions are obtained for slow and rapid variations in the amplitude and frequency of the field during the time of transit of the molecular beam through the resonator cavity 4256 measurement of microwave absorption in binary gaseous mixtures 4257 absorption and refraction of some polar gases as a function of pressure at microwave frequencies 4258 optical detection of hyperfine transitions of caesium atoms report of measurements made at frequencies of and to detect hyperfine zeeman transitions in cs 4259 microwave apparatus for the measurement of the refraction dispersion and absorption of gases at relatively high pressure 4260 a microwave spectrometer for the study of free radicals description of apparatus suitable for the study of short lived molecules in the gas phase and operating in the frequency range 4261 micromodulator a device for measuring the intensities of microwave absorption lines by means of a small electromagnet and power supply a free electron resonance is utilized to provide a standard comparison line at any frequency up to 4262 on force free magnetic fields the assumption that the lorentz force vanishes in cosmic magnetic fields which occur in regions of low density is discussed 4263 observations of discrete radio sources at a frequency of an interferometer system with long integration times is used to determine the flux densities of eleven sources relative to cygnus a 4264 the spectra of radio stars by considering all available measurements on the flux density of cassiopeia a it is concluded that its spectrum obeys a simple power law using this law the spectra and special indices of radio stars are derived including cygnus a virgo a and taurus a 4265 on the nature of the cygnus x radio source as derived from observations in the continuum and at the hydrogen line frequency 4266 results of a survey of galactic radiation at the results covering most of the sky north of are presented in the form of a contour map together with a list of reliably observed sources and regions with their features 4267 a new type of pencil beam aerial for radio astronomy 4268 a theoretical study of errors in radio interferometer type measurements attributable to inhomogeneities of the medium 4269 duration and bandwidth of short lived transients in solar noise histograms of single frequency measurements made at and a table of results for a two channel receiver covering the band are given see also of 4270 the variation of ionization along a meteor trail results are described of investigations using two spaced receivers to observe radio echoes from faint meteor trails the mean ionization curve is much shorter than predicted by present theory and the rise to maximum electron density more rapid than expected 4271 radio noise from meteors a note of attempts made in usa to detect meteor noise at frequencies of and no emission from meteors was detected itt is concluded that the efficiency of conversion of the kinetic energy of meteors to radio energy is less than per unit bandwidth 4272 analysis of meteoric body doppler radar records taken during a germinid shower period the prevailing wind speed in the region has been determined using a cw doppler radar and three station pulsed radars operating simultaneously at about and the body doppler frequency and its fluctuations indicate a wind speed of and a turbulence scale of about on the night of december 4273 a cosmic ray increase related to solar activity a large increase in cosmic ray activity measured with telescopes of small solid angle was observed to accompany a sustained increase in the f layer critical frequency during the period september february 4274 temperatures and electron densities in flares as derived from spectroscopic data 4275 type emissions and the origin of cosmic rays associated with chromospheric eruptions 4276 the origin and maintenance of geomagnetism its secular variation and its inversions 4277 orbital behaviour of earth satellites sources of perturbation are considered with particular attention to the effect of the oblateness of the earth for which an analysis is developed n and recent contributions are reviewed 4278 radio doppler measurements on the russian satellites at the national standards laboratory from observations made on the transmission at one station values for the period n and other orbit parameters were deduced using simple methods 4279 sputnik last days in orbit the satellite was tracked by using a cw reflection technique see of june and was found to break up in a complex manner over a period of days possible break up mechanisms are suggested 4280 effect of air drag on the orbit of the russian earth satellite comparison of theory and observations 4281 measurement of cosmic radiation on the sputnik preliminary results obtained by means of two independent recording instruments located in the second artificial earth satellite are shown graphically a min increase in intensity was recorded on november above latitude 4282 radio scintillations of satellite graphical recordings of the signal from satellite are reproduced the scintillations observed are correlated with scintillations of cosmic rf sources recorded during the same period results indicate that the ionospheric irregularities responsible for the scintillations must lie below km corresponding recordings from satellite show significantly less scintillation activity at perigee than on preceding and following days 4283 some effects of the fine structure of the ionosphere on transmission received from the russian earth satellite anomalies in doppler observations of the satellite are discussed it appears practicable to make a detailed study of the lower boundary of the f region by an analysis of doppler frequency discontinuities in conjunction with accurately known orbit parameters 4284 on the results of the electron concentration determinations in the external region of the ionosphere made on the basis of radio signals from the first sputnik brief description of the method of observation of radio signals from the satellite to determine the exact time of its rising and setting calculated values of electron density range from electrons cm at to electrons cm at 4285 rocket measurements of electron concentration in the ionosphere by means of an ultra short wave dispersion interferometer investigations have been carried out since at heights up to using rockets equipped with transmitters operating at and signals were recorded at the ground by two different oscillographic methods results indicate that the true height of f layer reflections is km lower than the effective height recorded by an ionospheric sounder 4286 apparent saturation in f layer at sunspot numbers near there is a departure from the linear relation with f layer critical frequency which is attributed to a combination of high sunspot numbers and local summer daytime conditions 4287 horizontal ionospheric drifts in the f region at equatorial latitudes systematic measurements of drift made at waltair india by the spaced receiver method from february to january are analysed the component is invariably higher than the ns component the prediction of phase reversal of drift at a latitude of is confirmed see also of july and below 4288 similarities in the characteristics of solar radiation at cm and in the far ultraviolet values of the activity index based on e layer data for slough have been correlated for a ten year period with the monthly mean value of solar rf noise flux measured at ottawa the close correlation found and results of an analysis of eclipse data support the conclusion of denisse and kundu of 4289 equatorial spread f and magnetic activity analysis of data for ibadan nigeria for the years and shows that the incidence of spread f on international quiet days is higher than that on international disturbed days 4290 diurnal variation of deviative absorption in the f region of the ionosphere note of absorption measurements near the critical frequency daytime reduction of deviative absorption is ascribed to thermal expansion of the f layer 4291 anomalous variation of total absorption of radio waves reflected from the f region of the ionosphere around midday observations made at banaras using frequencies higher than f layer critical frequency show two maxima one before and the other after local noon the first maximum has been attributed to thermal expansion of the f region the effect of which is normally observed before midday the second coincides with the usual maximum of total absorption observed at lower frequencies after midday 4292 investigation of horizontal drifts in the e region of the ionosphere in relation to random fading of radio waves measurements of e region wind velocities v and frequency of fading n were made at and the linear relation which is in agreement with theory is deduced 4293 ball lightning and thermonuclear reactions it is suggested that ball lightning is formed by radiocarbon due to the action on atmospheric nitrogen of thermal neutrons liberated by lightning discharges see also of 4294 height distribution of the red auroral line in polar aurorae luminosity curves along vertical cross sections of auroral forms recorded by means of a photoelectric photometer are analysed 4295 some observations of aurora using a low power frequency modulated radar an experimental cw radar is described which provides information on range and radial motion of auroral echoes a histogram of the range distribution of echoes from reflecting areas north of ottawa shows a maximum at 4296 polarization of atmospherics comment on of august and authors reply 4297 whistlers in the antarctic observations made from at scott base showed considerable activity including bonks tweeks long and short whistlers and periods of strong sferics but no dawn chorus it is probable that the whistlers are propagated from lower latitude regions first along the appropriate magnetic flux line and then by ionospheric reflection 4298 automatic recorder of the waveforms of atmospherics description with circuit diagrams of component units of film type recording equipment in operation since and of similar design to that described earlier of 4299 the exploration of space by radio a detailed review of different branches of the subject 4300 transistors reduce relay servo size 4301 new type constant voltage rectifier a constant voltage supply for use as a floating battery power source is described its output rating is at 4302 a high speed rotary switch and some applications the general requirements of high speed switches are discussed with particular reference to applications in information sampling systems details and applications of a rotary switch permitting rotational speeds of up to rev min are described 4303 the principle of stabilization of constant impedance devices n and its application to a transistor power supply the useful operating range of a shunt type voltage regulator is expressed in terms of a utilization coefficient general relations derived are applied to a two transistor circuit of the type described earlier of november particularly suitable for stabilization of valve heater supplies 4304 computing bit by bit or digital computers made easy an introduction to the subject with explanations of the specialized terminology 4305 can machines think a general survey of the capabilities and limitations of digital computers 4306 computers and automata recent developments in the field of automata and non numerical computers are reviewed some typical machines including games playing machines are described a comparison is made between the operation of computers and of the brain 4307 fundamentals of digital computer programming the process of programming is explained in relation to a typical but simplified stored programme computer using basic instructions elementary arithmetical and logical computation are illustrated the ability of the computer to modify its own programme is demonstrated 4308 influence of programming techniques on the design of computers new techniques r are discussed which take advantage of the high speed checked operation of the computer to perform the routine work of programming 4309 analogue digital computers a comparison the operation of analogue computers is described the problem of simulation in real time is used as a basis for comparing analogue and digital computers in respect of speed accuracy convenience the mathematical operations discussed include addition subtraction multiplication division evaluation of polynomials and other functions extraction of square roots and solution of differential equations 4310 the system design of the ibm type computer and attention is directed specially to the new features of this machine which include improved arithmetic and logical facilities and the control of the extensive input and output arrangements directly from the stored programme bit instructions cover distinct operations 4311 engineering description of the ibm type computer a detailed description is given of this high speed computer for large scale scientific work a complete installation includes analytical control unit es storage unit magnetic tape and magnetic drum readers and recorders punched card reader alphabetic printer punched card recorder power distribution unit and power supply unit a note on maintenance is included see also above 4312 the arithmetic element of the ibm type computer a storage circuit giving a delay is described its output is at either or used in conjunction with direct coupled diode switching this arrangement leads to simplifications in shifting registers and in performing division and testing for zero in the accumulator 4313 the swac national bureau of standards western automatic computer design features and operating experience this high speed computer uses a williams tube main storage system an auxiliary magnetic drum storage system and punched card input and output systems and a review is presented of problems solved by the computer during the preceding year for a less detailed account see and 4314 the design and construction of a high speed electronic differential analyzer 4315 improvement of an iteration process suitable for automatic division electronics computers having n organ rf division are provided with a subroutine for the computation of reciprocals an improvement of this subroutine is proposed which permits a reduction of about in the number of operations without affecting the accuracy 4316 use of a computing machine as a mechanical dictionary the time required to locate a stored word is reduced by applying binary division principles in the searching process 4317 industrial uses of special purpose computers an account is presented of the analysis of a simple machine control problem and the design of a suitable special purpose computer to perform the task economic factors are also briefly considered 4318 an method for synthesizing sequential circuits an theory is developed from design procedures suggested by huffman and moore enabling intricate relay systems to be built up from an initial dias by successive application of simplifying reductions a unique circuit is finally obtained 4319 a nonlinear resistance capacitance circuit an amplifier in a negative feedback loop is used to provide the nonlinear resistance in an analogue equipment representing air pressure variations 4320 a photoelectric analogue computer for investigating the dynamic behaviour of linear systems apparatus is described for determining the output function of a linear system such as an amplifier or servomechanism when the input and transfer functions are known the two known functions are represented by appropriately shaped apertures in diaphragms interposed between light source and photocell the mechanical system used to produce the required continuous variation of the input function is described in detail 4321 high density tape recording for digital computers 4322 standardization of electronic components a survey with particular reference to the activities of the international electrotechnical commission 4323 the impedance of chokes resistors and capacitors at high frequency analysis indicates that in order to represent the impedance variation of cylindrical inductors resistors and capacitors at frequencies above the first resonance point equivalent circuits are needed combining a ladder network with simple parallel or series networks nonuniform field distribution along the component can then be taken into account the validity of the theory is confirmed by reference to measurement results shown graphically the effect of an earthing lead on a lead through capacitor is demonstrated 4324 contact noise composition resistors is considered as consisting of a number of parallel circuits each containing an equal number of particles and the same number of contacts of equal resistance it is shown that the noise energys of such a homogeneous system is equal to that of a single contact and that for a given gradient of the applied direct voltage it is determined by the degree of dispersion and the specific resistance of the conductor material expressions are also derived for heterogeneous systems and imperfect contacts 4325 printed resistors preparation of resistors by injection moulding is described the effect of ink composition and the printing and curing processes on the resistor characteristics are described 4326 magnetic pulse modulators mathematical analyses are given of and charged series type saturable reactors for generating pulses in radar systems automatic core resetting is achieved the production of pulses of duration and the prevention of parasitics in the output are discussed and a circuit is described enabling the thyratron cathode in a charged modulator to be operated at ground potential 4327 a multistable transistor circuit 4328 proof of a theorem on the equivalence of two pole networks with only two types of impedance element 4329 theorem on the reactive energy in an electric dipole in a state of variation analysis is based on differentiation of the operational impedance a simple formula is derived giving the instantaneous difference between the stored magnetic and electric energy 4330 a step by step method for designing waveguides and oscillatory systems 4331 some fundamental properties of networks without mutual inductance elementary methods not involving determinants are used to prove theorems on the voltage and current gains obtainable from a resistance network the results are used to determine properties of general networks without mutual inductance rc networks are investigated by a method simpler than that 4332 synthesis of ladder networks to give butterworth or chebyshev response in the pass band 4333 ladder networks with similar quadripole sections formulae for the section input and output currents and voltages and input impedances are derived directly from kirchhoffs laws using determinants 4334 on node and mesh determinants an extension of the analysis presented by seshu 4335 initial transients in some special passive networks with amplitude and frequency modulation it is shown that for multistage selective circuits there is an optimum coupling for which the output corresponding to unit step input is aperiodic and free from overshoot the performance of two frequency shift circuits is studied and the existence of an optimum ratio of shift to keying frequency is demonstrated a formula is derived for calculating distortion factor for two circuit band pass filters with 4336 new filter theory of periodic structures theory for linear passive quadripoles is developed in terms of characteristic reflection and transmission factors which can be specified by references to the standing wave pattern on lines connected to the input and output the relations between these factors and the usual circuit constants particularly the image function of symmetrical circuits are studied the method is illustrated by examining multisection structures combining quadripoles and loss free lines the uses of these characteristic factors leads to major simplifications in dealing with loss free structures where most of the work can be done graphically 4337 a ten kilowatt low pass filter the filter is designed for use in the aerial feed lines of transmitters working in the frequency range and discriminates by about against any frequencies in the television band which may be present as harmonics in measuring the effectiveness of the filter account must be taken of radiation from sources other than the aerial 4338 a piezoelectric high pass filter a lattice filter is considered whose special feature is the use of transformers in its arms with crystals included in the secondary circuits the main parameters of the filter are determined and formulae are derived for calculating the resonances and antiresonance frequencies of the arms a method is proposed for designing the filter elements and for calculating its basic loss the experimental curve of a filter designed in this manner shows a sharp cut off 4339 a high q rc feedback filter description of the design and construction of a acceptor filter which will maintain a of stable to within over one hour and a of to within over considerable periods the circuit uses a twin t rejector filter in the negative feedback path of an amplifier 4340 a voltage controlled attenuator a three stage voltage controlled germanium diode attenuator is described transmission may be varied over a range exceeding decibels by a control signal push pull operation is discussed and various applications are suggested 4341 an s band variable attenuator for high power working the description is given of a waveguide insertion attenuator in which the loss in r f power is produced by the action of a column of water flowing in a glass tube mounted in the waveguide continuous variation of attenuation being obtained by adjustment of the water column height resonance effects in the water column are exploited by choosing the cross sectional dimensions of the glass such that an optimum attenuation per unit length of tube is obtained experimental results are given for a model covering the range the input being at any setting and over the greater part of the range satisfactory operation has been achieved in an evacuated test system fed by a magnetron delivering peak power at a wavelength of various modifications in design are suggested for use with higher mean powers 4342 the graphs of active networks results obtained previously are used to develop the properties of the graphs of linear networks including valves and transformers 4343 linear and nonlinear effects in reactance and oscillator circuits the analysis presented of the behaviour of a reactance valve in various circuits is based on an expression for the anode current containing terms up to the third degree in trid and anode voltages two nonlinear effects are considered the primary effect of the curvature in the valve characteristic and the secondary effect due to the presence of harmonic components in the applied signal these were also investigated experimentally and the results are presented graphically a circuit for reducing the effect of nonlinearity was also investigated 4344 stability of oscillation in valve generators a comprehensive theory of stabilitys is developed which is applicable to a large class of harmonic oscillators the paper is concerned mainly with the terminal regenerative type of oscillator with grid leak bias but the analysis applies also to circuits with fixed grid bias and to terminal oscillators all known forms of instability appear as special cases of the general theory and some new forms are predicted stability is determined by the nature of the roots of a characteristic equation and stability criteria are obtained in the form of inequalities between the parameters of the amplifier and feedback network a modified form of nyquist locus diagram can also be used when the feedback network is symmetrical with respect to the oscillation frequency the characteristic equation can be factorized to give independent criteria for frequency and amplitude stability hysteresis effects and periodic instability are analysed in detail in addition to the general treatment specific forms of the various parameters which appear in the stability criteria are worked out for a three halves law amplifier with a semi linear or exponential grid current characteristic quantitative experimental confirmation is provided 4345 effect of electrical fluctuations on a valve oscillator the effect of slow normal fluctuations is considered expressions are derived for the one dimensional probability density functions for amplitude and phase an approximate method is shown for calculating the correlation functions for amplitude and phase variations 4346 the frequency response analysis of nonlinear systems if the waveform at the input to the nonlinear elements in the system is approximately sinusoidal the analysis may be carried out on the assumption that all harmonics generated by the nonlinear elements can be ignored analysis of on off control systems on this basis gives results within about of the exact solutions for both transient and steady oscillations 4347 synthesizing crystal stability the output from two crystal oscillators combined to give a beat frequency is squared and triggers a blocking oscillator producing a pulse which is used to quench a tunable oscillator the tunable oscillator locks to harmonics of the signal 4348 an electromechanical stabilizer of the frequency of a klystron in the method proposed a portion of the klystron output is applied to a cavity resonator the natural frequency of which is modulated by a separately excited vibrating diaphragm the output of the resonator is detected amplified and through a phase detector applied to the klystron reflector the theory of the method is discussed and its accuracy is determined a comparison with the resonance frequency of the absorption line of ammonia has shown that the relative frequency error of the method is of the order of 4349 subaudio oscillator tunes to cycles a beat frequency oscillator using carrier frequencies of about provides an output of up to constant within over the frequency range with per hour drift and distortion the need for low frequency amplification is avoided by the use of a high level mixer circuit consisting of two se rectifiers with balancing adjustment to eliminate the d c component 4350 some transmission line devices for use with millimicrosecond pulses a phase inverter impedance transformers and a valve heater isolating transformer are described all comprising coaxial cable sections 4351 generation of harmonics of a given fundamental theory and experimental results are given for a frequency multiplier based on use of a c r tube in which a ribbon beam is deflected across a metal target with an appropriate profile suitable beam forming structures are described 4352 noise in u h f amplifiers general noise effects in u h f amplifiers of any type are considered relations between the noise parameters are established using the method of the transfer of the current generators proposed previously general expressions for the noise factors are derived and the minimum number of noise parameters required to characterize a circuit is deter mined a concept of partial noise parameters is introduced 4353 a negative impedance converter for use as a two terminal amplifier a specified stable negative impedance may be generated by connecting a positive impedance between the output and input of an amplifier possessing a high degree of negative feedback an amplifier suitable for use in transmission line systems is described 4354 etched wiring simplifies magnetic amplifier design 4355 active networks deals with circuits including valves transistors and other devices there a sections on the principles of analogue computers servo systems and wave shaping circuits as well as on general aspects of amplifiers and oscillators 4356 the correction of observational data for instrumental bandwidth the formula relating t readings instrument having t apparatus function to th true values of an observed function is stated a three point interpolation operator can be chosen to simulate the spreading action of a class of functions under certain conditions the interpolation operator has an exact inverse which when applied to gives a function which is a better approximation to the accuracy obtained is discussed effect of the method on the standard errors in the measurement is found 4357 electromechanical analogies a discussion of the physical significance f various analogies and of circuit concepts and terminal representation in mechanics 4358 state of research on photoelectricity a survey is presented of research since references 4359 velocity of light from the molecular constants of carbon monoxide from infrared spectroscopy measurements the value of is deduced for the velocity of light with a standard deviation of a short account of the work is given in 4360 simple color computer gives tristimulus values trichromatic coefficients or the c i e colour specification system are automatically computed on a simple analogue machine 4361 an interesting phenomenon observed on some dielectrics a glass tube either empty or containing a polar liquid or a metal rod rotates continuously when placed in an inhomogeneous electric field of sufficient strength if the electrodes and part of the tube are immersed in carnauba wax or a higher alcohol stearic acid palmitic acid or xylol 4362 field dependent conductivity in nonuniform fields and its relation to electrical breakdown a method is given for calculating the resulting field distribution when the conductivity is a function of the field strength this is applied to a point plane electrode system in an amorphous solid with the assumption that the conductivity at low field strengths is electronic and that the conductivity at high field strengths is described by a relation due to frohlich the results show that for polymethylmethacry late with average fields of the order of the reduction in maximum field strength from that calculated for constant conductivity can be a factor of five or more the magnitude of the reduction depending on the degree of non uniformity of the field various other insulating materials are also discussed 4363 study of gyromagnetic resonance in the penning gauge conditions in the penning gauge are particularly favourable for studying r f radiation resulting from gyromagnetic resonance of electrons both longitudinal oscillations thermal agitation electrons involved resulting in accumulation in the anode planes the presence of plasma has an important effect on the potential distribution introducing a radial electric field the equations of electron motion are established some particular solutions indicate the possibility of a circular path in the anode plane with an angular frequency about half the gyrofrequency with values of magnetic induction between and radiation at decimetre wavelengths was produced measurements of the radiation are described investigation of the complete spectrum emitted indicates that coherent oscillations may occur the results are compared with those of other workers 4364 influence of light on the mechanism of gas discharges results of previous experimental work are reviewed the variation of the discharge current with the intensity and frequency of the incident light and in particular the reversal of this current variation in a certain voltage range are interpreted in terms of space charge effects 4365 the mechanism of high field electron emission from tarnished metal surfaces a theory of field dependent thermal emission is proposed which takes into account the existence of patch fields due to variation in work function over the surface 4366 numerical ray tracing in electron lenses corrections are suggested to liebmanns formulae for tracing paraxial rays a more accurate method is developed applicable also to marginal rays and is compared with methods suggested by other workers the use of the constancy of the wronskian determinant as a criterion of accuracy of paraxial ray tracing is discussed 4367 effect of space charge on the propagation of intense beams of charged particles a review about a third of the references given are to russian work 4368 a method of finding a large class of electrostatic and magnetic fields for which the solutions of the fundamental equation of electron optics may be expressed in terms of known functions exact solutions of equation are of great interest for various types of e s and magnetic fields until recently such solutions were known only for a very limited number of cases grinberg in particular indicated a class of fields for which the trajectories of electrons are expressed in terms of cylindrical functions solutions are now found for a much larger class of fields 4369 velocity distribution of electrons in presence of an alternating electric field and constant magnetic field two cases are considered theoretically the electric field varies sinusoidally and te variation is amplitude modulated case is of interest in the investigation of ionospheric crossmodulation the effect of collisions between electrons is taken into account 4370 resonant cavity measurements of the relative permittivity of a d c discharge measurements at and on low pressure d c discharges in a mixture of hg vapour alone decrease of permittivity with increase of discharge current was noted in all cases in case the cavity q factor exhibited a minimum at a value of discharge current depending on the resonance frequency this is attributed to electron resonance theory of the method is given 4371 general theory of magnetic masses at rest and in movement theory is presented based on the analogy with electric charge 4372 magnetostatics with ferromagnetic materials a variational principle is formulated and proved in the theory of ferromagnetic materials in the field of electric currents a direct method is developed for investigating magnetic fields in the general case of a nonlinear dependence of permeability on magnetic field strength 4373 comments on the nonlinear electrodynamics some solutions of the equations presented earlier are examined 4374 description of the electromagnetic field by means of matrices the properties of matrix tensors are briefly considered and the quantities characterizing an e m field are then expressed in matrix form 4375 note on plasma electron oscillations brief report of the results of experiments on hot cathode discharges in hg vapour or ar at pressures of the order of and discussion of their relation to the work of wild 4376 the perturbation of an electromagnetic field by small deformations of a metal surface a general expression is derived for the perturbation due to the deformation if the deformation is slight this perturbation can be found by the usual method of quadratures the method is applied to the problem of the diffraction of a plane wave at a step the height of wich is small compared with from this the well known formulae of rayleigh for reflections from small and smooth irregularities are easily derived 4377 study of the local electromagnetic field at the junction of three dielectric media analysis is given for the case of three media with a common edge 4378 a diffraction problem analysis is presented for the case of a plane wave incident normally on an infinitely long perfectly conducting strip 4379 scattering of electromagnetic waves from a lossy strip on a conducting plane an examination is made of the error introduced in the analysis of radiation and propagation problems by assuming perfect conductivity in media such as the ground which are in fact imperfectly conducting the result of the approximate calculation is compared with that of an exact calculation involving elliptic wave functions for the approximation to be permissible the surface impedance o the lossy regions should not exceed times the impedance of free space 4380 hydromagnetic waves in ionized gas the equation representing the field in a moving isotropically conducting medium is discussed and expressions are derived for the velocities of the ordinary extraordinary and waves for gas pressures much less than and much greater than the magnetic pressure 4381 new technique for high resolution microwave spectroscopy spectral lines of width substantially less than the doppler width are produced by containing the gas in a pillbox shaped cavity of height about and diameter large compared to 4382 the zeeman effect in ammonia microwave spectra the zeeman effect was investigated experimentally using magnetic fields up to oersted results indicate that the line shows a change from the zeeman effect to the paschen back effect at field strengths near oersted 4383 theory of the nernst effects in ferromagnetic metals on the basis of a two band model with one band nearly empty and the other nearly fully occupied theory for the nernst effect can be derived simply from that for the hall effect 4384 the hall effect and related phenomena a brief review is presented of recent work on the theory of the hall effect in ferromagnetic in strongly paramagnetic and in semiconducting materials practical applications of the effect such as in the power amplifier are also mentioned 4385 reliability of atomic masses in the chromium germanium region discrepancies between atomic mass values obtained from transmission data and those obtained by mass spectrometer methods are discussed the mass spectrometer values for may be in error but those for the other elements from are considered to be accurate 4386 lunar occultation of a radio star and the derivation of an upper limit for the density of the lunar atmosphere brief report of observations made at cambridge england of the passage of the moon cross the large diameter radio source in gemini wavelengths of were used 4387 chord construction for correcting aerial smoothing a graphical method of correcting for aerial smoothing in radio astronomy simpler and no less accurate than methods described previously 4388 the influence of noise on radar meteor observations an experimental investigation has been made of the minimum detectable echo power from meteor trails using radar equipment with incoherent detection for optimum signal noise ratio the pulse width must exceed the width of the tube spot extraterrestrial noise is predominant receiver noise figure being of second order importance variations in the effective aerial temperature introduce corresponding variations in the observed meter rate using artificial echoes a minimum signal noise ratio of is found to be necessary for detection the most important parameter is the total received signal energy it is not likely that meteors of smaller size can be made observable by improving receivers 4389 diffusion coefficients from the rate of decay of meteor trails an estimate of the diffusion coefficient in the meteor zone is obtained by an extension of huxleys theory of ambipolar diffusion the absolute value of the diffusion coefficient thus calculated and its gradient with height are confirmed by comparison with results of measurements made at adelaide using radar technique at a wavelength of the theory appears adequate to account for the observed variation or diffusion coefficient with height 4390 the identification of sunspots by means of chromospheric faculae 4391 influence of temperature and humidity on the electrical constants of the ground 4392 comparison of records of the horizontal component of the terrestrial magnetic field at kerguelen and at heard island the records confirm that magnetic activity is particularly strong during the equinoxes the correlation coefficient for the two stations is about ionograms obtained during the strong magnetic variations are characteristic of a highly disturbed ionosphere 4393 nol vector airborne magnetometer type the instrument previously described has been modified so as to be suitable for use in all latitudes and to simplify the reduction of results 4394 a recording magnetic variometer description of an electronic magnetometer designed for continuous measurement of changes in the earths magnetic field at one place variations as small as oersted can be recorded 4395 notes on the distribution of in high latitudes an examination of experimental data shows that the equivalent overhead currents for the preliminary reverse impulse in this type of magnetic storm in the northern hemisphere are represented by current flows across the polar cap from the longitude corresponding to that corresponding to and by the resulting two vortices extending to lower latitudes a clockwise vortex in the afternoon hemisphere and a weaker counter clockwise vortex in the forenoon hemisphere 4396 the effect on geomagnetism of the solar eclipse of an examination of records of magnetic declination from observatories near the path of totalit y shows that a maximum magnetic effect occurs at the time of totality appearing as a diminution of normal daytime departures from the night time value of the declination quantitative agreement with theory is shown 4397 survey of airborne microwave refractometer measurements results of measurements made at various places in the over land and off the east and west coasts are summarized variations of the vertical distribution of refractive index are studied in relation to time and place particular attention is paid to the fine detail of the refractive index structure see also of 4398 amplitude scale and spectrum of refractive index inhomogeneities in the first meters of the atmosphere report of an extensive series of observations made using two refractometers at various levels on a tower the correlation between the refractive index variations and variations of meteorological conditions is studied 4399 seasonal and latitudinal temperature changes in the ozonsphere computations are presented relevant to the elucidation of the temperature structure in the middle atmosphere 4400 hydromagnetic resonance in ionospheric waves the large scale travelling ionospheric disturbances detected by various workers in the layer may be partially explained as an electron resonance effect produced when an initial atmospheric disturbance generates natural modes of electromagnetic oscillation as a result of hydromagnetic coupling 4401 some features of the layer observed at the ionosphere field station haringhata calcutta photographic records are reproduced showing how the ionization originates at layer level moves downwards and forms a sporadic layer 4402 recombination and ion production from the total electron content revised values are given for the figures suggested previously for the mean recombination coefficient and the mean rate of ion production in the layer results of observations at ibadan for magnetically quiet and disturbed days are plotted and discussed 4403 a consideration of the mechanism of electron removal in the layer of the ionosphere possible mechanisms of electron removal are discussed in the light of observations no satisfactory theory of the phenomenon exists 4404 variation of during solar eclipses records obtained by minnis at khartoum in and by stoffregen in the north of sweden in are discussed and compared with observations from various stations in a decrease of during the eclipse is found only at places where the eclipse is total or nearly so the typical eclipse configuration of sun moon earth is thought to be in some way responsible for the associated preliminary increase of 4405 the lunar semidiurnal oscillation in the ionospheric absorption of radio waves vertical incidence absorption measurements made at pennsylvania state university during appear to confirm earlier work by 4406 geomagnetic activity and average deviations of daytime layer critical frequencies in different geomagnetic latitudes analysis of data from six ionospheric sounding stations and one geomagnetic observatory shows a distinct dependence of the average daytime deviations from median valves on the geomagnetic latitude the seasons and the sunspot cycle the effect on the prediction of ionospheric disturbances is discussed and the reliability of predictions is assessed 4407 sporadic movements reports of radio amateurs on reception in n america are consistent with atmospheric movements at height of with speeds averaging about data on winds at heights up to determined by various methods indicate that at all heights the winds are predominantly from the east during summer and from the west during winter 4408 the auroral layer ionization and auroral luminosity an empirical relation is established between the photon emission within the negative nitrogen bands of aurorae in zenith and the maximum electron density in the layer the recombination coefficient in the layer during aurorae is in medium to strong aurorae the mean electron density deduced from critical frequencies is between and electrons echoes observed during aurorae may be explained as back scatter from the ground reflected at low incidence from the auroral layer 4409 the effects of anisometric amplitude patterns in the measurement of ionospheric drifts measurement of ionospheric drift by determination of time shifts between fading curves of ionospherically reflected waves received at three spaced points is discussed and the errors involved in assuming that the amplitude pattern on the ground is statistically isometric ar evaluated from recordings of fading curves on a mean error of in the direction of drift was found the greatest error being the errors are not generally systematic 4410 the shape of irregularities in the upper ionosphere observations of radio stellar scintillations made with three spaced receivers on a frequency of show that irregularities in the amplitude pattern on the ground are regarded statistically elliptically shaped the ratio of major to minor axis being at least the direction of the major axis of the corresponding ellipsoidal ionospheric irregularities appears to be along the lines of force of the earths magnetic field estimates of the drift velocity of ionospheric irregularities based on the assumption that the ionospheric pattern has spherical symmetry are hence subject to error 4411 some waveforms of atmospherics and their use in the location of thunderstorms the main types of atmospherics waveforms recorded in southern england are illustrated and their use in estimating range is discussed in an analysis of recordings made during one year of the waveforms recorded by day and of those by night were suitable for this purpose most night time storms within a distance of produce some waveforms from which range may be determined with an accuracy within by day the corresponding distance is in summer and in winter 4412 the pulse transfer function and its application to sampling servo systems 4413 the frequency response analysis of nonlinear systems 4414 the stability and time response of fast operating closed loop pulsed radar circuits the paper deals with the stability and time responses of a sampling servo system typical of range measuring and overall feedback circuits used in pulsed radar equipments in which the loop response time is not many times greater than the pulse repetition time the case of a high speed radar controlled missile may be such a system conditions under which nyquist plots can be made are given expressions for the output both at and between the sampling times are obtained in terms of the input functions of the system the operation of the system in the presence of noise is considered in the appendix a short list of transformations suitable for analysis is included 4415 the temperature dependence of the capacity of the copper oxide rectifier the variation of the capacitance at the metal semiconductor boundary is calculated on the assumption that it is caused by the temperature variation of the free charge carrier concentration in the semiconductor the calculated results are compared with experimental results for the temperature range from 4416 properties of selenium rectifiers with various impurities se rectifiers were prepared with halogen and halogen compound impurities and their characteristics were investigated the effect of fluorine and fluorine compounds on the conductivity was nil that of alkali halides small and that of bromine pronounced thallium bromide copper bromide tellurium and arsenic have a deleterious effect on the rectifier properties results also show that useful rectifiers can be made using very pure se 4417 semiconducting ignitors for ignitron rectifiers a detailed report on an experimental investigation is presented as a result of which methods are proposed for the design and manufacture of ignitors based on silicon carbide 4418 on the design of rectifiers with electron stabilization the design of a stabilized rectifier should be divided into two stages calculation of the limits of stability of the limiting values of the mains voltage and load current for normal operation of the rectifier and determination of the coefficient of stability suitable methods for dealing with stage are proposed details of the calculation are set out and the case of the regulating valve with a shunt is discussed separately 4419 an attempt to simplify coding for the manchester electronic computer two main simplifications are made both at the cost of increased machine time to ensure that all quantities involved in a calculation are represented to the required degree of accuracy every number occurring is associated with its own scale factor again in using the two levels of storage provided arrangements are made so that instructions are written out as if for a one level store a program in the simplified form is described 4420 a magslip isograph the terms of a polynomial equation to be solved are represented by alternating voltages of varying time phases obtained from magslip transmitters the instrument described is capable of solving sixth degree equations having real coefficients and may be used for the e valuation of polynomials 4421 a flutter computer with low gain amplifiers low gain amplifiers are used thus avoiding drift troubles the principle of the computer is to shift all the poles of the solution to the left in the complex plane being a stable solution of the problem the method is useful in low stiffness problems 4422 basic chassis for experimental work design details are given for a universal unit for use in computers for manufacture in small quantities 4423 an approximate method for obtaining transient response from frequency response a rapid method for finding the transient response of a linear system whose frequency response is known numerically but not as an analytical function involves use of a specially constructed transparent cursor the technique can also be used to deal with the inverse problem or to derive a analytical function representing the behaviour of a system of which either the frequency response or the transient response has been measured 4424 transformer design on insertion loss principles wide band transformer data can be calculated using the normalized values for the circuit elements of high pass and low pass networks derived from insertion loss theory for reactive quadripoles examples of which are tabulated by considering the transformer equivalent circuit as part of a tchebycheff filter network of higher order significant improvements can be made in the transmission characteristic by introducing special low permittivity layers between windings further improvement is possible 4425 perpendicularly superposed magnetic fields digest of a paper to be published in theory is outlined for a cross field reactor comprising a hollow ferrite toroid carrying one annular winding internally and one toroidal winding externally the device can be used as an low level converter or modulator as a variable inductance or as a frequency multiplier of divider 4426 analysis of optimum shape for magnetic amplifiers digest of paper to be published in 4427 composite multistable circuit with natural quinary cycle a circuit composed of binary and ternary stages is used based on design principles described previously details are given of a decade unit embodying the circuit 4428 nbs buaer preferred circuits program report of investigations made by the n b s in conjunction with the u s navy bureau of aeronautics of the feasibility of standardizing the circuits used in electronic equipment a similar account is also given in 4429 topological and dynamical invariant theory of an electrical network 4430 linear transmission of pulses at centimetre wavelengths analysis for the transmission of pulses of arbitrary shape by waveguide and cavity resonator systems is based on use of laplace transforms using theory presented previously a calculation is made of the transfer function for a system of weakly coupled cavity resonators 4431 the maser new type of microwave amplifier frequency standard and spectrometer 4432 influence of the order of overtone on the temperature coefficient of frequency of at type quartz resonators 4433 magnetic fields in small ferrite bodies with applications to microwave cavities containing such bodies an analysis is presented of the field inside small spheres and cylinders of ferrite excited by circularly of linearly polarized magnetic fields in cavities the formulae derived are used to calculate the detuning and change of value of the cavity on introducing the ferrite body or conversely to determine the ferrite permeability tensor from the observed changes in the cavity characteristics 4434 increasing the factor of the cavity resonator by regeneration a brief note on the cavity resonator used in conjunction with the molecular beam oscillator a factor of has been obtained for periods of up to 4435 the graphical determination of the geometrical parameters of loss free linear quadripoles the methods described previously are applied to determine the iterative impedance and iterative transfer constants 4436 application of the wiedemann effect to the magnetostrictive coupling of crossed coils an electromechanical quadripole is described comprising a tubular magnetostrictive ferrite core carrying crossed coils one wound toroidally and the other as an external helix theory is presented in terms of an equivalent circuit the device can be used for filtering gating phase reversing etc successful experiments with ferroxcube cores operating at frequencies between are reported 4437 catalogue of power law and tchebycheff type filter up to order four table give the circuit diagrams and the normalized values of the circuit elements in maximally flat response and tchebycheff type filters terminated and with a short or open circuit at one end for different values of the pass band reflection coefficient corresponding attenuation characteristics are given in diagrams the application of the tables is illustrated in five numerical examples 4438 electrically controlled audio filters design theory based on the work linvill is presented for a low pass and a high pass filter both having cut off frequencies continuously variable between the cut off characteristic may be controlled by the signal for investigating the structure of speech signals experimental results are reported 4439 nd receivers to be operated with a single aerial in the frequency range a coaxial line construction with tuned cavity resonator is used a four coupler system with separation of between channels can provide adjacent channel reduction of with insertion loss of 4440 equivalent equalizer networks the various types of frequency response curves obtainable with practical networks of the derivative equalizer type are analysed and the equivalent constant resistance networks are determined 4441 improvement of stabilized pound oscillator adjustments of the oscillator is facilitated by means of a sawtooth generator with switching arrangements such that it can be interpolated at carious points in the circuit the attainment of the desired oscillator characteristic being indicated on a c r o 4442 junction transistor blocking oscillators circuits have been designed producing pulses with rise time using transistors with cut off frequencies of a few details of the regenerative transformer coupling are discussed triggering requirements and the effects of loading are evaluated experimental results support the theory 4443 stabilization of pulse duration in monostable multivibrators pulse duration stabilization of triggered circuits by feedback is described practical circuits suitable for frequency division and pulse generation in television equipment are illustrated 4444 transistor pulse generators numerical design data are given for four circuits using ge junction transistors and one using a si transistor pulse rise times as low as are attainable at repetition frequencies up to pulse durations are variable from 4445 saturable reactor frequency divider a saturable reactor is used in conjunction with a rc network to provide a circuit capable of producing a pulse output at the frequency or a submultiple of the frequency of a sinusoidal input a circuit providing synchronizing pulses for a radar modulator at half the frequency of the power supply is described 4446 automatic drift compensation in d c amplifiers the circuit discussed is similar to that described by offner it may be used in systems where periodic interruption of the input and noncontinuous compensation are permissible as in analogue computers sampling amplifers etc 4447 optimum tube utilization in cascaded distributed amplifiers analysis is presented taking account of the bandwidth narrowing factor introduced by cascading stages this factor is evaluated for an amplifier using constant r bridged t lines a numerical example is discussed 4448 rejection factor of difference amplifiers analysis shows that the rejection factor of a differential amplifier can be made arbitrarily large without necessitating pre selection of valves or exact equality of the two halves of the circuit the theory is supported by experimental results the parameter termed rejection factor is the same as that termed transmission factor by parnum 4449 magnetic amplifiers as control components the advantages and limitations of magnetic amplifiers for voltage and current control switching and amplifying are compared with those of various other devices important properties are tabulated 4450 a germanium diffused junction photoelectric cell 4451 low level magnetic amplifier a two stage push pull amplifier is described in which a high degree of negative feedbacks is used obtain stability and linearity with high input impedance by careful balancing of components the zero drift measured in terms of input power is reduced to the order of 4452 transistor power amplifiers discussion of conditions for junction transistors handling sinusoidal signals indicates that the maximum possible output is not necessarily limited by the maximum allowable collector dissipation limitations set by the cariation of current gain with emitter current become particularly significant in class b amplifiers because of their very high efficiencies push pull class b operation is preferred to class a of the three possible basic connections the common collector arrangement is preferred as providing the best compromise between gain and distortion and permitting the simplest design of output transformer no great advantage is found by using complementary and transistors applications involving nonsinusoidal signals are discussed briefly 4453 predictable design of transistor amplifiers the transfer characteristic of a multistage low frequency amplifier using junction transistors may be made independent of the transistor characteristics by the use of degenerative current feedback at the same time improving linearity the importance of stable biasing arrangements is emphasized 4454 simplified design procedures for tuned transistor amplifiers 4455 maximum power transfer in transistor amplifiers the theoretical treatment of transistor amplifier performance is simplified by restricting consideration to the condition of maximum power transfer when it is possible to make a rapid assessment of the available power gain for a particular configuration in terms of the transistor parameters curves show the relation between maximum power gain current gain and transistor constants for grounded base and grounded collector arrangements 4456 properties of pore conductors 4457 some considerations regarding the principle of phase invariance it is shown that the conservation laws characterizing the ether can be derived from the principle of phase invariance provided a complex field is used to describe the ether 4458 tamm equations of state of electrons at the surface of a crystal and surface oscillations of lattice atoms a review about half of the references are to russian work 4459 photo effect in metals a critical survey with particular reference to the theoretical development of the subject 4460 electroluminescence excited by short field pulses an extension of a previous investigation is reported pulses of duration were used the luminescence decay rate is highest for the shortest pulses results are consistent with previous conclusions regarding polarization effects a threshold pulse duration of about is estimated to be necessary for the accumulation of polarization charges 4461 dependence of light amplification in phosphors on light intensity differential chromaticity thresholds in the direction of primary blue in a trichromatic synthesis system 4462 dielectric properties of ice at very low frequencies and the influence of a polarizing field measurements at frequencies down to are reported the loss factor passes through a low frequency maximum which is distinguishable from that associated with the dipole dispersion by its different temperature dependence the effect of impurities is to shift the maximum towards higher frequencies application of a unidirectional field does not affect the permittivity of the pure crystals but eliminates the low frequency dispersion when impurities are present the observations are consistent with macdonalds theory 4463 the dielectric constant of an imperfect nonpolar gas 4464 electron phonon interaction in metals the role of electron electron interactions in determining th electron phonon interaction in metals is investigated by extending the bohm pines collective description to take into account the ionic motion 4465 single band motion of conduction electrons in a uniform magnetic field 4466 the general motion of conduction electrons in a uniform magnetic field with application to the diamagnetism of metals 4467 theory of the electrical conductivity of a plasma the calculation presented is based on integration of the boltzmann equation in which the atoms ions and electrons are not treated as rigid perfectly elastic spherical scattering centres 4468 the importance and the origin of modes of description of magnetogalvanic effects 4469 statistical description of assemblies with collective interaction part the various formulations of the carrier kinetics the range of validity of approximations made in analyses by other workers is discussed 4470 pulse controlled cathode sputtering and electron emission 4471 electron liberation by low energy ions at metal surfaces and in gases two experimental methods of investigation are described the disturbing influence of photo ionization was completely eliminated results indicate that in certain cases ionization in the gas by collision f ions may be important 4472 mechanism of uniform field breakdown in hydrogen 4473 growth of current between parallel plates analysis for the initial stages of a discharge involving secondary electron emission is presented in an alternative form to that given previously 4474 reduction of the cathode fall of a normal glow discharge by illumination of the cathode experimental results indicate that the relation between the normal cathode fall the cathode work function and the current density due to illumination is given by where is constant whose magnitude depends on the ionization potential of the gas and i another constant a special based cathode with and adsorbed layers was used 4475 measurement of electric fields as applied to glow discharges a magnetically compensated zero deflection electron beam method is described using automatic recording field strengths between and can be rapidly measured and tube wall potentials can simultaneously be recorded 4476 electron emission from cathode surfaces after glow discharges brief account of experiments made to elucidate exo electron emission phenomena 4477 emission experimental measurement of the average electron current density from tungsten the results of the experiments reported support the theory presented previously 4478 quantum effects in the interaction between free electrons and electromagnetic fields a discussion of the possibility of arranging experiments so that the spread of an electron beam in a transverse field due to the quantum dispersion of the energy exchange can be distinguished from that due to practical experimental factors 4479 two problems in geometrical optics and application of the results in electron trajectory calculations 4480 a semi empirical expression for the first townsend coefficient of molecular gases the formula derived by druyvesteyn and penning is discussed and is modified on the basis of different assumptions regarding the energy dependence of the scattering cross sections of the gas molecules 4481 atomic negative ion photodetachment cross section and affinity measurements the spectral distributions of the and cross sections for photodetachment have been measured the measurements are consistent with the theory of chandrasekhar a curve has been fitted to the results for the threshold of this cross section the affinity of is found to be electron volts no evidence is found for resonance at the threshold or for the existence of excited ions the apparatus is described in detail 4482 dipolar ferromagnetism at 4483 asymptotic expansions of solutions of the equation investigated is important in the theories of wave propagation a direct method is developed for obtaining more general asymptotic expansions than those given previously 4484 strict theory of the diffraction of electromagnetic waves by plane screens analysis is based on the hertz or fitzgerald vector which can be represented by a double fourier integral the fourier amplitudes giving the angular distribution of the far field are derived from a system of simultaneous integral equations which can be solved approximately by developing in certain orthogonal systems an alternative method of solutions is an iteration process based on the kirchhoff approximation the relation with huyghens principle and with the variation problem of diffraction theory is established 4485 diffraction of microwaves by long metal cylinders report of an experimental investigation at about using parallel plate equipment based on that described by and cylindrical obstacles of transverse dimensions comparable with calculated and experimental results for circular cylinders are in good agreement and are used as a basis for studying diffraction by square and rectangular cylinders the method gives reliable information about scattering from obstacles of forms such that no exact theoretical solutions are available 4486 on the scattering cross section of an obstacle the relation between th scattering cross section and the scattered amplitude for an obstacle in an incident plane wave previously discussed by is here established by a calculation of the energy flow when the incident wave emanates from a point source the sum of the scattering and absorption cross sections is determined by the value of a certain field in the neighbourhood of the source the discussion is presented in terms of an wave but is adaptable to sound waves or atomic collisions 4487 possible methods of obtaining active molecules for the molecular generator the use is suggested of an auxiliary field to produce resonance transitions between the energy levels in the molecules such as to increase the fraction of active molecules in the beam 4488 the maser new type of microwave amplifier frequency standard and spectrometer experimental results with the device described previously are compared with predictions from theory particular attention is given to operation with ammonia molecules an amplifier noise figure of unity should be attainable under certain conditions 4489 influence of an inhomogeneity of the high frequency field in nuclear magnetic resonance theoretical results show that to a first order approximation the inhomogeneity has no effect on the signal amplitude provided that the conditions for a maximal signal in a homogeneous field are fulfilled 4490 radio stars and their cosmological significance a survey presented as the lecture 4491 location on jupiter of a source of radio noise earliest records of radiations and of visually observed activity on jupiter are discussed in relation to the observation of a source by this source is probably identifiable with the visibly disturbed region observed by fox 4492 on the great importance of th r f radiation from the planet jupiter continuation of the previous discussion of the observations reported by the cyclic variation of relative position of points on jupiter and on the earth is examined based on considerations of temperature and composition the hypothesis is advanced that the observed radiation is produced by continuous eruption of solid electrified blocks of iron with linear dimensions of the order of such eruptions could be expected in the vicinity of the large red spot on jupiter the relevance of the hypothesis to astronautical problems is briefly indicated 4493 monochromatic radiation of deuterium at a wavelength of from the centre of the galaxy a brief report is presented of observations indicating the presence of deuterium in the interstellar space the concentration is about that of the non ionized hydrogen a block diagram is given of the equipment used in conjunction with a dipole aerial at the focus of a diameter parabolic reflector 4494 note on the electrophysical determination of the velocities of meteors the question is briefly discussed whether the trail is electrically reflecting immediately after passage of the meteor or only after the ionized cylinder has expanded to a certain diameter the answer is decisive for the theory of the origin of the interplanetary material 4495 the giacobinid meteor stream an account is given of the systematic radio echo observations in the years the unexpected return of the meteor shower during the daytime in and the significance of its absence in are discussed 4496 influence of the age of centres on their radiation at centimetre wavelengths continuation of investigation reported previously th flux from an active centre appears to vary directly as its sunspot area for the first days of its life after which it decreases more slowly than the sunspot area the corresponding aging function is shown graphically 4497 brightening of the solar limb in the far ultra violet locations and relative intensities of sources controlling the and layers as provisionally determined from measurements of electron density made at slough and inverness during the solar eclipse of indicate brightening of the solar limb near the equator and darkening of the limb at the poles the intensity distribution over the solar disk is similar to that found by christiansen and warburton for radiation on 4498 electromagnetic induction in a two layer earth the theory developed by is extended to determine the induced field on the surface of a medium whose conductivity is a function of depth the results are applied to evaluate the field induced when an oscillating magnetic dipole is placed on the surface of a flat two layer earth 4499 a measurement of the earths magnetic field by nuclear induction th free precession technique outlined by is used 4500 daytime enhancement of size of sudden commencements and initial phase of magnetic storms at huancayo statistical analysis of data for the period shows that the frequency of occurrence of is independent of the time of day but that the average size of and of initial phases of magnetic storms is greater during daylight hours the size is also found to vary directly with the amplitude of the diurnal variation of both phenomena may be due to electrojets in polars latitudes caused by the sun 4501 magnetic effects during solar eclipses records taken in south africa at the time of the annular eclipse of the sun on show a decrease in intensity of the geomagnetic field horizontal component in accordance with theory but also an increase in the vertical component 4502 observation of an ozone hole over the alps observations are reported which throw light on the relations between vertical air streams in the stratosphere and the vertical distribution of ozone 4503 movements of irregularities in the region summer night observations of fading patterns of transmissions from three broadcasting stations spaced about apart at the vertices of a triangle are consistent with large scale movements in the region from east to west with velocities of rapid fading with a duration of a few hours is considered to be due to scattering by clouds showing turbulent velocities of 4504 world wide daily variations in the height of the maximum electron density of the ionospheric layer a formula relating is applied to determine world wide latitudinal variations of the results so obtained being in good agreement with results published by local observatories in middle and higher latitudes rises in summer daytime and falls in winter daytime near the equator there is a daytime rise throughout the year 4505 a discussion on the variation of region height further evidence is adduced in support of the authors suggestions regarding the distribution of ionization in the region 4506 contribution to the study of the effect of geomagnetism on the layer results of an analysis of observations for and confirm the dip in the value of at the magnetic equator reported by there is also a minimum in the values of the factor and the at the magnetic equator 4507 radio star scintillations and ionosphere the observed intensity at the surface of the earth of radiation at a frequency of from a radio star has been studied a relationship is shown to exist between the fluctuations of scintillations in this observed radiation intensity and the angle of its incidence on the level of the earths ionosphere the occurrence of these scintillations is compared with other ionospheric phenomena as determined by vertical soundings from the earth the probable cause of the fluctuations has been localized to a source in the high ionospheric regions 4508 effect of radiation from solar flares on the ionosphere and the earths magnetic field variation in the earths magnetic field and the corresponding variations in the ionic density of the layer due to solar flares are recorded the value of the intensity of ultraviolet radiation before it enters the atmosphere is obtained the constant relating the ionic density and the accompanying magnetic variation is also estimated 4509 geomagnetic distortion of the region on the magnetic equator 4510 researches on the geomagnetic distortion in the ionosphere observed facts of the geomagnetic distortion in the ionosphere theoretical study on the geomagnetic distortion in the layer characteristics of the layer on the magnetic equator effect of gravity and ionization pressure gradient on the vertical drift in the region world wide observations made during the sunspot minimum period and during the second polar year are analysed and discussed theoretically the anomalous distribution in the region above the magnetic equator may be explained by vertical electron drifts caused by the electric field an ionospheric model consistent with the results of rocket experiments is used the particle density at altitude must be of the order of 4511 studies on the disturbances in layer associated with geomagnetic disturbances earlier work is summarized and discussed 4512 day sky brightness to measurements made with rocket borne stereocameras suggest that the brightness is due entirely to rayleigh scattering by air molecules there is no evidence of high altitude clouds 4513 double doppler radar investigations of aurora the power spectra of auroral echoes of signals on are compared with observations of the visible aurorae and with simultaneous echoes of signals on and using standard high resolution radar equipment a number of auroral models are considered in a discussion of the results 4514 auroral echoes observed north of the auroral zone on at a site north of the accepted auroral zone maximum radar echoes on a frequency of were readily obtained from the north but practically none from the south the range of the reflecting points was from to these results are in agreement with the theory of reflection by aurorae suggested by and developed by requiring near perpendicularity of radio ray paths to the lines of the earths magnetic field on transmitting towards the south across visible aurorae on propagation associated with aurora was almost nonexistent as required by the theory 4515 measurement of the arrival angle of whistlers it is suggested that storeys theory on the origin of whistling atmospherics could be tested by determining their arrival angle by a phase measurement method based on that of using a pair of aerials spaced apart along the direction of the horizontal component of the geomagnetic field 4516 standards on graphical and letter symbols for feedback control systems 4517 low ripple adjustable regulated power supply a unit giving and output of with an output impedance described 4518 transistor converters a transistor in a relaxation oscillator is arranged to interrupt a circuit energy is stored in the transformer inductance during the on period and is delivered to the output circuit at an increased voltage during the off period the circuit thus acting as a step up device design and operation of practical arrangements are discussed a shorter account of the work is given in wireless world 4519 germanium power rectifiers 4520 improving the performance of the series electronic voltage regulator compensating networks for improving the performance of the conventional series electronic voltage regulator circuit are analysed the theory is compared with measurements made on a fully compensated circuit 4521 effects of heater voltage variations of valves in certain stabilizer circuits calculations further to those presented previously show that in series parallel stabilizer circuits having a resistor in the cathode lead of the amplifier the effect of heater voltage variations is not serious because the two valves produce output voltage changes of opposite sign 4522 electronic computing machines and their uses basic design of digital computers is described programming for suitable types of problem is discussed and illustrated by examples 4523 an simple electronic fourier synthesizer an experimental model of a machine for two dimensional fourier synthesis is described which incorporates magnetic drum storage of the required sine and cosine functions 4524 simplified analog computers differential analyser is described based on ten identical operational amplifiers which may b used for integration multiplication etc as required by the particular problem the arrangement is very flexible and may be used with external circuitry for the generation of special functions required in synthesizing particular input analogues 4525 some aspects of the design of a d c amplifier for use with a slow analogue computer the errors introduced as a result of an h t resistance common to several amplifiers is calculated and a criterion for the accuracy of a linear computer stated 4526 transistor amplifiers for use in a digital computer 4527 contribution on the calculation of the total impedance of parallel connected impedances a method of calculation involving use of a special transparent rule and a simple nomogram is described and illustrated by a numerical example 4528 stability criteria for an electrical or mechanical system with distributed parameters for electrical or mechanical systems with distributed parameters or with an element producing a finite time delay to be stable all the roots of the appropriate characteristic equation must be negative or have negative real parts if these equation is expressed in the form then for positive must be positive and must be greater than a certain critical value which is a functions of the example is given of the application of these criteria to a servomechanism 4529 a tapered strip line for pulse transformer service a rolled up construction is described for an exponential line impedance transformer the impedance is at one end of the line and at the other pulse as long as can be handled 4530 the turnover phenomenon in thermistors and in point contacts germanium rectifiers the turnover power in thermistors increases as the square of the absolute ambient temperature the similarity i form between the reverse characteristic of a teristic of a thermistor a thermal hypothesis for rectifier turnover but in the latter case the turnover power decreases approximately linearly with ambient temperature the type of function necessary to reproduce the rectifier characteristics at turnover is discussed such a function cannot be derived from existing theories of rectification 4531 a survey of the application of ferrites to inductor design 4532 influence of ratio on magnetic properties of toroidal cores the optimum design of cores for magnetic amplifiers is discussed a theoretical result is obtained assuming a parallelogram shaped hysteresis loop and an experimental investigation is reported the dependence of the optimum tatio on the magnetic properties of the core material is indicated 4533 electrically variable gas dielectric capacitor a neon tube placed between the plates of an air dielectric capacitor give a variation in dielectric constant proportional to the tube current maximum variation of capacitance is about the device may be used for frequency control of self excited oscillators 4534 a simplified method of solving linear and nonlinear systems the method described uses the transform directly to determine the responses of linear and nonlinear systems approximately the solutions are given as time series representing the values of the response at equally spaced instants both constant and time varying systems are considered 4535 the harmodotron a beam harmonic higher order mode device for producing millimeter and submillimeter waves high power oscillations are generated by exciting a single higher order mode in a cylindrical cavity by means of a bunched beam of electrons 4536 simultaneous approximation for the amplitude and delays time of an ideal low pass filter using the flow analogy analogies between transmission phenomena in networks and current flow in a potential fields are discussed a distortion free low pass filter can be represented by two superposed fields one with parallel flows corresponding to the distortion free aspect and the other with radial flow corresponding to the filter aspect such a representation involves a finite residual error which cannot be eliminated without introducing instability but which can be reduced indefinitely by increasing the delay time 4537 electromechanical filters for carrier and sideband selection torsional type filters comprises cylindrical resonators with coupling necks are discussed descriptions are given of two filters with bandwidths of respectively using a particular alloy known as the temperature variation of frequency is parts per millions magnetostrictive transducers made of this alloy or of ferrite are used spurious modes of vibration are reduced by a balanced arrangement of the transducers and by mechanical damping in the end supports 4538 a push button attenuator for frequencies up to details are given of resistance attenuator providing attenuation up to steps with an interpolation step of each section comprises a network with the shunt arm bridged by capacitance to compensate the inductance of the series arms 4539 cherenkov radiation a brief explanation is given of the mechanism of cerenkov radiation which may find application in oscillators 4540 cathode follower phase shift oscillator analysis indicates that better frequency stability is obtained by connecting the phase shifting network between grid and cathode than by connecting it in the anode circuit calculations are made for three typical circuits 4541 investigations of the characteristics of bi stable multivibrators the characteristics are discussed theoretically with reference to the design of reliable counting and switching units design procedure is illustrated by two numerical examples one of a binary counting unit with counting rate up to at supply voltages between the other for a pulse counting rate at supply voltages between and a modification of the latter circuit using a double triode instead of was used at counting rates up to 4542 the diode pump integrator the designs of a diode circuit for integrating a train of pulses is discussed and conditions are established for linear and nonlinear operation an application to a frequency sensitive relays with quick on off characteristics is described 4543 a logarithmic voltage quantizer details are give of an analogue to digital converter which provides an output pulse whose duration is proportional to the logarithm of the input voltage the output pulse duration being determined by counting the number of fixed frequency pulses occurring in the same interval range of input voltage is with a threshold input pulse length of 4544 analog to digital data converter the required conversion is performed by arranging an oscillator generating pulses at a repetition rate proportional to the analogue voltage to feed a digital counters for a fixed period the oscillator described has a range of four decades stability is better than of maximum pulse frequency 4545 the compensation of wide band amplifiers at high frequencies analysis is given for various coupling arrangements including and special two and four terminal networks 4546 distortion in feedback amplifiers analysis is presented for frequency dependent feedbacks consideration is re stricted to cases where the distortion products are comparatively small and the nonlinear elements can be described by a power series with only a few terms formulae are derived for a number of third order products 4547 analysis of the common base transistor circuit mathematical errors in a are pointed out 4548 transistor circuit for resonance coefficient multiplier use of transistors in multiplier circuits is discussed the input admittance is calculated and the conditions for stabilization against self oscillations are derived design and performance of experimental arrangements are described composite transistors may be used 4549 transistor amplifiers for use in a digital computer pulse regenerative amplifiers for a synchronous binary computer are based on use of external feedback so that a negative resistance transistor characteristic is not required by using semi gated feedback allowance can be made for the slow recovery of ge diodes incorporated in the circuit 4550 schaltungstheorie und messtechnik des dezimeter und zentimeter wellengeb theory and applications of four six and eight pole networks are covered circle diagram representation is used to show transformation properties of four pole networks 4551 the refractive indices of water vapour air oxygen nitrogen and argon at experiments indicate that the refractive indices of water vapour air anden are modified at microwave frequencies in the manner to be expected from dipole theory the values for nitrogen and argon should not vary with frequency and this is confirmed 4552 the dielectric theory of electronic interactions in solids the long range part of the coulomb interaction of the electrons in solids is treated by regarding the solid as a homogeneous dielectric sustained oscillations are shown to be possible in metals and are identified with the plasma oscillations discussed by bohm and pines 4553 the capacity and field of a cylindrical trough with a plane conductor in the axial plane of symmetry 4554 poissons partial difference equation the greens functions and their asymptotic behaviour for poissons partial difference equation in two and three dimensions are discussed and the distribution of potential and current in a regular grid of wires is calculated the method may also be applied to non isotropic grids and can be extended to triangular and hexagonal grids in two dimensions and probably to more complicated patterns in three dimensions 4555 theory of electrical conductivity in metal the fluctuations in the potential in the electron ion plasma of a metal and the electrical resistance due to the scattering of electrons by these fluctuations are calculated 4556 number of states and the magnetic properties of an electron gas a theoretical investigation of the thermodynamic properties of conduction electrons in metals 4557 the infrared faraday effect due to free carriers in a semiconductor 4558 growth of pre breakdown ionization currents in hydrogen experiments are briefly reported the results of which indicate that the mechanism of primary ionization is the same over a range of pressures from a few 4559 theory of langmuir probes a note contrasting results of langmuirs theory with those of the authors precise theory of the spherical probe at low pressures and negative probe potential electric microdischarges in a dynamic vacuum account of an experimental a theoretical investigation of undesired discharges occurring as a result of surface imperfections in vacuum apparatus operated at high voltage experimental electrode systems similar to those in electron microscopes were used the phenomena are distinguishable from field emission and involve repeated secondary emission of electrons and h ions for voltages applied in very short pulses the upper limit before onset of microdischarges is higher than for continuous voltages 4560 some factors influencing field emission and the fowler nordheim law departures from the normal fowler nordheim law which have been observed at fields up to have previously been ascribed to space charge field distortion it is shown that certain other effects due to failure of the image law non uniformity of work function and to passible surface irregularities could produce simular effects 4561 electron emission from metal surfaces after mechanical working a fuller account of work described previously electron multiplication by secondary emission was used to facilitate the the observations 4562 a study of the structure of abraded metal surfaces a report is presented of an experimental investigation of the spontaneous and photoelectric electron emission from abraded surfaces in various atmospheres all the metals investigated responded to radiation in the near ultraviolet which form excess metal oxides responded to wavelengths in the visible range also from the observed rate of decay of emission it is inferred that both thermal and oxidation phenomena are involved previous theories that the emission depends on exothermal processes are considered untenable 4563 theory of thermal conductivity of a plasma the treatment is similar to that used previously for investigating the electrical conductivity of plasma 4564 particle transport electric current and pressurehe problem discussed by tonks is treated without detailed analysis of particle trajectories qualitatively similar results are obtained 4565 a note on the paramagnetic relaxation the theory given explains experimental results obtained by gorter for the dependence of the spin spin relaxation time on the static field strength 4566 electromagnetic theory of moving matter 4567 magnetic field due to circular current analysis is simplified by applying recent work on elliptic integrals 4568 production of millimetre waves by a magnetic undulator measurements hav made on a device of a type described previously and using an electron beam from a pulsed linear accelerator with a meaam intensity of the output power was about intermediate between the values corresponding to complete incoherence and complete coherence of the elementary vibrations the spectrum extended from with a maximum at 4569 transmission of electromagnetic waves through inhomogeneous layers layers are considered in which the dielectric constant is graded from the value unity at each face to a maximum value at the mid plane the variation being either linear or exponential dielectrics are prepared satisfying this specification by forming ordinary homogeneous materials into a series of wedges or the like thus producing a space periodic structure reflection factor measurements made in free space and in waveguides are reported variation of reflection factor with layer thickness is shown graphically for moltopren paraffin and trolitul variation with angle of incidence is shown for trolitul the experimental results are compared with values of the reflection factor calculated from solutions of maxwells equations for the appropriate conditions such structures can give good transmission of microwaves over a wide frequency band 4570 generation of submillimeter waves brief preliminary note describing radiation observed unexpectedly when a bunched high energy beam of electrons was passed through a simple rectangular waveguide 4571 pulse techniques in microwave spectroscopy methods are described for exciting gases to states from which they emit coherent spontaneous radiation in the microwave frequency region the excitation is produced by the application of short pulses of microwave power the power subsequently radiated by the gas is calculated for several cases and experimental methods used to detect the radiation are described the problem of sensitivity is discussed and compared to the sensitivity obtainable i a continuous absorption experiment the operation of a high resolution microwave spectrometer which produces lines substantially narrower than the usual doppler width is described the method used to stabilize the klystron used in these experiments which is a modification of the pound method is given 4572 spin echo serial storage memory methods are discussed for storing information in the form of pulses in a nuclear magnetic resonance system by use of the free induction spin echo technique th storage capacity in liquids is expressed in terms of the thermal noise of the detecting apparatus the self diffusion of the molecules and the relaxation times undesired echoes arising from the interaction of input pulses are eliminated by and magnetic field modulation techniques glycerin and solutions of paramagnetic ions in water provide storage times of with a storage capacity of the order of echoes larger capacities expected from liquids with long relaxation times are not realized owing to self diffusion 4573 the hall effect in metals at high frequencies theory is developed in terms of a surface hall coefficient calculations are made for a metal with two overlapping energy bands and the variations with frequency and with field strength are shown graphically for some special cases at very low frequencies the hall coefficient is constant over a range of higher frequencies it increases as the square root of the frequency and then becomes constant again the frequency variation of the phase angle between current and hall is also investigated 4574 quantum theory of magnetostriction the theory of magnetostriction in hexagonal single crystals is developed on the basis of a polar model by considering the magnetic and magnetoelastic interaction of electrons in the lattice the energy spectrum of the crystal at low temperatures the free energy and the temperature dependence of magnetostriction constants are calculated 4575 some consequences of the influence of elastic deformations on superconductivity magnetostriction analysis of conditions at the transition from the normal conduction to the superconduction state in tin indicates that magnetostriction mainly in the direction of the quaternary axis is to be expected conditions for are more complex 4576 effect of defects on lattice vibrations the theory of the effect of localized defects such as impurities holes and interstitials on the vibrations of crystal lattices is developed 4577 international research in radio astronomy special reports published by the international scientific radio union and entitled respectively discrete sources of extraterrestrial radio noise the distribution of brightness on the solar disk and interstellar hydrogen are noticed 4578 results of observations of discrete emitters of cosmic radio emission on wavelength results are given of a determination of the flux at originating from the omega nebula orion nebula cassiopeia taurus supernova and a source near the galactic centre sagittarius when these values are plotted together with observations at other radio wavelengths and in the case of the crab nebula also at optical wavelengths the results suggest that one mechanism may be responsible for radiation both at optical and radio wavelengths 4579 the day recurrence tendency of cosmic ray intensity the day cycle variations of cosmic ray intensity precede those of magnetic activity by about five days it is tentatively suggested that the same solar disturbances are associated with both phenomena 4580 diurnal variations in the number of shower meteors detected by the forward scattering of radio waves experiment the theory developed is applied to derive the expected diurnal variations of the meteor signal rate for four showers as observed by means of a particular forward scatter transmission path these results are then compared with the experimental signal rates the good agreement obtained indicates that the approximations inherent in the theory are sufficiently accurate for practical purposes the results also indicate that very few meteors if any are observed under conditions which do not satisfy the requirements for specular reflection 4581 the decreasing phase of the last solar cycle as indicated by measurements at the astronomical observatory at rome detailed observations are compared with those obtained at zurich 4582 thermal upward flow in the ionosphere the possibility of atmospheric waves due to heating effects of solar radiation is established vertical thermal flow in the region may give rise to ion drift along the magnetic lines of force this may explain anomalous diurnal variations in the layer by applying the theory to observed ionospheric data for the north american zone estimates are obtained for the velocity of the ions and of the thermal flow 4583 the detection of the current system in ionospheric radio sounding anomalies found in the application of chapmans theory of ionosphere layer formation of theory of ionosphere layer formation to layer phenomena are explicable if it is accepted that the current system modifies the diurnal variation of electron density in the layer most probably by some form of vertical drift mechanism similar phenomena are found in the layer 4584 the night time lower ionosphere as deduced from a theoretical and experimental investigation of coupling phenomena at experimental work over the period is described and the results are compared with theoretical results given by curves show seasonal and diurnal variations of the night time layer in the coupling region region models for the sunset period for are proposed the variation of electron distribution during the night is deduced from a recombination coefficient model suggested by all available experimental data tend to confirm the theoretical analysis 4585 different stations the possibility that the day to day changes in absorption at slough swansea and freiburg are identical is examined statistically after allowing for known sources of error it is considered that the residual differences in summer months are too small to be significant but that it is probable that real differences occur in winter in both cases the minimum probable correlation for the swansea slough comparison is very high 4586 selective annotated bibliography on ionospheric propagation includes some references covering the period 4587 measurements of the mean lifetime of the metastable state of the oxygen atom in the upper atmosphere during auroral displays the mean lifetime of the level is found to vary between and 4588 stability criteria for an electrical or mechanical system with distributed parameters 4589 advances in vibratory power supply techniques a brief review of british commercial vibrators a table of the comparative performance of three typical vibrator units is given 4590 the germanium junction rectifier the junction is produced by alloying a controlled quantity of with a crystal about square and thick with resistivity about the manufacture electrical characteristics and methods of assessing the performance of the rectifier are described applications are grouped into use with resistive load use with battery load and pulse and miscellaneous by virtue of its high efficiency this rectifier can be used for high powers with comparatively simple cooling systems 4591 high temperature area type titanium dioxide rectifiers modifications in the methods of production including the deliberate introduction of impurities have led to improvements over the performance reported previously in respect of maximum operating temperature reverse forward resistance ratio and reproducibility of characteristics satisfactory operation at temperatures above for hundreds of hours is reported 4592 behaviour of as depolarizer 4593 low voltage stabilization a form of secondary cell is described having applications to the cathode biasing of valves it provides a stable voltage of about which is practically independent of the current passed the impedance is and is independent of frequency 4594 the program controlled electronic computer at munich detailed illustrated description of a machine designed for calculations on scientific problems a binary internal system is combined with a decimal external system the word length is binary digit the magnetic drum store rotates at mean access time is and capacity is words teleprinter tape is used for input and output with photoelectric scanning also for the input diodes are used the power consumption is 4595 an accurate electronic multiplier an account of developments of the time division multiplier described by a design giving long term stability and increased speed of operation is described 4596 magnetic core circuits for digital data processing systems circuits for interconnecting toroidal cores used to perform various functions in digital computers are discussed a single diode loop permits unconditional transfer of information from one or more transmitting cores to one or more receiving cores a split winding loop permits conditional transfer and hence logical operations an inhibit loop is also described the operation of shift registers cycle distributors counters etc is explained 4597 a digital potentiometer description of an instrument developed for use with a teleprinter perforator for feeding measured voltage readings into an electronic computer by comparing the input signal voltage with a series of reference voltages the former is represented in integers on a binary or decimal scale tests on a stage instrument described indicate that a reliable stage unit with a reading time under can be constructed with readily available components 4598 the isograph an electronic root finder the instrument described is designed on the principle of harmonic synthesis short circuited and open circuited delay lines fed from a matched frequency sweep generator being use to produce the sine and cosine terms respectively by controlling the amount of frequency sweep any desired interval of the argument can be expanded and the accuracy of measurement thus increased 4599 character recognition for business machines arabic numerals are scanned by a column of photocells whose outputs modulate a pulse generator system to give signals usable in computers characters are read at a maximum rate of operation is not critically dependent on style or size of type 4600 glossary of terms relating to automatic digital computers 4601 formulas for computing capacitance and inductance a collection of explicit formulae in terms of elementary functions legendre polynomials and functions and elliptic functions formulae for mutual inductance and for the forces acting between current carrying coils are also given 4602 new active circuit element using the magneto resistive effect a basic circuit is considered comprising a bridge with resistance arms lying in toil in the bridge diagonal analysis indicate that bistable operation is possible with reasonably short resolving time it may be necessary to operate at low temperature a design is described using layers in gaps of shaped electromagnets tristable operation is possible but not practical 4603 chlorinated diphenyl capacitors a survey of production technique advantages of chlorinated diphenyls over mineral oil as impregnants for paper include higher dielectric strength and higher permittivity applications include use in power factor correction capacitors 4604 generalization of variation and compensation theorems for parameters of an electrical circuit the effect of impedance variations in one or more branches of a network on the current in one of the branches is calculated using matrices 4605 thickness shear and flexural vibrations of rectangular crystal plates analysis is given for the infinite plate the simply supported rectangular plate and the rectangular plate with one pair of parallel edges free and the other pair simply supported for previous work see 4606 the temperature variation of the frequency of at and bt cut quartz resonators measured frequency temperature characteristics can be represented analytically as power series three terms being sufficient to deal with the temperature range the influence of the order of overtone on the temperature coefficient is discussed see also of february 4607 calculation of shunt resistances of rhumbatrontype cavities the calculation is facilitated by deriving the expression for the shunt resistance in a form in which the axial electric field strength is the only independent variable 4608 travelling wave resonator a circuit comprising a directional coupler with the secondary arm ports connected to form a continuous loop is used for storing energy extracted from the primary in a wave which circulates around the loop an x band version used in testing for high power breakdown is briefly described presented at the national electronics conference 4609 an expression for the powers of a matrix and its application to iterated networks 4610 optimum characteristics of linear pulse systems conditions for minimum distortion of pulses in linear systems the analysis is applied to particular filter circuits the results are embodied in three theorems 4611 a general theory of reactive non dissipative l sections elementary theory is developed based on fosters reactance theorem 4612 the design of filters using only rc sections and gain stages a method is described of synthesizing filters using rc sections within a feedback loop design information is given for high and low pass filters of and per octave slope and fixed cut off frequency and others of approximately and per octave slope whose cut off frequency is variable continuously by the adjustment of a single element 4613 the polar guide a constant resistance wave guide filter the filter described comprises a circular waveguide with spaced radial line cavities by means of which a linearly polarized input wave is converted to a circularly polarized wave and subsequently re converted the device can handle high powers a design for a television vestigial sideband filter is described 4614 statistical design and evaluation of filters for the restoration of sampled data 4615 t stub calculation for transmission line filters a method is presented which has advantages over earlier methods in respect of flexibility and ease calculation it is applicable whether the stubs in a filter are true reciprocals or not and also in cases where another element such as an isolating stub is combined with a stub to give a required frequency response 4616 an oscillator for very low frequencies a circuit giving sinusoidal oscillations with periods of or more uses cathode follower connected triodes as phase shift elements 4617 frequency stability of point contact transistor oscillators the duality relation between circuits using the voltage controlled negative impedance base input characteristic and those using the current controlled negative impedance emitter input or collector input characteristic is demonstrated stabilization criteria for both cases are derived analytically and are confirmed experimentally 4618 a frequency stable transistor audio oscillator of very simple design a circuit is described in which a point contact transistor maintains oscillations by supplying current pulses to a series circuit during half cycle periods when the emitter is conducting frequency stability is improved by including a diode in the emitter circuit 4619 high sensitivity and accuracy pulse trigger circuit a pulse height discriminator is described which incorporates a highly stable differential negative resistance provided by a type multi electrode valve by virtue of current division between screen grid and anode this circuit is compared with that of kandiah in which the negative resistance is provided by a cathode coupled pair of valves the discriminator threshold can be set in the range with stability within 4620 subtracting counter using dekatron tubes 4621 active quadripoles with intermediate point earth is earthed generalized analysis is presented using matrices the treatment is suitable for any valve or transistor circuits that can be considered as series parallel or parallel series networks and facilitates the development of some useful new circuits 4622 effect of component tolerances in low frequency selective amplifiers an analysis amplifiers with wien bridge or twin t selective feedback networks are considered when the networks are designed for maximum selectivity the factor of the amplifier relatively sensitive variation network component value this sensitivity can be reduced by suitable choice of component relative values but a higher gain is then required to obtain the same selectivity 4623 amplifier stage with monotonically rising response to a step signal the problem is to combine the monotonic response shortest possible rise time starting from consideration of a simple coupling and analysis based on laplace transforms the coupling circuit giving the required response is found in the form of a network with parallel vertical and series horizontal arms 4624 valve amplifiers for very low frequencies amplifier circuits are briefly reviewed an descriptions are given of a high gain voltage amplifier using two triodes and a low output impedance current amplifier using four triodes in a push pull arrangement 4625 distributed amplifier using tubes with secondary emission description of a two stage amplifier with three type valves in each stage having a gain of a bandwidth of 4626 magnetic amplifier design a practical approach 4627 transistor operating conditions the use of the collector current voltage characteristic curves in the designs of earthed base transistors amplifiers is discussed and numerical examples are given 4628 raising the cut off frequency of transistors results of experiments with and transistors support herzogs calculations of the rise of cut off frequency attainable by connecting a neutralizing inductance in parallel with the capacitance between collector and emitter 4629 high gain transistor amplifier the advantages of transistors over valves as low level high gain amplifiers with low noise properties are discussed and illustrated by a commercial application in a gramophone pre amplifiers in which a single transistor stage takes the place of two or more valve stages 4630 broadband transistor feedback amplifiers negative feedback amplifiers involving three cascaded common emitter junction transistor stage are discussed with large feedback stability conditions can be determined with sufficient accuracy by considering the forward and return paths of the feedback loop separately the maximum feedback possible without instability depends on the frequency characteristic of the transistor current gain this characteristic can be represented with adequate accuracy by a minimum phase approximation amplifiers with overall gain of and negative feedback of are described in which stability is secured by means of phase advancing networks in the return path 4631 a comprehensive work on the analysis and synthesis of linear networks forming one of a series presented by the centre national communications 4632 the general statistical problem in physics and the theory of probability an extended discussion leads to the conclusion that the problems of statistical physics in which the theory of probability does not apply may be more important than those in which it does 4633 quantum theory of fluctuation on the basis of an analysis of method of measurement an operator is constructed for the spectral density of a fluctuating variable the classical dynamic variables are replaced by time dependent operators the theory is used to deduce law for a particular case and to calculate the shot effect for free uncorrelated electrons 4634 a general approach to hysteresis a alternative formulation of the domain model a comparison is made of various methods of formal representation of hysteresis phenomena in terms of a domain model a symmetrical treatment is developed permitting the equations to scanning curves within a hysteresis loop to be written in a simple form 4635 improved value of the velocity of light derived from a band spectrum method a more accurate result than that reported previously has been obtained by using a new interferometric technique the new value is 4636 theory of scattering by an inhomogeneous solid possessing fluctuations in density and anisotropy 4637 memorandum on electrical and magnetic units digest of a paper presented to the society the various units systems in use are examined disadvantages of the and systems are indicated a new system is proposed called the this is based on four fundamental units and retains the practical units such as the volt together with unity values for the dielectric constant and permeability of vacuum 4638 the electron phonon interaction according to the adiabatic approximation 4639 superconductivity at millimeter wave frequencies preliminary results of experiments on at frequencies between and are reported residual resistivity is observed at these frequencies 4640 the electron affinity of hydrogen in a microwave gas discharge experiments show that hydrogen in a microwave gas discharge is a much better electron captor than its calculated capture cross section would indicate giving de ionization times in t r switches comparable with those obtained with water vapour 4641 disappearance of adsorbed gases from dielectric surfaces under electrodeless discharge 4642 studies of externally heated hot cathode arcs the low voltage form of the ball of fire mode discussion in terms of a model based on the observation that the stream of electrons entering the ball plasma from the cathode plasma is scattered so completely that the electrons within the ball have a maxwellian energy distribution theoretical predictions are compared with probe measurements 4643 ionization and desorption due to strong electric fields experimental investigations of the intensity distribution of field type electron emission from single crystal points covered with thin films of other material are reported where surface compounds of with or are present a characteristic change of the emission distribution is observed after application of an opposing field the change is attributed to local ionization an electron being released into the interior of the metal and a positive ion being emitted into the vacuum if the field is strong enough to overcome the image force the field ionization of physically adsorbed molecules or atoms requires relatively strong fields quantitative estimates are made of the pull off field strength and its temperature variation 4644 a method for the systematic calculation of an electron optically effective field distribution with specified imaging properties analysis is given for a purely magnetic field 4645 high field electron emission from irregular cathode surfaces the enhancement of the field in front of an emitter due to surface irregularities is studied in detail with reference to mechanisms proposed by and by the enhancement factor varies with distance from the surface and is also field dependent the results afford and explanation of anomalous conduction variations in liquids and gases 4646 space charge effects in electron optical systems a discussion of spherical aberration in beams exhibiting a waist conditions for transition from waist to cross over are examined experimental results support the theory 4647 mean free path for discrete electron energy losses in metallic foils 4648 transmission of electrons of energies below aluminium oxide films of thickness 4649 critical examination of the theory of plasmas based on mean free path in the light of the method based on the distribution function derived by solving boltzmanns equation discussion indicates that the distribution function method is more suitable than the mean free path method for calculating the conductivity of anisotropic plasmas velocity analysis of thermionic emission from single crystal tungsten it is suggested that the departure from a maxwellian distribution observed by hutson is due to the finite resolution of the analyser 4650 spin deviation theory of ferromagnetism 4651 the origin of ferromagnetism in transition metals analysis of experimental evidence indicates that the energy band concept constitutes a more satisfactory basis for the theory of ferro magnetism than the hypothesis that the magnetic carriers are bound to individual atoms the occurrence of fractional number of carriers is explained on the basis of close range interactions between carriers associated with the same atom the absence of ferromagnetism in heavy elements such as a consequence of strong spin orbit coupling 4652 influence of crystalline electric fields on antiferromagnetic transitions 4653 on the ampere force a re examination of the expressions for the force taking account of war burtons comments 4654 source representations for debyes electro magnetic potentials theory of radiation presented is discussed debye potentials can be used for all points even within the source distribution this leads to an alternative methods for the direct determination of multipole expansions 4655 electrodynamics of turbulent ionized media the scattering of power in a turbulent ionized medium is discussed to be applicable for arbitrary values of electron density analysis should take account of multiple scattering suitably modified forms of naviers equations are indicated 4656 subharmonic oscillations in a nonlinear system with positive damping 4657 theory of total reflection the theory of total reflection of an elliptically polarized plane wave is developed from expressions for the energy density and the poynting vector using the notation of the earlier paper results indicate that at total reflection the mean flow of energy in the refracted wave contains a com ponent normal to the plane o incidence this component is zero in non total reflection and in two special cases its magnitude is proportional to the wavelength in the first medium 4658 maximum transmission of electromagnetic waves by a pair of wire gratings an experimental investigation was made of the transmission waves through a pair of parallel wire gratings with various wire and grating spacings for various angles of incidence results are compared with values derived from theory 4659 semi asymptotic series for the diffraction of a plane wave by a cylinder the technique described previously involving watson transform is used to develop series up to where and is the radius of the cylinder 4660 variational formulation of two dimensional diffraction problems with application to diffraction by a slit diffraction particularly of waves is discussed analysis shows that for incident plane wave the complex amplitude of the far zone diffracted field can be expressed in a stationary form of the type indicated by levine schwinger the case of a diffracting slit of infinite length and finite width treated in detail for normal incidence the results agree with those 4661 on integrals occurring in the variational formulation of diffraction problems 4662 the diffraction of electromagnetic waves at a grating consisting of parallel conducting strips a rigorous solution is given for diffraction of a normally incident plane wave the width of the strips being equal to the spaces between them graphs show the reflection and transmission of the wave for various ratios of strip width to wavelength and the amplitudes of the diffraction spectra 4663 diffraction of centimetre waves by a conducting sphere in a waveguide measurements were made at a frequency of using a hybrid arrangement results indicate that reflection coefficient is proportional to sphere volume dispersion of results is attributed to small geometrical irregularities the work is preliminary to a study of the diffraction of waves by clouds 4664 scattering of electromagnetic waves from a random surface the medium below the surface is assumed to be perfectly conducting so that the far zone form of the stratton chu solution can be used the mean and covariance of the approximate expression for the scattered radiation are determined for both vertical and horizontal polarization 4665 interaction of electromagnetic waves of radio frequency in isothermal plasmas collision cross section of helium atoms and ions for electrons theoretical and practical aspects of the laboratory experiments described previously are discussed and results of measurements using he gas are presented the ratio of the effective cross sections of ions and atoms for electron collisions is about at an ion density of at room temperature 4666 nonlinearity of propagation in ferrite media measurements are briefly reported both losses and phase shift varied with temperature at constant power level the results are compared with those of 4667 investigations on artificial dielectrics at micro wave frequencies the transmission of a wave through a parallel plate array was studied experimentally the observed variation of phase change with angle of incidence is in fair agreement with that calculated from the formula given by the difference between them is attributed to diffraction effects and the presence of higher order modes inside the array values are deduced for the minimum dimensions required to avoid diffraction effects 4668 resonance transitions induced by perturbations at two or more different frequencies expressions are derived for the alteration of magnetic resonance frequency due to the presence of a second oscillation at a nonresonance frequency applications of the formulae to nuclear resonance and molecular beam experiments are discussed 4669 improvement in a paramagnetic electron resonance spectrograph application to the study of diphenylpicrylhydra the sensitivity of apparatus operating in the band is greatly increased when the klystron source of nominal power is replaced by one of much higher power 4670 relaxation times in magnetic resonance the effect of motion of the absorption centres on the width of resonance lines is discussed on the basis of a random walk model and a simple picture is presented of the electron relaxation processes 4671 some devices for the stark modulation milli meter wave spectrograph an overall sensitivity of about in the wave range is attained as a result of appropriate design of stark cell frequency multiplier lock in detector and square wave generator 4672 thermodynamical theory of galvanomagnetic and thermomagnetic phenomena addendum to paper noted previously 4673 the optical investigation of the interdiffusion of metals the technique used involves the preparation of very thin films of known thickness 4674 fundamental formulas of physics a valuable reference book for every physicist 4675 spectroscopy at radio and microwave frequencies 4676 the identification of radio stars an examination is made of the possibility that the fainter radio stars classified by are within our galaxy the observed coincidences in position of radio stars and dwarfs appear to be significant 4677 absorption of radiation in the optical emission nebula this is the first reported case of absorption of radio waves by an emission nebula it leads to an estimated electron temperature of for the nebula 4678 east west asymmetry in the formation of new sunspots analysis of records covering many years indicates that about twice as many centres of activity are observed on the eastern half of the solar disk as on the western half 4679 an new index of solar activity based on ionospheric measurements the monthly mean relative sunspot number is assumed to contain a component constituting a direct index of solar activity together with an error component having a standard deviation of about a new index based on an analysis of the critical frequency of the layer over the period has been constructed whose residual error component is only one tenth that the magnitude of for a given month is computed from the mean noon layer critical frequencies at slough huancayo and watheroo and is based in effect on a calibration of the layer critical frequencies in terms of 4680 accuracy of solar flare observations the division of observed solar flares into more than three classes is not statistically justifiable more uniform and detailed reporting is required 4681 solar filaments and geomagnetic disturbances experiments to test kiepenheuers suggestion identifying the solar regions causing geomagnetic disturbances with dark filaments on the solar disk gave negative results 4682 the influence of the solar eclipse on the propagation of atmospherics in the frequency range a map shows the position of sources of atmospherics in europe at the time of the eclipse records of measurements over a two hour period show a marked eclipse effect on with a delay but little effect on an anomalous increase of field strength on is related to the reduction of the ionosphere earth duct cut off frequency resulting from the eclipse 4683 the stability of a homopolar dynamo the stability of the self exciting disk dynamo is considered taking into account the friction at the axle and the effect of an external electrical load in parallel with the field coils possible analogies between the results obtained and the motion of an electrically conducting fluid in a magnetic field are discussed the theory may be useful in explaining the magnetic field of the earth and of sunspots 4684 a method for the elimination of slow variations in the recording of pulsations of the geomagnetic field 4685 the diurnal variation of irregular geomagnetic fluctuations the diurnal variation o the fluctuations showing a maximum in late evening for middle latitudes is correlated with atmospheric turbulence in the ionosphere which is assumed to be hindered in daytime by electromagnetic damping there is also a pronounced seasonal effect this may be connected with the large scale circulation of the atmosphere 4686 thermal and gravitational excitation of atmospheric oscillations previous work is extended to include a unified treatment for both gravitational and thermal forcing functions from consideration of various atmospheric models it appears that thermal effects are far more important than gravitational ones in producing the solar semi diurnal pressure variation this is not confirmed by observation but the disagreement may be eliminated by assuming the possibility of heating other than by ground eddy currents 4687 nitrogen oxides and the airglow possible chemical and photochemical reactions which would account for the formation of nitrogen oxides in the upper atmosphere are discussed and are shown to provide a possible explanation of the airglow 4688 on the cooling of the upper atmosphere after sunset cooling in the and regions of the ionosphere is investigated theoretically assuming that heat transfer takes place only by conduction at a time after sunset the temperature is unchanged at altitudes below at a height of the maximum drop is there should be an appreciable increase of ion density in the layer but this will be offset except in equatorial regions by downward diffusion 4689 formation of the lower ionosphere the available evidence suggests that ions in the layer are mainly produced by photo ionization of photo ionization of at its first ionization potential should occur in the layer and further data are required to decide whether this layer is caused by such a process or by ionization by soft rays 4690 the measurement of normal layer critical frequencies at night the normal layer critical frequency at night is best determined from absorption frequency curves plotted as results of typical measurements taken with standard absorption measuring equipment are shown from the trend of variation it was possible to identify the associated absorption band on a few of the routine night time curves obtained at slough in spite of the presence of and other irregularities from the variation of with time a recombination coefficient of about was deduced but owing to the low transmitter power measurements of could not be made further work with higher power is needed 4691 night time measurement of positive and negative ion composition to by rocket borne spectrometer during a flight on only positive ions of mass number were detected in the region these are identified as ionospheric records for the same period and region show the existence of clouds 4692 viscosity in the region it is shown that viscosity is of primary importance for disturbances whose scale is smaller than the mean free path and cannot be described by an effective coefficient any initial disturbance on such a small scale will disappear very rapidly assuming normally accepted values for a altitude it follows that patches of ionization causing the twinkling of radio stars cannot be due to turbulence in the neutral gas as suggested by 4693 changes in the absorption of cosmic noise observed during two ionospheric disturbances curves are given showing the observed time variation of total absorption at at the period of ionospheric disturbances on following the suggestions of increased absorption is shown to be correlated with increased and is presumably due to region attenuation deductions are made as to the path and speed of the disturbances 4694 interpretation of ionospheric results during eclipses accounts published by various workers of the solar eclipse of have been analysed using the scale height variation concept introduced by the vertical distribution of terrestrial atmospheric temperature varies with latitude and the recombination coefficient in the layer is 4695 the recombination coefficient in the layer during aurorae in an earlier paper a mechanism involving variations in positive ion concentration was suggested to explain the abnormally high values of recombination coefficient during aurorae an alternative explanation assuming a high value of the negative ion electron ratio is shown to be in accordance with observed data 4696 variable frequency echo sounding of the ionosphere at oblique incidence the development of the technique described by is discussed with particular attention to synchronizing arrangements records obtained over two paths are compared with records of vertical incidence soundings at points on the paths 4697 heights of irregularities giving rise to the fading of waves a calculation is made of the relation between phase and amplitude for a wave propagated through a region of random absorption below the reflection level results agree with those obtained experimentally a method for estimating particle collision frequency in the absorbing region is presented based on that of from which data regarding the region may be deduced 4698 polarization of electromagnetic waves for vertical propagation in the ionosphere 4699 some remarks concerning ionospheric absorption work irregularities in the frequency dependence of observed absorption decrements are attributed to focusing effects due to curvature of the layers involved in the layer these effects occur particularly with third order echoes account should be taken of the effect in the analysis of absorption observations made during conditions of rapid fading 4700 ionospheric wind determination from spaced radio receiver fading records direct analysis of the fading patterns of reflected signals at three spaced receivers can indicate the true ionospheric wind and changes in orientation of the patterns without assuming any particular distribution of orientation a new method of analysis of the fading records is proposed together with an alternative method of observation in which a single fixed receiver is used in conjunction with a second one which is moved in a circle round the first 4701 ionosphere review consideration of the records of sunspot numbers and ionosphere data indicates that solar activity may increase rapidly to reach a maximum in the middle of with the monthly mean daytime reaching for east west transmissions and for southerly paths by 4702 vertical extent of auroral arcs and bands measurements on photographs taken from three stations indicate that quiet arcs and bands are confined to a narrow layer just about the level the thickness of this layer is most often between and and rarely from the ratio of the number of arcs and bands to the total number of observed forms it is inferred that the percentage of auroral time during which the luminosity is restricted to this layer is 4703 the effect of atmospherics on tuned circuits 4704 magnetic amplifier two speed servo system a system is described in which two half wave bridges type magnetic amplifier stages drive a full wave slave type output stage design data are presented for a number of systems 4705 a servo system for digital data transmission the stability of the servo system is affected by the quantized nature of the digital data and by time delays inherent in the transmission and digital systems a method of synthesis is discussed enabling a degree of prediction to be incorporated which ensures that the regenerated data do not lag on the original data under steady state conditions 4706 an electronic supply for use in the calibration of instruments description of a high power oscillator amplifier set with phase shift unit giving an output of at least at unity power factor within the range from each of two amplifiers the output voltage does not vary by more than during the time taken to calibrate point on an instrument scale 4707 transistor power converter capable of watts d c output a unit based on the circuit described previously has been developed giving output from a input experimental performance figures are given 4708 thyratron inverter uses controlled firing time the circuits described permits control of output voltage without saturable reactor with improved regulation efficiency and response speed one thyratron serves as control tube for extinguishing the conducting power tube at any desired phase 4709 electronic computers the main part of this issue is devoted to a series of papers on digital computers with titles as follows programme controlled computers from the punched card computer to the micro program control mechanism the parallel adding mechanism of the printing the results from electronic computers use of the electronic computer for solving complicated mathematical problems technical problems in the development of magnetic drum stores store resonator circuit and data input and output for the bull electronic computer assessment of quality of rectangular ferrites for electronic computers development of resistances for electronic apparatus transistors in computer technique properties required in germanium diodes for electronic computers 4710 the design construction and applications of electronic digital computers a survey of the whole field with a comprehensive bibliography a wide range of actual and projected applications in science and industry is discussed including process control and data analysis 4711 a transistor digital fast multiplier with magnetostrictive storage 4712 an electrostatic pulse generator pulse patterns required in electronic computers are generated by presenting a probe feeding a tuned amplifier to a suitably figured track on an insulated rotating drum carrying a voltage western electronic show and convention los angeles california the full text or an abstract is given of papers on various components equipment and techniques presented at the convention abstracts of all the papers are published in 4713 the resistance of sheets strips wires tubes and coils of various materials at frequencies between a method of calculation applicable to materials with widely different conductivities ranging from is presented the values of the resistance per square are found from sets of curves for material thicknesses of because of skin effect at high frequencies the curves for these thicknesses cover all requirements 4714 concavity of resistance functions it is proved that any network linearlys wound potentiometers fixed resistor has a curve of resistance versus shaft angle which is concave downward 4715 oscillations of coupled windings digest of paper using the mutual inductances functions the integral equation method of determining the natural frequencies is extended to take account of the effect of a transformer secondary winding 4716 the transfluxor 4717 symposium on microwave strip circuits 4718 variation with temperature of quartz resonator characteristics calculations based on the temperature variation of the piezoelectric constants of and quartz resonators indicate that the and resonators are particularly suitable for use in filters at temperatures as high as or over 4719 theory of electromagnetic resonators of almost conical shape a mathematical investigation is carried out of oscillations in a resonator formed by a spheroid and a confocal two sheet hyperboloid for the case of a small ratio between the focal distance and the wave length perturbation theory is modified to take into account the large deviation of the field from that in a resonator formed by a sphere and two coaxial cones 4720 theory of thin aerials in cavity resonators free oscillations in a cavity resonator containing thin metallic aerials or having narrow slot in its walls are considered formulae are derived for the natural frequency and eigenfunctions of such a system and for the decrement and of the resonator the results are used in a discussion of the excitation of a cavity resonator by thin aerials the problem is reduced to the excitation of the resonator by given external electric or magnetic currents several examples are considered in detail the analysis is continued in the following paper both tuned and untuned aerials are considered 4721 a matrix method in the solution of cascaded four terminal networks 4722 the geometrical representation of the parallel and the series reactance as a loss free parabolic quadripole further application of the method described previously 4723 calculations with noise voltages part passage of noise voltages through nonlinear elements the correlation function is used to calculate the modification suffered by a noise spectrum on passing through a quadripole with nonlinear elements the method is based on that of rice the quadripole characteristic is represented as an integral the relation between the correlation functions for input and output voltages is in the form of a double integral which can be expanded in a power series simple expressions are obtained when the quadripole characteristic comprises a sum of hermite polynomials an introduction to the various parameters used is given in part 4724 design of microwave filters with quarter wave couplings resonator diaphragms are constructed from triplets of inductive posts whose spacing and radii are chosen to prevent the generation of the first five non propagating modes this is sufficient to ensure negligible coupling at quarter wave separation measurements on filters at indicate a satisfactory performance 4725 normalized filter design the design chart presented for composite low pass filters permits predetermining the attenuation characteristic from trial design six normalized designs are presented as examples to cover a practical range of stop band loss 4726 attenuators and load materials preparation of iron araldite mixtures with ratios of by weight is described and results of loss measurements in the frequency range are reported the results are presented graphically 4727 a comparison of the noise and random frequency and amplitude fluctuations in different types of oscillator the nature of the random fluctuation in the output is dependent on the form of feedback employed and the method by which the output amplitude is controlled the frequency band over which the output power is distributed depends however on the relative magnitudes of signal and noise in the circuit rather than on the particular circuit employed the conclusion is that an oscillator should be operated at as high a level as possible consistent with stability and constancy of the circuit components 4728 frequency modulation noise in oscillators the discussion is confined to noise due to the discrete nature of the electron and the random motion of the electrons in the oscillator valve the spectrums ranges from zero to hundreds of the effect of the usual band pass filter on the noise modulation is determined and the power spectrum of the oscillator output is evaluated the theory is applied to several types of oscillator 4729 a wide band frequency modulated system with asymmetrical phase oscillator an analytical investigation is made of the operation of the oscillator symmetrical and asymmetrical arrangements are compared as regards linearity of modulation modulation sensitivity and frequency stability in a system 4730 a phase controlled oscillator description of an oscillator whose frequency is an exact multiple of the mains frequency the phase relation is maintained constant by a feedback loop and phase comparator 4731 a particular mode of relaxation oscillations in a triode valve operation of an arrangement witha very high resistance between the grid and the point of application of grid voltage is discussed the characteristic is two valued giving rise to relaxation oscillations 4732 junction transistors with alpha greater than unity 4733 transistorizing meacham bridge oscillators national electronics conference paper highly stable circuits using either point contact or junction transistors are described for operation at a frequency of 4734 experiments on the regeneration of binary microwave pulses a device consisting of a waveguide hybrid junction with a si crystal diode in each arm working at signal frequency gives sufficient regeneration to permit transmission of signals over a long chain of repeaters providing that the signal noise ratio at each repeater 4735 high speed counter uses surface barrier transistor the complete circuit is given of a four stage reversible binary counter used for decoding signals the high cut off frequency of the surface barrier transistors employed permits the attainment of a counting rate of pulses 4736 time signal generator employing decade counting tubes in a frequency dividing circuit operated in conjunction with a frequency standard and using two decade counters to effect the last stages of division from fluctuation of delay time for the leading edge of the seconds output pulse is and for the trailing edge or better 4737 disc seal circuit techniques 4738 stability problems with low frequency amplifiers with transformers in the feedback path measurements were made of the attenuation and phase variation of typical push pull output transformers over the frequency band outside the low frequency band the phase variation was compared with that of a minimum phase rotation network with the same attenuation variation the results indicate the possibility of simplifying the stability testing of the amplifier circuit by testing the transformer as a minimum phase rotation network 4739 e magnetic and negative electric feedback improve performance of single stage magnetic servo amplifier driving two phase induction motor and standard position servomechanism 4740 magnetic amplifiers in bistable operation flip flop operation can be achieved by over regenerative feedback the relation of the switching cycle to the steady state transfer characteristic is examined 4741 a study of transistors connected in parallel the performance of the parallel combination of transistors is studied in terms of a single equivalent transistor whose parameters re related in a simple manner to those of the individual transistors expressions are derived for the gain and the input and output impedances for the three basic modes of operation results of experiments with both point contact and junction types are in good agreement with the theoretical results 4742 a silicon junction diode modulator by the use of biased diodes in a specially designed bridge circuit is converted to over ange from audio frequencies to at least with a zero stability of better than at room temperature and 4743 theory of the autodyne detector for paramagnetic resonance 4744 use of logarithmic notation in science and engineering a unit for general logarithmic systems is proposed termed the jot the notation used is but the word jot is normally omitted advantages of the system are simplicity of calculation economy of notation simplification of units and simplification of representation of errors examples of use of the notation are given 4745 correlation between photons in two coherent beams of light principles used in the radio interferometer described previously are applicable to the measurement of the angular diameter of visual stars if the two aerials are replaced by mirrors and the detectors by photocells for operation of such a system it is essential that the time of arrival of photons at the two photocathodes should be correlated when the light beams incident on the two mirrors are coherent a laboratory experiment demonstrating the existence of this effect is described 4746 asymptotic solutions of maxwells equations involving fractional powers of the frequency the principal theorem derived indicates the method of obtaining steady state solutions provided that the behaviour of the corresponding pulse solutions in the neighbourhood of the singularities is known 4747 mathematical study of boltzmanns equation 4748 diffraction by a plane aperture with variable contour four dimensional extension of the formulae of classical diffraction theory of 4749 some theoretical and practical considerations of the johnsen rahbek effect the johnsen rahbek effect which is observed when a voltage is applied between metal and semiconductor surfaces in contact with one another is explained as due to the force across the gap which exists at all points except a few where contact is actually made the force increases with the voltage until the latter reaches the critical value causing field emission experiments with a clutch based on this effect are described the results indicate that such a device would be too unreliable for practical purposes the effect might be used in relays and gas flow valves 4750 dielectric properties of a lattice of anisotropic particles analysis is presented for a uniform lattice of similarly oriented particles of arbitrary shape and material the packing density is assumed to be such that interaction between particles must be considered but the induced fields can still be regarded as simple dipole fields two particular cases are examined a cubic array of ferrite spheres and a tetragonal array of disks in the latter case the calculated values of dielectric constant are in good agreement with experimental results reported by 4751 electronic interaction between adsorbed gas molecules and metal surfaces the interaction is discussed in terms of the structure of the gas molecules and the work function of the metal experimental investigations based on the variation of photoelectric sensitivity and resistance of thin films of the metal on adsorption of the gas are described metals used were ni and pt gases were water vapour and benzene vapour the investigation is relevant to the problem of conduction at the surface of semiconductors 4752 the diffusion of electrons in a gas at low temperatures laboratory measurements were made of electron agitation energy as a function of where is an applied electric field the concentration of gas molecules and the mean agitation energy of the molecules the gases used were 4753 international symposium on electrical discharges in gases the text is given of papers presented at the symposium held at delft in april the subjects discussed included fundamental processes in gas discharges instabilities and oscillations in gas discharges high frequency discharges and the dependence of breakdown on frequency and on the product of pressure and electrode separation methods of measurement arc discharges and spark discharges 4754 study of the induced electric discharge in rare gases experiments were performed using a tube of a few centimetres diameter and a frequency of aspects investigated included the conditions for starting the discharge and the radiation from the discharge theory is developed giving a quantitative explanation of the experimental results 4755 penetration of electrons and ions in aluminium the depth of penetration of to electrons and ions in aluminium has been measured it has been found that the thompson whiddington law for electrons does not hold for electrons having energies less than the practical range energy relation obtained for electrons in aluminium was found to be where is if is expressed in and in microns the practical range energy relation for light ions in aluminium was found to be where results are compared with those obtained by previous observers 4756 use of the knife edge method to determine aberrations of deflected electron beams the beam is caused to throw a shadow of a knife edge or wire on a distant plane theory is given and selected shadow pictures are reproduced 4757 collective oscillations and characteristic electron energy losses an attempt is made to give a simple theory of the interaction of fast electrons with thin films of solids adequate for interpreting results of past experiments and for suggesting new crucial tests 4758 secondary electron emission from thin layers of be an experimental investigation is reported of the secondary electron emission coefficient and the variation of secondary electron energy distribution with the thickness of thin layers of be for approximately monatomic layers of be on ni or ag and constant primary electron energy the secondary electron energy at which the maximum of the versus curve occurs is a minimum 4759 secondary electron emission from thin layers of silver an experimental investigation of ag films on ni or be base 4760 plasma oscillations at extremely high frequencies the analysis presented is applicable to plasmas in impurity semiconductors as well as those in gas discharges the design of generators based on standing waves in such plasmas is considered electron densities of the order of are required in a system discussed an electron beam is shot into the plasma which is confined between two parallel reflecting surfaces these may be the faces of a wafer of semiconductor whose thickness determines the natural oscillation frequency problems introduced by the slowing up of the electron beam in such a system are indicated 4761 magnetic systems associated with systems of permanent electric currents and their application to the numerical calculation of fields by superposing magnetic shells associated with the elementary tubes corresponding to arbitrary distribution of currents the associated magnetic systems are simply determined in this way a scalar potential inside the currents can be defined 4762 derivation of an expression for the scalar potential of a line current in the form of a curvilinear integral 4763 calculating the distance between equivalent poles of a bar magnet 4764 the barkhausen effect the only feasible mechanism to account for the phenomena associated with the barkhausen effect is one in which the movement of a limited section of a domain boundary is delayed by a nonmagnetic inclusion whose cross sectional dimensions lie within the range hysteresis losses in ferromagnetic materials may be reduced by the selective reduction of the number of inclusions whose size is within this critical range 4765 temperature dependence of ferromagnetic anisotropy in cubic crystals theories advanced by zener and by van vleck are reconciled they afford respectively low and high temperature approximations to the same physical picture namely an anisotropy decreasing with rising temperature due to statistical fluctuations from alignment of anisotropically coupled neighbour spins 4766 a discussion on magneto hydrodynamics the text is given of papers presented at the discussion noted previously 4767 some exact solutions of the lorentz invariant problem of the motion of two electric fluids 4768 some problems on obstacles placed in the path of electromagnetic radiation the relations between the incident reflected and refracted fields at the surface separating two media are studied using vectorial analysis with a system of coordinates attached to the surface both media may be dielectrics or one may be conducting the plane separating surface is discussed first and the analysis is extended to treat diffraction by a sphere exact formulae are derived for the re radiation gain and the total diffusion surface 4769 tensor scattering matrix for the electromagnetic field theory presented previously is extended to treat the vector field and to include absorption 4770 interaction of centimetre waves with plasma in the presence of a magnetic field experimental evidence of self interaction was sought using an wave of frequency in a circular waveguide containing a continuous discharge parallel to the direction of propagation and a transverse magnetic field absorption was observed passing through a maximum at the field strength value corresponding to the gyrofrequency an expression for the modulation depth is derived in terms of carrier frequency gyrofrequency and modulation frequency the term self interaction is preferred to self demodulation since the modulation depth may be either increased or decreased depending on the circumstances further experiments were made by transmitting an unmodulated wave through a plasma oscillating at low frequency in a eon tube of length the wave became strongly modulated the form of the wave envelope was modified greatly by application of a magnetic field while the modulation disappeared completely at the field strength corresponding to gyromagnetic resonance 4771 absorption of microwaves and radio waves in phenol cyclohexanol and bromo chloroethane 4772 new method for the observation of hyperfine structure of in a maser oscillator 4773 nuclear magnetic resonance in very weak fields a radio spectroscope for observation of resonance between the apparatus is described in detail the signal noise ratio is calculated and the result compared with values obtained experimentally study of nuclear magnetic resonance between proton resonance experiments are described variation of resonance curves with amplitude and with the characteristics of the scanning field is investigated 4774 theory of the autodyne detector for paramagnetic resonance 4775 observation of nuclear quadrupole resonances with a coaxial cavity spectrometer a note on the construction of a spectrometer based on a two cavity klystron oscillator and its operation in the range 4776 the stability of the equilibrium configuration of a current carrying wire in a magnetic field the problem is considered in relation to the investigation of the trajectories of charged particles by the floating wire method as discussed by loeb analysis shows that in certain cases when the field has focusing properties the configuration of the wire is unstable application of the results to a betatron problem is briefly indicated 4777 interplanetary magnetic fields and cosmic rays a discussion of the implications of the hypothesis that as a result of solar corpuscular emission a field free region is produced round the sun with a mean radius of the order of times the distance between the sun and the earth 4778 the measurement of the angular diameter of two intense radio sources an interferometer using post detector correlation is described and results of measurements of the diameter and structure of the radio stars cygnus a and cassiopeia a are given the interferometer operates on and uses aerials spaced at up to the remote aerial being connected via an radio link to the correlator 4779 apparent intensity variations of the radio source hydra a over a period of months about observations of the intensity of hydra a were compared with observations on other strong sources the results indicate that hydra a is relatively much more variable though no periodic changes have been detected possible mechanisms producing the intensity changes are considered 4780 rotation and other motions of the magellanic clouds from radio observations the motions have been studied by means of line radiation from interstellar hydrogen 4781 the angular size of the variable radio source hydra a preliminary observations on suggest that the size as well as the intensity of this source varies 4782 observations of solar and lunar radiation at millimeters further observations have been made using the method described previously measured values of atmospheric absorption are greater than values of water vapour absorption calculated by van vleck the transmittances of some materials at are tabulated 4783 investigation of sky brightness in the spectral region near during the solar eclipse of june the variation of the atmospheric infrared radiation excited by the incident solar ultraviolet radiation was investigated intensity variations observed at wavelengths of and indicate that the radiation from the corona is richer in ultraviolet than the radiation from the sun as a whole 4784 the distribution of radio brightness over th solar disk at a wavelength of centimetres the quiet sun two dimensional observations 4785 solar brightness distribution at a wavelength f centimeters part the quiet sun observations were made with a element interferometer to check staniers results obtained with a two aerial interferometer the observed limb brightening is reasonably consistent with that reported by obrien tandberg hanssen whereas stanier found no limb brightening the divergences may be related to actual differences consequent on the changing phase of the solar cycle 4786 correlation among magnetic storms solar phenomena and cosmic ray storms 4787 movements in the ionosphere report of royal astronomical society discussion held in november methods of measuring the movements and results obtained are briefly indicated an important piece of new information about the lower region is tha simultaneous observations on large scale ripples and the small scale irregularities producing fading show that these two types of irregularity travel with the same speed 4788 movement of sporadic ionization the horizontal movement of patches of daytime sporadic ionization has been observed by using system of spaced pulse transmitters and a central recorder the directions of movement are mainly between these velocities differ in direction from the region disturbances recorded at the same time and have only about half the speed 4789 electronic collisional frequency in the region over calcutta determinations of the collision frequency were made on the basis of appletons formula relating ionosphere reflection coefficient with the difference between the group and optical wave paths whithin the region values corresponding to different heights in the layer are tabulated the most probable value is electron 4790 on the influence of electron ion diffusion on the electron density and height of the nocturnal layer the influence of the earths magnetic field on electron ion diffusion will tend to reduce the atmospheric density in the region at night a lower limit for the maximum density of the value suddested in the earlier paper is possible other considerations tend to confirm the value originally suggested which agrees with extrapolations from rocket data if the true height of the layer is about 4791 on the occurrence of spread echoes in the region over japan analysis of published ionospheric data for japan for the period suggests that spread echoes occur more frequently in the north than in the south chiefly at night at the solstices and when solar activity is weak echoes of the most common type are attributed to reflections from irregularities in the upper regions of the layer which are normally masked in daytime others may be due to reflections from turbulences during magnetic storms of to ionized clouds passing through the normal layer 4792 photoelectric studies of the night sky light an attempt is made to correlate variations of night glow intensity with those of electron density in the layer the results are inconclusive 4793 russian ionosphere terminology russian equivalents are given for about english terms 4794 effect of the solar eclipse on the lower parts of the ionosphere and the geomagnetic field changes in layer electron density observed at a number of stations during the solar eclipse of have been examined and the resulting changes in conductivity deduced the effects are found to exist over a very much wider area than that eclipsed the calculated modifications in the current consequent upon the electron density changes provide a satisfactory quantitative explanation of changes in the earths magnetic field at the time of the eclipse 4795 lunar tide in sporadic at brisbane an analysis has been made of night time values of for the period results are tabulated and plotted on a harmonic dial the semidiurnal variation has a mean amplitude of and a mean phase of results are compared with those of 4796 the electrical conductivity of the ionosphere and disturbances of the geomagnetic field at audio and lower frequencies on the basis of assumed values for collision frequency and maximum electron density for the and layers values are calculated for the conductivity parallel and perpendicular to the magnetic field and for periods corresponding to certain critical frequencies the significance of the results is discussed in relation to the possibility of extraterrestrial origins for geomagnetic field disturbances 4797 daily variations of the electrical conductivity of the upper atmosphere as deduced form the daily variations of geomagnetism equatorial zone 4798 studies on the disturbances in layer associated with geomagnetic disturbances reports on work published previously are collected and discussed 4799 radio observations of the ionosphere at oblique incidence 4800 preliminary studies of the distribution of auroras in alaska the analysis of auroral observations for from five stations spread over alaska shows a zone at geomagnetic latitude for which the incidence of auroras is independent of magnetic activity at geomagnetic latitudes south of the incidence of auroras is markedly dependent upon magnetic activity 4801 auroral heights over west central canada results of an analysis of parallactic photographs of aurorae taken in at chesterfield suggest that auroral heights in this region are slightly greater than those observed from norway there is no definite evidence of a change of height with time after sunset 4802 observations of whistling atmospherics at geomagnetically conjugate points comparison of records obtained at points in n america and the new zealand appear to confirm storeys theory that whistlers and swishes are produced as the atmospherics travel along the dispersive paths constituted by the geomagnetic flux lines between the northern and southern hemispheres 4803 mains voltage stabilizers a fast acting stabilizer is described combining features of the magnetic and feedback types the voltage sensitive element is a bridge containing an indirectly heated thermistor a stability to within over the temperature range can be achieved for mains voltage fluctuations between and mains frequency variations between and and load variations from no load to full load recovery time is cycles 4804 nuclear batteries types and possible uses 4805 depolarization of electrochemical cells containing manganese dioxide 4806 recent patents on electrical accumulators for previous review see 4807 a mechanical binary decimal converter 4808 an electronic generator for functions of two independent variables a unit built at the chalmers university of technology is described the function is recorded on a photographic plate in the form of variable width columns these are scanned by a tube the output is either in the form of width modulated pulses or in the form of a voltage proportional to the function 4809 measurement of correlation coefficient the determination of the correlation coefficient of noise is based on the measurement of the coincidences of sign of rectangular pulses triggered by the incoming signals the instrument is described in detail and the theory of operation is given 4810 shock spectrum computer for frequencies up to an arrangement for investigating the effects of mechanical shock on electronic equipment installed in guided missiles comprises an analogue computer which operates on an accelerometer signal either direct or recorded and solves the differential equation for the part involved the result being displayed on a screen the computer can be tuned up to thus covering the range within which the fundamental resonance of any delicate structure is likely to occur 4811 transistor digital computers a brief account is given of circuit techniques involving the use of transistors and ferrite two stage storage devices described at the convention on digital computers held in london in 4812 the cryotron a superconductive computer component 4813 the gas filled diode as a digital storage element 4814 proceedings of the eastern joint computer conference 4815 parallel connected nonlinear impedances analysis based on a matrix method of representing complex vectors and locus diagrams are used to determine the equivalent single impedance for an arbitrary system of parallel impedances values of voltage resulting from given current loads and of current resulting from given applied voltages are hence derived the methods are illustrated by a numerical example taking two nonlinear impedances with ohmic resistance components the complete working diagram of the parallel system is obtained by combining the locus diagram with the characteristic 4816 subminiature transformers and transductors limitations associated with subminiature design are discussed in relation to audio and control frequency transformers and transductors below a certain size a toroidal shell construction has given results comparing favourably with laminated assemblies the signal power level of the transformers is sufficient for junction transistor circuits when this construction is applied to transductors the excitation and control field are orthogonally related a paper covering much of the same ground appears in 4817 transformer miniaturization using fluorochemical liquids and conduction techniques 4818 the stability of thermistors experimental results indicate that though the constants of two thermistors tested undergo changes over a period of months the changes are slow enough for temperature measurements to be made to an accuracy within over a range of in experiments lasting up to 4819 design of modern winding machines a short review in which and european methods are contrasted 4820 transfer function of relays with inactive zone and hysteresis the equation of transfer for the relay is calculated by the laplace transform method 4821 the cryotron a superconductive computer component the study of nonlinearities in nature suitable for computer use has led to the cryotron a device based on the destruction of superconductivity by a magnetic field the cryotron in its simplest form consists of a straight piece of wire about one inch long with a single layer control winding wound over it current in the control winding creates a magnetic field which causes the central wire to change from its superconducting state to its normal state the device has current gain that is a small current can control a larger current it has power gain so that cryotrons can be interconnected in logical networks as active elements the device is also small light easily fabricated and dissipates very little power 4822 batching and counting using gas filled decade tubes a range of units is described from which a variety of frequency meters batching counters etc can be quickly assembled circuit diagrams are given 4823 the impedance of shorted edge wound capacitors results on the frequency variation of the impedance of this type of capacitor obtained by leiterer are discussed using simple mathematics the analysis is given first neglecting losses and is then extended to take account of losses in the dielectric and in the thin metal films eddy currents in the projecting contact layer and in thicker metal foils are also taken into account the method is used to determine the transfer impedance of lead through capacitors 4824 the forming of the negative electrode of electrolytic capacitors an examination is made of the conditions under which undesired forming occurs formulae are presented for the decrease of the capacitance on repeated dis charging these enable load behaviour to be predicted and optimum design to be attained the theory is supported by experimental results 4825 principles of transistor circuits a comprehensive review covering amplifiers oscillators and flip flops 4826 tolerance limits in matching curves are given showing the level of power transfer from source to load for various degrees of mismatch 4827 report of advances in microwave theory and techniques 4828 impedance synthesis without minimization the synthesis procedure described for realizing a rational positive real function of the complex frequency variable by means of a network containing no mutual inductances is performed in three steps in which the computationally difficult minimization process is avoided 4829 the geometrical representation of combined linear quadripoles concepts of non euclidean geometry are used the representation of reactance quadripoles by a rigid system of two straight transformation lines and the determination of impedance transformations from geometrical reflections afford useful methods for treating composite quadripoles 4830 the geometrical quadripole representation of the double transformer the representation is effected by adapting the technique described previously 4831 the operating parameter cascade matrix of quadripoles 4832 waveguide filters filters having high and low insertion loss are produced by arranging inside a waveguide a number of suitably spaced dielectric sections constituting transformers 4833 band pass characteristics of low asymmetry an empirical design procedure is formulated leading to filter networks which compare favourably with conventional designs 4834 new rejector circuit a circuit used in some colour television receivers is described it uses a conventional parallel trap connected into circuit via a centre tapped bifilar wound coil with a resistance across one half it is characterized by negative inductance and capacitance the circuit is discussed further in 4835 a double slab ferrite field displacement isolator at brief description with performance figures of an isolator comprising a waveguide with two slabs of ferrite arranged with transverse symmetry and subjected to equal but oppositely directed magnetic fields the forward loss is over most of the range from to and varies by over any channel while the reverse loss is 4836 impedance transformation of linear terminal networks if outlets of a terminal network are terminated by variable reactances the resulting quadripole represents a variable transformer as the value of these reactances varies between the input impedance assumes all values of the transforming range this range does not include the entire right hand half of the complex impedance plane but only circular areas thereof an equation is derived for determining these circles the method is demonstrated in relation to a waveguide hybrid t 4837 fluctuations in self oscillating systems of thomson type amplitude and phase fluctuations in weakly nonlinear selfoscillating systems are considered using a symbolic differential equation describing the fluctuations of the random functions and the methods of the correlation theory a system with one degree of freedom is considered first and the general theory is applied to the case of a valve generator operating in the soft state the theory is then applied to passive systems with one and two degrees of freedom the effect of stabilizing the frequency of an oscillator by means of a high circuit is discussed the method of taking into account thermal fluctuations shown 4838 fluctuation of oscillations of klystron generator a theoretical investigation of noise in a reflex klystron is presented in a typical case the natural bandwidth of the oscillations is the results obtained by shimoda are believed to be in error 4839 frequency of the three phase coupled oscillator part non reactive anode load resistance report of an investigation of the effect of different types of cathode impedance on the oscillation frequency 4840 application of junction transistors to the generation of linear sawtooth waveforms 4841 ahalwo trigger circuits useful as sources of rectangular pulses a modified eccles jordan circuit having low output impedance and a development of schmitt cathode oupled trigger circuit are presented 4842 comparison of junction transistor and amplifier valve the quadripole equations are developed for the commonly used circuits important parameters and relations are tabulated for linear operation the valve can be regarded from the network point of view as a simplified limiting case of the class containing both valves and transistors analysis of a regenerative amplifier with distributed amplification analysis indicates that the application of distributed amplification in regenerative circuits such as the monostable multivibrator is limited by its inherent time delay 4843 component tolerance effects in feedback amplifiers analysis relating to and feedback networks is given resistor variation produces no asymmetry of the response curve in this respect the feedback amplifier is superior to the stagger tuned amplifier 4844 a direct current amplifier stage with asymmetrically earthed input a push pull cathode follower circuit is used with two valves having dissimilar characteristics and a special resistance coupling the usual phase reversing stage being omitted analysis is presented on the basis of a parabolic approximation to the characteristics design procedures for ensuring the requisite quiescent current and linearity conditions are indicated a numerical determination is made of the operating point for a circuit using one and one valve 4845 a note on sidebands produced by ferrite modulators 4846 microwave detector 4847 a simple microwave discriminator a cylindrical resonator with slightly disturbed symmetry has two closely spaced resonance frequencies for the mode corresponding to two waves with slightly different propagation velocities these can be detected separately by means of rectifiers a discriminator characteristic s given by the difference of the rectified currents as a function of frequency the dimensions of the resonator for a given frequency can be reduced by capacitive loading discriminators of this type are suitable for measurement and control purposes rather than for demodulation 4848 miniaturization and quality improvement of circuit parts coils transformers resistors capacitors quartz crystal units and filters developed by the nippon telegraph and telephone public corporation are described and illustrated 4849 circuit technique for generation of electrical test patterns in television 4850 a method of analysing periodicity a method of analysing an empirical function such as that corresponding to the record of an oscillation process is based on asymmetrical rather that symmetrical linear combinations of ordinates it permits detection of variations of phase as well as amplitude 4851 theory of radiation a survey of the application of quantum field theory to the interaction between charged particles and the electromagnetic field within this domain it is now possible to calculate any process with a precision olny limited by the labour of the calculations 4852 intensity of harmonic and combination components in the nonlinear distortions of complex oscillations the effect of linear quadratic and cubic response characteristics on triangular saw tooth and rectangular signals is considered results are tabulated 4853 ultraviolet absorption of atomic nitrogen in its ionization continuum the absorption of radiation of by the plasma of a discharge in an ionization gauge was measured by passing the transmitted radiation into a spectrograph various considerations indicate that the absorption is due to atomic nitrogen the absorption cross section of which is hence deduced 4854 the physical interpretation of the self acceleration of electrons the forces governing the motion of electrons are most easily understood if the point electron is considered as the limiting case of the finite size electron for self acceleration to occur it is not essential that the field energy be infinite but it is important that the mechanical mass of the electron by negative 4855 measurement of the specific charge o conduction electrons the theory of a method of determining by means of a special dynamo is given the device comprises a pair of concentric coils which together rotate with angular velocity about an axis parallel to the applied magnetic field the rectangular inner coil can also rotate about its own axis which is perpendicular ot the magnetic field the two resulting in the inner coil are due to induction and coriolis force acting on the conduction electrons if these are equal then where is the velocity of light and the magnetic field strength the estimated experimental errors are not greater than 4856 potential due to a uniformly charged disk formulae are derived applicable to any point the effect of free electron on lattice conduction the scattering of phonons by electrons is calculated assuming the usual electronphonon interaction for a parabolic band whose degeneracy temperature is comparable with the temperature of the lattice the contribution to the thermal resistance is given by an exact formula subject only to justifiable assumptions concerning phonon phonon inter actions with rising temperature the apparent mean free path of the phonons at first decreases as but reaches a minimum and then increases as energy and momentum conservations then allow only the tail of the electron distribution to contribute to the scattering the model is thought to apply to certain observations on germanium irradiated sapphire and conducting diamond 4857 ionization by relativistic particles a summary is given of theories of the relativistic increase of energy loss by ionization and of the density effect the experimental evidence as obtained with various types of counter is discussed and compared with theoretical predictions over references 4858 the ionization and dissociation of complex molecules by electron impact a review covering theoretical and experimental aspects of collision processes in polyatomic molecular gases over references 4859 ion oscillations in a cathode potential minimum a brief theoretical note 4860 the rotation of plasmoids in a magnetic field the motion of a luminous low pressure gas discharge in ne in the presence of a magnetic field and a superposed field of frequency about was found to be a function of the anode voltage of the output valve of the generator used 4861 formative time lags in the electric breakdown of liquid hydrocarbons 4862 the work function and patch field of an irregular metal surface calculations show that the lowering of the work function due to irregularities of the surface is entirely compensated by a patch field 4863 the breakdown of gases subject to crossed electric fields the effect of an auxiliary electric field acting at right angles to a field on the breakdown stress of various gases is investigated experimentally when the auxiliary field is unidirectional or of relatively low frequency its application raises the break down stress but when its frequency reaches the two fields appear to act independently a partial explanation is advanced the gases studied include air oxygen nitrogen hydrogen and neon 4864 spin deviation theory of ferromagnetism the non ideal spin deviations gas 4865 application of the bethe weiss method to ferrimagnetism 4866 classical electrodynamics as a distribution theory 4867 a derivation of generalized microscopic electrodynamic equations non relativistic maxwells equations and the constitutive relations are derived from the classical microscopic theory without making use of extensive assumptions so that the effects of the higher order electric and magnetic moments are retained in the equations 4868 on the theory of stationary waves in plasmas a mathematical treatment is presented appropriate to the case of a continuous non vanishing distribution of particle velocities a complete set of stationary plane wave solutions can be constructed there is no dispersion equation because for a given wave vector a continuous range of values of frequency is possible 4869 growing electromagnetic waves this growth of waves is considered in terms of baileys electromagneto ionic theory of the different wave modes predicted by this theory four are unreal the remainder comprise two pairs of hydromagnetic waves which become pure waves at a sufficiently high frequency one pair of modified sound waves and one pair of modified electron sound waves the growth of the waves may result from the trappings of ions between potential troughs of the space charge wave and the subsequent surrender of energy by the ions ion drifts may introduce important effects not indicated by the wave equations 4870 theory of wave propagations in a gyromagnetic medium the theory presented is relevant to propagation in ferrites byt the physical nature of ferrites is not discussed 4871 on the absorption of microwaves in some substituted phenols in the liquid state 4872 possible source of line width in ferromagnetic resonance brief theoretical discussion indicating the effect of the finite size of a sample on the dispersion of relaxation times 4873 the displacement of atoms in solids by radiation a survey covering theoretical and experimental aspects of the irradiation of solids by particles or rays effects produced in metals and semiconductors are described nearly references 4874 halo of radio emission and the origin of cosmic rays observations of radiation from nebulae indicate that a large fraction of the radiation comes from roughly spherical regions centred on the galactic centre and having radii of about kiloparsecs the particle density and energy conditions in these regions are considered in relation to the acceleration of cosmic rays 4875 a search for radiation from jupiter at and at following the observation of radiation from jupiter at records obtained at cambridge england of radiation received at and were searched for evidence of radiation from jupiter at these frequencies results were negative inferences are drawn regarding the source of radiation on jupiter 4876 characteristics of radio echoes from meteor trails the distribution of meteor magnitudes and masses the distributions are deduced from observations of sporadic meteors and various showers 4877 characteristics of radio echoes from meteor trails polarization effects the theoretical estimates of plasma resonance effects by were tested at a frequency of the polarization effects observed are in good agreement with the predictions for both short and long duration echoes but some unexpected results were obtained for meteor trails with line densities in the transition region of electrons the echo amplitude was found to be proportional to instead of the predicted where is the duration of the echo the discrepancy may be the result of diffusion by turbulence in the atmosphere 4878 meteor echo durations and visual magnitudes the statistical relation between the radio echo duration and the visual magnitudes was analysed using observations obtained during the years on about meteors over a range of magnitudes the relation is linear or nearly linear it is inferred that a meteor of absolute magnitude produces electrons per of path length 4879 radar echo duration and height of a perseid meteor triangulation data for a meteor echo lasting observed on are discussed 4880 daily maps of the sun a brief note announcing the inauguration of a service in which a number of observatories are cooperating to produce comprehensive records of solar phenomena 4881 solar corona and geomagnetism both coronal activity and geomagnetic disturbance vary directly with general solar activity except at the period of sunspot minimum when correlation between the two is negative geomagnetic disturbance is greatest when the earth is in the radial line of an active coronal centre an active centre appears to have a shielding effect on the outflow of corpuscles from the undisturbed solar areas 4882 a model for the solar enhanced region at centimeter range derived from partial eclipse observations records taken at three japanese observatories on frequencies between and during the partial eclipse of the sun on show a marked decrease on the observed flux during the period when a large sunspot group was eclipsed the location size and brightness distribution of the enhanced radiation region are derived a model for the quiet sun having a bright region near the limb on the equator is also suggested 4883 field in the polar region on absolutely quiet days analysis of data for the second polar year indicates that the field which is recognized as applying to the region between latitudes and also represents the daily variation in the geomagnetic field over the rest of the earth for absolutely quiet days 4884 report of observations of geomagnetic variations at aso and naze during the solar eclipse of 4885 introductory theory for upper atmosphere wind and sonic velocity determination by sound propagation theory applicable to a rocket grenade experiment is developed 4886 the atmospheric ozone as indicator of air streams in the stratosphere the photo chemical bases 4887 a method of determining the relative amounts of and region absorptions of medium and short radio waves the method is based on the concept of rela ation time the value of which for the layer is appreciably different from that for the layer 4888 region and the current system the complete equilibrium equation for the electron density in a solar controlled ionospheric region includes a term which depends on vertical drift and is usually neglected the layer critical frequency is then related to the zenith angle by the equation where is a constant and for an isothermal region has the value for recombination and for attachment values of deduced from actual observations lie between and these findings are discussed on the assumption that the variation of results from neglect of the vertical drift term the theory is supported by observations of singularities in the noon curves of latitude for several longitudes these singularities corresponding to normal values of coincide approximately with the position of the foci of the current system 4889 a new method of analysing ionospheric movement records technique based on optical diffraction systems is outlined the ionosphere is provisionally assumed to be a plane reflector and the image of a ground transmitter in it is regarded as a source of coherent radiation giving rise to a diffraction pattern on the ground corresponding to an inhomogeneity moving in or below the ionosphere from the geometry of the system a focal length is deduced and when the record of the diffraction pattern is converted into a variable density photographic record a corresponding visual focal length is obtained from which the velocity of the moving inhomogeneity can be determined the method has been tried at the new zealand dominion physical laboratory using aerials arranged at the corners of a triangle as suggested by mitra holograms showing some results are reproduced from these it is celar that moving objects far below the ionosphere can affect the records significantly 4890 movements of irregularities in the region continuing the work referred to in results for the period show that an east wind with an average velocity of predominates in the evening continuing throughout the night in winter towards sunrise winds in the reverse direction are frequent irregularities are estimated to be in extent 4891 sequential and lunar effects on the equatorial among the various types of which have been observed one shows apparent vertical movement on the ionogram and has been termed sequential by investigators at the national bureau of standards a study is made of this phenomenon using records from a number of stations the sub type investigated is that involving an region which first appears at a height of about in winter and in summer and then drops to normal level where it persists for some hours the latitude and time distributions of the phenomenon are briefly discussed 4892 on anomalous variations of critical frequencies and virtual heights of the and regions of the ionosphere latitudinal and seasonal variations of critical frequencies and virtual heights of the and layers for years of high and low sunspot activity are investigated anomalous variations are found analogous to those in the layer similar explanations are suggested 4893 the diurnal and annual variations of ionization an interpretation values of and log in the formula calculated from records for are tabulated the variation of these values is discussed and a model is derived for layer conditions in which the temperature gradient is smaller in summer than in winter 4894 a study of the total electron content of the region of the ionosphere over ahmedabad the total number of electrons in a column of unit cross section in the and regions up to the height of maximum electron density has been calculated for three magnetically quiet and three disturbed days in each month from the method of analysis is that suggested by assuming parabolic electron density distribution the relation between the semi thickness and for the layer shows that thick layers are associated with higher values of and that the parabolic distribution law does not hold for very thick layers 4895 determination of the region collisional frequency the collision frequency reaches its maximum at about noon and its minimum at about midnight the rate of rise of increases with cos 4896 a possible explanation of the drop in region critical densities accompanying major ionospheric storms an explanation in terms of increased recombination rates is suggested based on evidence that the abundance of at great heights is governed by vertical transport 4897 the spectrum of radio star scintillations and the nature of irregularities in the ionosphere simultaneous observations of the intense source in cygnus were made with a frequency sweep spectroscope a frequency sweep interferometer and a triangular spaced aerial receiving system most fluctuations are due to focusing by single lens like irregularities the fluctuation amplitude shows tow maxima one near midnight the other near midday for day time conditions at least the elongation of the pattern at the ground indicates marked anisotropy in the ionosphere irregularities 4898 correlation between noon and sunspot number analysis of data from four indian stations shows a linear relation between the running means of the sunspot number and the noon value of up to a limiting value of 4899 tilts in the ionosphere during the solar eclipse of directional measurements at nearly vertical incidence on the layer during the eclipse showed the existence of a tilt whose direction agreed with that expected from the geometry of the eclipse the magnitude of the tilt was also of the same order as that calculated from observed changes in the height of reflection oblique incidence bearing measurements on signals reflected from the normal layer failed to reveal any eclipse effect and theoretical calculation showed that no detectably large effect would have been expected in this case 4900 preliminary results of the ionospheric solar eclipse of an analysis of critical frequency data obtained in grahamstown during this annular eclipse the effects may be explained to a first approximation by assuming that the radiation responsible for the ionosphere structure is distributed uniformly over the suns disk values of recombination coefficient for the and layers are in good agreement with values obrained recently by independent methods 4901 observations of the lower ionosphere during the solar eclipse on propagation tests were made at on frequencies of during the eclipse the expected increase of reflection coefficient in the lower ionosphere was considerably delayed after first contact and normal attenuation values were restored before the end of the eclipse the magnitude of the effect and the delay of the maximum agreed with predictions from normal diurnal and seasonal variations based on a single layer model of the layer but the limited duration of the effect was consistent with a multilayer model observations of complex variations of very long wave ve atmospherics are also reported 4902 the influence of the geomagnetic field on turbulence in the ionosphere damping of turbulent motion of neutral particles is negligible for the smaller eddies in the higher regions electrons are constrained to move nearly parallel to the magnetic field this results in variations of electron density even when the density of neutral molecules does not vary these variations may be appreciable above 4903 on the disturbance daily variations and the lunar daily variations in the region of the ionosphere on the magnetic equator continuation of work reported previously on the effects of vertical electron drift dur to the electrical fields associated with the currents responsible for the diurnal geomagnetic variations 4904 layer electron model reduced from considerations of and wave absorption 4905 the propagation hole in the ionosphere 4906 the interpretation of measurements of radio wave interaction 4907 a comparison of the annual mean solar and lunar atmospheric tides in barometric pressure as regards their worldwide distribution of amplitude and phase 4908 the influence of individual variations in the field changes due to lightning discharges upon the design and performance of lightning flash counters flash counters responding only to the component of the field change are likely to be least subject to error this implies a preferential selection of very low frequencies examples are given indicating the extent of the inaccuracies encountered from statistics of rates of flashing and duration of discharges it is concluded that counters should have an insensitive period of about the design of counters is discussed and a simple circuit is presented 4909 low audio frequency electromagnetic signals of natural origin signals in the frequency range have been recorded in california over long periods the diurnal variation of signal amplitude closely resembles the diurnal variation of atmospheric potential gradients measured at sea it is inferred that these low frequency signals are atmospherics and that their mean amplitude is roughly proportional to the number of storms in progress over the whole world 4910 sunspot and geomagnetic storm data derived from greenwich observations includes explanatory notes and literature references and some diagrams 4911 a magnetic thyratron grid control circuit a circuit described previously is modified by including an source and a rectifier in the secondary circuit of the grid transformer changing the mode of operation to that of a reset magnetic amplifier a range of firing voltage phase is available the firing voltage builds up rapidly 4912 chemical generation and storage of electricity a review of recent work on fuel cells whose operation is based on oxidation of carbon and hydrogen and which give a low voltage output the particular importance of this type of cell is that it may give higher efficiency in the use of primary fuels 4913 some basic scientific problems relating to manganese dioxide electrochemical cells 4914 the short electronic analogue computer description o the design and operation of a general purpose computer designed for quantity production and capable of single shot and repetitive operation 4915 tridac a large analogue computing machine discussion a detailed description a shorter account was abstracted previously 4916 function generators based on linear interpolation with applications to analogue computing by using suitable combinations of diode circuits and high gain feedback amplifiers it is possible to generate functions without restriction to monotonic characteristics experimental results are presented for a sin generator in which the error is about of the maximum output 4917 construction and method of operation of modern integrating equipment general principles are discussed and a detailed description is given of an installation in germany the results are presented to three or four significant figures by counter mechanisms and in the form of curves on function benches curves of empirical functions are dealt with by photoelectric scanning errors do not exceed 4918 engineering multistage diode logic circuits design of computers using crystal diodes and transistors is discussed transistor input circuits directly coupled to multistage logic circuits may avoid the need for intermediate amplifier stages 4919 transistor circuits for analog and digital systems a summing amplifier an integrator and a voltage comparator using junction transistors are described together with a voltage encoder made up from them for translating voltages into equivalent time intervals for analogue to digital conversion 4920 an experimental transistorized calculator the machine is functionally identical with the calculating punch but the valves are completely replaced by transistors and 4921 an multiplier a relatively simple purely electronic multiplier circuit for differential analysers is described working with an upper frequency limit of for both factors accuracy is within about of full scale 4922 abac of the function for studying the initial complex permeability of circular cross section conductors at high frequency the impedance of the conductor is measured and the parameter is then found from the abac using a known formula the complex permeability is then derived using a given relation between and this abac supplements tht presented by prache which was not applicable to good conductors 4923 physical sources of noise the principal types of electrical noise encountered in circuits and valves are identified and the mechanisms giving rise to them are discussed equations used to represent noise phenomena are derived 4924 the impedance concept impedances and associated transfer functions are expressed in terms of a variable which is closely associated with time differentiation the fundamental properties of the world are discussed a general condition dor an algebraic equation to be free from roots with positive real parts is obtained a network whose characteristic equation has this property is stable conditions are deduced for a system to have a damping rate at least equal to a specified value the effect of adding terms in on the roots of a given cubic in is examined the effect on the gain and maximum obtainable feedback of the addition of a step circuit to a three stage amplifier is considered in detail 4925 properties and comparative tests on relay contacts 4926 toroidal transformers pass video bandwidths television video transformers are wound on supermalloy tape wound toroids having a low frequency permeability of diminishing with increasing frequency a bandwidth of is obtainable these transformers may be used for matching a coaxial cable and for interstage coupling in transistor video amplifiers 4927 transformer design chart the chart gives data for designing two winding transformers 4928 the theory and design of coaxial resistor mounts for the frequency band a design is described in which the resistive inner conductor has uniform diameter while the outer conductor has a tractrix profile lead in cones are designed to avoid discontinuity at the connections experimental results indicate that the impedance is within of the resistance with an extremely small phase angle at all frequencies up to the highest measured namely 4929 the operating mechanism of voltage dependent silicon carbide resistors measurements on aggregates of sic particles such as pressed powder show how thermal effects depend on grain size and the duration of the current pulse thermal and field effects can be separated by reference to resistance voltage characteristics at different temperatures for single contacts between crystals or between a crystal and a metal knife edge 4930 the specification of the properties of the thermistor as a circuit element in very low frequency systems an analysis based on sinusoidal applied voltages shows that a conductor whose resistance is a function of temperature may be represented by an equivalent circuit having a semicircular impedance locus an expression for the distortion of the waveform is also obtained and this is found to be small provided that the alternating current is less than a quarter of t steady polarizing current which flows in the conductor the impedance loci of a bead type thermistor are plotted by means of null technique a typical impedance varied from a negative resistance of at very low frequencies to a pure inductance of and then to a positive resistance of at high frequencies the use of the equivalent circuit is illustrated by designing phase shift networks suitable for use in the stabilizing of very low frequency control systems these circuits may be used in systems where either data transmission is employed 4931 problems encountered and procedures for obtainining short term life ratings on resistors account of investigations made at the battelle memorial institute on the extent to which length of life must be sacrificed when composition resistors are operating at high temperature a machine system for handling the data is described 4932 controlled transductors analysis of the behaviour of the single core auto self excited transductor is made for the condition when the control circuit has finite resistance control of full wave transductors and some push pull circuits with half wave and full wave outputs are referred to 4933 the residual time constant of self saturating transductors theoretical and experimental evidence is presented indicating that the main winding of selfsaturating transductor influences the time constant for small signals to an extent dependent on the blocking intervals of the rectifiers and on the main winding resistance the blocking interval is in turn dependent on the output amplitude this is consistent with the normal experience that transductor response becomes faster as the output increases 4934 a digital differential a simultaneous bidirectional counter circuit is described in which a dekerence in court between two independent pulse trains the circuit can also be used in frequency and speed control applications 4935 electronic switches for television 4936 the effective leaking resistance of several types of capacitors a rapid method of measuring leakage resistance based on rate of charge is described variation of leakage resistance with time was measured for commercial capacitors of values ranging from with various dielectrics at temperatures ranging from in most cases the best properties were exhibited by a capacitor having a polytetrafluoroethy dielectric 4937 a variable capacitance germanium junction diode for 4938 cascaded feedthrough capacitors by interspersing lossy ferrite washers between the stacked ceramic disks of capacitors of the type described previously the filtering properties for and are greatly improved such constructions are thus useful for miniaturized low pass filters properties of suitable ferrites are discussed 4939 national bureau of standards preferred circuits program 4940 invariance and mutual relations of electrical network determinants work by earlier authors is generalized the basic values of the impedance and admittance determinants are connected by a simple relation involving the determinant of the branch parameter matrix 4941 nonlinear network problems general analysis is presented for flow problems a number of theorems are proved relaxation methods are used 4942 transformation of the matrices of generalized admittances for various triode connections the usual three sets of connections for triode valves and for transistors are examined 4943 the correlation between decay time and amplitude response an investigation is made of the relation between the decay time and the delay time of the indicial response and the bandwidth and peak values of the steady state amplitude response for various minimum phase lumped parameter networks formulae are derived expressing the functional relation between decay time and the ratio where is the bandwidth at and that at a formula for delay time is derived which is valid for multistage circuits 4944 energy considerations for growth and decay transients in a simple resonator circuit analysis is presented for a series circuit values of current voltage being determined in terms of the characteristic resistance the solution of the differential equations is simplified by taking the energy of the circuit as the basic time variable since this is fixed by thinintial conditions 4945 overtone quartz crystal units the experimental crystal described is a circular plate carrying an evaporated metal film held at diametrically opposite points by springs attached to the lead terminals details are given of the lapping process and the frequency adjustment 4946 the most elementary geometrical representation of loss free linear quadripoles it is possible to describe impedance transformations in lossless and linear quadripoles by geometrical quantities and by cascade parameters an unambiguous geometrical representation in the form of a system of two transformation lines equivalent to the one transformation line of an impedance transformation is also possible and this leads to a new and unified method of representing the three different transformations by linear quadripoles and by elliptical and hyperbolic quadripoles as well as by the parabolic reactance quadripole this gives for the linear quadripoles an intuitive and elementary form of treatment which has proved to be very useful for the solution of many quadripole problems an impedance transformation using the images with respect to two transformation lines is given for the example of a parabolic reactance quadripole such as a series capacity 4947 interference spectra and aerial filters a note on the problem of the simultaneous operation of directional radio systems with pulse modulation the design of continuously tunable multi circuit diplexing filters for communication systems is discussed a frequency separation of is assumed between the associated transmitter and receiver and the asymmetrical nature of the transmitter spectrum is taken into account 4948 theory of synchronization of self oscillations of arbitrary form analysis is given for an oscillation containing only a few harmonic components the effect of applying a sinusoidal force of a frequency near the third harmonic is investigated by a method involving the use of fourier series coefficients 4949 discrimation of a synchronized oscillator against interfering tones and noise the discrimination exercised by a nonlinear regenerative tuned circuit against unwanted signals accompanying a synchronizing tone is due partly to the frequency response of the system and partly to the nonlinearity provided that the synchronizing signal has a greater amplitude than the unwanted signals after allowing for frequency response the phenomenon is analysed and measurements of discrimination against noise are reported the degree of discrimination can be very great when the synchronizing frequency is very close to the natural frequency of the circuit when the synchronizing tone is absent or is not dominant there is no reduction of the interference intensity or bandwidth 4950 a wide range phase shift oscillator an oscillator with a frequency range from below to over is described coupling is used a polyphase version is also described 4951 a grounded grid valve system with high stability characteristics 4952 frequency stability of oscillators with large grid and anode capacitances general analysis is given for the clapp circuit various factors affecting the frequency and the optimum distribution of instability components among the circuit elements and supply voltages are discussed 4953 the generation and application of rectangular pulses a survey of various known techniques covering both relaxation oscillators and monostable circuits a delay line pulse generator a free running multivibrator and a cathode coupled monostable multivibrator are discussed in detail the suitability of a valve for switching applications can be estimated on the basis of a figure of merit given by the ratio between the mutual conductance and the total interelectrode and stray capacitance transition times are about for circuits using high double triodes or pentodes and of the order of for circuits with low valves 4954 study of a flip flop with four positions of equilibrium by the methods of topological analysis analysis is presented in general terms for a two stage circuit assuming square law valve characteristics three possible states identified are static dynamic and impulse the eccles jordan and multivibrator circuits are particular cases an experimental circuit has been designed its performance agreed well with the predictions 4955 multivibrator circuits using junction transistors conventional circuits operating predictably at frequencies up to at least are described 4956 reduction of the minimum striking voltage of hydrogen thyratrons an auxiliary tripping circuit is described by means of which the output voltage of a line type thyratron pulse generator is made continuously variable from 4957 a temperature stable transistor an oscillator for telemetry purposes is described 4958 cascade amplifier a cathode coupled phase inverter circuit using cascode connected twin triodes is described as part of a high fidelity amplifier which does not require a specially designed output transformer 4959 analysis of a differential magnetic amplifier with flux reset control 4960 the smoothing of non formulated experimental laws by an averaging operation involving no spurious deviations a section of an experimental curve comprising points is assimilated to a second degree polynomial and the required ordinates are hence calculated without introducing spurious undulations 4961 a simplified mathematical approach to hysteresis losses the hysteresis loop such as a normal curve is approximated by an ellipse features resulting from harmonics being neglected calculations are thus simplified 4962 the absorption spectrum of nitric oxide in the far ultraviolet 4963 on asymptotic series fo functions occurring in the theory of diffraction of waves by wedges an asymptotic expansion of the integral expression for diffraction by a wedge at distances large compared with is obtained as the sum of a fresnel integral as leading term and an asymptotic series of inverse powers of the distance for small values of the distance the expansion takes the form of a series involving bessel functions 4964 multipotentials of multipoles general theory is presented applicable equally to magnetic or dielectric multipoles every multipole is shown to be associated with a scalar or vector multipotential which has spherical symmetry from the equation of this multipotential the usual scalar potential can be obtained by successive derivations 4965 the electrostatic centre of a conductor 4966 variation of volta potential with temperature experimental results show that the measured work functions of and depend on the experimental conditions rather than on the electron concentration or structural phase changes this was investigated in greater detail by 4967 investigation of the temperature dependence of the electron work function of metals and semiconductors the variation of the work function of copper and nickel sheets was determined from the characteristics of a special diode with a tungsten filament as a function of time temperature and degree of vacuum the temperature dependence was also investigated for type and results presented graphically indicate that for work function measurements on metals a vacuum better than is required 4968 on the molecular theory of electrostriction the case of a sphere of fluid dielectric subjected to a uniform external field is discussed from both macroscopic and microscopic points of view that part of the spur of the stress tensor which depends quadratically on the applied field is calculated for both nonpolar and dipolar dielectrics the lorenz lorentz and debye theories lead to the result that is zero but more modern theories lead to a different result 4969 millimeter wave absorption in superconducting aluminum available experimental evidence indicates that for wavelengths above the absorption is different for the normal and the superconducting states measurements are reported on a high purity al waveguide the ratio of surface resistivities for the superconducting and normal states is plotted as a function of temperature for various values the results are discussed in relation to alternative energy gap models 4970 very high frequency absorption in super conductors measurements indicate that the temperature at which the absorption departs from that in the normal state differs from the transition temperature by an amount strongly dependent on the frequency a brief discussion shows that this dependence follows immediately from the concept of a gap in the electron energy level spectrum of a superconductor 4971 glow to arc transition conditions for the glow to arc transition at moderately high pressures have been studied experimentally over this pressure range the transition is certain to occur only when the field reaches a critical value this result is consistent with a field emission mechanism for the transition 4972 theory of the high frequency discharge in gases at low pressures determination of starting conditions continuation of work reported previously the importance of secondary emission from the walls is emphasized experimental and theoretical curves of starting voltage as a function of pressure for frequencies of and are compared 4973 method of determining the cathode fall in a glow discharge a brief account is given of a method involving the use of a hot cathode discharge intive column surrounding the cold cathode in the other arm 4974 experimental verification of the wave mechanical theory of field electron emission methods described br are used to calculate the current density and field strength at a tungsten point and hence to estimate the accuracy of results obtained previously consideration is extended to the case when the tungsten is coated with foreign atoms 4975 electron emission from cold metal surfaces at medium field strengths report and discussion of measurements of the field emission of and cathodes gave the highest emission the lowest 4976 dynamics of ionized media the behavior of an ionized plasma is discussed in an approximation in which an individual particle is assumed to obey a fokker planck equation and where its interaction with the environment is incorporated in the coefficients of the partial differential equation 4977 the study of ferromagnetism in the institute of physics at the university of ferrara a short report outlining some of the more important results achieved both thin film and massive specimens have been studied research on internal dissipation is being pursued 4978 radiation emitted by a uniformly moving electron in electron plasma in a magnetic field results of the theoretical considerations presented indicate that cerenkov type radiation may be produced by charged particles not necessarily moving at relativistic speeds cosmic particles in the ionosphere the frequencies of the radiated ordinary waves lie in the range where is the plasma angular frequency that of extraordinary waves in the range where is the gyrofrequency extraordinary waves only are produced in weak magnetic fields and by relativistic electrons 4979 investigation of the propagation of signals in dispersive media using an acoustic model the theory of propagation of waves in a dispersive medium as developed by sommerfeld and brillouin is experimentally verified by measurements on an acoustic model which comprises a long hollow tube with closely spaced helmholtz resonators along it 4980 an approximate theory of the diffraction of an electromagnetic wave by an aperture in a plane screen theory based on the sommerfeld half plane solution is developed for certain regions the field can be conceived as arising from the flow of electric and magnetic currents along the edge of the half plane this concept is extended to apertures of arbitrary form the case of the circular aperture being studied particularly the theory is supported by results of measurements 4981 the magnetic screening effect of iron tubes the problem is approached by considering the induced pole strength on the surface of the iron the distribution of pole strength in general produces a magnetic field which varies from place to place over the screened region observations support the calculated values of screening ratio 4982 radio astronomy and the fringe of the atmosphere a survey presenting results of investigations on scintillations of radio stars in relation to the atmosphere in the altitude region on meteor echoes and on echoes from aurorae the determination of the total electron content in the earth moon space by the study of lunar echoes is discussed 4983 cosmic radio frequency radiation near one megacycle observations were made of cosmic radiation at and during the period march october at hobart tasmania photographs of specimen records are reproduced for values of the critical frequency near the observing frequency there is strong correlation between critical frequency and received amplitude for lower values of critical frequency the received amplitude increases to an independent limiting value the greatest intensity of the radiation arriving from the zenith when the plane of the galaxy was overhead was steradian at only ordinary ionospheric propagation was important in the observations recorded 4984 observations of emission from the sun during the solar eclipse of june at byurakan results presented graphically of intensity measurements during this partial eclipse show a decrease of up to the diameter of the sun and times the optical diameter at and respectively 4985 on deriving geomagnetic dipole field coordinates from cosmic ray observations the coordinates of an equivalent dipole representing the external geomagnetic field can be determined from measurements of the nucleonic component longitude and latitude effects in the region of the geomagnetic equator the measurement method and the relevant theory are outlined 4986 note on the adjustment of isomagnetic charts to mutual consistency 4987 variations in strength of wind system in the dynamo mechanism for the magnetic diurnal variation deduced from solar flare effects at huancayo peru 4988 electrophotometric investigation of atmospheric ozone during the solar eclipses of february and june 4989 abnormal propagation 4990 atmospheric temperatures and winds between rocket experiments made in new mexico between and september are described and the results are analysed the mean altitude distribution of temperature exhibits a maximum of about at with a lapse rate of about above the peak the highest wind speed was observed during winter its value was 4991 arctic upper atmosphere pressure and density measurements with rockets report of measurements made during and using rockets launched at an altitude of about from balloons the greatest altitude reached was about results deviated in some cases from previous rocket measurements 4992 electron distribution in the ionosphere addendum to an earlier note 4993 irregularity and regularity of the sporadic layer from observations at recording stations much information is obtained about the highest vertical incidence reflection frequency but less about the blanketing frequency results must be interpreted in statistical terms time and distance correlation functions are established diurnal seasonal and geographic regularities are discussed a sharp maximum in occurs at the magnetic equator no well defined influence of the solar cycle has been found and only a very weak lunar tide effect observations of the variation of reflection coefficient with frequency have been made apart from the routine evaluations in temperate latitudes in about a third of all cases there is no partial reflection in other cases local variations of electron concentration are such that the peak value mean value ratio is between and higher ratios are rare at low latitudes the variation may be more important ionograms of different stations have been classified for transparency scatter angle of incidence and layer development diffuse echoes exist often near the magnetic equator in most cases ionization originated as a thin layer of constant altitude transitory downward movements are responsible for in daytime a cumulo cirrus cloud layer is a good model for ionization possible ionization processes are discussed 4994 temperature distribution of the ionosphere under control of thermal conductivity bates theory is extended the energy absorbed in the region is assumed to be conducted downward into a denser region where it is dissipated by infrared emission calculations indicate that the atmosphere is isothermal above about and that there is a very strong temperature gradient between and the temperature in the isothermal region must be assumed to be to meet the requirement for the atmosphere near to support an region the low temperature at is due primarily to the lack of absorbed energy there rather than to the presence of a strongly emitting layer 4995 a new method for obtaining electron density profiles from records a practical and accurate method for reducing records to electron densities true height is described and used to analyse records taken at white sands direct measurements of electron densities in the ionosphere obtained with the aid of rockets are used to check the methos obtained by these two independent techniques are shown to be in excellent agreement twenty records were reduced for the period from all of which reveal a considerable degree of regularity in the height of the daytime and regions some of the profiles obtained are shown one of the illustrations shows a one hour sequence where the virtual height varied from whereas the true height remained essentially unchanged 4996 airborne ionospheric measurements the north po le area a brief preliminary report 4997 ionospheric observations at banaras during the total solar eclipse on june 4998 polarization of the echoes from the ionosphere details are given of an improved type of radio polarimeter similar in principle to that evolved by eckersley and farmer for operation in conjunction with high resolution sounding equipment with this arrangement it is possible to separate normal echoes from those received from thin layers or cloud type irregularities photographs of some observed polarization patterns are reproduced and briefly discussed 4999 the fading of radio waves of frequencies between 5000 the fading periods of the region coupling echo 5001 the determination of the horizontal velocity o ionospheric movements from fading records from spaced receivers a method is presented which does not require a long sample of record and which is valid for any distribution of orientation of lines of maximum amplitude the derived formula is compared with that of mitra 5002 a determination of ionospheric winds for a hour period results are given of an analysis using the method proposed by court of the fading records obtained at spaced receivers during an arbitrarily chosen period a diurnal variation of wind direction appears to be indicated 5003 on the deviations of the course of elements of atmospheric electricity on continents from the worldwide course extensive recordings show that continental deviations from the normal oceanic diurnal pattern potential gradient air earth current variations are caused mainly by positive space charges produced by urbanization industry and traffic and distributed by air movements 5004 relationships between aurora and sporadic echoes at barrow alaska report of observations of visual aurora made simultaneously with ionospheric soundings during the observations for three nights are described in detail analysis of the results shows that echoes at frequencies tend to occur when the aurora is near the zenith that there is a direct relation between the brightness of inactive aurorae and the top frequency of echoes and that echo ranges correspond with estimated slant ranges of visible auroral forms 5005 the annual variations of the atmospherics existence and explanation of a second maximum in winter if only strong impulses are counted records obtained at munich of the numbers of atmospherics received in frequency ranges and over a period of five years are analysed and evaluated from the meteorological point of view 5006 nirrc spectrograms of a type of whistler observed at college alaska made by analysing tape recording the nose whistler a new high latitude phenomenons are reproduced and discussed the initial or nose frequency depends primarily on gyrofrequency hence such observations should enable the effects of gyrofrequency and plasma frequency on dispersion to be separated thus leading to more reliable estimates of the ionization density in the outer ionosphere 5007 the interpretation of pulse trains associated with lightning flashes a treatment of the propagation of atmospherics by earth and ionosphere reflections assuming a radiation dipole source 5008 proceedings of fourth meeting of the mixed commission on the ionosphere publishers union radio scientifique internationale brussels contains papers presented in brussels in and discussions on them 5009 the electron voltaic effect in germanium and silicon junctions 5010 the effect of radioactive radiation on a photocell 5011 automatic control of power equipment for telecommunications and other essential services two types of no break generating sets are described an all electric battery operated equipment and a diesel electric equipment detailed descriptions are given of three electronic devices used with these sets a static exciter automatic voltage regulator making use of two saturated transductors an alternator synchronizer in which the generator and mains voltages are compared in a triode circuit speed regulator using a thyratron which feeds the control field of the motor and also incorporates alarm and protection devices 5012 servomechanism analysis gives the mathematical background for the analysis and design of servomechanisms including a clear introduction to the theory of laplace transformations 5013 stanford seattle whistler observations observations of times of occurrence of whistlers were made at seattle washington and stanford california for two hours every week from to in order to determine the percentage of shistlers received simultaneously at both locations the figure obtained was about this result is examined in relation to theories of whistler origin and propagation it gives support to theory 5014 a new serial digital decoder intermediate storage and an amplifier feedback loop are used making the decoder practically independent of clock timing pulses it can also be used in an analogue system to solve certain types of polynomial equation 5015 interconnection of electronic computers brief account of experiments on the joint operation of the and machines on business data processing work the former machine transmits control signals to the latter via a cable 5016 design and construction of small automatic computers with programming arrangement at the higher technical school in dresden illustrated description of a computer which includes about valves and measures the control desk is separate a magnetic drum store is used 5017 principles and application of electronic analogue computers typical examples of electrical analogues and the equipment for producing them are discussed and general design considerations are presented the saunders roe general purpose analogue computer is described 5018 new electronic analogue apparatus of the institute of automatics and telemechanics of the academy of sciences an illustrated description including block and circuit diagrams of the comprising a unit for solving linear differential equations of up to the sixth order a unit for solving nonlinear differential equations and a power supply unit as well as additional special purpose units 5019 design of a timing device and nonlinear units for an electronic differential analyser 5020 basic circuits used in digital automation commonly used circuits are described from a practical point of view with circuit diagrams and details of components 5021 an economical relay operated accumulator design details are given of a binary adder with a maximum capacity of about 5022 the hyperbolic field tube an electron beam tube for multiplication in analogue computers 5023 impedance and admittance surfaces three dimensional locus diagrams are used to investigate the variation of impedance and phase displacement in two pole circuits in response to variations of frequency resistance inductance or capacitance the impedance and admittance surfaces include straight lines corresponding to the important special case of zero phase displacement when the impedance is independent of the damping or detuning 5024 bridge and short arc erosion of copper silver and palladium contacts on break 5025 transformer design for zero impedance amplifiers lamination weight reductions of up to may be obtained without increased distortion in a transformer designed for an zero impedance output stage design formulae are given 5026 the stabilidyne a method for applying the harmonics of a quartz crystal oscillator to control the frequency of a receiver or transmitter is described for reception the signal frequency and a suitable harmonic of the crystal oscillator are separately mixed with oscillations from a common local oscillator and the two products are then mixed to obtain a frequency which is the difference between that of the signal and the crystal harmonic stability of the order of with a signal frequency of is readily obtained the characteristics of several industrial equipments are described 5027 a phase shift circuit for a wide frequency range a and a network are combined in such a way that the undesired phase changes at the outputs of the individual networks due to a frequency change cancel one another in the combined output 5028 calculations for ferroxcube pot cored coils a method of calculating core dimensions and windings is presented giving results accurate to within 5029 ferroresonant computing circuits the basic ferroresonant circuit and applications to switching and counting devices are described 5030 the equilibrium states of a bistable flip flop from the point of view of reliable and stable operation the influence of individual components on the functioning of the eccles jordan circuit is discussed and permissible tolerances for given performance are determined 5031 influence of an alternating voltage and a direct voltage on a nonlinear capacitor families of curves are presented showing measured variations of capacitance and tan as functions of a direct voltage and a voltage applied simultaneously for a capacitor with dielectric the curves facilitate determination of optimum working point for dielectric amplifiers 5032 linear systems the method of analysis presented previously is developed the treatment is applicable to all linear passive resonator systems whether damped or undamped 5033 possibility of free oscillations in a variable parameter resonant system comprehensive general analysis is presented for time variable linear systems 5034 papers presented at the conference on piezoelectricity 5035 the equivalent network of a piezoelectric crystal with divided electrodes a general equivalent circuit is worked out for the crystal treated as a quadripole for frequencies close to that of mechanical resonance 5036 spherical frustum cavities symmetrical spherical frustum cavities are studied as intermediate cases between the sphere and the cylinder resonance wavelengths and factors are determined by abeles method a wavemeter using a hemispherical cavity partly filled with is proposed curves are presented showing the variation of with cavity size for and 5037 theory of coupled endovibrators continuation of work noted previously a mathematical analysis is given of the propagation of waves in a chain of cavity resonators coupled by long narrow slots 5038 electromagnet oscillations in a parabolic tube as a particular case of the interactions of tow cavities through a throat free oscillations in a tube of parabolic profile and rectangular cross section are considered the tube is regarded as consisting of two cavities interacting through the throat the wave equation is derived and solutions are found for the cases where the two cavities are identical and not identical experimental results are in good agreement with the theoretical conclusions 5039 calculation of the natural frequency of a type cavity partly filled with an absorbing dielectric the system considered comprises a re entrant cylindrical cavity resonator with a solid dielectric specimen in the form of a truncated cone placed between the base of the cylinder and the butt end of the inner conductor formulae derived for the natural frequency and the damping can be used also to determine the components of the complex dielectric constant of the specimen this analysis also provides the theoretical basis of the measurement method described by works and others 5040 ferrites in resonant cavities a formula is derived for the frequency shift produced by introducing a sphere of ferrite into a resonant cavity 5041 parallel network a simplified design method is presented based on finding an equivalent network which is more amenable to mathematical treatment 5042 a note on bandwidth the concept of bandwidth is examined in relation to networks such as integrators which are not designed to provide faithful transmission of a waveform the bandwidth of such a network is defined as the maximum bandwidth of the input signal for which the output does nt differ from that of an ideal network by more than a prescribed amount 5043 resistance capacitance filter networks with single component frequency control 5044 a practical method of designing active filters a method for designing filters for the frequency range below about with sharp cut off is based on consideration of five basic variables namely two resistances tow capacitances and the gain from these further practical parameters are derived by taking the products of resistance and capacitance the ratio of resistances and the ratio of capacitances the active elements can in many cases be simple cathode follower circuits design data for a number of different cases are tabulated 5045 the design of low frequency high pass filters the design of a twin network incorporated in a feedback amplifier circuit is discussed and details are given relating frequency response to phase shift in the amplifier the use of compensating sections for securing a flat pass band characteristic is considered and a practical example is worked out 5046 new rejector circuit bifilar trap comments on of 5047 theory of noisy four poles english version of paper originally published in 5048 nonlinear coupled systems analysis applicable to valve oscillator circuits generally is presented different types of oscillator are distinguished topologically 5049 amplitude limitation in oscillators an oscillator which includes two biased diodes in the grid circuit to limit oscillation amplitude is analysed amplitude of oscillation and harmonic distortion are calculated and represented by curves from these curves it is observed that oscillations can be modulated linearly no frequency modulation occurs during amplitude modulation and harmonic distortion is very low also the circuit is found to be adequate for high frequency stability the distinctive feature of the circuit is shown to be that the static conditions of the valve such as bias voltage and direct anode current are independent of the oscillation amplitude a practical circuit is described 5050 developments in sound reproduction 5051 docile behaviour of feedback amplifiers a docile amplifier is one that remains stable when connected to any passive network of a specified class a simplified geometrical approach is used to derive the docility criteria for passive end loading ideal transformer feedback bilateral passive feedback and arbitrary passive feedback 5052 notes on the design of distributed amplifiers the treatment used takes account of the self capacitance of the coils and the effect of using anode and grid lines with different propagation speeds the latter effect can be useful in avoiding the large increase in gain of the derived filter type amplifier at the upper end of the band 5053 differential amplifiers with asymmetrical output the basic circuit discussed comprises a pair of similar triodes with equal resistances in anode and cathode leads when equal phase voltages are applied to the two grids voltages in phase opposition are produced at the cathode of one valve and the anode of the other the output is taken from the mid point of the circuit connecting these two points theory of operation is presented and two experimental models are described 5054 design of push pull magnetic power amplifiers the method is described in detail and is illustrated by discussion of a amplifier with a power amplification of and internal feedback 5055 principles of construction of magnetic amplifiers with a low sensitivity threshold 5056 high frequency operation of magnetic amplifiers digest of paper published in operation at high frequency makes possible power gains and bandwidths unattainable at power frequencies since a given power can be controlled with a smaller core 5057 junction transistors at high frequencies methods of stabilizing transistor amplifiers are discussed and formulae are presented for calculating the characteristics of a linear amplifier at any frequency and for determining the principal parameters of junction transistors with common emitter common base or common collector connections curves are given of maximum gain as a function of frequency 5058 the successive derivation of experimental laws refinement of the method of smoothing experimental curves described previously 5059 on the use of gram charlier series ot represent noise the stochastic time series produced by the random occurrence of identical events is considered if the waveforms corresponding to the individual events and to the resulting autocorrelation function and power spectrum are each represented by a gram charlier series relatively simple relations exist between the different sequences of coefficients if the noise bandwidth is not too great the number of terms in the series is small enough to permit computation the formulae are applied to the analysis of experimental data for noise associated with reverse current in a si diode 5060 on the theory of the acousto electric effect when an acoustic wave passes through an insulated solid it gives rise to an electric field in the direction of propagation the influence on this phenomenon of thermal lattice vibrations at temperatures above the debye temperature is investigated theoretically the calculations indicate that the field is proportional to both the intensity and frequency of the acoustic wave the effect is so small that it would not generally be observable in cu but is larger by several orders of magnitude in ge 5061 symposium on luminescence brief summaries are given of about papers read at the symposium held at minsk 5062 birefringence resulting from the application of an intense beam of light to an isotropic medium 5063 a new model of classical electron 5064 electron physics tables eight parameters are tabulated relating to the energy and motion of electrons accelerated by a potential difference 5065 magnetic moment of the electron a survey of experimental and theoretical work indicating evidence of anomalies 5066 electrostatic charges in plastics experimental evidence is presented that the static charge on plastics is a volume charge distribution rather than a surface distribution the charge contained in a plastic that has been in contact with metal is found to drain out of the plastic by a flow process which depends both upon the resistivity of the plastic and upon the possibility of neutralization of surface charges by opposite charges external to the plastic such as in air 5067 field dependence of magnetoconductivity a theoretical calculation is made of the dependence of the elements of the conductivity tensor on the magnetic field for the case of a crystal with arbitrary energy band structure the results are the same as would be given by a superposition of electron gases whose cyclotron frequencies are related harmonically the strengths of the harmonics depend on the band structure the diagonal of the conductivity tensor are monotonically decreasing functions of the magnetic field strength 5068 the characteristics of a discharge at a probe at a positive potential and the measurement of the associated gas density 5069 t t n the floating probe method for the measurement of ionized gas revised expressions are obtained for the positive ion current and electron temperature for the usual double probe method a triple probe method is proposed for measurement of energy distribution in electrodeless or discharges and the applicability of the techniques is discussed 5070 formulae for the mean losses of energy in collisions of slow electrons moving in diatomic gases approximate formulae are derived which correspond closely with results of experiments for electrons of low energy the formulae are relevant to the theory of interaction of radio waves 5071 two electrode high frequency discharge at pressures from to atmospheric an experimental investigation is reported of discharges in nitrogen and argon at frequencies of to and variation of running voltage with electrode separation and variation of electric field with pressure are shown graphically and photographs of discharges are reproduced 5072 theoretical interpretation of field emission experiments experimental results obtained by various workers on field emission from tungsten and barium on tungsten surfaces are discussed in relation to theories regarding the nature of the surface potential barrier and the distortion of the field by space charge 5073 kinetic theory of the lorentz gas case of maxwellian molecules discussion of differences between the views and results of the author and those of 5074 use of the boltzmann equation for the study of ionized gases of low density the behaviour of the gas in a strong magnetic field is discussed 5075 on the dipole resonant mode of an ionized gas column calculations show that the multiple resonances found by were created by the discontinuities in their approximation to the gaussian function and that the actual gaussian distribution exhibits only one resonance 5076 fundamental equations of a classical non conservative electromagnetism 5077 the computation of coils for producing uniform magnetic fields and constant field gradients calculations for helmholtz coil systems are presented for the field at the mid point on the axis to be uniform the second derivative of the field in the axial direction must be zero at that point for the field gradient to be constant the third derivative must vanish families of curves suitable for design purposes are derived 5078 incidence of electromagnetic waves on double infinite grids the system considered comprises a double grid of parallel metal rods the grids are spaced apart and the rods in each grid are spaced apart the rods in one grid being staggered by an amount relative to the rods in the other grid the radius of the rods is calculations are made of the reflection coefficient and the refractive index corresponding to three values of for and for normal incidence with 5079 a method for integrating maxwells equations maxwells equations for propagation of waves are integrated for the case where the functions representing the wave contours are separable applications are discussed showing the relation between the theory and geometrical optics 5080 variational method for the calculation of the distribution of energy reflected from a periodic surface 5081 experimental study of the diffraction of microwaves by rotationally symmetrical apertures measurements at have been made using circular and annular apertures the results indicate that diffraction calculations based on kirchhoffs approximation are accurate to within at planes as close as twice the diameter of the aperture the accuracy improving as the distance increases 5082 rigorous solution of a particular diffraction phenomenon diffraction of a plane wave by a perfectly conducting infinitely thin screen is analysed using an infinite system of algebraic equations and an infinite number of unknowns for th case of the electric vector parallel to the screen edges the procedure is to calculate the vector potential for the surface assuming a sinusoidal distribution of parallel straight line currents extension of the method to the more general case of arbitrary direction of electric vector would be feasible using electronic computers 5083 structure of a magnetohydrodynamic shock wave in a plasma of infinite conductivity the analysis presented is relevant ot problems of solar radiation the ionosphere and cosmic rays 5084 growing electric space charge waves theory presented previously purporting to explain the operation of the electron wave valve and the origin of solar emission is shown to be unsound alternative theory is given 5085 some measurements on the spectral line shape and width of a paramagnetic resonance absorption line measurements on hydrazyl at a frequency of about are reported 5086 the motion of charged particles in weakly variable magnetic fields analysis is simplified by considering in place of the actual particle which follows a helical path an equivalent particle following a mean path and having a magnetic moment 5087 interaction of excitons with lattice vibrations in polar crystals 5088 early history of radio astronomy 5089 cosmic radio sources observed at a survey has been made over most of the celestial sphere between declinations and using a narrow pencil beam discrete sources giving flux densities of about were identified including which may not have been previously reported nearly all the discrete sources are associated with irregularities of the background radiation 5090 radio emission from novae and supernovae attempts have been made to observe the radio emission at from two supernovae and ten novae keplers star was the only reasonably certain identification a comparison with radio observations of other supernova remnants suggests a constant ratio between the present radio emission and the maximum emission of light it is concluded that for common novae which are not detectable as radio sources this ratio must be smaller than for supernovae the galactic radio emission near the plane of the milky way could be largely the integrated emission of supernova remnants but common novae could not contribute appreciably 5091 the masses of the magellanic clouds from radio observations 5092 radiation from jupiter an examination of records at sydney shows that bursts at observed in and previously ascribed to a terrestrial cause were in fact due to radiation from jupiter this confirms the observations of some new observations are also mentioned the usefulness of jupiter radiation for studying propagation conditions near the sun is pointed out 5093 observation of an eclipse of the crab nebula report of observations at frequencies of and during the occultation of the crab nebula by the moon on the radio source corresponds closely to the visible structure of the nebula it is deduced from this result that the electron density in the lunar atmosphere is 5094 the daily variation of the cosmic ray intensity measured near the sunspot minimum 5095 a note on the interpretation of transient echoes from the ionosphere comment on a note by recent radio echo work on meteors shows that a midday maximum is often observed in the rate of occurrence of meteors observations with narrow beam aerials on show that a tendency during the months for the main peak to occur at is completely reversed from to when the major peak occurs during the daytime 5096 the suns general magnetic field 5097 the solar outburst observations by the royal greenwich observatory cosmic ray photographic and magnetic observations are presented records of the intensity of atmospherics on a frequency of show a very substantial decrease in received signal level at which appears to be attributable to the cosmic ray increase associated with the flare 5098 a long wave anomaly associated with the arrival of cosmic ray particles of solar origin on records of atmospherics received on a frequency of at the royal observatory show a sudden decrease coinciding with the time of arrival of solar cosmic ray particles in the dark hemisphere of the earth 5099 some unusual radio observations made on records of sky wave signals obtained at on frequencies showed very strong absorption during the occurrence of the solar flare of this date on the main effect was a decrease of in the reflection height on frequencies at upsala almost complete absorption occurred from sunrise until the late afternoon 5100 symposium on the earth satellite program vanguard of outer space the text is given of seven papers presented at a symposium held in dealing with various aspects of the plans for launching earth satellites during the international geophysical year 5101 the crust as the possible seat of earths magnetism magnetic material in the earths crust to a depth of will be highly permeable as a result of temperature and pressure conditions interaction between solar corpuscular streams and a very weak initial magnetic field in the crust will magnetize it to saturation the estimated magnetic moment of the shell agrees with the observed magnetic moment of the earth 5102 long period variations in geomagnetic activity analysis of data shows that correlation between the sunspot number and the magnetic figure is markedly improved by taking means for the year sunspot number cycle and for the year sunspot magnetism cycle in place of annual means 5103 theory of the rocket grenade method of determining upper atmospheric properties by sound propagation theory applicable to projected experiments is developed from earlier work a knowledge of the composition of the atmosphere and of the velocity of the sound of the explosions is assumed 5104 electron distribution in the ionosphere analysis of records by the method described earlier suggests that the ionosphere consists of three chapman layers and and that the temperature is uniform 5105 effective tilts of the ionosphere at places about fuller account of work described previously 5106 the rates of production and loss of electrons in the region of the ionosphere from the results of the rates of production and loss of electrons in the region are deduced bradburys theory of the formation of the layers is shown to be self consistent it gives a scale height of for the ionizable constituent of the atmosphere between and this result agrees better with the atmospheric model deduced by bates from rocket experiments than with the model deduced from experiments made on the ground limits are established for the movements caused by electron diffusion under gravity 5107 the formation of the ionospheric layers and it is shown that an electron loss coefficient varying with height in the manner suggested previously would explain the known facts about the splitting of the layer and might also be a factor in determining the height of the peak of electron density in the layer 5108 the distribution of electrons in the undisturbed layer of the ionosphere the variation of electron density with height is deduced from records obtained at watheroo huancayo and slough and the form of the typical layer for magnetically quiet days is described in a series of curves detailed tabulated results are available at the cavendish laboratory 5109 processes controlling ionization distribution in the region of the ionosphere rocket measurements at heights approaching suggest that the atmospheric density in the region may be some times less than previously deduced from radio experiments if the new value were correct diffusion of ionization under the forces of gravity and of its own pressure gradient would be likely to affect the shape and height of the region notably an investigation was made of the possible effects of diffusion processes at such levels the results indicate that a region with arbitrary height distribution of ionization will by diffusion assume the form of a chapman region after a time which for levels is a few hours if the radio determinations of density are correct but only a few minutes if the rocket determinations are correct it is suggested that there must be a systematic error in the rocket observations 5110 observations and analysis of ionospheric drift spaced receiver fading observations made at puerto rico during on and indicate average drift speeds of and respectively the data are thought to apply to the layer and the data to the layer owing to random changes the method of similar fades is less reliable than the correlation method of evaluation 5111 automatic recording of ionospheric characteristics following the proposals of nakata a device is proposed which gives a direct record of 5112 ionospheric recorders and sporadic brief report of tests made at brisbane disproving the statement which has been made by various workers that the observed frequency characteristics of the region vary rapidly with the overall sensitivity of the recording equipment 5113 spread layer echoes and radio star scintillation correlation is noted between observations of radio star scintillations at one station in equatorial africa and of spread layers at another distant disturbed magnetic conditions in winter cause decreased layer spread 5114 ionospheric observations during the solar eclipse of observations made at haringhata miles of calcutta are reported the recorder used provided a frequency sweep from to in the observed variation of shows that the disappearance and reappearance of the ionizing radiation source for the layer was not symmetrical with respect to the time of the eclipse maximum the ionization of the layer also showed a marked drop during the eclipse an observed drop in the ionization of the layer may or may not have been an eclipse effect 5115 lunar variations in the ionosphere the global pattern of the observed lunar variations of the height and electron density of the region is summarized new analyses being presented for canberra brisbane and washington the height variation has an amplitude of maximum height occurs at lunar hours at moderate latitudes and at lunar hours at the geomagnetic equator the variation of has an amplitude of the maximum occurs at about lunar hours at moderate geomagnetic latitudes and at lunar hours near the geomagnetic equator theory is developed on the basis of a current system at a height of about the tidal winds needed to drive the current the potential distribution in the dynamo layer and the resulting periodic vertical drifts of ionization in the higher layers are calculated the lunar variations in are calculated taking into account probable height variations of recombination coefficient and ionization production rate the results are in good agreement with observations it is concluded that the amplitude of the lunar tidal wind near the layer is about times greater than that on the ground 5116 influence of variable flow of positive solar particles on the wind in the ionosphere qualitative results of a calculation of the interaction of electrodynamic and hydrodynamic forces in the ionosphere at a height where the two forces are of the same order of magnitude indicate a distribution of wind velocity and direction similar to that observed by hoffmeister and shown in shows the variation of the and components and of the resultant of the wind velocity over a day period 5117 oblique transmission by the meteoric layer 5118 the nature and detectability of clouds and precipitation as determined by radar 5119 measurement of atmospheric absorption on using solar radiation measurements were made at various times of day using a radiotelescope described previously only a part of the attenuation observed during sunset can be attributed to absorption by oxygen and water vapour the remainder about is so far unexplained 5120 the height of emission of the line of the air glow as observed on the jungfraujoch a mean altitude of is deduced 5121 a theory of scattering by nonisotropic irregularities with application to radar reflections from the aurora the existence and aspect sensitivity of auroral echoes can be explained as back scatter from nonisotropic columns of ionization parallel to the earths magnetic field of length about and diameter caused by turbulence in an region having a maximum electron density about times the normal value but the theory fails to explain the rapid fading rates associated with auroral echoes 5122 low frequency atmospheric noise levels in southern and central africa detailed report of measurements made to determine the interfering effect of atmospherics on radio navigation aids results are presented graphically and discussed with reference to local thunder conditions 5123 meteors the text is given of the papers presented at the symposium reported previously 5124 the design and operation of transistor converters circuits are discussed in which a junction transistor is made to oscillate and thus to chop the current from a battery the chopped current is fed to a transformer or ringing choke and the stepped up voltage output is rectified and smoothed design procedures are described in detail see also of 5125 germanium and silicon power rectifiers the development of junction power rectifiers is reviewed and the special features of a unit rated up to are described for a shortened version see 5126 germanium power rectifiers the production and characteristics of junction rectifiers capable of handling current densities of the order of at an ambient temperature of are described and compared with those of other rectifiers some suitable circuits are indicated 5127 an voltage stabilizer a temperature limited diode placed in one arm of a resistance bridge controls the output voltage through a saturable reactor and autotransformer 5128 wafer cells the burgess dry battery is described and discharge characteristics are given the cells are of sandwich construction hermetically sealed and the construction affords substantial savings in size and weight as compared with earlier types of dry battery 5129 the logical design of an idealized general purpose computer a detailed discussion emphasizing the distinction between the logic requirements and the particular physical form of a digital computer 5130 analog computers for the engineer a rewiew of computer techniques with tabulated data for some commercially available types 5131 electronic methods of analogue multiplication a general survey of the principles used different systems are compared as to accuracy speed and complexity 5132 high speed electronic analogue computing techniques 5133 an analog computer for the solution of tangents a modified wheatstone bridge arrangement is described permitting computation of the tangents of angles between and only linear elements are used the accuracy achieved is within part in the design of plug in units is discussed 5134 design of diode function simulators 5135 digital computer techniques brief report of a convention held at the institution of electrical engineers london in papers were presented the full text together with reports of the discussion is to be published in three sections as a supplement to 5136 a variable multiple pulse stream generator apparatus designed for checking the logic of electronic computer circuits which require numerous pulse streams for their operation is described the electrostatic pickup described previously of is used 5137 analog computer for the differential equation a high precision electromechanical system developed from that mentioned previously uses a torsion pendulum whose motion corresponds to the given expression the solutions are obtained from photographic records of the motion 5138 binary adder uses gas discharge triode 5139 pulse circuits fabricate computer code disk frequency divider counter gate and wave shaping circuits control optical circle dividing machine to produce bit pattern on photosensitive glass disk used for analog to digital conversion the code disk has a pattern accuracy of inch and can be made in about hours for another account see 5140 an introduction to electronic analogue computers 5141 an experimental investigation of subharmonic oscillations in a nonlinear system forced subharmonic oscillations in a circuit containing an iron core are studied damping is reduced by means of feedback so that measurements can be effected at very low driving voltages and subharmonics up to the ninth results are in good agreement with theory developed by lundquist for low driving voltages 5142 frequency conversion with positive nonlinear resistors positive nonlinear resistors are defined as two terminal devices through which the current is a real finite single valued nondecreasing function of the voltage across the terminals with the added condition that when subjected to an almost periodic voltage such a resistor will absorb power at some frequencies and supply power at other frequencies analysis indicates that modulation efficiency cannot exceed unity that subharmonics are not produced and that the efficiency of generating an harmonic cannot exceed 5143 winding focus coils with aluminium foil coils of al foil with a thin coating of al oxide are wound with no additional insulation 5144 polychloronaphthale impregnated paper capacitors polychloronaphthale waxes are particularly suitable for use as impregnants in paper dielectric capacitors having stable characteristics at temperatures as high as or over in certain cases an aging effect is avoided by allowing the wax to cool from the liquid to the solid state under the influence of an or field this phenomenon is discussed in relation to the dipole nature of the waxes 5145 industrial measurement of the temperature coefficient of ceramic dielectric capacitors 5146 tantalum solid electrolytic capacitors a capacitor with low volume capacitance ratio is obtain ed by forming a layer of on a porous ta anode and then depositing a number of coatings of to form a solid electrolyte the unit is further coated with graphite and a layer of alloy is sprayed on to form the cathode temperature frequency and life characteristics are reported 5147 inter reciprocity applied to electrical networks a new concept inter reciprocity is introduced which is useful in the study of nonreciprocal networks when a particular topological operation termed transposition is performed on a given linear network the initial network and the resulting transposed network are said to be inter reciprocal application of the theory to a variety of general and special circuit problems is illustrated the noise properties of gyrator triode and transistor networks are discussed 5148 the effect upon pulse response of delay ariation at low and middle frequencies calculations are given for the magnitude and form of the distortion introduced into a square wave by a network or system which exhibits uniform transmission except for increasing phase delay in the low mid frequency region the fractional peak distortion is found to be equal to twice the area under the curve relating to frequency where is the delay relative to that at high frequencies the waveform of the distortion is given for several simple shapes of curve for this distortion is especially characteristic of vestigial sideband systems and occurs in television as a pre shoot before a transition and as a smear after it 5149 feedback theory further properties of signal flow graphs continuation of theory presented previously 5150 transient behavior in a ferroresonant circuit an analysis is made of the response to a sinusoidal voltage of a circuit including a nonlinear inductor for certain frequency values of the applied voltage there are three possible values for for the flux in the inductor of which the middle value is unstable the differential equation representing the circuit has been solved using an analogue computer for the case when the system is released in the region of the lower stable state the solution corresponds to two sinusoidal oscillations of different amplitude and frequency if the system is released in the region of the upper stable state the solution corresponds to an oscillation modulated in amplitude and phase for certain values of the parameters 5151 measurement of the factor of cavity resonators using a straight test line 5152 some general properties of nonlinear elements general energy relations an analysis is made of power relations in networks with reactive nonlinear elements two equations are derived relating the powers at different frequencies the only assumption introduced is that the nonlinear characteristic is single valued the theory is relevant to the operation of modulators demodulators and harmonic generators 5153 tables of phase of a semi infinite unit attenuation slope the five figure tables published previously are to appear together with newly prepared seven figure tables as 5154 fundamentals in the synthesis of loss free quadripoles from lines with continuous non uniformities the synthesis is facilitated by appropriate choice of line coordinates and a polynomial representation of the characteristic impendance application to problems of wide band transformation and matching are illustrated 5155 impedance quadripoles for the frequency compensation of aerial input impedance networks with one or two frequency independent resistances are discussed which are capable of effecting wide band matching with lower losses than reactive circuits at frequencies up to or above composite coaxial line sections are used in an application to a dipole aerial for use with a parabolic cylinder reflector he compensating coaxial line serves as support for the dipole 5156 normalized representation of transients in filter amplifiers with double elements the response of amplifiers with frequency dependent negative feedback is analysed for various pulse and step waveforms the frequency spectrum corresponding to a train of square pulses is determined 5157 a solution to the approximation problem for low pass filters a method of synthesizing filters is described in which elliptic functions are used to effect a transformation in the complex frequency plane which results in a symmetrical arrangement of the zeros and poles some design charts are included 5158 a particular case of the application of the matrix method to radio engineering use of the matrix method in analysis of the operation of quadripoles including thermionic valves or transistors is discussed a simple method is proposed for carrying out the necessary transformations to the formulae on passing from the one case to the other 5159 application of electron spin resonance in a microwave oscillator or amplifier 5160 constant frequency oscillators comment on 5161 bridge stabilized oscillators and their derivatives reprinted from general analysis is presented for the operation of the bridge stabilized feedback oscillator and modifications obtained by interchanging bridge elements crosswise or by unbalancing the bridge are discussed 5162 frequency stability and quartz controlled oscillators the operation of some commonly used types of crystal controlled oscillator is reviewed frequency can be held constant to within a factor of over period of months by using a bar crystal resonator 5163 bistable circuits using triode pentodes note on the operation of multivibrator type circuits in which one feedback path is provided by connecting triode anode to pentode screen leaving one grid free for triggering gating or modulation 5164 simple method for producing pulses of short duration and large amplitude pulses of duration about and peak to peak amplitude about are obtained from the tuned secondary of a transformer in the cathode circuit of a thyratron 5165 applications for tandem transistors the tandem transistor consisting of two transistors housed in a single container and cascaded so that one acts as the base leak for the next may be used as an amplifier with high input impedance and in various applications in which single grounded emitter stages are normally used 5166 superregenerative transistor oscillator the circuit described generates pulses of tone at a rate of the performance with different values of quench capacitor bias feedback is shown graphically 5167 investigation of special frequency dividers with large dividing ratio two frequency dividers and one pulse counter are developed on the basis of kroebels work these give stable dividing ratios of and at input pulse frequencies of and respectively the counter can handle irregular pulses spaced at intervals of 5168 a new high slope multigrid valve and its application in pulse and switching circuits 5169 a point contact transistor scaling circuit with resolution simple circuits using normal point contact transistors are described features contributing to the short resolving time are the prevention of bottoming of collector potential and the absence of capacitors a typical scale of ten circuit uses seven transistors seven pulse transformers and crystal diodes wide tolerances on the transistor parameters are permissible 5170 a junction transistor scaling circuit with resolution the basic circuit discussed is a binary scaler using a differentiating transformer instead of capacitors for coupling the speed of operation thus depends only on the transistor characteristics scale of and scale of circuits built up from the basic circuit are described 5171 disc seal triode amplifiers the design of a resonant type coupling network for discseal triodes operating in the earthed grid connection at frequencies in the range is considered a coaxial form of line is adopted tuning for a small range can be by a screw or for a larger range by a built in capacitance complete amplifiers can give output and gain using three stages 5172 higher pentode gain note on the use of a transistor as an anode load 5173 noise in an amplifier stage with negative voltage feedback the problem is considered with particular reference to the input circuit of an amplifier for a magnetic tape recorder analysis indicates that frequency distortion inherent in the system can be corrected by use of negative feedback at the input valve and indicates the existence of an optimum ratio for the input transformer from the point of view of signal noise ratio 5174 triode cathode followers for impedance matching to transformers and filters design curves derived from measurements on five different types of triode are presented 5175 an improved type of differential amplifier a differential amplifier stage capable of giving a high rejection ratio with unselected valves and components and without a balance control is analysed and a particular amplifier is described in some detail the stage is particularly suitable for converting balanced to unbalanced signals 5176 comparison of some magnetic amplifier circuits with internal feedback 5177 push pull magnetic amplifier with direct current output 5178 decicycle magnetic amplifier systems for servos digest of paper published in improvements in circuitry and core materials and the adoption of pulse techniques make possible systems whose response times are one tenth to one hundredth of a cycle of the power supply frequency 5179 a ferrite microwave modulator employing feedback an amplitude modulator with good linearity is obtained by applying feedback to a gyrator comprising a ferrite rod in a circular waveguide section interposed between rectangular waveguide sections the feedback circuit is based on linear detection of the amplitude modulation by means of a crystal limitations of the arrangement are discussed good results have been obtained with sinusoidal modulating signals of frequencies up to 5180 handbook preferred circuits navy aeronautical equipment gives design details and characteristics of the standardized circuits discussed previously supplements are to be issued from time to te 5181 linear feedback analysis a useful introduction to the subject 5182 electron plasma oscillations in an external electric field the oscillation frequency is calculated assuming that the electron distribution function satisfies a given kinetic equation 5183 fields and stresses in dielectric media expressions are obtained for the mechanical forces at the boundary of an isotropic dielectric caused by an electric field results are verified in particular cases by electrolyte tank experiments 5184 on the energy dissipation of conduction electrons undergoing elastic scattering by impurities a brief theoretical note on the mechanism responsible for the energy dissipation in conduction in metals 5185 theory of galvanomagnetic phenomena in metals the theory is developed without making any special assumptions regarding the conduction electron dispersion law and the form of the collision integral 5186 anomalous skin effect assuming arbitrary collision integral results of a calculation of the surface impedance show that the ratio equals for an arbitrary electron dispersion law and an arbitrary collision integral is proportional to and is independent of temperature in the anomalous skin effect temperature range 5187 statistics of electron avalanches in a uniform field the statistical distribution of the number of charge carrier pairs about the mean was determined experimentally by measurements on discharges in ethyl alcohol results agree with theory 5188 surge voltage breakdown of air in a nonuniform field experiments on discharges between a spherical and a plane electrode are described and a tentative explanation of the breakdown mechanism is presented 5189 investigation of a discharge in the frequency region between high frequency and audio frequency at low gas pressure 5190 investigation of the high frequency discharge the dependence of the ignition and operation potentials in and on the gas pressure and the geometry of the discharge space was investigated in the frequency range results presented graphically are in agreement with the diffusion theory of 5191 influence of an adsorbed film of dipole molecules on the electron work function of a metal experimental results indicate that films of molecules decrease he work function of by up to as compared with a decrease of up to produced by 5192 auger electron emission in the energy spectra of secondary electrons from and analysis of the observed energy distributions of the secondary electrons for a range of primary energies reveals subsidiary maxima at points along the energy axis characteristic of the target meterial but independent of the primary voltage the positions of these points are consistent with an auger process origin for the electrons with these energies 5193 investigation of the inelastic reflection of electrons by a cuprous oxide surface the energy losses of electrons on reflection at monocrystalline or polycrystalline surfaces are equal to the energy required to transfer electrons of the crystal lattice from filled to permitted zones the mechanism involved is similar to that responsible for the appearance of discrete groups of true secondary electrons 5194 production and use of high transient magnetic fields technique for the production of pulsed magnetic fields of strength or over is discussed capacitor discharge arrangements are used with impact resistant solenoids comprising massive single layer helices pulse durations range from to measurement of the magnetoresistance of is one of the applications mentioned 5195 radio frequency physics brief report of the annual conference held at geneva of the organization which is concerned with the use of radio frequencies in the various branches of physics some papers were presented the subjects including dielectric and magnetic properties electron resonance of various types and associated effects and microwave spectroscopy which gives papers from the conference held at paris covering a similar range of subjects and including also some material on atmospheric physics 5196 application of electron spin resonance in a microwave oscillator or amplifier a brief analysis indicates the condition for a paramagnetic substance located within a cavity resonator and subjected to a direct magnetic field to supply power instead of absorbing it from the field results of preliminary experiments indicate that it should be possible to produce oscillations using a small sample of si containing a suitable impurity providing a concentration of about paramagnetic centres per 5197 radiation from molecules in the presence of a strong high frequency field it is shown that in addition to an absorption of the energy at a frequency where are energy levels of the molecule emission takes place at a frequency which is a function of the matrix element of the dipole moment corresponding to the transition and the field strength of the field in a typical case and the field strength is the value of is then approximately the radiation is only present if the elements and are not equal to zero 5198 fourier transform method for the treatment of the problem of the reflection of radiation from irregular surfaces 5199 incidence of an electromagnetic wave on a cerenkov electron gas analysis is presented for the interaction of an wave in a retarding medium with an electron gas moving through or near the medium at a velocity exceeding that of the wave in the medium for electron densities exceeding a critical value the gas acts as a mirror for the incident wave possible laboratory experiments for investigating the problem are outlined 5200 method of calculating electromagnetic fields excited by an alternating current in stratified media the expressions for the field due to a dipole in the boundary of a stratified half space are developed in a form suitable for evaluation by a modern computer the characteristics of the strata are assumed to be independent of time and of the field the permeability is constant and the conductivities are arbitrary the conductivity of the surface layer is finite 5201 absorption devices for centimetre electromagnetic waves and their acoustic analogues a survey of the operating mechanism of three types of absorbers homogeneous material wedges and resonance absorbers 5202 thermo and galvano magnetic effects in strong fields at low temperatures thermoelectric force resistance and hall effect of a metal in a magnetic field at low temperatures are calculated using a two zone model of the metal 5203 an investigation of monochromatic radio emission of deuterium from the galaxy 5204 gravitational influence of jupiter on some geophysical phenomena consideration of astronomical observations from ancient times onwards has indicated apparent variations in astronomical time attention is drawn particularly to a variation having a period of years this is also the period taken by the sun the earth and jupiter to return to the same alignment and relative distance it is suggested that the combined gravitational action of the sun and jupiter causes tidal motion in the earths crust the apparent variation of astronomical time corresponding to a real displacement of the meridian 5205 atmospheric attenuation of solar millimeter wave radiation measurements have been made of the absorption of solar radiation by atmospheric water vapour at wavelengths down to about the results are combined with theoretical formulae for the absorption spectrum of water vapour 5206 origin of the meinel hydroxyl system in the night airglow 5207 a photometric unit for the airglow and aurora 5208 note on the variations of atmospheric ozone as a function of height observations confirming those of paetzold are reported 5209 symposium on ionospheric drifts brief report of symposium held at new delhi i 5210 accurate height measurements using an ionospheric recorder a method for the calibration of an ionospheric recorder is described which corrects errors in height measurement arising from the distortion of the echo pulse in its passage through the receiver the amount of this error depends on the echo amplitude and is shown to vary in an approximately linear manner with the width of the recorded echo trace several methods of checking the calibration confirm that it is reliable to within using a calibrated recorder and an expanded timebase it is possible to measure region equivalent heights to this order of accuracy the systematic error due to pulse distortion will in general cause the heights recorded in routine ionospheric measurements to be from to too high some consequences of this for predictions are mentioned 5211 monthly mean values of ionospheric characteristics at rome in the period hourly values are tabulated for the critical frequency and virtual height of the and layers and for the percentage of occurrences of the layer brief particulars are given of the sounding schedule operated and the conventions adopted in the calculations 5212 sporadic echoes from the region over ahmedabad an analysis is made of records for the sunspot minimum period the diurnal and seasonal variations of as a whole are interpreted as variations in the relative contributions of three distinct types of namely a thin layer observed at with a maximum frequency of occurrence at late evening which is observed at with a minimum in the afternoon and maximum towards the end of the night and at developed by the vertical downward movement fo the layer and observed only during the daytime 5213 a new theory of formation of the layer electron pairs generated in the upper part of the region diffuse rapidly downwards under gravity but at sufficiently low heights they are rapidly lost by the mechanism of charge transfer and dissociative recombination suggested by bates and massey giving rise to a maximum ionization density at a greater height this theory gives results in accordance with observations 5214 the structure of the layer as deduced from its daily variations observed variations in the region may be accounted for by assuming that in consequence of the decrease with height of the effective decay coefficient the maximum electron density in the region is at a level above that of maximum electron production and that vertical semidiurnal tidal drift is nonuniform at the level of maximum electron production the rate of production varies inversely as temperature an attachment coefficient of at is indicated with a solar temperature of 5215 geomagnetic control to the diurnal variation of the layer on the temperate latitude the longitude effect demonstrated by appleton is examined the observed diurnal variation is consistent with geomagnetic control of the thermal vertical flow in the region seasonal variations are also observed 5216 comparison of at four observatories in japan observations over the solar activity half cycle are correlated with sunspot numbers on a long term basis the magnitude of the variation of is a function of latitude 5217 negative oxygen ions in the upper atmosphere the affinity and radiative attachment coefficient of atomic oxygen the influence of negative ions of atomic oxygen on the physics of the ionosphere and night airglow is re examined in the light of new experimental determinations of the oxygen affinity and photodetachment cross section the radiative attachment coefficient is calculated from th photodetachment cross section there is no evidence of a resonance at the threshold where the attachment coefficient is approximately 5218 observations of ionospheric absorption at the theory of ionospheric absorption is outlined and measurement difficulties due to fading are discussed the procedure at the netherlands station is to determine the apparent reflection coefficient for vertically incident waves using pulse transmissions with display of the echo amplitude total absorption and absorption index are hence derived the equipment is described and some results are reported 5219 on the existence of a transition level in the ionosphere and its experimental evidence and effect 5220 back scatter ionospheric sounder 5221 a correlation treatment of fading signals 5222 on the propagation of whistling atmospherics it is shown that the dispersion of whistling atmospherics propagated along the lines of force of the earths magnetic field should be greatly dependent on the geomagnetic latitude of the observing point the change in the magnetic field intensity along a line of force produces an upper frequency limit for whistler propagation which at latitudes greater than should fall within he usually observed frequency region of dispersion curves showing this critical frequency are given for geomagnetic latitudes and 5223 sudden decrease in low frequency atmospheric noise during the cosmic radiation storm of february note of observations on at churchill manitoba the relation of the disturbance to solar flare conditions and to the proximity of the station to the auroral zone is briefly discussed 5224 influence of the horizontal geomagnetic field on electric waves between the earth and the ionosphere travelling obliquely to the meridian a more general case than that noted earlier is considered briefly results indicate that the differences in the type of atmospherics waveform arriving from south east and from south west are due to differences not in the propagation but in the nature of the discharge which may occur over the sea in one case over land in the other 5225 the low frequency noise of the geomagnetic field grenets investigations of the source of disturbances are discussed observations made in the sahara are reported a telephone cable formed into a circular loop of diameter was used as aerial in conjunction with a multistage amplifier and pen recorder the total frequency band explorable was the results indicate that the low frequency pulses received are almost entirely due to atmospherics this confirms grenets theory 5226 electromagnetic phenomena of natural origin in the band a report is presented of observations made at an isolated region in oregon in the summer of air core detector coils were used one with an effective area of for observing the vertical magnetic field component and another with an effective area of for the horizontal north south component voltage waveforms proportional to the field and to its time rate of change were studied by means of photographic records from oscillographs the signals recorded are predominatly of burst type the horizontal component being more intense than the vertical the level of activity exhibits a systematic diurnal variation comparison with the incidence of atmospherics suggests that the low frequency signals are associated with lightning while the timing of the daytime maximum indicates that the propagation mechanism is different from that for the atmospherics 5227 the propagation f a radio atmospheric 5228 propagation of audio frequency radio waves to great distances 5229 electromagnetic momentum and elect on inertia in a current circuit the magnetic energy of a current circuit is identified with the kinetic energy of the mass equivalent of the total energy of the conduction electrons the concept of momentum in a current circuit is used to determine the force on the end wire of a long rectangular circuit and to bring the known effects of electron inertia in a circuit within the scope of theory an on off servomechanism with predicted change over a general method has been divised f r achieving optimum switching with an on off control system the practicability of predicting the ideal switching time has been demonstrated with a model experiment for wich responses to step ramp and parabolic input functions have been found to compare favourably with those of an orthodox system 5230 the dual input describing function and its use in the analysis on nonlinear feedback systems 5231 thermoelectric cooling a brief account is given of theory of thermoelectric cooling published by the academy of sciences moscow and of experimental results temperature differences habe been obtained applications being investigated include cooling of components in radio and electronic equipment 5232 diffused junction silicon rectifiers development types with current ratings for reverse peak voltages over are described operation is satisfactory at temperatures 5233 the forward characteristic of the diode theory for the diffused junction diode indicates thet the forward characteristic should be similar to that of the simple diode until the current density approaches lnoma ies in the characteristic at low current densities are unrelated to the presence of the weakly middle region 5234 thermoelectric generators basic design formulae are given abd discussed using a semiconductor layer thick with thermoelectric coefficient a temperature difference of across it and a heat input of a d assuming a specific mass of and an efficiency of an output of may be obtained 5235 bibliography of literature on mathematical simulation about items are listed including books conference reports and papers about references are to russian literature 5236 electronic differential analyser of the krzhizhanovski energetics institute of the academy of sciences the analyser comprises operational amplifiers four multipliers and four function trans ormers with a harmonics generator the basic circuits are described differential equations up to the order have been solved equations up to the order could be handled 5237 magnetic shift register correlator printed decimal digits are easily recognised by a magnetic shift register using digital to analog converters at each stage recognition is obtained using a waveform fitting function instrumented with the shift register for correlation 5238 triangular wave analog multiplier 5239 high density williams storage 5240 bit storage via electro optical feedback the use of a device including a photoemissive cathode and a luminescent anode as a computer component is discussed 5241 review of industrial of heat transfer to electronics techniques for controlling the temperature conditions of operation of electronic equipment are reviewed with particular reference to conditions in fast aircraft and missiles particular examples discussed are an air cooled valve cold plate techniques for cooling miniature and subminiature equipment valves designed for operation at surface temperatures near evaporation cooling of miniature transformers by means of fluorochemicals the importance of the subject of heat transfer to designers of electronic equipment is stressed and training programs at the massachusetts institute of technology are mentioned 5242 fast rise pulse generator with high pulse repetition frequency description of a single pole multi position switch in which mercury is ejected through a rotating nozzle on to a series of contact pins thus generating pulses having a rise time at repetition rates with peak pulse power 5243 on concavity of resistance functions a short proof is given of a theorem presented by shannon and hagelbarger 5244 ferromagnetic coupling between crossing coils discussion of the operation of devices comprising a toroidal and a solenoidal coil wound on a common cylindrical saturated ferromagnetic core gating coincidence and signal storage applications are mentioned 5245 self healing in metallized paper capacitors the physical and manufacturing techniques involved in the production of truly self healing single layer metallized paper capacitors are described 5246 decomposition of the derivative of the impedance for a two terminal network extension of theory presented previously 5247 design data for ladder networks design data for networks with up to nine branches and attenuation curves for networks with up to eleven branches are presented in expansion of previous work 5248 directional channel separation filters networks are discussed which combine the properties of directional couplers with those of conventional filters such networks are useful for channel combining separating micro wave communication systems and in installations where a single aerial is shared by several systems designs using waveguides coaxial and strip lines and lumped constant circuits are indicated the performance of some experimental filters is described 5249 low pass filters for metre waves filters intended for suppression of harmonics in measurements and having cut off frequencies of about comprise three sections with lumped constant components the construction and method of adjustment are described 5250 a low pass band pass frequency transformation a simple transformation is presented for converting a low pass insertion power ratio into a band pass ratio the technique facilitates the design of band pass filters when the attenuation curves on either side of the pass band are required to be asymmetrical 5251 a unidirectional attenuator with delay line and ferrite element for the frequency band the attenuation afforded by various devices comprising ferrite tubes surrounding helical lines and in turn surrounded by tubular magnets was investigated experimentally results are presented graphically the attenuation obtained with the final design was about in the forward direction and in the blocking direction 5252 frequency doubling and mixing in ferrites analysis is presented indicating th particular polarization and frequency conditions under which frequency doubling and mixing will occur in ferrite devices of the type discussed by ayres et al 5253 the derivation of the six terminal network curve its graphical interpretation and its application in determining the transformation properties of loss free six terminal and eight terminal networks 5254 tuned circuits containing negative resistance analysis indicates that the combination of a current controlled negative resistance with a parallel tuned circuit or of a voltage controlled negative conductance with a series tuned circuit yields a bistable circuit rather than a self sustaining oscillator 5255 the gain characteristic inside the pull in range particularly in transmitters and wobbulators 5256 oscillator frequency stability the case of an oscillator connected to a mismatched load by a long feeder is considered in addition to hysteresis effects with resonant loads a type of instability occurs which takes the form of a periodic modulation of the oscillation frequency stability criteria appropriate to both effects are derived for various circuit arrangements results of experiments with a triode oscillator operating at are reasonably consistent with the theory in general the hysteresis type of instability predominates 5257 novel circuit for a stable variable frequency oscillator a circuit designed to reduce the effect of resonator frequency drift uses a multiloop feedback arrangement with three oscillators maintained at frequencies such that one is the sum of the other two the sum frequency being controlled by a quartz crystal while the other two are controlled by variable resonators the circuit and frequency drift temperature characteristics of an experimental oscillator are shown 5258 hard tube pulsers for radar developments in design of high vacuum valves make possible the construction of blocking oscillator pulse modulators comparable in size and efficiency with line type thyratron modulators with advantages in stability resulting from the pulse shape 5259 current derived resistance capacitance oscillators using junction transistors two circuits using phase shift networks suitable for use at very low frequencies and one with a phase shift network giving a maximum frequency of are described 5260 pulse scaler circuit with high resolving power a circuit with a resolving time of is based on a step by step capacitor charge and a rapid discharge process the scaling factor can be varied from without loss of stability as a frequency divider the circuit is limited to the range input pulses must be at least peak to peak 5261 high frequency electronic counter a circuit suitable for the frequency divider following the subcarrier generator in a colour television receiver is based on a triggered binary cascade with feedback the high counting rate is achieved by incorporating a gating arrangement 5262 an input amplifier for a pulse height analyser the analyser described can be gated by pulses coincident with the pulses to be measured the error introduced being of the maximum output pulse height variation of the input amplification enables the scale to be expanded for detailed examination of part of a spectrum 5263 a nines complement decade counter with recorder a brief outline of decimal counting using weighted binary digits is given with special reference to systems giving complements of nine a binary decade electronic counter arranged so as to allow the reading of nines complements which may be used to represent negative numbers is then described in the circuit arrangement used in this counter the maximum counting rate remains the same as that of a simple binary counter recording of the number counted is made on teledeltos paper the record and counter reset being carried out simultaneously 5264 gate selects pulses for spectrum analysis a circuit permitting isolation of pulses from to wide at repetition rates up to per sec is described 5265 nonlinear distortion and stability of reflex circuits two single valve and three two valve crystal detector reflex amplifier circuits are discussed the coefficient of non linear distortion is calculated for the various circuits and the results are plotted as a function of the parameter the relative change of slope of the curve from the value at the working point due to the applied signal can theoretically be made zero by using a pair of identical valves in the circuit shown in the stability criteria are also discussed 5266 decade amplifier the circuit incorporates rc and direct coupled stages and a chopper stabilizing amplifier giving a bandwidth of with a gain of in steps the equivalent input drift is output is up to 5267 isolating direct current amplifiers a circuit providing an output direct current or voltage proportional to an input direct voltage and having no common point between input and output uses fixed frequency crystal controlled oscillator in conjunction with a discriminator whose phase is varied by means of an electromechanical modulator which converts the input signal into a capacitance variation several applications are mentioned 5268 wide band linear amplifier the amplifier de cribed is designed for use with a common aerial to provide a distribution system for a ship frequency coverage is with suppression in the bands nominal gain is performance figures are given the level of intermodulation and cross modulation products is low 5269 synthesis of amplifiers with triple tuned coupled circuits 5270 unity gain voltmeter amplifier 5271 behaviour of saturable reactors in magnetic amplifiers a detailed analysis is presented of the behaviour of a magnetic amplifier in which the core material is assumed to have a square characteristic systems with single cores two series connected cores and two parallel connected cores are considered with sources of infinite and low impedance results are presented graphically upporting experimental evidence is mentioned briefly 5272 measurement considerations in high frequency power gain of junction transistors 5273 transistor amplifier for radar video the design of a video amplifier suing si transistors suitable for airborne radar systems is discussed high frequency compensation is obtained by rc degenerative feedback in a grounded emitter circuit with temperature stabilization of emitter current bias 5274 transistor preamps discussion of practical design considerations for pre amplifiers for use with gramophones with a boosted low frequency response and a flat response main amplifier and with microphones the pre amplifier in this case having a flat response 5275 a amplifier employing transistors the amplifier described comprises an input stage a driver and a class b stage with overall feedback the maximum output is measured at with total harmonic distortion mainly third harmonic the sensitivity at the input terminal is about minimum total distortion is at an output of about 5276 design of a simple linear frequency discriminator the discriminator described consists essentially of two tuned circuits with the parameters chosen to minimize second and third harmonics design information is presented in graphs 5277 statistical properties of a moving waveform 5278 the giorgi system of units and the rationalization of the equations of electricity 5279 new theorems on the electrostatic field the law of least capacitance is discussed the concept of the intermediate electrode is introduced to facilitate the formulation a system of two cylinders with parallel axes is considered and an examination is made of the variation of the total capacitance of the system on dis placing the imaginary intermediate electrode constituted by an infinitely thin metal sheet shaped to coincide with one of the equipotential surfaces the analysis is extended to systems of spheres and other geometrical forms formulae giving attractive and repulsive forces for numerous particular cases are tabulated 5280 field ionization of gases at a metal surface and the resolution of the field ion microscope 5281 field desorption report of a study of the action of strong electric fields in removing adsorbed films of ba th etc from a w surface using a field emission microscope and maintaining the metal surface positive 5282 electronic conduction in solids with spherically symmetric band structure elastic scattering of electrons by ionized impurities and inelastic scattering by the non acoustical modes of the lattice vibrations in a homopolar crystal are discussed for electrons whose energy is a nonquadratic function of the wave number vector 5283 acceleration of electrons by an external force field the usual proof that an electron in an energy band reacts to an external force as though it had an effective mass is shown to be invalid it is shown however that for static externally applied fields modified energy bands can be found for which the acceleration theorem is rigorously correct 5284 the penetration depth in impure superconducting tin a new method is described for measuring the surface impedance of metals at low temperatures and at radio frequencies using this method the surface impedance of normal tin and the penetration depth in superconducting tin have been studied at about frequency as a function of impurity content the measured surface impedances agree well with the values expected and the penetration depths increase with impurity content in confirmation of pippards observations 5285 cyclotron resonance under anomalous skin effect conditions results to be expected from attempts to observe cyclotron resonance in metals are discussed 5286 mobility and space charge of ions in nonuniform field teh equations developed lead to a generalization of the child langmuir power law to cover the case of arbitrary pressures 5287 the carrier density in a plasma and its determination by means of the pulse probe the pulse method discussed does not depend on particular assumptions regarding the transition layer between the unipolar layer and the undisturbed plasma theory apparatus and experimental results are described 5288 statistical study of electron avalanches in gaseous discharge for low pressures the pulse size distribution at potentials below the breakdown value agreed with that given by the townsend theory assuming the absence of space charge at atmospheric pressure the discharge was modified probably by space charge and pulse size tended to become uniform 5289 starting of an electrical gas discharge in a uniform alternating field in the sub critical range when the half period of the alternating field is greater than the duration of an ionization step the number of ionization steps in a half period varies with frequency and with field strength over this range the breakdown voltage frequency characteristic is positive but beyond a certain value of frequency it becomes negative later undergoing a further inflection so that at a frequency of it is again positive comprehensive experimental results illustrating these phases and the influences of pressure and electrode separation on them are presented 5290 contact phenomena in plasma discontinuities of potential between parts of a plasma which differ in electron concentration and temperature are considered theoretically by the classical contact potential theory of metals the validity of this treatment is confirmed experimentally 5291 investigation of electron emission from superconductors 5292 secondary electron emission from metals under the action of ions and neutral particles experimental results obtained by bombardment of clean metals with ions of and neutral atoms of the inert gases show that the coefficient of secondary emission increases linearly at particle velocities up to for proton bombardment a ma imum occurs at a velocity of 5293 investigation of characteristic energy losses by the retarding field method the energy distribution of electrons and the angular distribution o their paths after passage through thin foils of and are studied 5294 dependence of secondary electron emission upon angle of incidence of primaries 5295 secondary electron emission from dielectrics experiments are described in which in order to avoid changes in the structure of the target due to electron bombardment the primary beam was switched on for only so that there was one incident electron for about atoms of the emitter surface and the destruction of the target could therefore be neglected the results obtained are different from those usually quoted a new interpretation of the phenomenon is given 5296 model for collision processes in gases small amplitude oscillations of charged two component systems continuation of work reported previously 5297 large amplitude plasma streaming and charge segregation 5298 the magnetostatic force on two circular cylindrical conductors carrying uniform steady currents the magnetic field dur to two parallel conductors in a nonuniform magnetic field is determined for the case when the conductor material si magnetic general expressions are deduced for the magnetostatic force and are investigated for particular examples 5299 fluid self excited dynamo the possibility that a simply connected perfectly conducting fluid body could generate an increasing external magnetic field by acting as a self excited dynamo is demonstrated by exhibiting a cycle of motions that doubled the external field each cycle the essential feature of the motion is that interior points become surface points 5300 analysis of traces of impurities in rare gases by ultra high frequency excitation of optical radiation technique is discussed in which a cell filled at low pressure with the gas to be analysed is arranged in the field of a continuous microwave oscillation generated by a magnetron 5301 cerenkov radiation from extended electron beams near a medium of complex index of refraction if ferrites are used in place of simple dielectric media the radiated power can under suitable conditions be increased 5302 variation with electron energy of the collision cross section of helium for slow electrons continuation of previous work on the interaction of microwaves in gas discharge plasmas momentum transfer between atoms and electrons with energies between and is investigated the electron density being not less than about experimental results appear to indicate a slight variation of momentum transfer with electron energy 5303 motion of a sphere through a conducting fluid in the presence of a strong magnetic field 5304 basic processes of gaseous electronics a comprehensive review scattering and diffraction of radio waves one of a series of monographs on mathematical methods are indicated for solving problems encountered in the study of radar performance and aerial systems 5305 hydromagnetic dynamo theory the equations of magnetohydrodynamic are used to study the mechanism whereby cosmic magnetic fields such as those of the earth of sunspots and the sun and of magnetic stars are generated and maintained 5306 the nature of radiation from radiogalaxy the continuous optical radiation from the jet in the core of the galaxy is explained quantitatively by the presence of relativistic electrons with energies of moving in a magnetic field of approximately relativistic electrons with energies of diffusing into the galaxy are probably the source of emission 5307 impulsive radio signals from the planet venus report of reception at the ohio state university of radiation at a wavelength of the observations were made using an interferometer array of horizontal elements with reflectors the peak power in a burst is estimated to be about per of bandwidth this is about of the value estimated for a burst from jupiter on the basis of power considerations the mechanism involved could be o lightning discharge type a record obtained on is reproduced and discussed 5308 class radio signals from venus at a wavelength of reception of radiation with a different waveform from that discussed previously is reported this radiation designated class is of a more sustained nature lasting for a second or longer and varying at an rate a record of a series of pulses observed on is shown the radiation appears to have a bandwidth of at least on studying tape recordings signals resembling echoes were oted these may be due to reflection from the moon 5309 large amplitude plasma streaming and charge segregation 5310 on the propagation of radio waves through the upper ionosphere 5311 review of ionospheric effects at and 5312 inadequacy of recombination as the source of light from enduring meteor trains critical discussion of the suggestion made by that the column of light produced by a meteor is due to recombination of the meteoric ions and free electrons 5313 observations of solar radio radiation during the eclipse of observations made at cracow using apparatus operating at about with a parabolic aerial of diameter are reported records for and are shown for comparison with those for the eclipse day 5314 a note on the annual variation of geomagnetic activity and regions results of an investigation are given associating recurrent day geomagnetic activity with regions of the sun around years of sunspot minima the association of sequences with various solar features of the disk and corona is also indicated for a longer account of related work see 5315 charge transfer in the upper atmosphere collision processes involving charged solar particles entering the upper atmosphere are discussed charge transfer reactions involving solar and ions are likely to excite spectrum lines of these elements and of the atmospheric gases in the case of at auroral levels the ratio of the density of to ions and the effective recombination coefficient for the layer are derived 5316 on a pitot tube method of upper atmosphere measurements a method is presented for deducing atmospheric density pressure and temperature at heights up to 5317 thermodynamic method for measurement of the refractive index of the atmosphere description of the radiosonde apparatus is described which is capable of determining the distribution of temperature pressure and humidity variations with a fineness sufficient for radio propagation calculations 5318 the altitude of the line in the night airglow measured from a rocket measurements using rocket borne photometers show that the layer from which the line originates lies between and with peak luminosity between and 5319 distribution of the night airglow and layers measured from a rocket an experiment similar ro that described by confirms the results for the line and shows that the sodium lines are excited in a layer of altitude between and 5320 determination of the alpha ray emission of materials constituting the earths surface it is concluded from measurements that ray emission is not an important factor in the ionization balance of the lower atmosphere 5321 influence of magnetic field on convective instability in the atmospheres of stars and in the ionosphere of the earth the case of a medium with anisotropic electrical and thermal conductivities is considered in a plasma which does not contain a large number of neutral particles the calculated influence of the magnetic field on convection is essentially different from that predicted by the magnetohydrodynamic approximation in the ionosphere the influence of the magnetic field is small owing to the presence of a large number of molecules 5322 electron resonance in ionospheric waves certain features of large scale travelling disturbances in the layer are explained as electron resonance effects whereby small initial disturbances are amplified estimates of ionospheric parameters based on this interpretation are in good agreement with values to be expected 5323 two types of development of the layer at ahmedabad the sequence of phenomena leading to the separation of and layers after high level sunrise is summarized and illustrated by photographic records the existence of a layer which is photo ionized by solar radiation at a height of about is indicated 5324 world wide spread records from widely distributed ionosphere stations for the period of the last complete sunspot cycle show that the spread equator is roughly parallel to the geomagnetic equator swinging pf latitude over the cycle 5325 the solar ray spectrum and the density of the upper atmosphere data derived from rocket experiments give a measure of the flux density of solar rays incident on the layer from the rate of ray absorption at heights between and the atmospheric density is computed to be about one third of the current rocket panel average values 5326 ionospheric effects produced by solar flare radiation 5327 the effective recombination coefficients in the and layers during the solar eclipse of the contribution to the ionization of each of two isolated sources of radiation assumed to exist near the east and west limbs of the sun is derived and expressed as a linear function of where is the effective recombination coefficient during the eclipse on equating the corresponding functions for khartoum and ibadan it is found that for both places as against the value obtained for khartoum on assuming that the intensity of ionizing radiation fell to zero at second contact for the layer it is concluded that 5328 interpretation of ionospheric measurements made during solar eclipses by combining observational data obtained at khartoum and ibadan during the eclipse of a determination is made of the recombination coefficient in the layer the most probable value is this result is at variance with the conclusions reached by and implies absence of radiation from the corona 5329 ionospheric observations during the solar eclipse of strong ionization prevented the accurate observation of but was reliable and assuming complete cut off of the ionizing radiation at totality gave the layer data are consistent with a solar model in which and of the radiation was emitted from areas near the west and east limbs respectively originated in an undefined area which may cover the greater part of the suns disk the changes in indicate a marked solar control of the layer and assuming a recombination law give measurements absorption are consistent with the solar model deduced from the layer data and give a theoretical treatment is given of the eclipse changes in the region 5330 systematic investigations of the influence of geomagnetic activity on the nocturnal critical frequencies of the layer results of a statistical analysis of data covering a period of years are presented graphically the probability that a geomagnetic activity index of magnitude determined over a period is followed by an ionospheric storm is in the summer of a sunspot maximum year and in winter the corresponding figures for a index in a sunspot minimum year are respectively 5331 ionospheric absorption at dakar 5332 calculation of charge density distribution of multilayers from transit time data a method is discussed for calculating the electron density distribution in the ionosphere from data obtained using a rocket borne variable frequency transmitter or pulse reflections from higher layers it is not possible to obtain a solution free from ambiguity 5333 characteristics of auroras caused by angular dispersed protons 5334 secondary processes due to absorption of the lyman lines emitted from aurorae discussion indicated that the line of the hydrogen lyman series emitted from aurorae my be effective in ionizing in the lower atmosphere but not to the extent required for polar blackouts absorption of the lyman line by oxygen atoms is not significant in ordinary aurorae 5335 on the waveform of a radio atmospheric at short ranges calculated values for the waveform at various distances up to from the discharge are shown graphically the ionospherically reflected wave is not taken into account and the discharge producing the atmospheric is represented by an idealized function 5336 a balanced unregulated dual power supply a circuit is described for simultaneously providing positive and negative voltages which remain equal in face of line voltage variations practical details are given for a unit supplying a graph shows the performance of the unit used with a amplifier providing a balanced load 5337 semiconductor solar energy converters a concise review of the physical fundamentals includes brief discussions of radiant energy absorption in semiconductors the effect of junctions and the energy conversion efficiency 5338 efficient and reliable transistor high voltage power supply the system comprises a battery a transistor oscillator crystal rectifier and corona type regulator the output is about at 5339 life test results on selenium rectifiers tests on a representative selection of rectifiers for radio and television equipment show very great variations in shelf life useful life and temperature characteristics the need for drastic derating is suggested 5340 trends in computer input output devices 5341 design of computer circuits for reliability factors influencing the choice of components and precautions taken during the initial circuit design and mechanical construction of the edsac machine are described 5342 a circuit for analogue formation of a quarter squares multiplier using a triangle carrier waveform in the squaring circuits is extended to give division simultaneously with multiplication this is achieved by controlling the slope of the triangle carrier waveform so as to be proportional to the divisor z 5343 an automatic electron trajectory tracer 5344 standards on electronic computers definitions of terms 5345 high temperature components new materials and methods of production to meet service demands are briefly described 5346 printed circuits 5347 winding method for coils with parallel windings theory is presented indicating the purpose for which parallel wound coils are suited and practical examples are described 5348 p n p n transistor switches 5349 ten channel time division multiplexer a magnetron beam switching tube forms the basis of a contact single channel circuit giving switching times of about the tube is used in conjunction with a gating system a gate circuit is described which permits the examination of signals in the microvolt range 5350 nonlinear tuned capacitors the design and production of very small tuning capacitors using ba sr titanate ferroelectric dielectrics is described examples are given of applications to oscillators for the frequency range with power outputs of 5351 formulae relating some equivalent networks explicit formulae are obtained for the elements of a network without transformers which has the same driving point impedance as an arbitrary two loop passive network 5352 an existence theorem for driving point impedance functions 5353 waveguide components with nonreciprocal properties the mechanism of the nonreciprocal effects occurring when an e m wave is propagated through a magnetized material particularly a ferrite is discussed the gyrator the isolator and the circulator are described 5354 further aspects of the theory of the maser 5355 variation of the quality factor of piezoelectric crystals as a function of pressure measurements were made on a quartz crystal and on a rochelle salt crystal using apparatus described results are presented as curves for values of log decrease of pressure below about does nor affect value design of a toroidal cavity resonator by the method of curvilinear coordinates the application of the formulae derived is illustrated by a calculation of the resonance frequency of a cavity of given dimensions the calculated value agrees well with the experimental value restrictions on the shape factors of the step response of positive real system functions extension of previous analysis of the transient response of networks 5356 theory of nonlinear coupling in a novel ferro electric device a device which can be used as a modulator or as a frequency divider or multiplier comprises a block of ferroelectric material witnh electrodes arranged on two pairs of facing sides on connecting an inductance across one pair of electrodes a resonant circuit is provided in which the capacitance varies periodically oscillations being sustained when the frequency of this parametric excitation is twice the resonance frequency of the circuit analysis is presented using the mathieu equation 5357 the analysis of three terminal null networks a simple method of analysis is presented the twin t and bridged t networks are treated as examples 5358 by pass filters by pass filters are described having three pairs of terminals and between two of the pairs but only a limited band of frequencies is transmitted between either of these pairs and the third pair of terminals 5359 an improved crystal band elimination filter an all pass network consisting of two filters in parallel is described suitable for applications in which it is required to transmit a wide frequency bands within the range internal impedance transformations eliminate the need for high ratio transformers 5360 the field displacement isolator a nonreciprocal device with forward loss about and reverse loss about over a wide band at about is based on use of a single ferrite slab spaced from the wall of a rectangular wave guide and having a resistive strip on one face optimum field conditions in the waveguide are discussed 5361 operation of an amplitude limiter theoretical and experimental evidence suggest that the stray capacitance shunting the nonlinear element causes a parasitic phase modulation of the out put signal and limits the efficiency a neutralized circuit is shown and design formulae are given 5362 two terminal junction devices for frequency conversion and computation 5363 mutual synchronization of three coupled oscillators with weak couplings the syst m investigated theoretically and experimentally comprises three triode valve oscillators coupled by small capacitors between the grids of the first and second and second and third valves approximate expressions are derived for the frequency and amplitude of the oscillations in each oscillator the regions where mutual synchronization takes place are shown in a graph where are respectively the frequency differences between the first and second and the third and second oscillators 5364 stable local oscillator for s band radar a continous frequency range of is obtained using six crystal oscillators tunable over over lapping ranges of the desired output frequency is obtained by means of harmonic amplifiers 5365 a possible construction of amplitude analysers a circuit is described by means of which pulses with amplitudes exceeding or lying within certain limits can be counted 5366 influence of large fluctuations on an electronic relay the probability of untimely triggering by fluctuation voltages is considered theoretically the cases discussed include the effect of fluctuations on a relay with or without inertia both in the presence and in the absence of regular pulses the effect on a coincidence type circuit is also discussed 5367 effect of component tolerances in low frequency selective amplifiers some experimental results results obtained previously by analysis of may have been verified experimentally using the operational amplifiers of the analogue computer of january trailing edge of pulse in cathode follower eith capacitive load the decay time of a rectangular pulse at the output of a cathode follower can be shortened by connecting a triode in parallel with the cathode resistor and capacitor and controlling the triode grid voltage coupling from the anode of the cathode follower tetrode valve the circuit constants are such that the triode impedance decreases momentarily at the end of each pulse 5368 the design of tetrode transistor amplifiers methods are discussed for determining suitable loads when the two port parameters of the transistor are known charts are presented ofr determining power gain and input impedance as functions of load circuits described as examples include a common base amplifier a common emitter video amplifier and amplifiers centred at and respectively predicted and measured gains are compared 5369 servo amplifiers use power transistors high efficiency in a class amplifier using power transistors is obtained by providing the collector power by full wave rectification of the power supply 5370 micro power operation of silicon transistors 5371 interferometric spectroscopy in the far infra red the response of a thermal detector to the resultant of two interfering infrared beams wal measured using a reflection interferometer with the path difference varied up to the spectral information is displayed in a fourier transform obtained by analysis of the resultant intensity path difference curve an instrument with aperture has been made for studying atmospheric transmission at submillimetre wavelengths 5372 an extension of the circle and sphere theorems theory relating to cylinders and spheres immersed in two and three dimensional electric fields is extended to include certain other boundaries along which either the electric potential or the current function takes a constant value 5373 on the bohm pines theory of a quantum mechanical electron plasma analysis indicates that as a result of neglecting certain conditions discussed by adams the bohm pines theory may give incorrect results 5374 concerning the papers by s e khaikin s v lebedev and l n borodovskaya criticism of papers abstracted and back references 5375 integrals of interest in metallic conductivity 5376 oscillations and fluctuations in gas discharges a tentative classification is made of different forms of disturbance encountered in gaseous conductors constituted by low pressure tubes a distinction is drawn between cases where the gaseous conductor acts as a circuit unit possessing resistance capacitance and inductance any of which may be positive or negative and cases where internal disturbances occur in the gaseous con ductor which are practically independent of the external circuit the origin and nature of electron an ion oscillations is discussed 5377 electrical breakdown in argon at ultra high frequencies report of measurements made using resonant cavities at a frequency with pressures ranging from 5378 thermionic emission field emission and the transition region the combined thermionic and field emission from a metal is studied as a whole a general expression is derived in the form of a definite integral relating the emission current to the field the temperature and the work function modified forms of the richardson schottky and fowler nordheim formulae are shown to be respectively valid over limited regions of low field and high temperature on the one hand and low temperatures and high field on the other and expression is also derived for the emission current in the transition region 5379 secondary electron emission from single crystals of alkali halide compounds experiments were caried out which show that the dielectrics investigated differ from metals in respect of the dependence of the coefficient of secondary emission on the energy of the primary electrons and also in respect of the secondary electron energies which in this case are approximately uniform 5380 field of a uniformly charged disk and magnetic field of a thin circular cylinder coil with contiguous turns traversed by a direct current the field of the uniformly charged disk is used to study that of the coil by virtue of the magnetic ee between the coil and a magnet of the same shapquivalence between coil and magnet and same shape with opposite magnetic poles on the two end faces formulae for mutual and self inductance are hence derived 5381 electrodynamics of moving media and the theory of the cerendov effect the generalized frank andtamms formula fot the total energy radiated as cerenkov radiation by a swiftly moving charged particle in a medium of dielectric constant and permeability has been derived employing the invariance of the phenomenological electrodynamic equations of maxwell the scheme is self consistent and the idea of the indetectability of the ether wind is contained in it it is found that the cerenkov radiation is times larger than that predicted by the frank and tamms formula for experiments are suggested to detect strong cerenkov radiation in highly permeable mediums 5382 pulsed coherent generation of millimetre waves by nonrelativistic electron bunches the production of microwaves by bunched electron beams incident on metallic or dielectric anticathodes or by interaction with strong localized fields is briefly discussed and energy relations are stated 5383 the effect of the surface curvature of a convex metal body on the radiation from a source on its surface the radiation is usually calculated fron reflection formulae derived by replacing the convex surface by a plane the magnitude of the error thus introduced is estimated 5384 the diffraction of a cylindrical pulse by a half plane a method of analysis is used which enables the greens function to be derived two transformations and two inversions are involved 5385 diffraction pattern in the plane of a half screen measurements are briefly reported for the case of plane polarized radiation incident normally on a half plane and polarized parallel to the diffracting edge the results are discussed in relation to a formula derived by andrews and the observations of harden 5386 integro differential equations and babinets principle for plane screens with directional conductivity analysis is presented for diffraction by screens formed of parallel conducting wires four cases are distinguished a finite parallel wire screen alone nondirectionally conducting screen surrounded by an infinite parallel wire screen cases and are complementary in the sense of babinets principle so also are cases and there is no special relation between cases and or and 5387 electromagnetic radiation from electron plasma theory developed by bohm and pines and back references is extended to treat the coupling between longitudinal and transverse plasma oscillations arising from the quantum fluctuation of electrons interacting with the field the theory may provide the explanation of the outbursts of solar emission molecular ringing semiclassical radiation theory is used to describe the response of an assemblage of two state molecules driven by an electromagnetic field when the field is suddenly removed the assemblage does not immediately become quiescent it continues to radiate in diminishing amount this coherent molecular ringing return to the values they had at the beginning of the driving pulse the ringing radiation may exhibit a delayed peak 5388 radiation of electromagnetic waves during the uniform motion of electric charges near an inhomogeneity the radiation occurring in nonuniform waveguide in which a given convection current is flowing and the transient radiation due to the passage of finite bunches of charge through ideally conducting grids are considered theoretically using the methods of perturbation theory 5389 theory of molecular oscillator and molecular power amplifier 5390 further aspects of the theory of the maser problems relating to saturation effects and cavity resonator design for the device discussed previously of february are examined various types of noise and oscillator frequency shift are considered the theoretical minimum detectable beam intensity when the maser is used as a spectrometer for the ammonia line is about molecules sec under typical experimental conditions 5391 a general purpose electromagnet details are given of a magnet for laboratory purposes with a soft iron yoke having low residual magnetism and poles of diameter together with a table showing the variation of the field in the centre of the gap with excitation and gap length distribution of radio stars a tentative explanation is given of discrepancies between the distribution derived by ryle from interferometer measurements at and that derived by pawsey from mills cross measurements also at as discussed at the recent jodrell bank symposium 5392 the radio source near the galactic centre recent observations on with the cross aerial are discussed in relation to earlier observations on and the position of the dominant source is shown on a contour map of equivalent brightness temperatures alternative models accounting for the observations and involving adsorbing regions are mentioned whichever model is assumed the nucleus of stars in the galaxy is not itself detectable as a source 5393 polarization measurements on three intense radio sources measurements have been made on radiation of wavelength from sources in cygnus cassiopeia and taurus the results indicate that there is no plane polarized component and no circularly polarized component in the flux from the first two of these sources the corresponding figures for the source in taurus are and respectively the george r agassiz radio telescope of harvard observatory the aerial of this instrument is a paraboloid of expanded aluminium wire mesh with a horn collector at the focus at wavelength the angular resolution is about thus the accuracy of setting and following is more than sufficient for research on discrete radio sources the receiver is a double conversion superheterodyne comparison radiometer with a channel comb filter at the second conversion frequency the instrument is to be used both for research and training 5394 some factors affecting the radio determination of meteoric velocities questions raised by hoffmeister of february are discussed further deceleration of meteors along the path prior to the point of measurement may br an important factor techniques for measuring the deceleration over an appreciable path length by the radio amplitude time method require to be developed existing techniques may be failing to detect faint meteors with hyperbolic orbits 5395 radar echoes from meteor trails under conditions of severe diffusion an expression is derived indicating that the power of the echo is proportional to and to where is the range for a given meteor velocity there is a critical height above which the effects of diffusion become serious a graph shows the critical height velocity curves for values of between and 5396 the multiple aerial interferometer at the nancay station 5397 radio frequency observations of the solar eclipse of june radio frequency power received from the sun at wavelengths of and was measured during the solar eclipse of junce the sun was essentially free from active areas and the eclipse curves obtained have been used to derive models give predicted eclipse curves in good agreement with the observed ones comparison has been made with models derived by other investigators on the same wavelengths 5398 the constancy of the scale of the relative sunspot numbers comparison of sunspot numbers with the greenwich data for sunspot areas over several cycles indicates that the proportionality factor increases with the latter but there is no significant variation of the scale of the relative sunspot number 5399 effective geomagnetic equator for cosmic radiation the distribution of the geomagnetic field extending far from the surface of the earth is investigated by using cosmic ray particles as probes measurements using the neutron intensity from the nucleonic component indicate wide discrepancies between the observations and geomagnetic coordinates derived from surface magnetic field measurements some anomalous observations of cosmic rays can be explained as due to the interaction of the rotating and inclined magnetic dipole field with a highly ionized interplanetary medium 5400 theory of solar eclipse effects on the earths magnetic field the deformation of the current during a solar eclipse is represented by a current function which is superposed on the system and moves with the eclipse the magnetic field components of are computed and the influence of the part induced in the earths crust is discussed 5401 upper air density and temperature by the falling sphere method technique and results are described of a method for investigating the atmosphere at heights up to a nylon sphere with a transponder aeriel erected a rocket near the peak of its trajectory 5402 turbulent mixing theory applied to radio scattering 5403 an experimental investigation of the band of ozone in the solar spectrum mean heights of atmospheric ozone have been investigated over a period of two years using strongs method a seasonal variation is observed with a minimum height in summer and range of 5404 determination of the vertical distribution of ozone from emission spectra 5405 electron density in a nonisothermal ionosphere continuation of work noted previously of electron density when the earths curvature is taken into account may be appreciable especially for the winter the corresponding difference in critical frequency may amount to for the period just after sunrise comparison of calculated and observed values of suggests that a representative model of an region can be based on the assumption that the temperature varies linearly with height up to the interface and then remains constant the parabolic law of variation of electron density is acceptable only for heights corresponding to reflection frequencies not less than times the critical frequency a general expression is derived relating temperature electron density density of matter recombination coefficient and adsorption coefficient 5406 resonance scattering by atmospheric sodium part theory of the intensity plateau in the twilight airglow numerical results based on theory of radiative transfer are compared with observations by various workers for a layer scattering solar d line radiation observed in the zenith distance winter observations indicate an absolute brightness slightly greater than given by the theory abundance of na appears to vary between summer and winter atoms 5407 the effect of ambipolar diffusion in the night time f layer the effect is examined in the light of recent low estimates of the density of neutral particles in the f layer and assuming that the rate of loss of electrons is proportional to the electron density with certain other simplifying assumptions may be expressed as a sum of functions which decay exponentially with time an approximately parabolic chapman model based on the most slowly decaying of these is discussed correlation is found between both and magnetic figure and the sunspot cycle variation of the f region temperature 5408 observation at akita of ionospheric drift simultaneous observations of the variations with time of the virtual heights of the layers were made at three observatories in japan during the period july august mainly at night drift velocities of the layers are deduced the results are presented in the form of histograms 5409 lunar variations of the layer at ibadan analysis and determinations for the layer made at ibadan from december to april shows semidiurnal lunar variations of considerable amplitude these variations in turn exhibit marked variations of amplitude and phase with season and with time of solar day values of the recombination coefficient in the layer deduced from the luni solar variations decrease exponentially with increasing height 5410 behaviour of the ionosphere at rome during the partial solar eclipse of june observed eclipse effects are compared with effects calculated on the assumption that the electrons are produced by photo ionization and removed by ionic recombination or attachment ot neutral atoms and molecules and that the ionizing radiation is distributed uniformly over the visible disk of the sun it is deduced that the electron loss rate is consistent with an ionic recombination process in the layer the attachment and recombination coefficients decrease with increasing height their variations during the eclipse are related to the vertical movements of the ionosphere seasonal variations between effects observed in a number of eclipses are explained in terms of different degrees of superposition of the and layers the existence of secondary minima of electron density is interpreted as indicating that a distinction must be drawn between the ionizing sun and the visible sun eclipse effects in the e layer are also discussed 5411 recombination and attachment in the and layers during the solar eclipse of december examination of the variations of electron density at heights in the region during the annular eclipse of december suggests that there combination process is predominant in the region in the region recombination and attachment coefficients decrease regularly with height possible explanations of the separation of the and layers are advanced 5412 theory of nonlinear effects in the ionosphere 5413 ionospheric sounding equipment the characteristics of the ionosphere are briefly reviewed and some soundings obtained at the tortosa station inaugurated in are reproduced the sounding equipment installed is identical with that used by the bureau ionospherique francais 5414 ionospheric prediction methods and the probable sources of error 5415 equatorial ionospheric absorption 5416 study of the selective fading appearing on the fct traces 5417 height distribution of auroral emissions 5418 measurement of auroral radiation a with a photon counter a copper cathode counter is satisfactory for measuring this radiation 5419 the level of interference due to atmospherics in the very long wave range and its diurnal and seasonal variations 5420 theoretical considerations governing the choice of the optimum semiconductor for photovoltaic solar energy conversion 5421 c r t power supply uses transistor oscillator a positive feedback oscillator using a transistor provides an output voltage which is doubled rectified and stabilized at a collector supply of is the only external power required for output current the overall efficiency is 5422 characteristics for half wave rectifier circuits voltage regulation characteristics form factor first harmonic and peak current values are given for half wave rectifiers with common type loads all in non dimensional variables 5423 silicon junction power diodes simplified semiconductor theory is presented and a description is given of three main methods of making junction diodes and of the properties of the diodes advantageous features and appropriate applications of these rectifiers are indicated 5424 wide range voltage stabilizers a unit is described based on a circuit by admiraal which gives a stabilized output voltage adjustable within the range with maximum load current of the stabilization ratio is about 5425 seac national bureau of standards eastern automatic computer a comprehensive description see also of is given of this computer which has been in operation almost continuously since the spring of a it is a synchronous machine operating at it has been expanded from its original form with increase in the number of thermionic valves from about to and of ge diodes from about to circuit modifications include the introduction of ac coupling using pulse transformers 5426 electronic circuits of the narec crystal diodes are used where practical for all nonlinear functions in this digital computer thermionic valves being used only for inversion or amplification all circuits are designed to provide low impedance output signals whose maximum and minimum levels are held to prescribed potentials the circuits are packaged in standard valve plug in units see also 5427 diagnostic programmes for the illiac a detailed description is given of a leapfrog programme for detecting faults this ensures that every component of the computer is tested under all the different conditions of use 5428 the logistics computer construction and operation of a digital computer for logistics research are described consideration of the particular requirements for this work led to a design incorporating high speed magnetic tape in addition to punched tape input and output equipment fixed sequence operation magnetic drum storage with capacity for decimal digits and plug board programming 5429 the remington rand type electronic computer construction and operation are described of a machine of moderate size for accounting purposes using thermionic valves and cold cathode gas diodes programming is directed by means of plug boards there are calculating steps and special steps and special steps each step is automatically tested by a reverse process a reproduce feature is included 5430 the design of the bendix digital differential analyzer the error reduction scheme employed by the bendix digital differential analyzer which utilizes both ternary intercommunication between integrators and trapezoidal integration is described a device for the v riation and automatic resetting of initial conditions is discussed together with an example illustrating its operation finally techniques employed for minimizing the size of the computer are considered 5431 theory of logical nets two values logic is applied to the study of digital computer circuits a logical net is an array constructed from a stroke element representing circuit components performing logical functions and a delay element representing storage components various types of net are defined their properties are correlated with those of the associated set of equations and a study is made of the operations they can perform the classification o digital computer circuits in this system is discussed 5432 dynamic circuit techniques used in seac and dyseac the circuits of these digital computers are standardized on the basis that ge diodes are used for all logical operations delay lines for storage and thermionic valves for amplification manufacture is simplified by using only two types of plug in unit 5433 the design of logical or and or pyramids for digital computers recent improvements in design technique are described leading to reduction of number of diodes required reduction of voltage and power requirements and speeding up of operation basic considerations involved in the choice of elements are discussed 5434 a survey of digital computer memory systems a survey limited to systems whose reaction time is shorter than human reaction time 5435 the logical principles of a new kind of binary counter auxiliary temporary storage in a binary counter is provided during intervals over which the main storage element is in state of change by elements having the same time indefiniteness as the main storage elements this leads to a device which has true and false ranks of storage elements the basic device is generalized to one with four modes of operation and the rules of number formation are discussed application to a computer is described 5436 combined reading and writing on a magnetic drum a technique is described which uses a single head for storing information and reading it back design of a suitable amplifier for this method of operation is discussed the process can be performed with successive cells at the repetition rate of sec the technique extends the use of magnetic drums to data processing as well as storage 5437 coded decimal number systems for digital computers from the very large numbers of possible ways of coding the decimal digits into sets of binary elements a restricted group of number systems is presented as being particularly adaptable for representing the decimal digits in digital computers as an example one number system of this group is presented which permits the construction of a very simple addition circuit 5438 an electromagnetic clutch for high accelerations unidirectional and bidirectional models are discussed of a clutch with many possible applications in the digital computer field 5439 a survey of analog to digital converters 5440 an analog to digital converter for serial computing machines a two stage process is used the analogue number being first converted into a reflected binary or cyclic code number which is then converted into the binary form as a time sequence with the least significant digit first 5441 effectiveness of two step smoothing in digital control computers the use of a digital computer as an element in a control system to smooth observational data is discussed analysis is presented for a two stage system in which the first stage has a high data handling rate and short smoothing time while the second has a low data handling rate and a long smoothing time 5442 an input output unit for analog computers a device is described which operates as a curve follower type of function generator to provide an input unit or as an x y recorder when used as output unit 5443 application of electronic differential analyzers to engineering problems 5444 the solution of partial differential equations by difference methods using the electronic differential analyzer 5445 analog computing applied to noise studies methods suitable for studying both linear and nonlinear systems are discussed 5446 edvac drum memory phase system of magnetic recording 5447 dead programmes for a magnetic drum automatic computer breakdown due to a wrong instruction can be prevented by blocking part of the magnetic drum memory for writing and placing in this dead part standard sub programmes which occur frequently 5448 electrical analogues description of the principles operation and applications of analogue techniques using conducting paper the electrolyte tank resistive networks or networks with both resistive and reactive components 5449 economic analogs discussion of the possibilities of using analogue computers of various types for solving problems of commerce industry 5450 elements of boolean algebra for the study of information handling systems terminology symbols definitions and proofs of basic theorems of boolean algebra are given as a preliminary to the use of this algebra for studying methods of minimizing the number of physical elements required on information handling or computing systems the method is illustrated by examples of design of computer circuits 5451 the correlatograph a paper tape recorder analogue device for the continuous display of the short term correlation function by means of a time time lag correlation factor plot intensity is described it was designed for the analysis of signals in a magnetic tape recording the electromechanical design is based on the af spectrograph of 5452 a myriabit magnetic core matrix memory description of an experimental information storage system providing random access to any one of bits in a few microseconds the system is an extension of that previously described by papian of details are given of the cores which are of ferromagnetic ceramic material and of diameter in and of the operation of the array 5453 machine aid for switching circuit design an experimental special purpose non numerical computer for analysis of relay circuits has as its input a relay circuit together with the specification the circuit is intended to satisfy the analyser checks the circuit against the specification makes systematic attempts to simplify the circuit by removing redundant contacts and establishes lower limits for the numbers and types of contact needed to satisfy the specifications this method is compared with the method in which the same operations are performed by coding them on a general purpose digital computer 5454 the mercury delay line storage system of the ace pilot model electronic computer 5455 the magnetic amplifier as an analog computer component 5456 an amfm electronic analog multiplier a multiplier is described in which frequency deviation and carrier amplitude are made respectively proportional to the two quantities to be multiplied the product is obtained by means of a foster seeley discriminator stabilization is provided by means of feedback the long term error is of full scale output 5457 electronic computers and telephone switching a discussion of the possibility of using digital computer techniques in automatic telephone switching systems 5458 an automatic telephone system employing magnetic drum memory the diad drum information assembler and dispatcher system is described a capacitive scanner acts as a commutator for conveying signals from subscribers sets to storage on magnetic drums these signals are combined with permanently stored information processed in accordance with built in programmes and used to control call switching circuits the technical feasibility of the system has been demonstrated by large scale laboratory experiments 5459 photographic techniques for information storage storage devices with capacities of bits and useful access times can be produced by means of photographic techniques the difficulty that rapid erasing and rewriting are not possible with photographic media is overcome by providing a small auxiliary unit such as a magnetic drum store flying spot scanners can be used for reading 5460 audio transformer design charts 5461 the design of a peaking transformer 5462 a wide band high power radio frequency transformer detailed description of a transformer forming part of the rf system of the birmingham synchrotron of it is designed for operation from a push pull amplifier and will deliver throughout the frequency range with a duty cycle of sec in every sec 5463 a crystal triode push pull amplifier the amplifier described uses two point contact transistors and is capable of delivery up to output power at an efficiency of a power gain of at harmonic distortion is obtained 5464 kerosene cooled transistors the temperature rise in the contact regions of a point contact transistor is considerably reduced by circulating kerosene around the junctions circulation is maintained by the natural convection currents set up 5465 the design of high q iron cored inductors design charts are presented for inductors not carrying dc the attainment of maximum q requires the reduction of overall losses including those due to core magnetization to a minimum for data on inductors carrying dc see of 5466 the study of a magnetic inverter for amplification of low input power dc signals the principle of operation of the magnetic inverter differs from the conventional magnetic amplifier in that the load current corresponds to the even harmonic mmfs present in the asymmetrically excited iron core system power gains up to can be obtained with time constants of about sec when operating at the zero stability is within 5467 semiconductor diode gates the general properties of gate circuits are discussed and a simple design analysis of transmission type and switching type gates is given the results of an experimental check are noted and the suitability of point contact and junction type rectifiers for different purposes is discussed 5468 study and evaluation of the microphony due to vibration of the plates of a variable capacitor capacitance variations due to vibrations are investigated by observing the results distortion the latter being evaluated from the ratio between the third harmonic and the fundamental when a signal of amplitude about is applied this ratio is expressed as a function of the q of the measuring circuit details of which have been given previously of and the effect of variations of supply voltage is shown in curves 5469 the the fundamental theorem of electrical networks a fuller proof is given than that presented in the original paper of 5470 application of complex symbolism to linear variable networks the theory developed is based on frequency domain analysis equations are derived for networks containing one linear variable element the value of which varies periodically and is capable of being developed in a fourier series the usefulness of these equations for computations of magnetic and dielectric modulators and amplifiers is indicated 5471 the utilization of degenerate modes in a spherical cavity formulae are derived for calculating the coupling coefficients between an arbitrary number of modes excited simultaneously in a cavity resonator the perfect symmetry of the sphere gives rise to a high degree of degeneracy ie many independent field configurations with the same natural frequency experiments on a spherical cavity gave results in good agreement with the theory practical coupling devices discussed include irises loops and small volumes of conductor placed within the cavity 5472 microwave cavity resonators some perturbation effects and their applications first order perturbation theory is used to examine the change in resonance frequency and q of a cavity due to a small deformation of the wall an expression is derived for the coupling coefficient between the two degenerate modes h and e in the absence of perturbation these two modes can co exist applications of the theory to measurements of dielectric properties study of ferromagnetic resonance etc are described 5473 simplification of the tensor analysis of networks 5474 power and efficiency of passive quadripoles families of circle diagrams are used to study the output power efficiency insertion loss and attenuation of quadripoles 5475 investigation of nonreciprocal quadripoles in the centimetre wave range devices based on the faraday rotation of guided waves are investigated see eg of a method is developed for determining the quadripole parameters of these devices a waveguide arrangement adapted for measurements on gyrators is described results are given for a gyrator using ferroxcube iv factors to be considered in designing gyrators for particular applications are indicated see also of 5476 the design of zig zag filters formulae are derived for the computation of a filter with a known distribution of cut off and peak attenuation frequencies and given image impedances the matching conditions between the sections and the method of determining the order of sections in a ladder network by means of a zig zag diagram is explr design is given 5477 old and new methods for designing composite high frequency filter circuits and their application to filter circuits with low relative bandwidth a calculation based on that given by edelmann for tchebycheff type filters is used to extend schienemanns formulae for multistage filters of to the case of finite ripples of the response curve for low relative bandwidths simple formulae are derived for the form factors and time constants of the double circuit stages as the ripples tend to zero further simplifications can be introduced modification of the method is indicated to deal with cases where large ripples are permitted for the sake of selectivity 5478 practical calculation of jacobis sn elliptic function with special reference to the determination of the cauer parameter for filters with operative attenuation characteristics elliptic functions encountered in calculations of tchebycheff type filters are considered the method of deriving these functions and hence the attenuation frequency curve is shown in detail for the case of an antimetrical low pass filter formulae for calculating the functions are tabulated in an appendix 5479 quartz crystals for filters outline account of the characteristics of crystals and their use in filter networks 5480 electrical high frequency separating filter networks frequency separating diplexer and notch diplexer networks are described two classes of frequency separating networks are distinguished networks with series tuned circuits in parallel and parallel tuned circuits in series parallel parallel and series series tuned circuit networks the former are of the frequency rejector type the latter of the frequency acceptor type the application of theory is shown in several numerical examples of design of transmitter hf separating filter networks the results are compared with the observed characteristics 5481 the necessary and sufficient conditions for the physical relizability of a rank field impedance admittance matrix in the form of a passive multipole it is proved that every positive real matrix of rank where m is a finite integral number can be physically realized in the form of a passive multipole 5482 a critical review of researches into millimetric wave spark generators methods using cylindrical and spherical electrodes and arrays of these are discussed other methods are mentioned difficulties involved are indicated references 5483 magnetic control of the frequency of valve transmitters by means of an electrodeless gas discharge the tuned circuit inductor of an oscillator was wound round an argon filled spherical container in which an electrodeless discharge could be maintained and a magnetic field was applied parallel to the plane of the coil the oscillator frequency was found to vary almost linearly over a certain range of field strengths and was also dependent on the gas pressure in the discharge vessel 5484 bridge stabilized ultrasonic oscillator good frequency stability and low harmonic distortion are obtained by arranging a wienbridge rc oscillator so that no arm of the bridge is hunted by a low impedance an oscillator with five overlapping ranges covering is described 5485 frequency stability and accuracy of a crystal oscillator properties of crystals relevant to their use for frequency stabilization are reviewed the occurrence and elimination of crystal oscillations at undesired frequencies are discussed among the factors causing deviation of frequency from the nominal value the most important is the circuit arrangement the requirements for satisfactory crystal oscillator circuits are examined in detail a table indicates the frequency range maximum instability maximum inaccuracy maximum total frequency deviation and energy output of some known circuits 5486 frequency stabilization of a reflex klystron oscillator part of the klystron output is fed to a cylindrical resonator one of whose ends is constituted by a diaphragm which is vibrated at about kcs the detected output from the resonator which varies with shift of the klystron frequency is fed to a lock in amplifier to produce a control voltage which is added to the klystron reflector voltage 5487 the miller integrator as sawtooth voltage generator the theory of the miller integrator is discussed and practical circuits of the transitron and practical circuits of the transitron and sanatron an integrator with separate controlling valnent values is considered in detail 5488 the parallel tdc amplifier a low drift amplifier with wide frequency response discussion on of please note change in udc number 5489 a transistor pulse amplifier using external regenerated pulses having desired waveforms as required in synchronous serial computers are obtained by means of a circuit using a point contact transistor operated as an over driven amplifier with external feedback provision is made for synchronizing the output pulses with a master clock transformer coupling provides dc restoration 5490 neutralizing pentodes in radar if stages the effects of grid plate capacitance are cancelled without use of additional components tapped coils or balanced tuned circuits by using as neutralizing capacitor a screen bypassing capacitor providing slightly less than complete bypassing experimental methods are described for determining the required values of the neutralizing capacitors for radar and television if amplifiers 5491 the magnetic amplifier comparison of the elementary magnetic amplifier with the type using external feedback 5492 design of magnetic amplifiers an outline of basic design principles 5493 nonlinear capacitors for dielectric amplifiers the operation of the dielectric amplifier depends on the vas on the variation of dielectric constant with applied voltage requirements for materials suitable for high frequency small signal applications are discussed a two stage amplifier with rf power supply ad and gain of is briefly described 5494 new constructional techniques survey of modern methods for producing radio equipment including potting circuit printing and automatic soldering 5495 radio research special report fundamental processes of electrical contact phenomena 5496 on interaction of nonlinear oscillations general considerations regarding the existence stability and certain topological rules of selection between several oscillations are outlined the results are used to investigate the differential equation using the stroboscopic method of some special cases are examined 5497 the photoeffect in a uniform electric field it is shown theoretically that even very high external fields have little effect on the angular distribution of the photoelectrons or on the total effective atomic cross section 5498 free electron in an e and h field the general equations of motion are obtained for an electron in electric and magnetic fields particular cases for various angles between the field and velocity vectors are considered 5499 experimental studies of the motions of slow electrons in air with application to the ionosphere from experiments on the motion of slow electrons in air empirical formulae were deduced from which the electronic temperature collision frequency drift velocity and the average energy loss per collision ca can be derived the collision cross section of molecules of air and nitrogen at electron temperatures up to is directly proportional to the speed of the electrons the electron collision frequency in the ionosphere up to is linearly proportional to the pressure the important result that is proportional to and not to as believed hitherto where q is the agitational energy of the electron and q the energy of thermal agitation of the gas molecule is discussed briefly 5500 the case of charged density distribution versus semipermanent polarization as a basis for electret behavior it is shown that if an electret were composed of ordinary charge distributions its effects would diminish by in a day or two the observed effects indicate the existence of a semi permanent polarization and can be regarded as arising from a lag in the cancelling action of conductivity 5501 investigation of the interaction between an electron and a lattice oscillator by means of a one dimensional model 5502 the dielectric properties of water in solutions measurements have been made of the microwave dielectric constants and losses of water and some aqueous solutions over the temperature range using methods described by collie et al the dielectric constant of water at cm rises from at to at results for the solutions are tabulated and their interpretation is discussed 5503 the linear piezoelectric equations of state the different forms of the equations of state obtained from various combinations of stress strain electric field electric displacement and polarization are given in tabular form 5504 electro thermal behaviour of point contacts to semiconductors joule heating effects due to current flow through a point contact to a semiconductor with no barrier layer were investigated theoretically and the results were confirmed experimentally for tungsten points in contact with sintered disks of mg ti the values of the contact radius calculated from dc and ac experiments are in fair agreement as are the calculated and measured variations with frequency of the impedance to sinusoidal ripple superimposed on steady current minor anomalies in the dc characteristic are assumed to be due to field emission around the contact 5505 the ignition voltage of gas discharges in a transverse magnetic field over the pressure range torr experiments were made using a discharge space bounded by coaxial cylinders with a coaxial magnetic field a voltage of was sufficient to start a discharge at torr with a suitable magnetic field strength on the basis of these measurements and those of other workers expressions are derived relating ignition voltage to magnetic field strength electrode separation and configuration electrode material nature and pressure of the gas above a critical value of torr cm for air the magnetic field raises the ignition voltage below this critical value the magnetic field reduces the ignition voltage 5506 the growth of the high frequency electrodeless discharge the various stages in the growth of electrodeless discharges are discussed in detail with particular consideration of electron multiplication processes increase of the number of positive ions and the effect of charges on the wall of the discharge tube a new experimental technique for measuring the discharge current is described in which the large capacitive current across the external electrodes is balanced in a bridge circuit so that when a discharge occurs the unbalanced voltage after amplification and rectification can be used to give a proportionate representation of the value of the discharge current on a cro for measurement of the growth of the current with time hf voltage pulses are applied to the discharge tube and the timebase of the cro synchronized with the pulses oscillograms show how the growth of current depends on the pressure the nature of the gas the excess voltage and the frequency of the applied field in the initial stage the properties of the tube walls mainly control the multiplication process and thus the starting field in the later stages the properties of the gas become important and so determine the total time of growth of the discharge for previous work see of 5507 secondary electron emission of crystalline mgo single crystals of mgo in bulk form cleft along the plane were used the maximum secondary emission ratio is about at room temperature and with a bombarding voltage of about no correlation between conductivity and yield was established increase in temperature led to a decrease in yield the most probable energy of emission is about theoretical considerations based on band theory support these observations 5508 collisional effects and the conduction current iin an ionized gas a first approximation to the transport equation for the conduction current in a binary ionized gas id derived the collision damping factor derived is a weighted mean of the electron and ion collision frequencies which is times the electron collision frequency corresponding approximations made to the equations of conservation motion and thermal energy when combined with maxwells equations yield a set of equations for the investigation of the interactions between an ionized gas in motion and the associated radiation field the results are applicable to the solar atmosphere and the h h and lower ionosphere regions 5509 the magnetic fields produced by uniformly magnetized ellipsoids of revolution formulae graphs and tables are given for the numerical evaluation of the field strengths in the equatorial plane and on the magnetic axis of prolate and oblate spheroids 5510 the influence of domain structure on the magnetization curves of single crystals neels model for the domain structure of a single crystal of iron in the form of a strip parallel to the direction was used in the calculation of magnetization curves depend explicitly on the width of the crystal comparison between the calculated curve and experimental results for a si fe crystal shows good agreement particularly at low field values 5511 induction phenomena consequent on the movement of material in primary magnetic fields and their experimental applications part experimental bases discussion of unipolar induction using this term in its broad original meaning viz induction of electricity due to movement f of material in a magnetic field simple experiments demonstrating the basic phenomena are described 5512 induction in a conducting sheet by a small current carrying loop analytical solutions are derived for the cases where the loop axis and the plane of the conducting sheet are mutually perpendicular parallel the results are applicable to problems of electrical shielding and prospecting 5513 an identity leading to a solution of kirchhoffs problem for damped waves 5514 electron currents in thin oxide films on aluminium at low electric field intensities the electron current in films formed on al in suitable electrolytes depends on the temperature and on the hyperbolic sine of the product of the field strength and a constant dependent on barrier dimensions the oxide film barrier height and trough to peak width are ev and respectively the theoretical current voltage curves given show good agreement with experimental results the origin of the electron current and the presence of trapped charges in the oxide layer near the electrolyte surface are discussed 5515 radio research special report fundamental processes of electrical contact phenomena 5516 conditions for the occurrence of electrical discharges in astrophysical systems theoretical considerations of a large ionized mass of gass in motion show that neutral points of the magnetic field are unstable so that a small perturbation will start a discharge the orbits of particles in the field are considered particles with very large energies may be involved such discharges may account for aurorae and may also occur in solar flares and the interstellar gas 5517 the length of ionized meteor trails the length of the meteor ionization column is defined as the distance between the most widely separated points along the trail from which normal incidence radio reflections can be obtained using a radar system of prescribed characteristics a statistical study is made of the length distribution of trails based on measurements made at two observation stations a spaced km apart and operating with a cw output power of about on the mean trail length found was meteors up to the sixth magnitude were detected 5518 cosmic origin of radiation at radio frequencies discussion of possible ways in which rf radiation from stellar sources may be produced 5519 some fundamental results and problems of radio astronomy a clear and concise survey of measurement techniques is given together with a discussion of the theories of the origin of rf radiation from the sun and the radio stars the results measurements of the line emission of interstellar hydrogen on a wavelength of cm are briefly discussed in relation to the problem of the structure of the milky way 5520 collisional effects and the conduction current in an ionized gas 5521 note on a proposed three component aeromagnetometer by identifying stairs photographed with a small nonmagnetic camera mounted on the fluxgate gimbal mechanism of a total force aeromagnetometer it is possible to find the magnetic declination and dip 5522 conference on radio meteorology summaries are given of paper for presentation at the conference at the university of texas november 5523 exploring the ionosphere by means of rockets summaries are given of papers presented at a conference held at oxford under the auspices of the royal society 5524 the charge on the ionosphere the total charge on the inner side of the ionosphere is shown to be zero 5525 study of the ionospheric d region using partial reflections pulse echo observations were made with a transmitter of peak power and with the receiver located where the noise level was very low results showed that below the e layer there were two reflection regions a region of greater electron density around extending up to the normal e layer and having minimum ionization at noon a region around km where a distinct ionized layer forms during the day attains a maximum ionization at noon and disappears at night in echoes from this region both magneto ionic components were present the extraordinary being the stronger the ratio of the two magneto ionic components of a discrete echo at a particular range was within the uncertainty of observation independent of fading but varied with time of day and from day to day from this ratio the collision frequency and electron density for this range of heights were determined 5526 two cases of large f region disturbance associated with small magnetic disturbance during oct at canberra and brisbane and to a lesser extent at other places in this area of the world hourly values of and showed departures from monthly median values typical of those observed during a considerable magnetic storm the days in question were international quiet days two other though less striking cases have been found from analysis of the records 5527 the distribution of f region ionization at high latitudes the linear relation between critical frequency and sunspot number is found to hold with reasonable accuracy in the arctic contour charts of a and b have been prepared in coordinates of latitude and longitude for fixed hours and months typical examples are shown and the general features particularly the effects of the auroral zone and geographical factors are pointed out 5528 some statistical results on the phenomena associated with ionospheric storms data covering the years on height of maximum ionization o of the f layer and absorption in lower layers were analysed to determine the probability that a particular day will be a storm day for a given set of solar conditions a day is considered to b be a storm day if the mean variation of these three parameters studied separately in relation to the effects of sunspots m regions and solar flares is such as would cause a fall in muf or a rise in luf positive results were obtained only for the parameter f except for storms associated with m regions at sunspot minimum the probability that a given day will be a storm day does not exceed for the first day of a storm but many reach on subsequent days it is concluded that only during the sunspot minimum period can ionospheric storms be forecast on solar data alone 5529 the ionosphere during the partial solar eclipse observed at buenos aires august the decrease in in the number of free electrons in the f layer during the eclipse was mainly due to ion recombinations a simultaneous decrease in the f layer was preceded by an appreciable increase the two layers were clearly separated indicating a high recombination coefficient above the f layer rapid decrease of the critical frequencies of both layers was observed during the occultation of two sunspots 5530 experimental studies of the motions of slow electrons in air with application to the ionosphere 5531 typical scattering of radio waves by electron clouds in the sporadic e layer the three main types of scattering deduced by eckersley of from fixed frequency observations are confirmed by specially selected records of swept frequency echo soundings made at lindau 5532 the relation between rain current and rate of rainfall consideration of the drop size distribution in rain leads to a relation very similar to the first of simpsons formulae 5533 the effective separation of discharging points the effective separation ie that spacing of points in rectangular array which would give the same current density as actually occurs with an earth connected point in discharges o of atmospheric electricity is m for high field strength 5534 the aurorae general characteristics of aurorae are described and the connection between aurorae and both solar activity and geomagnetism is shown and the auroral spectrum is discussed and various theories of the aurora are critically reviewed 5535 an investigation of whistling atmospherics a comprehensive report of an experimental and theoretical study of whistling atmospherics at frequencies is given whistlers may or may not be preceded by ordinary atmospherics produced by lightning strokes at a distance of km the diurnal and annual variations of th the properties of both types were investigated explanatory theory of their origin advanced by eckersley of is developed measurements of the degree of dispersion indicate an electron density in the upper atmosphere considerably larger than expected this result is explained on the assumption that electrons are falling in from outside and this might account for the relation between the occurrence of whistlers and magnetic activity 5536 design methods for control systems the nyquist diagram method of analysing feedback systems is discussed stability problems can be simplified by using a method based on the attenuation frequency characteristics the speed control of a dc motor is considered as an example 5537 fast response high current thyratron power supplies for inductive loads several methods for energizing loads such as fields of large motor generators solenoids magnetic clutches and electromagnets are discussed including the half wave circuit with an optimum value of capacitance in parallel with the load this method provides the fastest response for the equipment required 5538 standby generating plant for the manchester edinbugh television radio relay link description of equipment driven by an ic engine which automatically restores the supply voltage at unattended relay stations in case of mains failure for more than two seconds the sets are given daily test runs remotely controlled from attended stations 5539 electric batteries recent patents discussion of improvements in leclanche type cells alkaline batteries cells with dished plates or with bipolar electrodes hgo cells and weston standard cells 5540 application factors for electrical resolvers the device described resembles a small motor and was originally designed for solving a trigonometry problems in conjunction with analogue computers possible applications for control purposes in industry are discussed 5541 magnetic drum design a chart relates the various parameters involved 5542 step switch converter digitizes analog data 5543 review of new materials and techniques in high fidelity transformer design 5544 transistors theory and application part grounded emitter and collector circuits formulae and typical values of parameters are tabulated for various circuit arrangements for junction and point contact transistors part of january 5545 transient analysis of transistor amplifiers 5546 the electrical conductivity and current noise of carbon resistors the variation of resistance with temperature pressure and magnetic field in several types of carbon resistor was measured down to liquid he temperatures the dependence of the noise spectrum on the current intensity temperature and magnetic field was also investigated the law holds at all temperatures 5547 basic fuse types for electronic equipment types with slow medium and fast action are described 5548 tolerances and temperature coefficient of coils with ferroxcube slugs extension of a previous discussion of from the point of view of insensitivity to variations of core permeability and of temperature the closed core with air gap is best the rod core with long coil next and the rod core worst see also of 5549 a variable inductor an af inductor is described in which core hysteresis effects are eliminated the inductance being controlled by moving a magnet in relation to the cores q values at and at are possible experimental filters using the inductors are also described 5550 current trends in miniature relay design design of relays for airborne electronic equipment is discussed 5551 the optimum dc design of flip flops a simple criterion is derived by means of which it can immediately be seen whether or not a flip flop circuit corresponding to specified requirements is realizable a numerical example is given 5552 the eit decade counter tube 5553 polycathode counter tube applications the use of dekatrons in millisecond timers batching counters and cro time markers is described the basic decade units are capable of counting up to per sec see also 5554 a method of approximate steady state analysis for non linear networks approximate solutions for the fundamental and third harmonic are obtained by a three stage method involving a first approximation to the fundamental frequency solution usually accurate to within a third harmonic solution generally within using an equivalent circuit which is dependent on the first fundamental solution a correction to the fundamental solution using third harmonic quantities which brings its accuracy to within about adaptations of some standard techniques of solving linear steady state problems for use with this method of analysis are described appendix by gh rawcliffe 5555 effective circuit bandwidth for noise with a power law spectrum analysis is developed for a tuned rlc circuit for noise with a frequency spectrum given by an arbitrary power law the effective bandwidth is presented in terms of that for white noise 5556 the piezoelectric oscillations of a quartz crystal at its odd even and half odd harmonics the results reported in were confirmed by observing the diffraction patterns of the oscillating quartz 5557 flexure mode quartz oscillators details are given of the modes of motion electrode arrangements and electrical performance of the duplex xy and nt types typical frequency temperature curves and graphs of other crystal characteristics are shown a crystal controlled af oscillator is described and the circuit diagram including component values is given 5558 loci curve theory applied to high frequency networks the application of the method is shown for the evaluation of such response curves of four terminal networks as are produced by the variation of one parameter examples are given of the calculation of a wide band thermistor mount using a rectangular admittance chart and the variation of the input reflection coefficient with frequency of a given transformer using a smith chart 5559 antenna matching network efficiency charts are presented for estimating the transfer efficiency of matching networks 5560 conformal mappings for filter transfer function synthesis conformal mapping provides a practical way of solving the es potential problems previously considered of analysis in the mapped plane also yields convenient methods for predetermining the number of poles and zeros required to meet given design specifications 5561 theory of maximally flat and quasi tchebycheff filters the synthesis of a quadripole with a prescribed attenuation function is described this function has to satisfy certain conditions the synthesis s is carried out for maximally flat and quasi tchebycheff low pass filters the results being presented in curves suitable for calculating the values of the circuit components the treatment is extended to band pass filters by means of a well known frequency transformation 5562 rlc lattice networks correction to paper noted 5563 band pass filters a method is presented for synthesizing constant resistance networks to have maximally flat or tchebycheff type response characteristics a numerical example of each type is calculated 5564 high frequency filter problems in television transmitters coaxial line filters for the partial suppression of the lower sideband are discussed particular attention is paid to arrangements suitable for high level modulation in which the filter is spatially separated from the output stage and its input impedance is maintained constant over the frequency band 5565 electrical control of valve transmitter frequency by means of an electrodeless gas discharge the tuned circuit inductor of an oscillator was wound round an argon filled cylindrical container in which an electrodeless discharge could be mained the oscillator frequency was nearly linearly proportional to the anode voltage and was also dependent on the gas pressure see also 5566 noise properties of lc oscillators previous analyses based on the concepts of forced oscillations and disturbed free oscillations of are discussed the extent of the am and the fm resulting from the presence of noise is examined 5567 pseudoresonant and phase shifting quadripoles as frequency determining elements in rc oscillators rc oscillators with a sinusoidal output are divided into two main groups according to the type of rc network they include equivalent circuits are obtained and simple expressions are derived for the frequency of stable oscillation and for the condition for self excitation 5568 theory of triode oscillators with coaxial resonators a study of disk seal triode oscillators the conditions necessary for maintaining oscillations are derived the width of the frequency range with a fixed tuned grid circuit is calculated from the valve parameters deviations from the theoretical value encountered under working conditions are discussed a general criterion for mode separation is established 5569 pulse generator with variable repetition frequency and pulse width an instrument designed around the eq nonode valve is described the principle of operation is that of the detector of the pulse repetition frequency can be varied between and or higher the duty factor from to and the amplitude from to the pulse flank occupies of the pulse period pam pwm and pphm can be used a complete circuit diagram including component values is given 5570 wide band amplifiers using secondary emission tubes the applications of an experimental valve particularly at vhf in rf or if amplifiers cr tube deflection amplifiers and distributed amplifiers are described and discussed the transconductance of this valve is the input and output capacitances are and respectively and the sum of anode and screen currents is ma the valve construction has been described by mueller 5571 a method for the amplification of extremely small thermoelectric voltages a more detailed account of the dc amplifier noted in of is given the threshold voltage is with a source impedance of a circuit diagram including component values is given 5572 noise factor of conventional vhf amplifiers a simple treatment is presented the various types of circuit and valve noise are indicated the concept of available power is explained and noise factor is efined in terms of available power gain analysis is given for triode input stages based on common cathode common grid and common anode connections experimental results are given for various amplifiers for a mid band frequency of curves show the effect of source resistance on the midband noise factor and the variation of single frequency noise factor over the band and results are also tabulated for different valves and circuits the best noise factor with a given valve can only be determined experimentally the need for further improvement in the noise performance of valves is emphasized 5573 multiple feedback audio amplifier the power output of the williamson circuit is increased and the power supply requirements reduced by using tetrode output valves with anode to grid feedback 5574 stability of a grounded grid amplifier the general conditions are investigated for the self excitation of uhf grounded grid amplifiers the precise formula and an approximate one for the frequency and the condition for self excitation are derived the dependence of the stability of the amplifier on circuit constants is considered the results are shown graphically 5575 methods of magnetic amplifier analysis 5576 pcm coding system uses special tubes the system uses a ten target ribbon beam switching tube for sampling and a tube with ten stable positions determined by crossed electric and magnetic fields for coding descriptions of tubes and circuit are given 5577 printed circuits some general principles and applications of the foil technique methods of producing printed circuits are discussed from the viewpoint of the printer the foil technique is suitable for both general and special applications the main processes involved namely printing etching fusing mechanical patterning transfer and multilayer technique are described various characteristics of foil conductors are examined and some particular applications are indicated 5578 johnson noise and equipartition 5579 the value of the constant in wiens displacement law the observed value of the wavelength at which maximum radiation occurs for a black body at a given temperature depends on the band pass characteristics of the instrument used as a consequence wiens constant can assume different values 5580 demonstration of electroluminescence by means of a multilayer colour film contact photographs were made of electroluminescence effects in a phosphor at field strengths of and a frequency of the results indicate a direct excitation process without the intermediate step of a gas discharge 5581 the diffraction of an arbitrary pulse by a wedge an extension of the conical flow method used by keller and blank the coordinates chosen are such that the characteristic cone and the two planes intersecting to form the wedge each become constant coordinate surfaces the problem is then solved by separating variables and expanding the boundary conditions in terms of solutions of the ordinary differential equations which appear the results are shown to apply to the special case investigated by keller and blank 5582 theory of diffraction of electromagnetic waves at a perfectly conducting disk and related problems the problem considered in of for plane em waves is solved generally for the case of spherical waves particular solutions are also obtained for the diffraction at an ellipsoid of revolution for a solenoidal em field a method for the numerical solution is outlined for the case of diffraction at a disk at a circular aperture and at an ellipsoid of revolution valid for approximately where as is the radius or half the distance between the foci as appropriate 5583 scattering of electromagnetic waves at an uneven surface scattering of waves incident at an angle such that no part of the surface is in a shadow is considered theoretically application of the results to two particular cases shows that surfaces of a trochoidal form will give appreciably greater backscatter than a sinusoidal surface of the same amplitude and wavelength 5584 the theory of electronic conduction in polar semiconductors the present problem has been considered before by several authors but many of the results which have been given are either incorrect within certain limits by solving the boltzmann equation for the velocity distribution function of the conduction electrons in a crystal in which the scattering is due to the polarization waves of the lattice exact expressions are obtained for the electrical conductivity and the thermoelectric power in the form of ratios of infinite determinants simple approximate solutions are derived and are used in the discussion of the dependence of conduction phenomena upon the temperature and upon the degree of degeneracy of the electron gas 5585 the transient period of the skin effect analysis is given for the distribution of current in cylindrical conductors solid or hollow during the period between application of a voltage and attachment of a steady state 5586 impedance of solid and hollow cylindrical conductors to current pulses continuation of work noted in above a quantitative solution is obtained for the initial value of the ratio between the instantaneous voltage and current 5587 electrical discharges recent work on electrical discharges is surveyed under the following headings the breakdown of gases in static fields high frequency discharges cold emission phenomena the regime of space charges breakdown is regarded as a consequence of the development of pre breakdown ionization currents by primary and secondary processes which are themselves controlled by the nature and geometry of the cathode the important part played by surface films in the cold extraction of electrons from electrodes is described rf plasma oscillations and the generation of noise by discharges is discussed 5588 fundamental processes of the initiation of electrical discharges the production of electrons initiating the spark discharge from polished and tarnished metal surfaces was investigated the field applied was of the order of 5589 electron emission resulting from the impact of ions on molybdenum and carbon targets experiments were made using normally incident polyatomic ions of energy between and the number and energy distribution of the emitted electrons did not depend on the target material the energy distribution of the electrons was independent of the nature and energy of the incident ions but the number of electrons emitted per ion increased with the energy of the ions and depended on the nature of the ions 5590 a variational formulation of the multi stream electro dynamic field equations a non relativistic approximation to diracs new variational formulation of the single stream electrodynamic field equations is presented using vector notation and mks units throughout the hamilton jacobi theory of a rotational space charge stream is developed the variational formulation is generalized to the multi stream case both for a finite number and a non denumerably infinite number of streams 5591 induction phenomena consequent on the movement of material in primary magnetic fields and their experimental applications part translation the minkowski field equations are presented in a form to suit the particular conditions a definition is given of apparent dielectric constant sommerfields treatment of unipolar induction is extended to magnetizable bodies unipolar induction in the case of translational motion is identified with es induction in the material at rest 5592 the hissing arc and radio frequency self generated oscillations in the dc carbon arc 5593 radio astronomy part methods of observation theory and technique of methods of observing extraterrestrial sources of rf radiation are reviewed 5594 evidence of harmonics in the spectrum of a solar radio outburst measurements of rf outbursts on november and may show a dynamic spectrum comprising two widely spaced frequency bands having a drift with time from high to low frequencies the ratio between frequencies of corresponding peaks was close enough to to suggest a harmonic relation between the bands the emission may take place in the corona at frequencies equal to the natural plasma frequency and its harmonics 5595 radio observations at the time of an ascending solar prominence the solar prominence reported by das and sethumadhavan below was observed in sydney and records of radiation on and were obtained noise bursts preceding and following the eruption were also recorded 5596 eruptive prominence of february and associated radio noise burst three bursts of noise associated with the prominence were recorded at kodaikanal with a radio telescope working on these occurred when the topmost parts of the prominence were at about and respectively above the limb though present day theory indicates that at radiation cannot ordinarily escape from the sun unless generated at a height km no active sunspot group was observed in the vicinity of the prominence 5597 radio radiation from the supergalaxy a low intensity source was observed in march on with position corresponding approximately to the plane of the local supergalaxy described by de vaucouleurs 5598 the galaxy explored by radio waves the full text of the halley lecture for this includes a short account of radio astronomy n and of the results of observations made at cm and other wavelengths 5599 a search for radio emission from the orion nebula short report of interferometer observations at a frequency of 5600 a model of the radio frequency radiation from the galaxy the model has been designed to give agreement both with the observed values of equivalent aerial temperature and with the observed isophotes over the frequency range the actual mechanism of generation of radio energy is not discussed 5601 the distribution of the discrete sources of cosmic radio radiation 5602 the south magnetic pole in and the comparative displacements of the north and south poles from to 5603 recording the geomagnetic field at port martin the records were obtained by the adelie land expedition during the period january details are given of methods and results 5604 electromagnetic variometer for the vertical component of the geomagnetic field an instrument is described it operates on the same principles as the electromagnetic seismograph 5605 further determinations of the vertical distribution of ozone during eclipses of the moon 5606 propagation measurements in the ionosphere with the aid of rockets measurements made at white sands are reported continuous waves with harmonically related frequencies namely and were radiated from the rocket to two ground stations the higher frequency wave is practically unaffected by the e layer and serves as a reference the ordinary and extraordinary components of the lower frequency wave with frequency multiplied by re separately heterodyned with the reference wave the refractive indices of the medium are determined from the resulting beat frequencies together with a determination of the geomagnetic field and of the electron collision frequency at one altitude the lorentz polarization term can be neglected results are given and discussed 5607 the reflection coefficient of the long wave the propagation equation is solved and the reflection coefficient deduced for long waves incident vertically on a region of low electron concentration such as that situ ted below the e layer results are given for two cases based on different assumptions regarding the vertical gradient of concentration comparison of these calculated results with observations on and waves indicates that there is a considerable gradient of electron concentration in the layer 5608 dissociative recombination in the e layer an examination is made of the consequences of assuming that electrons in the e layer disappear mainly by dissociative recombination it is shown that this assumption provides a far more satisfactory basis for explaining actual e layer observtions than ion ion recombination and that most of the atomic processes involved are amenable to accurate laboratory measurement 5609 ionosphere observations in the kerguelen isl nds an ionosphere station has been established by the spim at port aux francais regular observations started in february monthly mean values of and for six months are tabulated the results demonstrate the great influence of the geomagnetic field 5610 some regularities of the ionospheric f region the f layer regularities observed by ratcliffe are confined to a few stations only and disappear when the bifurcation of the f layer is large if the ion content of the f a and f layers is considered as a whole the regularities become much more marked n and are observed at slough falkland islands and singapore even when the bifurcation is large peaks observed in the monthly mean values are attributed to tidal effects the results are in conformity with the view that the f and f layers constitute a single ionization region 5611 lunar tidal variations in the sporadic e region lunar tidal variations in the e layer are deduced from a statistical study of records from various stations the maximum amplitude of the lunar semidiurnal variation of e for a period of a year resembles that of the f layer in summer it is larger than that of the f layer especially in middle latitudes the magnitude of the height variation is similar to that of the f layer the maximum height variation occurs about six hours after the lunar culminations and the maximum value of e two or three hours later possible explanations of the phenomena are discussed 5612 the distribution of the ionospheric disturbances during the geomagnetic bay a statistical analysis based on ionospheric data obtained at widely distributed stations 5613 on a change in geomagnetic declination accompanying intense sporadic e layer ionization analysis of geomagnetic and ionospheric data obtained at kakioka and kokubunji respectively indicate that the geomagnetic declination exhibits increased diurnal variation a few hours after the appearance of an intense e layer it is inferred that the e layer ionization is probably due to the incidence of particles 5614 a procedure for the determination of the vertical distribution of the electron density in the ionosphere see also 5615 optic axes and critical coupling in the ionosphere the similarity between the phenomena of double refraction in crystals and in the ionosphere is discussed the ionosphere problem is studied by introducing a reference system based on the principal directions of the three dimensional dielectric ellipsoid these depend only on the direction of the earths field and are essentially constant over the ionosphere optic axes can exist in the ionosphere in the presence of collisions and this is precisely the condition for critical coupling between the ordinary and extraordinary modes the analysis is illustrated by reference to a possible set of ionospheric conditions 5616 raindrop charge and electric field in active thunderstorms measurements on over drops are reported the average charge was esu for positively charged drops and esu for negatively charged drops 5617 on the electrification of snow an account is given of experimental investigations of the charging produced by pouring snow from a vessel into a funnel and blowing snow on to an insulated target the results are relevant to problems of precipitation static 5618 radar echoes from a growing thunderstorm the growth of hail in cumulus clouds is studied theoretically in relation to the first appearance of radar echoes the results are in good agreement with earlier observations 5619 auroral radio echo table and diagram for a station in geomagnetic latitude 5620 radio noise from aurora failure of attempts made during and to detect cm auroral radiation observed in is attributed to the decreased intensity of auroral displays and of sunspot activity 5621 electrical properties of the blizzard the programme of the expedition to adelie land was not intended to cover the study of blizzards but the interference with radio reception due to this cause was found to be so bad that an investigation was instituted when a meter was connected between the aerial feeder of the atmospherics receiver and earth a current of was observed varying with the intensity of the wind some days later in identical weather conditions the same current intensities were measured but with reversed sign to explain this result extended measurements were made of the charge collected using horizontal aerials arranged at right angles to the wind the rf noise spectrum of the blizzard was also studied using a receiver with a frequency range of records were also made of reception of wwv and wwvh on and for correlation with anemometer and charge records the results indicate that the sign of the charge collected depends on the temperature of the blizzard reversal occurring at about the rf noise is closely related to the wind and intensity of the blizzard 5622 audio frequency spectrum of atmospherics results are reported of simultaneous recordings of the frequency components in the band the frequency of the largest component in the slow tail decreases as source distance increases and is higher at night than by day while for the oscillator part the opposite effect occurs selective attenuation at frequencies around is indicated 5623 the variation with distance in the range km of atmospheric waveforms records of the electric field variation of a violent thunderstorm made at distances of are analysed over portion which cov large and rapid increase in field strength corresponding t to the return stroke of the lightning discharge theoretical and experimental results for the waveform the ratio of the maximum es field to the net es change and the current in the discharge are in fair agreement 5624 die ionosphere intended primarily for the physicist who wishes to make a rapid survey of ionospheric physics space has been found in most cases not only for a brief review of the background but also for an indication of more recent developments 5625 design charges for an on off control system discussion a simple and rapid method is presented for determining the step function response of an off system consisting of a pure time delay or distance velocity lag an exponential time constant and an integration 5626 self excited two phase thyratron inverter details are given of a unit providing an output of at from a input 5627 programme design for the csiro mark computer computer conventions 5628 programme design for the csiro mark computer programme techniques 5629 recent electronic computers and their applications digital computers are described and compared in respect of operating and speed and structure 5630 a mathematical basis for an error analysis of differential analysers 5631 analogue computer for aircraft design a compact general purpose instrument designed for economical quantity production 5632 an analog to digital converter a device for giving the angular position of a slowly rotating shaft as a binary number uses a mechanical counter which goes from zero to full capacity during one revolution of the shaft the counter may comprise a series of cams associated with switches on application of a reading pulse the number registered by the counter is made available as a pattern of pulses the arrangement being suitable as an input device for a digital computer 5633 servo systems for performing mathematical operations by combining servomechanisms with computing systems involving mechanical or electrical analogies loading effects which tend to introduce inaccuracies are eliminated an outline is given of procedures for addition and subtraction determination of powers and roots solution of triangle and integration 5634 the univac tube program account of an integrated programme starting with the design and initial selection for ensuring reliable performance of valves in a large scale computer 5635 rapid parallel z calculations use of a special graph paper with both polar and rectangular coordinates facilitates the calculation a ruler is the calculation a ruler is the only instrument required in this graphical method 5636 the calculation of nonlinear networks by means of composite straight line characteristics many circuit problems are simplified by substituting for an actual curved characteristic an approximation built up of rectilinear sections use of the method is illustrated by studying the characteristics of iron cored coils with and without hysteresis and with and without magnetic bias and t by analysing the free oscillations of a circuit including an iron cored coil emphasis is a laid on the point that the actual shape of the nonlinear characteristic is less significant than the simple fact of its deviation from linearity 5637 harmonic and intermodulation distortion in power law devices explicit expressions are derived for the intermodulation components produced when two sinusoidal voltages are applied simultaneously to a device such as a diode whose transfer characteristic can be represented by a simple power law formula results of practical importance in intermodulation distortion testing are presented graphically 5638 components for severe conditions of use a discussion of the factors to be considered in the design of capacitors and resistors for use under extreme temperature and humidity conditions particularly when the components are required to be as small as possible the use of ceramic covered wire for the windings of transformers etc to withstand high temperatures is mentioned 5639 frequency discrimination and stabilization of square wave modulated microwave transmissions the method described is a modification of that due to aurell mit technical report no the frequency of the oscillations from a reflex klystron is compared with the resonance frequency of a high q cavity and a correction voltage depending on the frequency difference is fed back to the klystron reflector electrode via the modulator where it is combined with the square wave modulation voltage the method of alignment of the microwave circuits is discussed in detail and the effect of misalignment on the discriminator characteristics is shown 5640 properties and applications of thermistors 5641 theory of the boella effect a discussion of the mechanism causing the drop in the resistance of composition resistors at hf abstracts a similar variation of resistance with frequency has been observed in electrolytic solutions effect comparative measurements were made on resistors of three different types namely ceramic rod with helical carbon film low resistance type carbon resin composition in ceramic case high resistance type and capillary tube containing a solution of cuso in water electrolyte type the boella effect was most marked in case variation of resistance with electric field strength is also observed the explanation given is alternative to that of howe 5642 natural frequencies of coils and windings digest only calculations for an equivalent circuit consisting of reactors only were made using punched card equipment an ac network analyser the effect of neglecting the mutual inductance between elements partly or completely is shown graphically very close agreement with measured natural frequencies was obtained 5643 air core coil design for crossover networks simple analysis is given for determining the correct wire gauge and optimum coil dimensions for specified values of q and l results are shown in charts and numerical examples illustrate their use 5644 three phase transudctor circuits for magnetic amplifiers 5645 transistors theory and application part switching circuits using the transistor counter circuits relaxation oscillators etc using point contact transistors are described 5646 the phase bistable transistor circuit corrections to paper noted in of 5647 the eit decade counter tube corrections and addendum to paper noted in of february 5648 a note on the network postulates kirchhoff law that the sum of the potential differences about any closed path of branches is zero is repl ced by a version making no explicit references to paths of branches the resulting law can be interpreted geometrically in terms of orthogonal subspaces of a certain vector space the network definition given is readily shown to be invariant under changes of basis the equivalence between the new definition and the classical one is established 5649 the return difference matrix in linear networks bodes concept of the return difference is generalized by replacing the quantities concerned by matrices a formula for the fractionated gain is derived which is a generalisation of thevenins theorem formulae are also derived for the stability of a circuit for the variation of its output as a result of imperfections of the circuit elements and for the input and output impedance the method is particularly useful for analysing multiple loop feedback circuits 5650 a graphical contribution to the analysis and synthesis of electrical networks the contribution of the poles and zeros of a network function to the steady state characteristics at real frequencies is considered by means of vectors and the connection between attenuation and phase is thereby accentuated bodes relation between attenuation and phase in minimum phase networks is derived by considering the contributions from individual singularities and using a known definite integral in a real variable details are derived for the construction of a series of templates useful for finding pole zero positions which yield certain attenuation phase and delay characteristics and vice versa the method is illustrated by examples including the estimation of the phase and delay characteristics corresponding to the given attenuation characteristic of a minimum phase wide band amplifier 5651 the relations between circuit pass band and signal build up time two pass band criteria are discussed namely the bandwidth between the points and the bandwidth defined in terms of special distribution it is shown that these are not uniquely related and that it is not possible to determine the time constant of a circuit solely from a knowledge of its bandwidth 5652 voltage reference node description of a general method of analysing linear networks by nodal analysis without specifying the node to which all voltages are referred the network can be represented by an indefinite admittance matrix which can be brought to a definite form by omitting the row and column corresponding to a specified reference node the method is useful for dealing with valve circuits with earthed grid or earthed anode stages or with no earthed electrodes 5653 fused quartz ultrasonic delay line memory the digit storage unit described is of the type comprising a slab of fused quartz providing a folded transmission path methods are indicated for eliminating spreading of the ultrasonic beam and mode conversion at the reflecting surfaces thus reducing the intensity of spurious signals an ultrasonic frequency of is used and pulses with a dynamic range of can be stored at rates 5654 some notes on the properties and manufacture of piezoelectric quartz crystals the frequency stability temperature coefficient and activity of quartz resonators are discussed and the relation between these properties n and the oscillation frequency of a circuit including the crystal is examined the performance of some typical units is shown graphically 5655 double compensated tunable cavity two frequency temperature compensation of hermetically sealed cavities filled with dry inert gas is described a typical performance curve is shown 5656 differentiating circuits passive network and feedback amplifier types of differentiator are discussed and the performances of two variants of the latter type are compared 5657 determination of the input impedance of linear quadripoles by a graphical method the data required are the characteristic impedance the load or terminal impedance and the propagation constant of the quadripole two examples are worked out 5658 build up phenomena in minimum phase networks wheelers paired echo method is used to evaluate the network response to a single pulse and to a step voltage the method is fundamentally a simplified application of the fourier integral and is particularly useful for evaluating the distortion with a minimum of computation 5659 the equivalent q of rc networks further comments on of brown 5660 theory of twin t rc networks and their application to oscillators the conditions are established which the circuit elements must satisfy for the network to produce infinite attenuation at one frequency and for the output to be either in phase or in phase opposition with the input at on varying two elements in a particular manner the slope of the phase frequency characteristic at is compared with that of a resonant lc circuit one valve oscillators incorporating such networks are discussed with particular attention to distortion and stability results of measurements on an oscillator are compared with values calculated from theory 5661 design procedure for crystal lattice filters the technique of filter design is described and formulae for the electrical and mechanical constants of cut quartz crystals are given a bridge net work of two divided electrode crystals operating at has an image impedance of 5662 the basic design of constant resistance crossovers a simple mathematical analysis of the attenuation and phase characteristics for constant resistance filters consisting of up to four elements the frequency response is shown graphically 5663 a band pass filter for low frequencies critical comment on of and authors reply 5664 duplexing filter design at mcs the cavity resonator type filters described are used in commercial communication equipment with transmitter and receiver operating with a frequency separation of both receiving and transmitting filters have a bandwidth of 5665 a comparison of the properties of certain materials used in low power microwave attenuators results of measurements on morganite antistatic gutta percha and carbon loaded bakelite indicate that if suitably sealed to prevent ingress of moisture morganite is the best from the point of view of stability 5666 dc restoring of variable width rectangular pulses the well known diode dc restoring circuit is discussed the effect of deviations of source impedance diode forward resistance and coupling capacitance from their ideal values is investigated the analysis is illustrated by a practical example 5667 starvation circuits and their limitations the under running of valves is deprecated on technical grounds the valves so operated generally tend to be unstable with variations in the supply voltage and with age 5668 a controlled frequency oscillator with frequency memory an arrangement is described in which a phase comparison afc system is used to keep a first oscillator in tune with a second pilot oscillator at a given instant the control loop is broken thereafter the first oscillator continues to operate at the frequency at the cut off instant and subsequent frequency variations of the pilot oscillator are determined from measurements of the phase difference between the two oscillators a practical circuit which holds frequencies in a band centered on is described 5669 oscillator characteristic equation the equation for an oscillator circuit using a triode is developed in a form involving the differential coefficients of the dynamic resistance of the triode measurements on a hartley oscillator are reported which are in good agreement with the theoretical results over most of the oscillation characteristic particular features of the oscillation characteristics are discussed and the constants of the triode and the tank circuit are deduced from them 5670 effect of valve noise on oscillators the magnitudes of the valve shot effect and circuit thermal noise in oscillators are compared when the oscillatory circuit is connected to the grid the valve noise is relatively negligible when the oscillatory circuit is connected to the anode the valve noise preponderates 5671 tuned circuit oscillators at uhf the design of a disk seal triode oscillator for frequencies up to is discussed the causes of spurious resonance and their elimination are considered 5672 high frequency resistance capacitance oscillators the relative merits of shunt capacitance and shunt resistance oscillators are discussed the conditions of oscillation are analysed and the upper frequency limits are examined 5673 sinusoidal and relaxation oscillations sustained by nonlinear reactances descriptions are given of various combinations of nonlinear components eg a saturating choke with linear components eg a capacitor whereby negative resistance characteristics can be obtained either of the type in which current is a single valued function of voltage or of the type in which voltage is a single valued function of current practical applications are discussed 5674 a transistor mcw adapter a miniature keyed af rc oscillator is described 5675 magnetic converter dc amplifer the dc amplifier described comprises a magnetic second harmonic converter followed by an ac amplifier dc signals with power as low as can be amplified 5676 audio nomographs charts are presented for designing a pentode af amplifier to have desired gain and bandwidth the method involves the use of separate equivalent circuits for the upper middle and lower parts of the frequency band 5677 disk seal triode amplifiers for decimetre wavelength radio links amplifiers for increasing the transmitter output power and receiver sensitivity in existing links are considered grounded grid circuits are used simple formulae are derived for gain and bandwidth giving values in good agreement with experimental results obtained with type and type valves 5678 magnetic amplifier circuits and applications a chronological survey 5679 the surface barrier transistor part circuit applications of surface barrier transistors the operating characteristics of the surface barrier transistor are discussed and two amplifier circuits are described namely a wide band low pass amplifier and a band pass amplifier for a centre frequency of this type of transistor combines the ability to operate at vhf with the low power consumption o of the junction type part below 5680 mechanized production of electronic equipment an illustrated account is given of production methods developed at the national bureau of standards based on modular design a steatite water is used as a basic unit on which components are printed or mounted over printed wiring six of these wafers are automatically stacked and connected to form a plug in unit automatic silver painting tuning dip soldering and testing machines are used for other accounts see tech news bull nat 5681 automatic assembly of electronic equipment description of a complete production line for a radar chassis attaching machines fix components on a printed circuit base plate 5682 a flexible plated circuit the wiring initially formed as a thick cu electrodeposit on a stainless steel plate is stripped off on a cloth backed adhesive tape the complete manufacturing process is described 5683 the ignition mechanism of an electric gas discharge in a transverse magnetic field at pressures of torr continuation of work noted in of january a nonuniform field is obtained by making the radius of the outer cylinder much greater than that of the inner the ignition characteristic ignition voltage magnetic induction electrode separation obtained by calculation is compared with measurements in ar the agreement is good the ionization coefficient is independent of pressure and the electron replacement coefficient is proportional to pressure with high voltages and low magnetic fields the electrons are produced mainly by ionic bombardment of the outer cylinder and by ion collisions in the gas with low voltages and high magnetic fields the electrons are produced mainly by ionic bombardment of the end surfaces a formula relating the electron replacement coefficient to the ratio between the mean free path and the parameter of the cycloidal electron trajectory gives results in good agreement with those derived from the observed ignition characteristics 5684 study of high frequency fluctuations from light sources using phototubes and tuned radio frequency amplifiers observations have been made at frequencies up to using two different amplifiers for the ranges below and above the methods of connecting the photocell to the amplifiers are described the spatial distribution of some types of oscillation along the axis of vapour discharges was investigated attempts to observe fluctuations of light from the sun have been made only during quiet periods and have so far yielded negative results 5685 calculation of the behaviour of sparks with resistance and self inductance in the circuit 5686 analogue computer solution of the differential equation for a spark gap the differential equation derived by weizel is easily solved by means of the pm ott integrator 5687 neutralization of ions and ionization of atoms near metal surfaces when an ion or an atom approaches a metal surface neutralization or ionization processes are often possible the franck condon principle is applied in the determination of the probability of electron transfer such transfers are limited to definite ranges of separation from the surface most secondary electron emission is due to an auger type process the contribution due to de excitation of metastable atoms being very small 5688 ionization phenomena in gases a brief summary of papers presented at the conference held in oxford in july the subjects discussed included the spark arc glow and hf discharges gm counters and fundamental processes 5689 theory of ionized media with distant boundaries continuation of work noted in of the theory is developed for a configuration in which the electrodes are relatively close while the boundaries are relatively distant experimental results confirm the theory the solution of the differential equations involved and summarized theory of the potential distribution in the mercury vapour rectifier arc are given in appendices 5690 ionization of gas by electrons a statistical analysis is made of the ionization produced by an electron when it is absorbed in hydrogen linear integral equations are obtained for the average number and the mean square fluctuations of the ion pairs these are evaluated approximately for high values of incident energy 5691 on the current induced in a conducting ribbon by a current filament parallel to it the discussion presented makes use of results obtained previously of and constitutes one stage in the determination of the diffraction pattern obtained with a system of aerials in the presence of a metal reflector of arbitrary size and shape 5692 microwave optics account of a symposium held at mcgill university montreal in june 5693 solution of electromagnetic scattering problems as power series in the ratio dimension of scatterer wavelength the calculation of the successive terms in the series expressing the scattered field requires only the solution of standard problems in potential theory together with the evaluation of certain potential integrals the series can be calculated as far as desired if laplaces equation can be solved but the calculation is increasingly complex for successive terms the spries can be calculated as far as desired if laplaces equation can be solved but the calculation is increasingly complex for successive terms the special case of scattering by a perfect conductor is also considered and its relation to the problem of diffraction by an aperture in a conducting screen is indicated expressions for the distant field are derived 5694 electromagnetic scattering by an ellipsoid in the third approximation the method described in above is used to evaluate the first three terms of the power series in those in the term in vanishes because of the symmetry of the scattering body the result is expressed as the sum of two elliptic integrals which are functions of the three principal axes of the ellipsoid the special cases of the spheroid perfectly conducting ellipsoid perfectly conducting disk and of diffraction by an elliptical or circular hole in a perfectly conducting screen are considered 5695 the vector wave function solution of the diffraction of electromagnetic waves by circular disks and apertures part oblate spheroidal vector wave functions part the diffraction problems the vector wave functions considered are the solenoidal solutions of the vector helmholtz equation oblate spheroidal vector wave functions are defined and the expansions for plane polarized waves in terms of them are obtained a unique solution is obtained for the diffraction by an infinitely thin perfectly conducting circular disk and by a plane conducting screen two separate groups of these functions are combined to fulfil the condition at the rims of the aperture and disk using the spheroidal coordinate system 5696 diffraction of electromagnetic waves by an aperture in a large screen the approximate solution of the three dimensional diffraction problem is obtained by using a single component of the hertz vector the results are applied to the calculation of the field in the plane of a circular aperture which is large compared with the wavelength experiments confirm some of the theoretical results 5697 diffraction of electromagnetic waves by two parallel half planes the field of a plane wave diffracted by the edges of two parallel conducting sheets has been measured close to the diffracting edges for various spacings between the sheets experimental results for a spacing of one wavelength are compared with values derived from theory presented by clemmow of the agreement is satisfactory 5698 electronic and ionic impact phenomena this work is likely to be the standard reference book on the subject for some time to come 5699 the radio echo from the head of meteor trails calculations based on diffraction theory give values for the intensity of head echoes in agreement with observation and also indicate that the ratio between the intensity of the head echo and that of a specularly reflected body echo should be proportional to the radio wavelength and inversely proportional to the difference in range between these echoes other anomalous meteor echoes may arise from discontinuities associated with visual flares 5700 radar determination of the height of disappearance of meteor trails of known radiant observations were made during the period august at meudon using radar equipment operating on a wavelength of with a peak power of about curves representing the time variation of the distance of the theoretically nearest reflection point for various values of the height at which the trails disappear are shown together with observed nearest reflection points from the comparison it is deduced that the mean value of h is about km 5701 a symposium on radio astronomy at jodrell bank account of the proceedings at the symposium held in july 5702 the distribution of radio brightness over the solar disk at a wavelength of centimetres part the quiet sun one dimensional observations assuming the distribution over the solar disk to be circularly symmetrical at this wavelength the derived radial brightness distribution shows marked limb brightening the observed distribution of brightness is in fair agreement with the calculations made from solar models involving a chromosphere and corona provided that the coronal densities lie between and times the values usually quoted conclusive evidence of a quiet level rf emission was obtained part of 5703 two uhf radiometers mcs and some radio astronomy applications details are given of improved radio noise receiving equipment used for continuing the experiments previously reported a power supply unit stable to within part in for mains variations of a parabolic reflector aerial for and a dipole aerial array for are described measurements of the distribution of rf brightness over the sun are reported these include observations made during the solar eclipses of and 5704 progressive variation of the shape of the sunspot curves statistical analysis of the sunspot numbers for the eleven year cycles since indicates that the asymmetry of the curves is increasing thus giving support to gleissbergs theory that there is another cycle with a period the order of thousands of years 5705 measurement of variations in atmospheric refractive index with an airborne microwave refractometer the cavity resonator refractometer described is essentially the same as that used for previous measurements of birnbaum observations were made at heights up to examples of strip records obtained are reproduced the variations were negligible for distances m large increases of refractive index were observed on entering cumulus clouds and intense fluctuations were noted within the clouds 5706 airborne magnetometer for determining all magnetic components description of the airborne vector magnetometer type an enlarged and modified form of the instrument previously described by felch et al of 5707 measurements of the terrestrial magnetic field in the e layer two methods are outlined both based on determination of the gyro frequency which is related by a simple formula to the intensity h of the geomagnetic field in the lower part of the e layer the first method is based on the double hump resonance curve and the second is based on the self demodulation of radio waves at carrier frequencies near gyrofrequency a stable is given of values of h determined by these methods in italy 5708 a universal time component in geomagnetic disturbance evidence of a universal time component in diurnal variation of the geomagnetic disturbance is obtained from an analysis of k index figures 5709 low frequency noise in the range continuation of previously noted investigations of and of the correlation between lf em fluctuations and geomagnetic and solar phenomena a pickup loop with an effective area of was used with an amplifier having a gain of and a recorder with chart speed of an operating site with low noise characteristics was chosen evidence was obtained of frequent storms in the noise frequency range studied a diurnal variation similar to that of the cheltenham k indices was observed analysis indicates significant correlation between the lf noise and solar noise observed days earlier 5710 daily variation of amount of ozone in the atmosphere observations made at mount abu and ahmedabad from nov to april showed a substantial increase of ozone during night hours with rapid change over from day to night values after sunset 5711 an interpretation of vertical incidence equivalent height versus time recordings on the results of observations made in pennsylvania usa between january and april are shown graphically and discussed one form of echo regularly observed during magnetically disturbed nights is due to one type of sporadic e stratum recorded group and phase heights are compared and the differences compared with those predicted from theory results are also given of a preliminary investigation of the effects of solar flares 5712 investigation of travelling disturbances in the ionosphere by continuous wave radio continuous records of the signal intensity of cw transmissions over a path at and indicate an f layer disturbance velocity of transmission modes up to and respectively were observed simultaneous signal intensity records of two in line transmitters p apart operating at showed a constant min interval between the corresponding maxima indicating a disturbance velocity of 5713 the effect of soft x rays from the solar corona on the formation of the normal ionospheric e layer a calculation has been made previously of the soft x rays from the solar corona vol the results are used to determine the height at which the radiation is absorbed and the number of electrons present at this height under equilibrium conditions the results agree well with observations of the normal e layer 5714 the structure of the f region of the ionosphere the effects of temperature cycles of a decay coefficient which is nonuniform with height and of vertical tidal drifts are considered the diurnal and seasonal height variations of the f region are explained qualitatively by postulating in addition to the vertical tides acting on an isothermal chapman region a diurnal temperature cycle this requires a decay coefficient which does not change rapidly with height on an alternative hypothesis involving discontinuities in the height gradient of the decay coefficient tidal drifts are still necessary but a diurnal temperature cycle is not of major importance 5715 world wide diurnal variations in the f region the chief characteristics of the variations are described in terms of the sunspot minimum anomaly the sunrise anomaly and the diurnal range anomaly these anomalies are evaluated quantitatively and extracted from the observations to determine the normal curves the world distribution of these anomalies is studied and explanations are suggested variations of do not appear to be related either to the sunspot cycle or to the variation 5716 the electron content of the f layer above singapore a comparison of the estimated total ionization present in a unit column below the level of maximum ionization density of the f layer in and in 5717 geomagnetic and ionospheric relationships the effect of a magnetic disturbance on various geomagnetic and ionospheric parameters is investigated by choosing days on which the sum is markedly different from that of the adjacent days most of the parameters show a peak or trough corresponding to that of the disturbance following it with a delay of hours particular attention is called to some peculiar seasonal effects to features of of the sporadic e layer at slough and the vertical movement of the f layer at huancayo 5718 the effect of the magnetic equator on the ionization of the e layer observations made at stations at different latitudes in africa and europe are analysed daytime values of e show a pronounced maximum at the magnetic equator observations of the e blanketing frequency indicate that the e minimum ionization ceiling is not subject to the effect which exists only for the ionization clouds 5719 winds in the ionospheric regions a model for the region between and height is constructed from considerations of the temperature gradients and the observed wind velocities according to this model the wind is south west in the e and f regions and north east or east in the f region its velocity increases from at km to at there is a seasonal variation in the magnitude of the velocity but the model does not involve any diurnal or seasonal changes of direction such as have been reported by observers 5720 results relating to the critical frequency and the transmission factor of the ionosphere f layer 5721 a note on auroral interaction the modulation of a radio wave due to a moving auroral reflecting screen is discussed 5722 a nonlinear servomechanism with several independent variables 5723 radioactive charging effects with a dielectric medium the characteristics of a cell consisting of a ray source a polystyrene dielectric separator and a collector made of carbon or metal were investigated radioactive current and voltage sources similar to this cell are feasible the arrangement offers a simple way of studying the effects of radiation on electrical processes in solids 5724 the problem of heating in the selenium rectifier formulae for the calculation of heat losses are derived design for good efficiency and low temperature rise is discussed in detail with reference to the operational demands of various applications in power rectification typical characteristics curves are given 5725 recent developments in ignitrons 5726 stabilization problems in physics a review of voltage current and magnetic field regulators the performances of various stabilizing valve circuits and primary regulators are compared and the importance of good control of filament heating voltages is emphasized special problems of stabilization in nuclear physics are mentioned 5727 a stabilized dc supply unit for output voltages of to a circuit is described in which the whole of the output voltage variation is available for controlling the amplifying valve so that the gain is the same for any output voltage down to zero the control valve is a pentode whose screen grid voltage is stabilized by means of a stabilizer tube the filaments of the amplifying valves which are also fed from this source have low consumption variation of the output voltage is for mains fluctuations up to 5728 relaxation oscillations in voltage regulator tubes relaxation oscillations may occur if the regulator tube is shunted by a capacitor and the load line intersects the tube characteristic on the low current side of the minimum methods of modifying the circuit to prevent these oscillations are indicated 5729 an alternating current stabilizer a stabilizer for a valve heater power supply uses a diode operating with low heater voltage as the error detector and a transductor as the control element the output voltage can be maintained constant to within 5730 industrial tube generator for low frequencies a detailed description is given of a three phase valve generator suitable for supplying an asynchronous motor at frequencies from to 5731 phantastron computes pulse width ratios description of an analogue computer developed for determining the ratio of the widths of two pulses occurring simultaneously in two channels of a radar system the output is readily convertible into digital form other applications are indicated 5732 programme control of an electronic computer 5733 digital computers at manchester university an account is given of the development of the universal high speed computer its features include a cr tube store for binary digits an intermediate store for more than digits completely automatic transfer between the two stores a fast multiplier and input and output systems using hole teleprinter tape 5734 the construction and operation of the manchester university computer the account particularly stresses techniques used to achieve reliability and ease of maintenance and includes details of the performance over a period of about weeks see also above 5735 universal high speed digital computers a decimal storage system discussion three decimal digit storage systems using cr tubes are described the best compromise as regards speed of operation storage capacity and reliability is obtained with a cr tube screen comprising ten separate elements in a serially controlled store holding words of decimal digits the digit period was and could be reduced to these results compare favourably with those for the binary store used in the manchester university computer 5736 the design and testing of an electronic simulator for a hydraulic remote position control servo mechanism discussion on of 5737 analogue computers for feedback control systems 5738 transformer analogue network analysers the use of voltage transformers as multipliers for complex quantities is explained a network analyser is described comprising a measuring section and a number of identical panels each with two multiplying units these panels can be used to represent impedances admittances etc negative resistance and unilateral mutual inductance can easily be represented applications discussed include the solution of linear simultaneous equations 5739 valve reliability in digital calculating machines a discussion of measures which can be taken to reduce the number of valve failures and to reduce the inconvenience caused when failures do occur 5740 recent advances in cathode ray tube storage modifications have been made to the system described by williams and kilburn of and used in the manchester university computer the defocus focus system and the signal amplifier are discussed particularly an account is given of experimental work undertaken to clarify the storage mechanism the theoretical basis of the system is examined the original theory through inaccurate in detail is satisfactory for practical purposes and can be used to predict storage results the tube operation is analogous to that of a triode valve the collector bombarded spot and surroudning screen surface corresponding respectively to the anode cathode and control grid 5741 a multi decade predetermined counter the automatic four decade counter described is a modified version of that noted in of february the maximum counting rate is per sec and the minimum duration of a complete cycle of counts is ms 5742 directional coupling with transmission lines adaptation of devices developed in connection with waveguides to forms with open wire lines for use at lower radio frequencies 5743 response of an amplifier stage with antiresonant circuit to an input voltage whose instantaneous frequency varies linearly as a function of time analysis is given for an input which can be represented by a particular fourier integral 5744 equivalent network representations for solid and mercury delay lines an equivalent network representation is obtained from consideration of the piezo electric properties of the quartz crystal used to convert the electrical energy into ultrasonic energy a formula is derived for the transfer function of the line when mercury and fused quartz lines are compared on the basis of the gain bandwidth product only the fused quartz line is superior but other factors eg production of spurious signals must be taken into account when selecting a line for a specific application 5745 characteristics of an elliptical electromagnetic resonant cavity operating in the te mode equations and graphs are presented of the resonant wavelength and quality factor of elliptical resonant cavities operating in the te mode both components of this mode are treated and distinctive characteristics of each are shown as a function of eccentricity of the cavity 5746 interaction between classical electron and quantized electromagnetic field the equations of motion are solved by a method involving the corresponding difference equations and an expression is derived for the probability of transition between a high energy state and neighbouring states of the field inside a resonant cavity 5747 the transformation properties of loss free quadripoles between homogeneous lines and a proof of weissflochs transformation law using circle geometry a method for evaluating certain parameters in the application of weissflochs transformation law and back references this law has applications in measuring technique and circuit theory in the cm and dm regions 5748 on the synthesis of reactance poles using theory developed by belevitch formulae are derived for the elements of the impedance or admittance matrix of a loss free quadripole which when terminated by a resistor realizes a prescribed physical driving point impedance 5749 a block diagram approach to network analysis an extension of the method described by graybeal to electrical networks with examples of application in the analysis of ladder bridged t and parallel t networks 5750 ferrites in microwave applications a discussion of the microwave faraday effect and of the mechanism of power absorption in ferrites plane wave theory is given and is extended to cover waveguides the measurement and applications of the effects are surveyed see also of 5751 coupled lines as high frequency transformer systems comprising two parallel two conductor lines r are considered voltage and current distribution and input impedance are calculated in terms of terminating impedance overlap length and coupling an indication is given of the requirements to be satisfied for wide band operation and some particular arrangements are discussed 5752 tentative graphical representation of the image transfer coefficient of ladder type filters with or without losses the method is based on the expression of the image transfer coefficient as a function of frequency in accordance with the classification of filters given previously of and 5753 a set of octave band pass filters for frequencies between and filters designed for eliminating harmonics are described in order to achieve the desired sharp cut off on the high frequency side the filters are operated into an abnormally low impedance about a tenth of the centre frequency impedance 5754 broadband rotary waveguide attenuator the attenuator comprises three collinear sections of round waveguide each with a resistive film arranged in a diametral plane the middle section is rotated to obtain the desired attenuation some performance figures are given for an experimental model the characteristics are independent of frequency 5755 a general network theorem with applications slightly modified reprint of paper noted in of 5756 chameleon oscillator an oscillator giving high frequency stability and using relatively few components is based on a cathode coupled hartley circuit with resistance in the cathode lead 5757 the measure of activity of oscillators and the performance index the measure of activity of an oscillator is defined as the ratio of grid voltage amplitude to anode current amplitude in crystal controlled oscillators it is proportional to the crystal performance index the measure of activity is evaluated for several common types of oscillator 5758 design of heterodyne oscillators the choice of frequencies for producing a given beat frequency and the design of the variable tuning capacitor are considered precautions required to ensure frequency stability are discussed 5759 the operation of generators for steep fronted waves when the self inductance of the generator is taken into account in the analysis a third order differential equation is obtained simplification is introduced by taking advantage of a particular solution graphical methods of investigation based on the work of bergeron are also outlined 5760 transistor oscillator for use in multifrequency pulsing current supply discussion of an oscillator for use in the transmission of digital information at frequencies in the band over telephone trunk lines performance details are given 5761 introduction to the use of electronic tubes in pulse techniques circuit phenomena produced by switching are briefly reviewed and the operation of valves as nonlinear or switching elements is discussed as an introduction to the consideration of some well known pulse circuits 5762 a special time discriminating selector for electronic pulses a circuit is described which is able to select the last of a series comprising an arbitrary number of pulses distributed in an arbitrary number of pulses distributed in an arbitrary way within a fixed time interval 5763 determination of the noise factor of various amplifiers by a comparison method the relative noise factor can be determined by using a standard type signal generator connected to the input of the amplifier and a band pass filter coupled to a valve voltmeter at the output 5764 wide band if amplifiers bandwidths such as are required for dealing satisfactorily with very short pulses are achieved without necessitating alignment of the amplifier with a particular set of valves by using a negative feedback design technique the amplifier is treated as a series of pairs of valves the first of each pair operating without and the second with feedback a table gives component values in a form requiring a minimum of computation a particular stage amplifier designed by this method for a centre frequency of had a bandwidth of to the points and an overall gain of about the response varied only very slightly when all the valves were changed 5765 magnetic amplifier uses conventional inductors 5766 negative inductance cuts magnetic amplifier lag the speed of response of a magnetic amplifier is improved without reducing its sensitivity by balancing out the effect of control circuit inductance by means of a negative inductance device comprising a valve with an iron cored mutual inductor 5767 the design of a practical dc amplifier based on the second harmonic type of magnetic modulator discussion on of 5768 transistors theory and application part cascading transistor amplifier stages formulae and values of circuit parameters are tabulated for various possible arrangements using point contact or junction transistors 5769 power transistors for audio output circuits 5770 physical basis of thermal noise an examination is made of methods developed by various workers for analysing circuit noise due to random motion of charge carriers it is concluded that it is not necessary to postulate thermodynamic equilibrium in order to be able to calculate the thermal noise 5771 principles of transistor circuits a comprehensive work on transistors and their circuitry written by nine members of the staff of the electronics laboratory of the gec company of america 5772 modulators and frequency changers for research development and maintenance engineers high power transmitting modulators are not treated 5773 graphical presentation of oscillator resonance applicable to the study of nonlinear systems 5774 derivation of the laws of geometrical optics from maxwells field theory 5775 the diffraction of electromagnetic waves by a semi infinite circular waveguide formulae are obtained for the currents on the waveguide and asymptotic expressions are derived for the longitudinal components of the electric and magnetic vectors in the waveguide at large distances from the mouth 5776 a collective description of electron interactions part collective vs individual particle aspects of the interactions 5777 the electromotive force developed by a creeping zinc crystal 5778 theory of plasma waves in metals the hartree approximation is used to investigate the effect of the crystal lattice on plasma oscillations in metals a formula is derived for the oscillation frequency for free electrons this reduces to that given by bohm and gross for insulators there are no oscillations in metals with occupied d bands there is strong coupling between the plasma oscillations and the d electrons causing frequency broadening 5779 theory of ac space charge polarization effects in photoconductors semiconductors and electrolytes linear theory is developed for solid or liquid materials containing charge carriers which can move freely within the material but are blocked by the electrodes the carriers may be electrons holes ions or ion vacancies the general solution for the admittance of the material is obtained for an arbitrary ratio between the mobilities of positive and negative carriers and is discussed for some special cases results are compared compared with those derived from other theories 5780 the field emission initiated vacuum arc part experiments on arc initiation the experiments were carried out under conditions of high vacuum and clean cathode surface results show that breakdown is immediately preceded by recognizable emission anomalies that breakdown occurs at a critical current density of the order of for applied microsecond pulses in the range and that breakdown is independent of cathode bombardment 5781 the field emission initiated vacuum arc part the resistively heated emitter theory is developed for the heat flow in an emitter of geometry approximating to that used in the experiments reported in above the calculations support the view that breakdown is initiated by a resistive heating process 5782 space charge effects in field emission a progressive reduction of the observed field current below values expected from the empirical law for increasing values of the potential is attributed to space charge the current density expected in the presence of space charge is calculated from the fowler nordheim field emission theory using values of the cathode electric field obtained from a solution of poissons equation for plane electrodes with boundary conditions appropriate to field emission the result is a generalization of childs equation and is asymptotic to it when the applied potential is large compared with the value for appreciable field emission 5783 brillouin flow with thermal velocities a type of electron flow in a constant magnetic field is described the beam of electrons is supposed to be everywhere in thermal equilibrium and the usual brillouin flow is found when the equilibrium temperature tends to zero some considerations are put forward bearing on the choice of a suitable beam temperature in specific problems 5784 a modified theory of production of secondary electrons in solids difficulties in previous theories of energy loss and secondary electron production in metals are removed by replacing the coulomb interaction between a primary electron and a lattice electron by a screened coulomb interaction 5785 magneto ionic theory of weakly ionized gases in the presence of an oscillating electric field and a constant magnetic field the velocity distribution functions for a nonuniformly ionized gas are calculated by solving the boltzmann differential equations explicit expressions are derived for the magneto ionic conductivity the dielectric tensor the hall effect the deflection of the electron beam and the generalization of langevins mobility formula comparison is made with other methods of calculation 5786 the conductivity tensor of electron plasmas in the presence of a constant magnetic field assuming the mean collision frequency to be independent of velocity it is shown that the form of the ct of velocity it is shown that the form of the conductivity tensor given by jacel and kahan above differs from that given by huxley of in order to represent the magnetoresistance terms correctly by jancel and kahans method closer approximation is necessary 5787 some magnetic properties of metals part surface corrections of the landau diamagnetism and the de haas van alphen effect an expression is given for the magnetic moment of a large but finite system of electrons in terms of the volume and two mutually perpendicular surface areas together with constants independent of the shape of the system the theory is verified by calculating the values of the constants for two different shapes corrections to part are noted 5788 a two electron example of ferromagnetism the method of dealing with problems of ferromagnetism on the basis of energy band theory vol is applied to a simple case 5789 the law of induction a survey of the literature indicates a lack of clarity on this subject the law of induction is formulated generally in terms of a geometrical entity called the flux line which exists in te field of a solenoidal vector 5790 induction phenomena consequent on the movement of material in primary magnetic fields and their experimental applications part fundamental theory for very general cases theory applicable to any type of motion is developed 5791 motion of an electron in a magnetic undulator rigorous solutions are obtained for the equations are obtained for the equations of motion of an electron in a millimetre wave generator of the type described by motz et al of 5792 frequencies and power of waves radiated by a magnetic undulator continuation of investigation noted in above the dimensions of an undulator for generating mm waves are determined from rigorous calculations of electron trajectories the results differe greatly from values derived from classical theory the values found for radiated power are of the same order 5793 the equations of propagation of electromagnetic waves in an ionized gas two different methods are used to derive the equations for the propagation of em waves in an ionized gas subjected to a time varying em field and to a constant magnetic field terms depending on past states are found to occur 5794 effect of a metal plate on total reflection the phase changes which occur on total reflection are modified when a metal plate is placed near and parallel to the reflecting boundary by moving the plate the phase difference between plane waves of equal amplitudes polarized in and perpendicular to the plane of incidence can be varied from up to the positive value obtained without the plate this has been confirmed experimentally using a wavelength of and a perspex prism when the refractive index is there are two positions of the plate for which the reflected wave is circularly polarized the electric vector rotating in opposite directions for these two positions 5795 theory of a conductor near the boundary of two media the electromagnetic field due to an oscillation of angular frequency in the conductor can usually be split into two components a cylindrical wave field and a spherical wave field near the axis of the conductor which is parallel to the boundary plane the field is of a special type the condition for the existence of the two components is derived and applied to particular cases 5796 deflection of high energy electrons in magnetized iron the effective magnetic field acting on electrons traversing a ferromagnetic medium is shown by experiments to be equal to the flux density 5797 radio echo studies of meteor ionization the physical properties of the meteors and the columns of ionization which they produce and the properties of the atmosphere in the meteor ionization region were investigated using mainly pulse equipment operating in the waveband the development of a satisfactory theory of scattering of radio waves from meteor trails together with the theory of evaporation from meteors makes possible the detailed interpretation of the radio echoes obtained in particular the estimated incident flux of meteors is found to be sufficient to maintain a continuous ionospheric layer extending from down to below which ionization will be distributed in patches becoming fewer and larger with decreasing height over references 5798 observations of solar radio noise storms observations indicate that simple storms ie those caused by a single bipolar group of sunspots exhibit a directional effect varying with wavelength 5799 radio noise bursts from solar m regions the passage of m regions is characterized by a notable increase in the short term variability of noise intensity at m 5800 ionization and recombination processes in a plasma and the ionization formula of the solar corona for a plasma not in thermodynamic equilibrium formulae are derived for the photo ionization the ionization by collisions the recombination with emission of light and the recombination due to triple collisions by equating the number of collisions by equating the number of collision ionizations with the number of photorecombinations an ionization formula is obtained for the solar corona from which the temperature of the corona can be estimated 5801 radio frequency radiation from the spiral nebula messier the intensity measurement of the radio source observed has been combined with previous observations to determine the ratio between the radio flux and the light flux for individual nebulae the calculated flux from a nebula of apparent magnitude is at 5802 an extended radio frequency source of extragalactic origin extension of observations noted in of 5803 statistical analysis of geophysical time series notes are provided on dealing with the effects of linear and periodic trends on standard deviation and correlation coefficient significant tests in coherent series are discussed 5804 the phased superposed epoch method of analysis and an application to geomagnetic activity a method is described in which geomagnetic activity variations are analysed by grouping the data according to their phases increasing decreasing or no change as determined by considering the characteristics for pairs of successive days 5805 geomagnetic activity and the sunspot cycle a table is given for the last four sunspot maximum epochs of the numbers of magnetically calm days and of slightly moderately and highly disturbed days together with sunspot numbers and a measure of the prominence activity geomagnetic activity shows correlation with prominence activity rather than with sunspot activity 5806 diurnal magnetic variations near the magnetic equator observations made at nine places in south india are analysed in conjunction with observations for south america high diurnal ranges of h occur in a belt of latitude with a maximum near the magnetic equator 5807 abnormal ionospheric absorption observed during february observations from stations all over the world are analysed very high absorption was observed during the period february within a limited region the eastern and western limits of the affected region are not known accurately because of the sparseness of stations no effect was observed in america or in the far east the southern limit was observed in africa roughly along the line joining casablanca and djibouti an explanation involving corpuscular radiation fits the observations better than one based directly on wave radiation from the sun the absorption is thought to occur in low altitude ionized layers such as that detected by gnanalingam and weekes of 5808 a self consistent calculation of the dissociation of oxygen in the upper atmosphere part three body recombinations continuation of work noted in of results based on the assumption that recombination occurs mainly as a three body nonradiative process indicate that dissociation occurs at a level about higher than that previously calculated 5809 bifurcation of the e region the retardation time relative to an uhf reference signal of a radio signal of frequency about above the critical frequency was measured by rocket borne instruments electron density altitude graphs were derived from the retardation time time of flight records bifurcation of the e layer is clearly indicated the results are in close agreement with those calculated from records obtained with the nbs model c ionosphere recorder the separation of the electron density maxima was km 5810 direction finding studies of large scale ionospheric irregularities continuation of work noted in of a report is given of measurements on pulse modulated transmissions in the frequency range reflected from the ionosphere both vertical incidence and oblique incidence observations were made the directional variations of the reflected signals were studied and are interpreted as due to tilting or wrinkling of the constant ionic density surfaces in the ionosphere the results indicate large scale horizontal movements in the ionosphere in the e layer these appear to be of the nature of drifting clouds of ionization while in the f layer the effects are consistent with horizontally travelling ripples having wavelengths of and speeds up to the direction of motion is more often towards east or west than towards north or south and evidence of a diurnal variation has been observed 5811 reflexions from irregularities in the ionosphere complexities in records of and for the f region are shown to be due to curvature of the reflecting surface the order of curvature associated with travelling disturbances is calculated and the variation in the type of complexity is shown to result from differing group retardations in the different paths a base triangular system of three pulse transmitters and a panoramic type recorder were used respectively for and recording 5812 examination of the formation of the ionosphere f region continuation of work noted in of two different possible mechanisms are discussed namely photo ionization of and ionization by soft x rays the photoionization hypothesis is only acceptable if the dissociation of the is assumed to take place at a relatively high altitude of about km ionization by x rays of solar origin certainly occurs but a recent calculation of the spectral distribution of solar energy indicates too high an ionization at km 5813 recombination coefficient in the f regions a possible new process of ionization of nitrogen molecules discussion of a possible dissociative recombination process according to which the daytime solar radiation at visible wavelengths may be instrumental in ionizing nitrogen molecules if positively charged particles are present 5814 the solar eclipse of at gao ionosphere observations made during the eclipse are reported though the occultation was only partial a diminution of e and f layer ionization compared with normal days was observed the effect was very pronounced at hours when the sunspot near the western limb of the sun was obscured on the other hand when this sunspot disappeared on february as a result of the rotation of the sun there was no noticeable reduction of the e layer ionization the effect is difficult to explain in terms of classical theory the diminution of ionization of the f layer is significant 5815 ionosphere review twelve month running averages and monthly mean values are plotted for the sunspot numbers and the noon and midnight f critical frequencies from it is inferred that the critical frequencies are likely to decrease only very slightly before the next sunspot minimum and that the latter is to be expected between march and april 5816 the agrimeter for continuous recording of the atmospheric electric field description of an instrument based on measurement of the bound charge on a portion of the earths surface 5817 the pilot streamer in lightning and the long spark 5818 the study of lightning streamers with cm radar radar echoes were observed during the whole period between the successive strokes in a lightning flash some components of these echoes appear to be associated with the processes leading up to the next stroke photographic cro trace records of the stroke at its commencement and ms later are reproduced and discussed 5819 methods of synchronizing the observations of a sterics network methods in use in the british network are described 5820 analogue methods for optimum servomechanism design 5821 feedback control systems with dead time lag or distributed lag by root locus method generalization and application of the method originated by evans of 5822 synthesis of feedback control system by phase angle loci a modification of evans root locus method 5823 the use of nonlinear tachometric feedback to improve the transient response of a servomechanism 5824 stabilization of a servomechanism subject to large amplitude oscillation the frequency response method of analysis developed by kochenburger of is applied to a system containing a saturable amplifier and in determining the required nonlinear stabilizing filter 5825 stability limits for third order servomechanisms curves are derived giving directly the roots and coefficients of specified cubic characteristic equations their use in facilitating analysis and design of servo systems is explained and illustrated 5826 the analysis of sampled data systems full paper summary abstracted in of 5827 stable power supplies for microwave standards a description of the power supply system for operating the klystron frequency standards at the national bureau of standards 5828 selenium rectifiers factors in their application 5829 design of relays a symposium of papers dealing with design production service and measurements 5830 hhhfn analogue type multiplier a simple multiplying circuit is described in which rectangular pulses are modulated successively in width and amplitude in proportion respectively to the two factors a and b to be multiplied response times for the circuit tested were for the factor a amplitude and irrespective of amplitude for b 5831 a simple electronic multiplier the multiplication process described is based on the equation xy a method of squaring is used which depends on the fact that the areas of similar triangles are proportional to the squares of their heights a triangular waveform generator is described the device accepts both positive and negative input voltages 5832 electronic analogue computing a survey of modern techniques an indication is given of the kind of problem for which analogue computers offer advantages over digital types 5833 a new analogue computer a general purpose computer of differential analyser type designed for economic quantity production is described three basic elements are used viz scaling units essentially decade variable resistors function units comprising rc networks high gain amplifiers facilities for cro and graphical display are provided 5834 note on high speed product integrator errors arising in the potentiometer circuit of the integrator are discussed 5835 general survey of the operating principles of electrical analogue computers a survey with particular reference to computers constructed by the societe d electronique et d automatisme difficulties encountered in studying the accuracy of these machines are discussed 5836 a diode capacitor memory for high speed electronic computers ordinary linear capacitors are used as rapid access storage elements in a matrix arrangement the basic circuit consists of two diodes in series with the anode of one connected to the cathode of the other and the capacitor connected to the junction the other end of the capacitor is used for reading and writing and is connected to earth through a resistor 5837 a survey of digital computer memory systems correction to paper abstracted in of january 5838 elements of boolean algebra for the study of information handling systems correction to paper abstracted in of january 5839 application of digital computing techniques to physics problems involving matrices ordinary and partial differential equations functions occurring in crystallography and the random walk statistical method are discussed machine design and the training of personnel are considered briefly 5840 magnetic and dielectric elements for computers a survey of the applications of materials with rectangular hysteresis loops two classes are distinguished namely those depending on a high ratio of remanence to saturation and those for which the squareness ratio is important 5841 a low frequency oscillator an analogue computer for solving the differential equations of a mass spring system comprises a circuit producing simple harmonic oscillations with a frequency range of 5842 instantaneous multiplier for computers multiplication is performed by means of balanced modulators using standard if transformers and other components 5843 pulse height analyzer the equipment based on wilkinsons conversion principle of has resolution linearity and stability to within it can deal with input pulses at a rate of several thousand per second recording is made on teledeltos paper at a rate of up to pulses sec 5844 a new general method for frequency distortion correction of a given circuit in light current and instrument engineering the frequency dependent function eg the amplification factor is expressed as the ratio of power series of functions of the frequency and the condition for a minimal frequency dependence is found 5845 normalized phase and gain derivatives as an aid in evaluation of fm distortion the method previously described for evaluating the distortion for the quasistationary condition of is extended to take account of the finite rate of variation of the input signal frequency 5846 transient response of the grounded base transistor amplifier with small load impedance a transfer function relating junction transistor collector current to emitter current is derived from the diffusion equation the laplace transform technique is used to determine the variation of collector current in response to a step variation of emitter current collector current rise times evaluated from the theory are in good agreement with observed values 5847 thermistor production reprint with additional illustrations of paper abstracted in of 5848 tapped inductances maxwell coils for af are considered and a simple method is presented for calculating the position of the tapping to give a specified fraction of the total inductance 5849 graphical analysis of nonlinear circuits using impedance concepts approximate values of the reactance of moderately nonlinear inductors and capacitors are obtained by adding to the usual linear expressions terms involving the square of the current using this approximation the total impedance of an lrc circuit is obtained and plotted in the iz plane with frequency as a parameter the method gives a physical picture of the jump phenomenon in nonlinear circuits 5850 large reduction of free electromagnetic oscillations in cylindrical regions due to slight departures from cylindricity a theoretical investigation of the effect of small deformations on long cylindrical resonators with perfectly conducting walls the diminution of the field is proportional to the product of the relative distortion and the square of the ratio of the length of the cylinder to its radius standard mathematical notation is used and the expressions for are given in terms of bessel functions and the function which is defined as the root of j 5851 an asymmetrical finite difference network a study is made of a method of solving boundary value problems by means of electrical network analogies consideration is given to the special problems associated with curved boundaries and with the use of meshes of different size at different parts of the network a method is described by means of which the coefficients of the system of algebraic equations can be computed for an arbitrary distribution of node points and the position of the nodes can then be chosen to fit the particular conditions as an illustration the resonance frequencies and field patterns of a conical line cavity resonator are calculated 5852 a general rlc synthesis procedure procedure for synthesizing lattice networks is described 5853 unbalanced rlc networks containing only one resistance and one real transformer 5854 unilateral four terminal circuits networks of ge diodes and carbon resistors suitable for purposes of directional coupling and isolating are described 5855 high q coupled tuned circuits by means of a set of expressions developed as functions of a frequency ratio some aspects of inductively coupled high q resonant circuits are analysed considerations of finite very high q circuits lead to simple relations determining impedance characteristics of a fundamental system resonant frequencies rate of frequency deviation input conductance stored energy and power dissipation ratios 5856 two new equations for the design of filters equations are presented for designing constant k configuration filters with tchebycheff type characteristics for the case when the unloaded q of the elements is sufficiently high for them to be considered nondissipative both band pass and low pass filters are considered the band pass examples are mainly for uhf 5857 old and new methods for designing composite high frequency filter circuits and their application to filter circuits with low relative bandwidth correction to paper abstracted in of january 5858 nonlinear filters comment on of and authors reply 5859 electromechanical filters design and performance data are presented for if filters for the frequency range of the type comprising metal plate resonators interconnected by pairs of fine metal wires 5860 a general tchebycheff rational function the derivation is described of a function useful for the design of low pass filters 5861 electronic audio bandpass filter a narrow band filter with centre frequency adjustable from to is obtained by including a phase inverter rejection circuit in the negative feedback circuit of an audio amplifier 5862 attenuator design a chart is given for the design of constant resistance types of attenuator 5863 some not necessarily linear poles composed of linear poles and in some other poles linear relations exist between the voltages and the currents and the resulting impedance matrix is symmetrical a generalization to include nonlinear relations is given by the condition that must be symmetrical in and where is the pd between the and the zeroth terminal and is the current flowing into the terminal examples and properties of such poles are given 5864 the use of admittance diagrams in oscillator analysis discussion on of 5865 a new type of rc oscillator a circuit requiring a much smaller amount of valve amplification than the usual phase shift oscillator uses a specially designed twin t feedback network 5866 block diagram analysis of vacuum tube circuits the method is illustrated by analyses of an amplifier with current feedback from the cathode circuit and a phase shift oscillator 5867 amplitude variations in a frequency modulated oscillator analysis indicates how unwanted am is produced when fm is accomplished by varying the capacitance in a negative resistance oscillator circuit a numerical example is given 5868 the design of the eccles jordan circuit design formulae are derived from a fundamental analysis of the circuit their application is illustrated in the design of a high stability flip flop circuit using a valve 5869 the electronic switch an analysis of the operation of square wave generators 5870 bi stable multivibrator analysis continuation of paper abstracted in of april the operational calculus is used to analyse the eccles jordan flip flop circuit 5871 control of glow discharge triodes by means of very small currents a discussion of the desirable characteristics of a valve suitable for the generation of sawtooth oscillations using a grid cathode capacitor of value between and and a grid control current as low as the essential design points are small cross sectional area of the discharge space high current density at low currents short ion transit times and large difference between the striking and the operating potential these are achieved by arranging a wire point control electrode close to the cathode 5872 the efficiency of frequency multipliers using detector circuits an analysis is made of the harmonic frequency power obtainable in an oscillatory circuit connected to a generator via a detector whose characteristic is represented approximately by a hyperbola for harmonics of fourth and higher orders the calculations become very difficult it cannot be assumed that for any given harmonic the power is less than for the next lower harmonic 5873 design of wide band tuned amplifiers amplifiers with schienemann butterworth and tchebycheff band pass characteristics are considered in detail and formulae design curves and numerical examples are given 5874 loudspeakers and amplifiers for use with stereoponic reproduction in the theater a brief description of equipment and cinema installations 5875 the coaxial line amplifier 5876 dc amplifiers a survey paper with references 5877 investigation of the effect of unbypassed screen grid resistors on amplification factor a calculation is made of the negative feedback introduced by unbypassed resistors in the screen grid lead this arrangement is usual in dc amplifiers experimental results confirming the theory are presented 5878 an amplitude stabilized transistor oscillator an af oscillator using two junction transistors in push pull class c operation has its amplitude stabilized to within over wide ranges of supply voltage loading and temperature by comparing the output with a stable reference voltage obtained from a junction diode operated at breakdown 5879 distributed amplifiers some new methods for controlling gain frequency and transient responses of amplifiers having moderate bandwidths distributed amplifiers of moderate bandwidths for steady state applications may be constructed for almost constant gain up to or of cut off by methods including the insertion of extra sections into the use of networks whose image impedance at a shunt capacitance point falls to zero at the cut off frequency for waveform amplification the use of m derived low pass networks with added resistance elements is suggested the image delay is then almost constant over of the non dissipative pass band ad the image attentuation varies in approximately gaussian fashion with frequency over most of the pass band in this second case the maximum useful number of valves per stage is five 5880 development of a high fidelity preamplifier for use in the recording of bioelectric potentials with intra cellular electrodes the cathode follower circuit conventionally used to minimize the time constant of the recording system is discussed and its shortcomings are analysed an improved circuit using positive feedback is described 5881 gain stability of feedback amplifiers by proper choice of the phase single of the loop gain either the magnitude or the phase angle of the amplifier gain may be made independent to a first order of changes in the active elements th general theory is developed results obtained with an experimental amplifier show that over a narrow frequency range the unit can be made as stable as the passive components in the feedback network 5882 a low frequency selective amplifier analysis similar to that for a simple resonant circuit is presented for a feedback amplifier design and performance of an amplifier with a resonance frequency of about are outlined 5883 a minimal noise preamplifier for proportional counters and similar applications a negative feedback amplifier is described which is linear over an input range of db the maximum gain is and is attained over a frequency range of about signals of can be recognized 5884 fast response of magnetic amplifiers 5885 instability of self saturating magnetic amplifiers digest of paer to be published in differences between the major and the minor hysteresis loops of hipernik and their importance in dc triggering are discussed 5886 gain stabilized transistor amplifier gain is stabilized by using an unbypassed resistor in the emitter circuit of a junction transistor 5887 dc amplifier employing junction type transistors temperature sensitive resistors and junction diodes are used in conjunction with compensating networks to eliminate drift effects a two stage amplifier circuit having a drift in hours at room temperature is described 5888 building and using dielectric amplifiers a detailed account is given of th process developed at the national bureau of standards for preparing the capacitors used in dielectric amplifiers a two stage voltage amplifier and an output stage capable of driving a loudspeaker are described 5889 low temperature electronics a survey is made of the temperature dependence of noise and resistance over a range of temperatures approaching absolute zero practical applications of the results of low temperature research are discussed 5890 on statistical estimation in physics 5891 wave propagation in stratified media at normal incidence and application to transmission line theory electric waves optics acoustics wave mechanics an mechanical and electrical quadripoles a comprehensive analyse with numerous references 5892 step by step transition from wave optics to ray optics in inhomogeneous anisotropic absorbing media part solution of the equations for wave normal and refractive index by wbk approximation ray optical reflection and alternation the equations given in part of are solved the existence of particular points is established for which the transition canot be made 5893 the mechanism of electroluminescence part theoretical considerations an account based on destriaus treatment attributing the phenomena of electroluminescence to collisions of field accelerated electrons in the conduction band references 5894 rigorous analysis of the diffraction of electromagnetic waves by strip gratings a solution which is valid without restriction on wavelength angle of incidence polarization or grating constants is obtained in the form of tw fredholm integral equations of the first kind of the same structure as those derived to represent diffraction by slotted diaphragms in rectangular waveguides 5895 a collective description of electron interactions part coulomb interactions in a degenerate electron gas part of april 5896 a collective description of electron interactions part electron interaction in metals 5897 contact electrification the observed phenomena are described and various explanatory hypotheses are discussed effects of static and methods of c eliminating them are indicated references 5898 some measurements on a not selfsustaining gas discharge with an axial magnetic field report of investigations of the potential distribution inside the central arc column of the discharge the experimental arrangement consists of a cylindrical anode with a filamentary cathode at one end and a reflector at the other and a hot probe with electronegative gases deep troughs of negative potential are observed with electropositive gases the central plasma potentials are still negative in relation to the anode 5899 ions and barriers in electric discharges report of investigations on the effect of injecting ions into the spark gap and of the effectiveness of paper screens in blocking the ions 5900 a condition on uniform field breakdown in electron attaching gases the form of the curve relating t to at breakdown where e is the field strength p the pressure and d the electrode separation indicates the existence for high values of pd of a value of ep below which breakdown does not occur a study of the equation for steady state current in electron attaching gases suggests that this limiting value is nearly that for which the ionization and attachment coefficients are equal this is confirmed experimentally 5901 development of the theory of the positive column at low pressures part 5902 dioptrics of electron and ion beams with circular principal paths 5903 secondary emission due to bombardment of metallic targets with multiple charge ions an experimental investigation of the dependence of the coefficient of secondary emission on the energy of the ions sb bi and te targets were bombarded with sb bi and te ions respectively and ni targets with na ba and ca ions the results are shown graphically 5904 the motion of electrons in two combined magnetic the motion of electrons in two combined magnetic fields the focusing properties of the field of a homogeneously wound toroid have been investigated of analysis is now given for the case when this field is combined with a homogeneous field perpendicular to the plane of the toroid 5905 work function of clean and of oxygen coated au pt and pd based on the contact potential difference with respect toag values of the work function were found to be up to higher for the oxygen coated than for the clean surfaces 5906 auger peaks in the energy spectra of secondary electrons from various materials measurements on c be al ni cu ba pt and oxides of some of these are reported a description is given of the highly sensitive apparatus used characteristic peak due to auger electrons emitted as a result of absorption of a valence electron by an excited x ray level were observed for all these materials the structure exhibited by the peaks is related to the energy distribution of electrons in the valence band and complements that observed in soft x ray emission excitation of auger peaks by low velocity electron beams provides a method of investigating surfaces 5907 generalized ionization formula for a plasma a formula is derived which includes as special cases sahas equation the gas cloud ionization formula and the solar corona ionization equation 5908 the field along the axes of symmetry of equal semi infinite rectangular magnetic pole pieces the method of conformal representation is used the field along the axes of symmetry is calculated for a number of values of the ratio of the width of the pole pieces to the distance separating them expressions for the potential function are also given 5909 magnetic behaviour of a linear atomic chain at the absolute zero point for positive exchange integral a calculation of the magnetic moment indicates that the linear atomic chain is not spontaneously magnetizable 5910 on the statistical mechanics of matter in an electro magnetic field part derivation of the maxwell equations from electron theory an ensemble averaging method is used 5911 magnetic field due to a direct current traversing a solid conductor of arbitrary shape application to a cylindrical conductor laplaces law usually known as biot and savarts law is shown to be more suitable than amperes magnetic sheet concept as a basis for deriving formulae for the magnetic field of a conductor the vector potential is introduced 5912 cerenkov effect at microwave frequencies radiation of power excited by a beam bunched at and travelling close to the surface of a polycrystalline dielectric has been detected 5913 on the diffusion of decaying particles in a radial electric field an analysis is made of the diffusion of charged particles in a radial field in which the intensity is distributed according to an inverse square law 5914 electronic polarizabilities of ions in crystals 5915 interaction of a nonrelativistic particle with a scalar field with application to slow electrons in polar crystals 5916 capacitance of a spherical capacitor in a practical spherical capacitor the capacitance is not given exactly by the theoretical formula because the outer sphere has an aperture upper and lower limits are derived for the magnitude of the error involved 5917 radio frequency emission from cosmic ray electrons theory developed by schwinger is used for the quantitative investigation of the intensity and spectral distribution of rf radiation from cosmic ray electrons in interstellar magnetic fields an upper limit is deduced for the density of an electron component of the cosmic radiation 5918 the strength of meteoric echoes from dense columns calculations taking into account the refractive effects produced by ionization distributed at radii t radii greater than the critical density radius have been made for large highly ionized trails using geometrical optics and ray tracing methods the computed maximum radiated power from a diffusion formed trail is only of that calculated on the critical density radius method 5919 meteor echo duration and radio wavelength the durations of radar echoes from meteors have been observed simultaneously on and and also on and m the ratio of durations on two wavelengths decreases with increasing duration by a factor of two over the observed range deviating significantly from the accepted square law of wavelengths plotting the log of the ratio against the log of the duration yields two straight lines of different slopes one in the short duration range and the other applying to the longer echoes general empirical formulae are developed to predict the echo duration on one radio equipment in terms of the duration of the same echo recorded by another apparatus of different sensitivity and wavelength 5920 baileys theory of sunspot noise a discussion of the exchange of energy between the drifting electrons and the wave radiated from a transient disturbance is given which is more general than baileys of and which shows that amplification can occur under certain conditions consideration of a sunspot model having axial symmetry leads to the conclusion that amplification will occur only in exceptional regions 5921 the equations for a problem arising in dungeys investigation of baileys theory of sunspot noise see above 5922 the magnetic field strength in sunspots 5923 theories of solar phenomena depending on sunspot fields moving in the chromosphere and corona theories advanced by giovanelli and various other workers are found to be untenable when mechanical reactions between the magnetic fields and the conducting gas are taken into account 5924 a family of solutions of the magneto hydrostatic problem in a conducting atmosphere in a gravitational field a theoretical study of the equilibrium conditions in a quiescent solar prominence a simple model is obtained 5925 ionospheric and geomagnetic effects of solar flares geomagnetic crochets observed t amberley and apia new zealand between and simultaneously with dellinger fadeouts are considered in relation to subsequent magnetic and ionospheric disturbances their hourly and seasonal frequencies are examined and their augmentation of the normal diurnal inequality verified 5926 the h radiation from solar flares in relation to sudden enhancements of atmospherics on frequencies near 5927 radio astronomy part results of observations of cosmic radio noise sources a survey with references 5928 a survey of localized radio sources in the northern hemisphere report of a survey at a wavelength of made with the jodrell bank aerial system a marked concentration of the intense sources near the galactic plane was found the distribution of the weaker sources may be more nearly isotropic 5929 a radio survey of the milky way in cygnus cassiopeia and perseus report of a survey at a frequency of using the jodrell bank beam aerial and covering the region between and between and the isophotes of the absolute intensities are shown 5930 fine structure of the extraterrestrial radio source cygnus observations made at jodrell bank are reported 5931 radio astronomy see of january 5932 the relation between earth currents and geomagnetic variations a comparison was made between the time variations of e and h where e is the electric field and is the resultant vertical component of the geomagnetic variations fair agreement between the curves was obtained 5933 rapid periodic fluctuations of the geomagnetic fld part a new analysis is made of observational data mainly from eskdalemuir the type of c fluctuation changes at sunset from a continuous flux of disturbance to a comparative quiet punctuated by a short damped wave train a definite fine structure is observed in the spectrum of the daytime fluctuations 5934 the analysis of ionospheric records ordinary ray part tables presented enable the effect of the earths magnetic field to be taken into account when using the method of analysis of ratcliffe of appleton and beynon of using these tables theoretical curves can be constructed for a parabolic or a linear distribution of ionization and for all magnetic latitudes up to about 5935 variations of d layer attenuation at results of daytime reflection coefficient measurements made over a period of several years are analysed the noon value of the attenuation is neper in winter nearly neper in summer though the scatter of values is considerably greater in winter than in summer the excessive absorption observed in winter on short waves is not observed at this frequency the influence of the d layer on the propagation of atmospherics is discussed and the attenuation variations are compared with those of geomagnetic activity 5936 the contribution of solar x rays to e layer ionization a brief description of rocket experiments which provide positive evidence of soft x rays in the ionosphere to an extent sufficient to account for all the e layer ionization 5937 electric currents in the ionosphere part the conductivity the effective height integrated conductivity of the ionosphere calculated on the dynamo theory and taking account of inhibition of the hall current due to polarization of the medium is greater than the pedersen conductivity by a factor of at least and near the magnetic equator is further increased by a factor of to this calculation is shown to overestimate the reduction in total current flow in the ionosphere due to the shunting effect of the f region when the motion of the f region is considered the dynamo theory as presented here gives results in agreement with observations and accounts in particular for the anomalously large magnetic variations observed near the equator 5938 electric currents in the ionosphere part the atmospheric dynamo assuming semidiurnal tidal air flow the atmospheric dynamo problem is solved the ionosphere being divided into three regions each of appropriate conductivity compared with calculations assuming pedersen conductivity alone effective results give a current system similar in shape and phase though more intense and an electric field system markedly different an abnormally large east west current is found at the equator 5939 electric currents in the ionosphere part ionization drift due to winds and electric fields the motion of a cylinder of ionization of density differing from that of the surrounding medium tends to be such that the ionization density is greatly increased over part of its surface and diminished over another part the significance of this result in relation to sporadic e ionization and to long duration meteor trails is pointed out formulae are derived for the horizontal and vertical drift of ionization at all atitudes graphs are given which permit derivation of the true wind or field in a given ionosphere region from experimental observations of the drift velocities 5940 semidiurnal currents and electron drifts in the ionosphere the differential equations of the dynamo theory for the ionosphere are solved numerically under simplifying assumptions the tidal amplification estimated is about for the solar tide the current system in the e layer is in phase with the ground tide but for the lunar tide it it in phase opposition the calculated vertical electron drift is in reasonable agreement with lunar tide observations the calculated horizontal electron drift agrees with observations on long duration meteor trail echoes but the calculated phases are opposed to those obtained from fading measurements indicating that the latter refer to air movements and not to electron drift 5941 solar tides in the f region from the study of night time critical frequencies night time critical frequency variations at ionospheric stations are analysed by season and by latitude for semi diurnal solar tidal terms the amplitude and phase of the vertical drift velocity of electrons so found are consistent with accepted tidal theory and an estimate of the height gradient of the vertical drift is obtained two parallel analyses are made on the alternative assumptions that decay proceeds according to a recombination law or to an attachment law the low values found for the decay coefficients preclude any decision as to which of these two decay processes is actually operative 5942 anomalies of the ionosphere critical frequencies during a solar eclipse soundings made at rome during the partial eclipse of february are reported electron concentration minima were observed before and after the eclipse and at the maximum phase the cause of the first and last of these maxima is assumed to reside in the zone outside the visible disk of the sun 5943 determination of the location of the ionospheric current system responsible for geomagnetic effects of solar flares the height of the flare current system is calculated by a method depending on the time of maximum intensity of a geomagnetic flare effect and the enhancement of electron density at the relevant level if the flare current system forms part of the current system its height is but if it is independent its height is about km 5944 measurements of winds in the upper atmosphere by means of drifting meteor trails description of the doppler radar system and the associated equipment 5945 measurements of wind in the upper atmosphere by means of drifting meteor trails part results of measurements made during oct dec by the method described in above are discussed winds at heights between and are in general horizontal with a prevailing direction in october towards the north east and in november and december towards the east the hour and hour harmonic components represent anti clockwise rotation of the wind vectors the hour component being consistent with the phase of a semi diurnal tidal wind as deduced from barometric oscillations over the height range investigated the direction of the wind remains the same but the mean velocity increases with height 5946 the measurement of ionospheric absorption using observations of cosmic radio noise ionospheric absorption is specified by the ratio expressed in decibels of p the received cosmic noise power to p the power that would have been received in the absence of absorption from about a years observations of cosmic noise a standard curve of sidereal time can be drawn for all aerial directions analysis of records made at hornsby nsw from june to show that two main components due to absorption in the f and d regions respectively can be distinguished 5947 the waveforms of atmospherics a review of research during the preceding fifty years on lightning and on atmospherics showing the relation between the two phenomena 5948 harmonic fields in the propagation of long electric waves round the earth and lightning waveforms 5949 the propagation of very long electric waves round the earth and atmospherics 5950 the application of statistical methods to servo mechanisms the optimum transfer function for the desired response to a stationary random input signal containing noise may be determined by the wiener lee method in general when applied to servo mechanisms design the output will not necessarily have zero steady state error in order to overcome this disadvantage constraints may be applied in the wiener hopf equation such that any of the error coefficients of the servomechanism are zero and at the same time the output is optimized it is also possible to include prediction differentiation or integration of the input function as desirable outputs 5951 series operation of a glow discharge tube and a barretter the replacement of the series resistor by a barretter results in improved stabilization the operation of the type glow discharge tube with type barretter was investigated and the batch variations of the type barretter characteristics were examined 5952 stabilizer for alternating voltages the design of a biased reactor arrangement having good frequency independence and satisfactory speed of operation is discussed 5953 a stable source of high voltage a voltage regulator suitable as a voltage reference at about with current up to several milliamperes is described with the temperature controlled to within the e output is stable to within part in over hours effects of varying magnetic fields gauss are negligible 5954 aircraft protection from thunderstorm discharges to antennas the protection unit described consists of a capacitor in the aerial feeder lead together with a spark gap in parallel with a resistor connected between the aerial side of the capacitor and the fuselage a peak current recorder in the form of a steel strip magnetized by the current flow is included units of this type have been tested for over two years in commercial airliners 5955 an analogue computer for the solution of the radio refractive index equation 5956 automatic beam current stabilization for williams tube memories one of the storage points in the memory tube is used as a test point at regular intervals this is cleared and recharged and the output is sampled the beam current being adjusted to keep the sampled output at a constant level the whole operation takes to complete circuit details are given 5957 a note on calculating the total impedance of impedors connected in parallel three methods one involving use of a desk calculating machine and another use of a linear nomogram are compared and contrasted from the point of view of speed and accuracy 5958 nonlinear distortion of a random signal application to frequency modulation analysis is based on the instantaneous statistical properties of a random signal the energy spectrum for a given bandwidth being determined from the appropriate correlation functions application of the method is illustrated in the case of fm when propagation time is considered since the calculation takes account of intermodulation products over a complete frequency band the method has advantages over that based on intermodulation of discrete frequencies 5959 pulse permeability and losses in magnetic materials subjected to rectangular dc pulses 5960 transductor with high impedance control winding termination the dynamic behaviour of this transductor is represented by equations similar to those for a transductor with a low impedance control winding termination of 5961 matrix analysis of linear time varying circuits 5962 ire standards on circuits definitions of terms in the field of linear varying parameter and nonlinear circuits standard 5963 a coaxial magic t the basic design consists of a coaxial line t junction including a shielded loop whose axis is located at the centre of the t the operation is similar to that of the hybrid coil or the waveguide magic t two modifications are described one using direct coupling between the loop and the loads standing wave characteristics of experimental models for operation at wavelengths of about cm are given a swr can be obtained over a frequency band of about application to phase measurements is described briefly 5964 filter helix travelling wave tube part the filter helix a new circuit element for travelling wave amplifiers and oscillators 5965 the properties and manufacture of piezoelectric quartz crystals 5966 thickness shear and flexural vibrations of contoured crystal plates equations of motion expressing approximately and separately the thickness shear and flexural modes are derived from data on the coupled modes for a plate of uniform thickness of and of mindlin these equations are applied to the case of a plate of double wedge shape and a plate with bevelled edges results support the finding that thickness shear motion is localized at the centre flexural motion at the edges 5967 thickness shear vibrations of piezoelectric crystal plates with incomplete electrodes the method developed in above is applied to determine the influence of electrode length on thickness shear frequencies for a partially coated crystal these frequencies depend on the coupling between the coated and uncoated portions considered as separate systems 5968 suppression of overtones of thickness shear and flexural vibrations of crystal plates analysis showing how electrodes coated on the surfaces of thickness shear plates may be shaped so that only one resonance mode is excited 5969 derivation of equivalence theorem of a weakly coupled electromagnetic cavity resonator system a general proof of the equivalence between a system of weakly coupled cavities and a system of coupled resonant lcr circuits is derived from maxwells equations by means of a first order perturbation calculation the frequency dependence of the system is deduced from the equation of state the case of two coupled cavity resonators is considered in an example 5970 calculation of the resonant properties of electrical cavities the method described is based on measurements made on a model in a electrolyte tank calculated values of resonance wavelength and q are in good agreement with directly measured values 5971 characteristic functions of real resonators orthogonal characteristic functions for a piecewise inhomogeneous one dimensional system are considered in relation to resonators with energy losses at the boundaries the analysis provides an explanation of previously published experimental results 5972 an iterative method for network synthesis the numerical method described is based on the complex critical frequencies of the insertion loss function applications to networks with up to four poles and four zeros and to a crystal filter are illustrated 5973 synthesis of transfer functions with poles restricted to the negative real axis comment on of and authors reply 5974 radio frequency phase difference networks a new approach to polyphase selectivity 5975 quasi distortionless filter functions the quasi distortionless filter network function is specified by expressing the input and output functions as time power series and equating their coefficients such filter functions are derived and discussed 5976 the direct method of filter and delay line synthesis extension of previous work of the direct method consists in postulating an indefinitely recurring network in which each recurring element is coupled to all elements of the network and in determining the values of these elements and of their indefinitely extended couplings which will yield the exact phase characteristics desired within the exact pass band desired examples are given of the application of the method to the design of ideal band pass filters 5977 the synthesis of reactance networks consisting only of rejector circuits in series by the method of partial networks the modification required in a filter network with given resonance and anti resonance frequencies in order to introduce a further prescribed resonance or antiresonance frequency is determined numerical examples illustrate the method which is also applied to the reduction of the number of resonance frequencies and to a mechanical oscillator 5978 the historical development of filter theories 5979 elementary ladder type filters a system of classification of conventional ladder type filters based on image parameters is described an elementary filter is defined as a network with two prescribed image impedances and minimum attenuation these are generally composed of conventional half sections but in certain cases particularly for band pass filters synthesis involves sections with three branched impedances which cannot be resolved into matched half sections formulae with examples of networks for low pass high pass band pass and band stop filters are given in an appendix 5980 rc active filters a type of filter is described in which the active element is a negative impedance converter using transistors of the number of capacitors required is only equal to the total number of reactance elements in the corresponding lc filter theory is given and tests on low pass high pass and band pass filters are reported 5981 impedance transformations in band pass filters the design of band pass impedance transforming filters is derived from the equivalence between an asymmetrical band pass filter and a symmetrical section plus an ideal transformer 5982 design of a simple band pass amplifier with approximate ideal frequency characteristics the application of the pole and zero method of synthesis is illustrated 5983 fm transient response of band pass circuits a general formula is derived for the instantaneous deviation of output frequency resulting from a step change of input frequency calculations are presented for large frequency shifts in a single tuned circuit and for small frequency shifts in amplifiers with various numbers of tuned circuits for small input steps near the middle of the pass band the transient response is the same for fm as for am stagger tuning gives rise to overshoot but the extent of this is small if the amount of stagger is no more than enough to provide maximally flat response in the steady state 5984 one design method of band pass filter for vhf design formulae for band pass filters constructed of two wire and coaxial cables are derived and numerical examples are given the theoretical and experimental results are in fair agreement 5985 hereditary dynamic systems with discontinuities the characteristics distinguishing nonlinear from linear oscillations are examined a class of dynamic systems termed discontinuous is defined cases are discussed for which poincares topological methods can be used to determine the periodic solutions and the stability such systems are included in the larger class of hereditary systems defined by volterra ie systems whose operation is affected by their previous history 5986 single stage phase shift oscillator a method of design is developed in which the phase shifting network contains an arbitrary number of rc or cr cells and the value of the first series impedance is half that of the others simple formulae are derived for the network impedance and oscillation frequency 5987 transistor oscillators the self oscillation conditions and frequency deviation characteristics of a three point transistor oscillator are derived by analogy with the retarding field oscillator and a comparison is made with measured characteristics of point contact and junction type transistor oscillators various circuits are examined from the point of view of suitability of application of the two types of transistor the discussion is limited to the frequency range below cut off 5988 the audio frequency negative feedback amplifier as a filter circuit a single stage rc feedback amplifier is represented by an equivalent damped parallel lc circuit and a locus diagram for amplification is constructed the method is applied to a two stage amplifier an expression analogous to form factor in filter theory being derived in terms of feedback ratio this is useful for determining the effect of feedback on the frequency characteristic in af amplifier design 5989 bandpass amplifiers a design method is presented based on the required overall gain half power bandwidth and centre frequency of the pass band the amplifier considered is composed of a number of identical groups each comprising one or more amplifying stages and having a maximum flatness frequency response conditions for maximum possible gain are found regeneration due to anode grid capacitances is discussed the amount of distortion introduced into the frequency response is related to a regeneration coefficient when is sufficiently large oscillations occur stability conditions for single tuned and stagger tuned and stagger tuned amplifiers are derived 5990 distributed amplifier theory 5991 a new transformerless amplifier circuit four valves in a bridge circuit are driven in appropriate phase and amplitude so as to deliver equal power to a common load no dc flows through the load negative feedback is easily applied a and an amplifier are described response characteristics are flat over the audio range at all levels of operation the unit weighs including power supply and pre amplifier 5992 magnetic amplifier performs analytical operations 5993 audio automatic volume control systems applications of a vc are noted and various circuits are reviewed methods of eliminating audible thump occurring on application of a direct control voltage of deriving the control voltage and of reducing time delay are discussed measurement techniques are outlined 5994 the new compressor expander system of the french post office the new unit has improved operating characteristics and is less than one quarter the size of the former type of et al two si diodes replace the rectifiers in the potentiometer system and two ge diodes the double diode valve in the detector unit other valves are replaced by miniature types performance tests are reported 5995 proposal for a new aether drift experiment an experiment using standing microwaves is outlined 5996 deductions regarding the constitution of light energy a discussion based on the results of experiments previously reported of the field associated with a particle of light as defined by planck is nonoscillatory the frequency associated with the light being due to the circulation of em energy in the particle 5997 the mechanism of electroluminescence part applications to the experimental facts theory previously developed of may is used to interpret observed phenomena including temperature and frequency effects fluctuations of brightness corresponding to field alternations initial rise of brightness and surface effects good crystallization abundance of luminescence centres and donor levels and absence of other defects are conditions favouring the production of electroluminescence various theories of the phenomenon are compared in an appendix 5998 on a property of a family of equiangular spirals and its application to some problems of wave propagation 5999 the diffraction of waves in passing through an irregular refracting medium a relation is derived between the angular power spectrum of waves emerging from a thin diffracting screen random in two dimensions and the auto correlation function describing the irregularities of the field as it emerges from the diffracting screen the special case of an isotropic screen characterized by an auto correlation function which depends only on distance and not on direction is discussed for normal and oblique incidence multiple scattering of waves caused by volume irregularities of the dielectric constant is considered the angular power spectrum and the auto correlation function describing the irregularities of the diffraction field caused by multiple scattering in a thick slab are determined the results are compared with those obtained by hewish of for a thin phase changing screen the results are discussed in terms of problems arising in the study of radio wave propagation 6000 a note on uniqueness proofs for boundary value problems in potential theory and steady heat conduction by allowing the boundary to tend to infinity in two directions and considering the problem in a semi infinite region it is possible to prove uniqueness by classical methods for a very large class of boundary conditions 6001 variational methods for problems in resistance schwingers variational methods are used to calculate upper and lower limits for the resistance of a cylinder with a specified transverse distribution of potential at one end 6002 the evaluation of the surface impedance in the theory of the anomalous skin effect in metals a method is described for obtaining series expansions for the integrals which represent the surface impedance 6003 note on the quantitative development of the discharge characteristic 6004 investigation of ball lightning by means of models experiments with gas discharges are described 6005 ussr research on magnetism a brief historical survey with comprehensive bibliography 6006 effect of the surface on the magnetic properties of an electron gas the energy levels of free electrons confined in a finite cylindrical box with a uniform axial magnetic field are computed using the wkb approximation the form of approximation appropriate to various boundary conditions is discussed the results are used to calculate the susceptibility of the system 6007 on reciprocity theorems in electromagnetic theory five different types of sources of em fields are considered and the corresponding reciprocity theorems stated 6008 a scalar representation of electromagnetic fields it is shown that in a region which is free from currents and charges any em field may be rigorously derived from a single generally complex scalar wave function the momentum density and energy density defined in terms of this function differ from those given by the usual expressions but the differences disappear on integration over any arbitrary macroscopic domain 6009 induction of currents by moving charges an analysis is made of the field due to a charge moving between a pair of parallel disk electrodes connected externally by a conductor a general expression for the current flowing through the conductor is derived in terms of the electrode radius and separation and the velocity of the charge a periodic discharge could be obtained with particular values of and u 6010 electromagnetic waves emitted on detonation of explosives small electrical disturbances detected incidentally while using explosives to produce sharp stress pulses were later investigated separately the effect was displayed on a high speed cro the potential of a wire probe reached a maximum after about and then decayed to zero the effect is probably due to the production of positive and negative ions having different mobilities 6011 vector modifications inherent in the doppler effect for waves propagated in a dielectric medium the propagation of plane em waves in a moving medium is characterized by four vectors as compared with two for a stationary medium because the directions of the electric and magnetic fields no longer coincide with the respective inductions relations between these vectors are derived and their physical significance is discussed 6012 the electromagnetic transmission characteristics of the two dimensional lattice medium a theoretical investigation is made of systems with obstacles arranged to form a regular lattice in planes perpendicular to the direction of propagation the obstacles having elliptical cross section an examination is made of the influence of obstacle size shape and spacing and of the wave polarization on the transmission characteristics no restriction is introduced as regards the size of the obstacle in relation to the theory is relevant to problems of microwave lenses and transmission circuits of travelling wave valves 6013 microwave diffraction measurements in a parallel plate region diffraction of a plane or a cylindrical wave by wedges covered with silver foil was investigated experimentally by a probe method the wedge the line source and the probe were located between two large parallel duralumin sheets spaced in apart the measured values of field strength are compared with values derived from previously published theory 6014 radiation from a line source adjacent to a conducting half plane expressions for the field are obtained in terms of tabulated functions by using an alternative method of analysis to that of harrington 6015 the fields of a line source of current over a stratified conductor expressions for the electric and the magnetic fields are derived assuming the to be infinitely long and parallel to the conductor at large distances the results can be generalized to apply to any source of horizontally polarized waves situated on the surface of a half space consisting of an arbitrary number of layers 6016 absorption of microwaves in gases absorption coefficients in the cm waveband were determined for ammonia ethyl alcohol and acetaldehyde at a pressure of mm hg and for methyl iodide and acetone at cm hg and cm hg respectively 6017 the decomposition of thin films on bombardment with slow electrons the threshold energies of the bombarding electrons were determined for the onset of electron absorption decomposition and secondary emission the films investigated included and the alkali halides the experiments were carried out using diode or triode valve systems with an oxide coated cathode operated at as the source of the bombarding electrons 6018 radio astronomy part radiolocation of meteors a review of measurement techniques and results with a note on local ionization effects of meteors 6019 the effect of radar wavelength on meteor echo rate theory is given which includes the effects of high electron density the linear rate of trail formation and the initial column radius on the meteor echo power and hence on the number of echoes received the theories of lovell and clegg of and others are discussed critically a comparison with experimental results is made 6020 a note on solar terrestrial relationships corpular emission from the invisible solar disk and deflection of the particles into certain trajectors could account for the lack of correlation between particular solar and geophysical phenomena 6021 identification of sunspots previous work of indicates a statistical correlation between spots on opposite hemispheres during successive sunspot cycles analysis of sunspots between latitude and appears to support this view a number of sunspots are identified as being produced by the same original disturbance in the solar core the mechanism is explained on the basis of the magneto hydrodynamic theory of sunspots 6022 position and identification of a bright extended radio source in gemini more accurate observations are reported on a previously detected source of 6023 the radio brightness distributions over four discrete sources of cosmic noise the experimentally determined isophotes obtained from measurements with a variable aerial spacing radio interferometer at are compared with the optical features of the nebulae 6024 galactic radiation at radio frequencies part the sea interferometer the factors governing the interference pattern of a lloyds mirror type of interferometer at frequencies between and are discussed and three systems for reducing the effect of background noise are described 6025 galactic radiation at radio frequencies part low altitude scintillations of the discrete sources scintillations of four discrete sources of altitudes from to were observed at frequencies in the range to a strong correlation is established between the occurrence of scintillations and sporadic e part above bolton and slee 6026 note on geomagnetic disturbance as an atmospheric phenomenon possible relations between ionospheric winds and atmospheric electric currents associated with magnetic storms are briefly discussed 6027 the immediate source of the field of magnetic storms results of a comparison of mean values of initial phase of magnetic storms at huancayo cheltenham honolulu and san juan porto rico indicate that major immediate sources of magnetic field changes during storms in all phases are within or near the atmospheric region see also above 6028 a statistical survey of atmospheric index of refraction variation survey of microwave measurements made at heights of over the pacific ocean california and ohio using an airborne refractometer described by crain and deam 6029 an analogue computer for the solution of the radio refractive index equation a computer in use at the crpl comprises basic computation in use at the crpl comprises basic computation circuits incorporated in a bridge circuit a turn potentiometer is modified so as to give an approximately exponential variation of the resistance with the shaft rotation corresponding to the curve of the saturated water vapour term in the equation 6030 irregularities in the ionosphere electron clouds in both the e and the f regions have been detected at vertical incidence by means of the equipment described by banerjee and roy of photographs of typical echo records are shown the power and persistence of the echoes are discussed 6031 recombination and diffusion and spread echoes from the ionosphere the inclusion of a diffusion term in the differential equation of layer formation to account for ionization due to the influx of charged particles leads to a solution in terms of a doubly periodic elliptic function this solution indicates the possibility of a periodic variation of ionic density within the f layer such as to account for spread echoes which have been observed layers produced by ultra violet radiation are many wavelengths thick those due to particle ionization are only two or three wavelengths thick and are embedded in the background of ionization the existence of auroral curtains provides further evidence of ionization by particles 6032 origin of the e layer of the ionosphere the electron densities for the and f layers resulting from photo ionization of molecular and atomic oxygen are calculated on the basis of the work by moses and wu on the distribution of o and of o in and above the oxygen dissociation layer of and of while the results are in reasonable agreement with observations for the e layer it is not possible to account for the observed value of recombination coefficient for the f layer by any theory based on processes involving only oxygen atoms and molecules 6033 method of determining the true height of the ionospheric layers part application of the exact value of the refractive index ordinary ray case values obtained using the exact value of the refractive index appleton hartree are somewhat higher than those obtained with the approximate formulae used in part of 6034 recombination in the f layers the mechanism proposed by banerji of april is critically discussed 6035 further discussion of kelsos paper on a method for determination of the distribution of electron density in the ionosphere comment on 6036 correlation of magnetic auroral and ionospheric variations at saskatoon analysis of measurements made between december and april a connection exists between the maximum elevation of auroral light above the northern horizon and the maximum amplitude of variation of h some types of sporadic e reflecting layers appear more frequently during geomagnetic disturbances 6037 investigation of ball lightning by means of models experiments with gas discharges are described 6038 on the production of glow discharges in the ionosphere by winds a source of excitation of the airglow and aurora may be found in the potential difference generated by zonal ionospheric winds cutting the earths magnetic field a return path of current flow or glow discharge in the higher ionosphere appears plausible 6039 radio echoes observed during aurorae and geomagnetic storms using and waves simultaneously observations made at kjeller in and at tromsoe during early are reported echoes are only received when the aerial is directed towards the north the echo amplitude has a maximum value when the aerial is directed horizontally and decreases rapidly with increased elevation of the aerial the results indicate that there is no correlation between the position of visible aurorae and echo range but that there is a correlation between the occurrence of high e layer critical frequency and the reception of echoes during geomagnetic storms echoes on are observed only during the more severe phases scattering from the ground or sea reflected back vis an intense e layer is advanced in explanation of the observations 6040 step to frequency response transforms for linear servo systems five known methods for finding frequency response from a given graph of linear mode step response are discussed theory and practical computing routines are given for a new method based on straight line segment approximation to the given step response graph approximate laws relating cut off frequency and frequency and amplitude of maximum response to the shape and and time scale of the step response are derived discrepancies between experimental results and those derived from the theory are ascribed mainly to nonlinearity of practical systems 6041 electromagnetic shielding with transparent coated glass the shielding effectiveness of multilayer plane glass structures is investigated by determining their transmission factor for plane em waves three types of glass are considered at frequencies up to transmission line theory is used in the analysis the coatings being represented by shunting resistances theoretical and experimental results are compared attenuations of db and more can be obtained with tolerable loss of transparency 6042 the electron voltaic effect in pn junctions induced by beta particle bombardment 6043 supply for precision measurement a low impedance generator giving a highly stable comprehensive supply over the frequency range is based on a wien bridge oscillator with stabilized dc supplies 6044 voltage stabilizers for microwave oscillators analysis indicates that the effect of variation of valve heater voltage in commonly used stabilizers of is not serious in the case of series parallel arrangements but may be serious where a single series valve is used 6045 partial drift compensation in electronic dc analog computers for differential equations a method particularly suitable for computers with time shared elements is described the number of compensation points can be much smaller than the number of drift sources the method is illustrated by describing the compensation of a machine for computing direction cosines 6046 analog computing by heat transfer multiplier divider ac integrating and differentiating circuits are described based on the use of a thermal transducer this transducer consists basically of a pair of heater elements each one of which is in thermal contact with one of a pair of temperature sensing elements mounted in a wheatstone bridge circuit appropriate application to the heater elements of two electrical input signals creates a temperature difference proportional to their product between the sensing elements 6047 fosdic a film optical sensing device for input to computers an instrument is described for processing written records such as answers to questionnaires marks made with ordinary pen or pencil at special locations on microfilm are converted are converted into electrical pulses by means of a flying spot scanning system the pulses are recorded on magnetic tape for input to the computer see also 6048 fast acting digital memory systems a survey of moderate ad high speed storage techniques for digital computers 6049 penetration of an electromagnetic wave into a ferromagnetic material an investigation of the magnetization of metallic ribbon toroidal cores with rectangular hysteresis loop used as computer storage elements approximate solutions are obtained for the field inside the core under different conditions of loading theoretical and experimental output waveforms show close agreement for high magnetizing force and thickness of core material mil 6050 ferromagnetic spinels with rectangular hysteresis loops tests made on materials of different composition show to be most suitable for magnetic storage elements for rings of outside diameter inside diameter mil the coercive force is about oersteds and switch over time rings of outside diameter have a lower coercive force 6051 servo control of the position and size of an optical scanning system a method of controlling the position and size of a television type raster relative to arbitrary references by means of four servo mechanisms is described one of the applications of such a system is that of a reading device for punched cards a system for reading any one of a stack of cards without removing the selected card has been developed using the servo controlled raster the design of the servo mechanisms for this application is described in detail 6052 electronic circuit technique for a high speed computer commonly used computer circuit units based on a triode or ge diode are represented by a symbol indicating the unit and its mode of operation the functions of different combinations of different combinations of the basic units are listed and their application in a serial binary scale computer is illustrated using the notation described 6053 new flip flop chain circuits used in computers for counting to base and base modifications to the potter decade arrangement are described 6054 an improved experimental iteration method for use with resistance network analogues a development of the method previously described by liebmann of the error signals for a number of network nodes are displayed simultaneously on a cr tube screen so that it is always possible to work on the worst error instead of making adjustments cyclically 6055 the mercury delay line storage system of the ace pilot model electronic computer discussion on of january 6056 ime shared amplifier stabilizes computers drift in the dc operational amplifiers of analogue computers is reduced by connecting them periodically to the output of an auxiliary stabilizing amplifier the advantages of using a direct coupled rather than a chopper type of amplifier for this purpose are indicated circuit details are described including the switching and filtering arguments 6057 metal ultrasonic delay lines an experimental investigation was made with the object of finding a metal o or alloy suitable for the transmission of pulses at temperatures between and with a delay independent of temperature the effect of various constructions crystal attachment methods and materials and treatment of the delay line material was investigated the results are tabulated and shown graphically an isoelastic iron alloy containing cr and other minor constituents used with overcured epoxy resin quartz crystal attachments gave the best transmission characteristics a shorter account of the work is given in tech news bull nat bur march vol no 6058 the calculation of transients in dynamical systems 6059 a stable high speed multichannel pulse analyzer pulse selection in each channel is accomplished by a single discriminator whose threshold is set at a height corresponding to the upper boundary of the channel the channel width being determined by suitably shaping the incoming pulses 6060 frequency discrimination and stabilization of square wave modulated microwave transmissions 6061 pulling effect in synchronized systems synchronization of a valve oscillator with a low pass filter in the feedback loop is considered and the phase equation method of analysis applied with parameters m and t proportional to the detuning and to the filter time constant respectively for the operating point lies within the synchronization range but the system remains in the asynchronous state ie pulling effect exists for values of greater than a critical value for the system is synchronized and if this is an initial condition of the system synchronization will be maintained for values of up to unity a graph of the pulling function ie the relation between m and t obtained in part by analysis in part from experiment is shown the case of a limiter in the feedback loop is also considered 6062 the design of a radio frequency coaxial resistor characteristics of the cylindrical coaxial resistor intended for use as a reflection free termination are discussed and design curves given the jacket diameter is chosen to maintain the resistive component of the resistor at the required value the reactive component may be compensated in two ways the first suitable for resistor lengths consists in undercutting the line the second requires the insertion of a short circuited transmission line in series with the resistor and will give either perfect compensation over a restricted frequency range or less accurate compensation over a wide range the effect of the holder is taken into account 6063 iron free cylindrical coils with reduced external field the design of coils with zero magnetic moment is described and the necessary formulae are given the arrangement consists of three coaxial coils connected so that the outer coil produces a field opposing that of the two inner coils and of such magnitude as to reduce the external field to nearly zero the internal field is approximately equal to that of the innermost coil alone coils of this type are useful eg for focusing electron beams for magnetic measurements and for inductance standards see also 6064 design of high frequency coils for high currents a practical guide to the design of single layer air cored cylindrical coils and a short circuit variometer the dissipation of heat electrical breakdown potential and the various losses are considered formulae tables and an inductance coil dimensions nomogram are given 6065 the performance of dried and sealed mica capacitors good stability has been achieved in an capacitor by drying it for a year and then mounting it in a sealed container the interdependence of the variations of capacitance and power factor over the frequency range is discussed 6066 tantalum electrolytic capacitors a general review of types of electrolytic capacitors and problems of design manufacture and testing of ta types data are presented for three csf capacitors having volumes of and cm with average capacitances of and respectively at operation 6067 normalization of the frequency dependence of impedance and amplifier circuits outline of generalized circuit theory 6068 some observations on time considered as a complex variable results of applying this concept in fourier and laplace transformations are examined and its application to the analysis of transients is discussed a practical interpretation of reversing the real time complex frequency relation is given with reference to echo phenomena 6069 the transistor as a network element the use of transistors for reduction of dissipation elimination of inductance production of delay inversion of impedance is discussed improvements in performance can be achieved which would otherwise be unobtainable or uneconomic 6070 the brownian movement of linear and nonlinear systems the application of brownian movement analysis to systems with a nonlinear relaxation mechanism eg electrical conductivity is considered a statistical hypothesis is proposed which enables a calculation to be made of the brownian movement and corresponding frequency spectrum of such systems the results are relevant to the study of electrical noise 6071 note on the theory of brownian motion in nonlinear systems the hypothesis advanced by macdonald is shown to be not self consistent 6072 a new method of synthesis of reactance networks since the chain matrix of a cascade combination of quadripoles is the product of the individual chain matrices and since synthesis of a complicated network by the insertion loss method involves obtaining a number of simple sections to be connected in cascade the chain matrix is chosen for this purpose a method of factorizing any relizable chain matrix into two such matrices of lower order is presented repeated factorizationsections simple enough to be synthesized the method involves only simple algebra and a new theorem concerning reactance and impedance functions 6073 lumpsed parameter delay lines the application of rigorous filter theory to delay lines comprising a series of coaxial coils is difficult owing to the coupling between nonadjacent coils an experimental method of obtaining frequency characteristics is outlined the latter can be corrected by connecting a capacitor across adjacent coils filter theory is applied to give an indication of suitable capacitance values 6074 monotonic transient response restrictions are derived which must be placed on the poles and zeros of the system function of a linear system with lumped constants in order that the response of the system to a step function drive shall be monotonic system functions having up to three s zeros are considered a method of dealing with systems containing more than three zeros is explained 6075 distortion of arbitrarily shaped curves by rc sections a method is given of calculating the distortion by a rc network of any signal which is expressible as the sum of a power series and terms containing exponential functions of the circuit time constants tables and nomograms are given for calculating the output form given the input curve and vice versa for rectangular trapezoidal triangular parabolic and exponential type pulses 6076 matching circuits for asymmetrical wire aerials a comparison of various types of aerial coupling circuits used particularly at medium and long wave lengths and of the case of adjustment for use at different frequencies the discussion shows that the most advantageous circuits consist of two variable reactances used in conjunction with an impedance meter examples of this type for use at or at medium waves are shown 6077 action of periodic telegraphy signals on cascaded rlc resonant circuits the response to rectangular trapezoidal and sine squared pulses of a cascaded arrangement of up to three similar tuned circuits is investigated theoretically and the results compared with the response of a single tuned circuit of the effect of a bandwidth and signal repetition frequency is studied from the point of view of using the circuit for fourier analysis and for reception of telegraphy 6078 explicit formulae for the calculation of filter circuits with generalized parameters an extension of previous work of to the anti metrical low pass the symmetrical and the antimetrical band pass characteristic functions and the determination of the transmission factor 6079 the smoothing of loss attenuation in basic types of ladder filter the characteristics of basic and terminating half sections with losses are derived from image parameter theory and the results applied to show how the attenuation can be smoothed by introducing mismatch at the end of the end of the filter or by inserting series and or shunt resistors at properly chosen points within the network 6080 the transient response of rf and if filters to a wave packet discussion on of 6081 a stable voltage controlled logarithmic attenuator the variable impedance element is a triode operated so that the cathode impedance varies approximately inversely as the transconductance stabilization is achieved by the use of dc feedback with a suitable increase in loop gain design procedure is given for both high and low input types experimental results are discussed 6082 design of rc wide band degree phase difference network the arrangement comprises two all pass networks as described by orchard the pole zero pairs are first determined so as to give the difference of phase shift over the frequency band and the networks are synthesized from the response functions thus found design procedure is detailed step by step and is illustrated by a numerical example notes on construction and alignment are included 6083 a nonreciprocal microwave component in the presence of a steady magnetic field the permeability of a ferrite is an asymmetrical tensor this property is applied in the construction of a nonreciprocal device comprising a waveguide in which a ferrite block is arranged asymmetrically and parallel to the axis a static magnetic field being applied transversely experimental results are given 6084 valve oscillators with voltage controlled frequency dependence a discussion of various circuits in which reactance is varied by application of control voltage and a comprison of their performance in respect of band width and output at medium and high frequencies 6085 ultra low frequency three phase oscillator an oscillator for the frequency range uses three identical networks each comprising a polystyrene capacitor and a stable resistor in a stair arrangement radiating from the power supply the circuit is in effect a three stage amplifier oscillations occurring at the frequency for which the phase shift is in each rc network uses is made of the miller effect to keep down the size and cost of the frequency determining elements 6086 electronically tuned wide range oscillator a hel transmission line with ge diodes mounted at intervals of is used as tuning element in a colpitts circuit tuning is accomplished by applying a switching pulse to a selected diode to short the line the five tuning positions give frequencies of about and respectively the length of helical line required is very much less than that of a parallel conductor line for the same frequency satisfactory operation of an experimental model was achieved at switching rates up to pulses sec 6087 perturbations of a nonlinear filtered oscillator analysis summarized earlier and of the effect of a disturbance on the behaviour of an oscillator comprising a nonlinear amplifier feedback loop and low pass filter see also of 6088 audio oscillator uses new design a general generator covering the range in four bands has both low pass and high pass rc filters incorporated in the feedback loop to give good frequency stability and good waveform amplified agc is included in a commercial adaptation of the circuit 6089 positive gap germanium diode 6090 noise discriminator for periodic signals the periodic signal of any waveform is applied through a phase inverter to one pair of terminals of a resistance bridge including two diode rectifiers periodic pulses are applied to the other pair of bridge terminals during each pulse the diodes are unblocked and the signal passes to an integrating circuit with an adjustable time constant if the pulse frequency is slightly greater than the signal frequency the output obtained has the waveform of the noise free input signal and a much lower frequency random noise mains interference and any other disturbance of a frequency which is not a multiple of the signal frequency will not be reproduced the unit was designed for use with nuclear magnetic resonance apparatus 6091 subharmonic crystal oscillators the operating frequency of a relaxation oscillator can be stabilized at a submultiple of a crystal frequency in a conventional blocking oscillator with a crystal connected across the third winding of the pulse transformer frequency division by factors up to several thousand can be effected a multivibrator with crystal between anode and grid of one valve gave good frequency and pulse width stability when operating with a division factor of details of these two circuits are given three others have been examined namely a screen coupled phantastron a thyratron and a transistor circuit 6092 use of variable gain amplifiers in acoustic measurements 6093 harmonic distortion and negative feedback different methods of defining gain in relation to the output voltage input voltage characteristic of an amplifier are discussed for a nonlinear amplifier it is reasonable to base the definition on the average slope a method is indicated for constructing the characteristic of the amplifier with feedback from that of the amplifier without distortion can be reduced by means of feedback even for flat regions of the characteristic this result is in disagreement with that of rowlands of detailed analysis is given for several types of amplifier 6094 application of the multivibrator principle in counter tube amplifiers a description is given of a pulse amplifier based on a multivibrator circuit which gives an output pulse of amplitude with a leading edge slope of for a input pulse 6095 ae cathode resistor in the quiescent case 6096 cathode coupled valves a graphical method is described for investigating cathode coupled amplifiers the method is demonstrated in relation to a circuit using a type twin triode and involves the construction of composite load lines on the anode characteristics an initial trial solution must be found to determine the voltage across tan ac cathode follower circuit of very high input impedance a push pull amplifier for the range is described each half of the input consists of a cathode follower with gain approximately unity with a constant current cathode load constituted by a further valve the effect of grid anode capacitance in the input valve is reduced by driving the anode by another cathode follower in series with it input capacitance is and input resistance up to circuit modifications to obtain zero or negative input capacitance are explained 6097 flux preset high speed magnetic amplifiers 6098 parallel connected magnetic amplifiers a complete analysis based on a single valued bh relation is made for three types of load resistive inductive and capacitive transient response is considered analysis of feedback amplifiers shows clearly the jump phenomenon in the output characteristic 6099 high frequency transistor amplifiers transistor high frequency transistor amplifiers transistor equivalent circuits appropriate for hf wide band operation are presented input and output impedance and power gain for grounded base and grounded emitter arrangements are discussed the design of an if amplifier using four npn transistors is described as an example the bandwidth is centred at and the gain is pr stage 6100 transistor equations using h parameters transistor circuit calculations are simplified by making use of d fundamental parameters for the four terminal network corresponding to the base input common emitter circuit circuit equations in terms of these parameters are tabulated for the three basic configurations 6101 design of transistor power amplifiers methods are outlined for obtaining maximum power output consistent with acceptable distortion factors considered include stage gain and power supply using values obtanable with the transistor two numerical examples are worked out a class a push pull grounded base arrangement for a low distortion af amplifier and a clas b grounded emitter arrangement for a output stage 6102 temperature compensated dc transitor amplifier temperature compensated dc transistor amplifier the variation of transistor parameters with temperature is discussed compensation can be provided by using temperature sensitive resistors a description is given of an experimental dc amplifier compensated in this way 6103 pulse formation and supply for magnetrons discussion of the design of a modulator capable of handling pulses of the order of at wit a duration of an a repetition rate of per sec the method of pulse formation used is based on the slow charging of a capacitor the use of artifical lines for pulse shaping is described if a pulse transformer is used the charging voltage need not be unduly high 6104 trends of development in the field of electrical component for telecommunication component design is considered from the point of view of the physics and chemistry involved in meeting the requirements of operation over a particular frequency band operation under conditions of prescribed current waveform and intensity operation under peak loads operation at low loss operation under given ambient conditions operation under restrictions of tolerance stability and durability 6105 components exhibition trends in developments portrayed at the recmf show a review of the exhibition held in london april 6106 printed circuit design sources a detailed sources available in the usa 6107 standardization of printed circuit materials results of tests on metal clad plastic laminates for thermal endurance under simulated manufacturing conditions adhesion variation between the centre and the edge of the sheet bond strength during solder dipping ad hand soldering effects of dust are shown graphically these and other types of bond strength tests are discussed from the point of view of establishing quality standards and standard conditions of test the positioning of components to avoid bond stress and the proer choice of operating temperatures are also considered 6108 a theory of the electron an essentially classical theory is proposed by analogy with the gravitational theory of matter it is based on equations of the form suggested by mie in the mass of the form suggested by mie in the mass of the electron is accounted for by means of the energy of the field 6109 diffusion of pulsed currents in conductors theoretical investigation of the density distribution and the equivalent depth of penetration of a transient current for the case of a plane tem wave incident normally upon a plane conductor particular pulse waveforms are considered see also f 6110 the decay of the space charges in intermittent discharges in neon and argon the influence of the gas pressure and electrode separation on the decay of the space charges is investigated experimentally the decay times for both neon and argon appear to be of the order of sec and are nearly proportional to the pressure over the range of measurement about possible explanations of these values are discussed and the various regions of the static characteristic are related to the functioning of counters and periodic discharges 6111 the high pressure glow discharge in air report of observations on the glow discharge in air at a pressure of about mm hg between cu and w electrodes characteristics are given for discharge lengths of mm and currents of a 6112 spectrum intensities and radio frequency noise in a dc hydrogen arc rf noise generated by the arc was reduced by shunting the arc with a capacitor this caused an incidental modification of the ultraviolet spectrum the results suggest a connection between the noise intensity and the distribution of energy among the electrons 6113 investigation of the electron emission from nickel experiments show that the work function of a single crystal of n reduced in hydrogen is higher above the curie point than below it this result is shown graphically field strengths of about were used in measurements of electron emission from a point source photographs of the emission patterns are shown 6114 a note on the formula for the mobility of electrons with mean free path varying with velocity a correct generalized formula is derived for the electronic drift velocity in an ionized gas taking the townsend ramsauer effect into account 6115 theory of the work function of metals the polarizing action of individual electrons on the distribution of the remaining electrons in the conduction band is investigated by means of extended thomas fermi statistics and the effect on the magnitude of the work function is calculated in alkali metals the work function is determined largely by this polarization effect image force and only l slightly by the electrostatic double layer at the metal boundary 6116 fluctuation magnetic after effect thesis based on neels theory on the irreversible after effect in ferromagnetic materials which is identified with the residual loss earlier reports of the work were noted in of and of in which it should have been stated that the square root of the remanent magnetization is proportional to the logarithm of time elapsed from the suppression of the field and to the logarithm of the duration of application 6117 self consistent electrodynamics the idea of direct action between streams is applied to a continuous charged fluid and com ined with the new formulation of the electrodynamical laws of motion in terms of conservation of circulation a simple and rigorous integrated formulation is thus obtained from the maxwell lorentz differential equations applicable to co existing positive and negative fluids as well as vacuum exact solutions are obtained among them one which represents self consistent self maintained flow in a hollow tubular region of infinite axial extent it is hoped this tube might be bent into a torus and that an electron model will result from merely quantizing the one or two vortices around which this flow pattern circulates 6118 on the current induced in a conducting ribbon by a current filament parallel to it 6119 on a complete theory of diffraction of electric waves by a perfect conducting wedge continuation of work abstracted in of the analysis is revised and completed and errata are corrected 6120 diffraction of electromagnetic waves by an aperture in a large screen bekefis approximate formula is derived simply by another method 6121 one to two millimeter wave spectroscopy part experimental methods and results for ocs chf and ho continuation of work reported previously of multiplier and detector performance were greatly improved by using crystals small compared to the wavelength to be detected a new tuning technique based on known absorption lines was developed measurements made included that of a new water vapour line at 6122 a dc comparison radiometer 6123 revised data for the mean sunspot curve when the data for the present nearly concluded year cycle are included with those for the seventeen preceding cycles the mean curve exhibits a slightly steeper rise and a slightly shallower fall thus increasing its asymmetry 6124 controls of geomagnetic activity by sunspots showed that a decrease of magnetic activity occurs when two sunspots or groups of sunspots are symmetrically located on the solar disk with respect to the solar equator on the basis of this work and that of denisse of it should be possible to forecast each year on an average about perturbed and quiet days 6125 identification of the most powerful discrete sources of radio emission of the galaxy with the residual of supernovae exploded in the last years 6126 experimental determination of the total intensity of the terrestrial magnetic field in the lower region of the upper atmosphere e layer fuller account of work described previously of march 6127 plasma theory of the ionosphere the basic equations for the dynamic and electrical behaviour of the ionosphere are derived from the theory of a theory of a neutral plasma and are used to investigate the problems of diffusion of the plasma at layer boundaries em damping of air movements and tidal oscillations of the ionosphere 6128 electron density in the upper atmosphere and interpretation of the curves of ionosphere virtual height part a calculation is made of the optical path of a wave reflected by a chapman layer with a semithickness where h is the scale height comparison of the results with those obtained previously indicates that the lower half of such a layer is closely approximated by a parabolic layer of semithickness the electron density distribution is investigated for regions of superposition of the f and true f layers taking recombination into account the linear superposition formula used previously is found to be inadequate and is replaced by the formula where n and n are the independent densities of the f and true f layers 6129 a tentative model of the equilibrium height distribution of nitric oxide in the high atmosphere and the resulting d layer two possible processes for the production of no are considered three body recombination with o and photodissociation of into n and no the distribution of known constituents of the atmosphere in the range is discussed and the no height distribution derived for the two possible production processes d layer ionization characteristics are satisfactorily explained assuming photoionization of no at and the electron distribution is derived both for the case of photo chemical equilibrium of no and for a nonequilibrium distribution under the conditions of complete mixing 6130 the determination of the electron density distribution of an ionosphere layer in the presence of an external magnetic field the electron density distribution is determined by finding the actual heights at which waves of various frequencies are reflected these true heights are obtained from experimental curves by obtaining the exact solution as a convergent series of integrals of the integral equation giving the group height as a function of frequency the errors arising in the numerical work are shown by applying the procedure to hf curves obtained theoretically from layers of known shape and such errors are seen to be small compared with those made through use of other procedures 6131 regularities in the f region of the ionosphere justification of the assumptions made in of february is presented 6132 correlation between variations of surface pressure and ionospheric parameters a statistical analysis was made of meteorological and ionospheric data obtained at calcutta during the period of correlation between variations of ionosphere parameters and of surface pressure was found at least for some months of the year the results are in agreement with those obtained in australia by martyn ad pulley previously proposed tentative explanations based on variations of ozone content or the effects of circulation in the troposphere are examined further data are required in order to assess their correctness 6133 recent advances in the study of ionospheric winds the radio fading method developed by mitra of and the meteor trail echo method developed by manning et al of for investigating ionospheric winds are briefly reviewed and results so far obtained are discussed 6134 the effect of sunrise on the reflection height of low frequency waves the observed sudden changes of phase and amplitude of waves transmitted over distances of are discussed in relation to the geometry of the system at the change over from night time to daytime reflection height and respectively the effect cannot be due to photoionization of atmospheric molecules but may be due to the removal of electrons from negative oxygen ions by visible and near infrared radiation calculations are presented giving support to this view the rate of fall of the reflection height is discussed 6135 measurement of the electrical conductivity in the upper air by radioseconde description of a measurement technique using the gerdien conductivity apparatus in conjunction with a valve electrometer and an af modulated m american type radiosonde 6136 generation of electricity in thunderstorms a general account of the origin and nature of lightning 6137 the higher order modes in the propagation of long electric waves in the earth air ionosphere system and two applications horizontal and vertical dipole 6138 the pulse transfer function and its application to sampling servo systems discussion on 6139 measuring the effectiveness of shielding materials a method developed at the us naval research laboratory is described only a small sample of the material under test eg wire mesh or conducting coating is needed the sample is inserted between two shield cans containing transmitting and receiving aerials respectively and the attenuation increase produced by the sample is observed the frequency range investigated is it may be s possible to extend the method to higher frequencies by using waveguide technique 6140 thyratron inverter description of a unit giving at from dc mains 6141 rectifier with smoothing capacitor and high vacuum valves or selenium rectifiers exact equations are derived for a p phase rectifier circuit with a capacitance connected across the load for practical use approximate formulae are derived and their application is illustrated by the design of a two phase rectifier for an output of 6142 silicon pn junction power rectifiers and lightning protectors a method of preparing large area junction diodes is indicated in which donor eg or acceptor eg b impurities are diffused into high purity single crystals of si at temperatures above low resistivity surface layers are produced facilitating the application of contacts electrical characteristics are presented of a power rectifier and a lightning protector prepared by this method 6143 a simple mains unit for highly constant alternating voltages and currents a unit giving a voltage continuously variable up to and currents up to is described the voltage varying not more than with mains voltage variations up to and mains frequency variations up to 6144 a new dc electronic voltage stabilizing circuit the detecting element across the supply consists of a negative resistance and a positive resistance nce element of equal numerical values in series by controlling the negative resistance complete compensation can be achieved a circuit built on a similar principle but using a different type of negative resistance element was described by patchett of a stabilizer with an output of is described in detail the output can be maintained constant to within for an input fluctuation of and a load variation of the circuit is suitable for voltages from upwards 6145 relay standardization summarized report of proceedings of symposium on em relays held at oklahoma in june military applications were the main consideration 6146 recent patents on electrical accumulators review of developments for previous review see of 6147 arrangement of batteries and relays permitting the solution by analogy of nonlinear partial differential equations by means of a chain of resistances and capacitances 6148 scale factors for analog computers description of a design technique whereby scale factors relating analogue variables to the variables of the system investigated are first determined for true time operation 6149 a time sharing analog multiplier the circuit is based on the same principle as that of broomall and riebman of accuracy to within is achieved for a range of input voltages from to when the comparator voltage lies between and depending on the circuit arrangements multiplications per second were made indicating the suitability of the circuit for time sharing techniques but higher rates of operation seem possible 6150 system organization of the dyseac dyseac is a general purpose high speed digital computer incorporating the following special facilities external transfer operations concurrent with internal computing such transfers referring directly to any area of the internal storage system adjustment of speed of internal programme so that it proceeds in step with the external programme interruption of a programme for interpolation of new orders 6151 a simple analogue divider a circuit is described which provides an output voltage proportional to the ratio between two input voltages a pulse of duration inversely proportional to one input being used to gate the other input the results are accurate to within over a wide range of inputs an operational digital feedback divider in this divider the input pulses operate directly on the output the circuit forming a closed feedback loop in which the desired quotient corresponds to the only possible steady state the accuracy of the system can be selected by using the approprate number of significant digits from the eleven available new high frequency proximity effect formula 6152 an rms sensitive phase shifting circuit a circuit delivering an output whose phase depends on the rms value of the input uses a tungsten filament diode as rms current detector the diode is operated with voltage on the anode n and a voltage derived from the ac component of anode current is added to a fixed voltage to give the resultant variable phase output applications for control purposes are mentioned 6153 a double base diode a semiconductor thyratron analog 6154 a nomograph to facilitate the design of single layer resistance windings 6155 how to use thermistors review of thermistor characteristics and applications with tabulated data for rod disk washer and bead types 6156 current noise in composition resistors because of the inherent inhomogeneity of the resistor material and because the noise depends on the square of the current density modification of the resistor structure at a few points of high current density can have a large effect on the noise without greatly affecting the dc resistance experimental evidence in support of this view is given the effect may account for the observed lack of correlation between noise and dc resistance with large currents measurements made on resistors of the same rating but different types indicate a relation between noise coefficient and shape factor 6157 a new high speed bistable device for pulse sharpening description of a triode hexode flip flop circuit of generating pulses sec and its application in switching and scaling circuits 6158 rlc canonic forms a class of rlc networks is defined which has canonic structure in the foster sense lc and rl rc network and networks with slight dissipation may belong to this class in which case their analysis or synthesis is simplified examples of network synthesis illustrate the method 6159 bounds existing on the time and frequency responses of various types of networks six theorems are presented relating the transient and steady state responses of linear stable fixed lumped constant networks fourier transform analysis is used physical interpretations are discussed rise times and settling times being considered the overshoot or undershoot of the response to a step current input for a rc driving point impedance cannot be 6160 corner plots an approximation to the shape of the actual response curve for rl and rc circuits is obtained by suitable combinations of straight lines called corner plots the parameters involved are defined and rules for their determination by inspection of the circuit derived the method is not restricted to impedances but may also be applied to network transfer functions and is discussed in bodes network analysis and feedback amplifier design chapter 6161 matrix analysis of multiterminal transducers the multiterminal transducer is defined as a network with a set of n input terminals and a set of n output terminals it can be represented by its impedance admittance or transfer matrix special properties of networks exhibiting symmetry and or reciprocity are discussed the representation is classed as definite or indefinite according as the voltage reference terminals are or are not specified simple networks can be analysed by inspection more complicated networks may be treated as cascades of simple ones the method is illustrated by deriving the transfer matrices of some simple networks including a distributed amplifier section 6162 natural vibrations of a open cavity the field is expressed in a manner taking account of a set of oscillation modes associated with the cavity openings 6163 cavity resonator design charts charts applicable to square section and to circular section cavities are given 6164 a generalization of weissflochs transformation law the transformation law relating to a loss free quadripole between homogeneous lines is generalized by showing that all points on the transformation curve can be correlated with corresponding positions on the input and output lines between which the quadripole acts as an ideal transformer with a reactance in parallel see also of 6165 transient response in fm the fm response to the unit impulse and the unit step function is calculated for a network whose transfer function is known a meaning is assigned to the associated fourier integrals which diverge in the riemann sense the methos is generalized to any input function which vanishes for negative as an illustration of the method the impulse and the step fm responses of a single tuned circuit are calculated 6166 filter using coaxial transmission line as elements exact equivalent circuits are presented for coaxial line elements with sleeve or undercut sections taking account of capacitance or inductance effects at the discontinuities from the corresponding equations the performance of filters comprising one or more of such elements can be pred in terms of image impedance cut off frequency attenuation and band limits measurements on a tvariable usw filters results of an investigation of filters with distributed circuit elements and their equivalents with lumped lcr indicate the circuits suitable for usw use the filters described which consist of adjustabl cavity resonators and short lines include separating filters for metre ba d television and an adjacent channel suppressor for transmitters and transmitter receivers 6167 notes on a cause of frequency instability of partially plated piezoelectric crystals proximity effect external field conditions may have a marked effect on the resonance frequency of partially plated crystals movement of an object close to the resonator may produce a relative frequency shift of the order of or even as an extreme example a shift of about was produced by hand effect in a at cut crystal of diameter mm and electrode diameter the equivalent resistance simultaneously increasing by a quantitative explanation of the effect is given by reference to equivalent circuits 6168 the fluctuating character of the establishment of oscillations in an oscillator the build up of oscillations in a lcr oscillator by white noise potential fluctuations is considered theoretically 6169 a wide band oscillator using a conical helix tuning inductor description of an oscillator working over a frequency range of and using a single tank circuit between the grid and the anode of a triode the tuning circuit consists of a variable inductor formed by two conical helices connected at their apices by a large capacitor and two variable cylindrical capacitors for the high frequency end the leads connecting the coils to the grid and the anode are used as transmission lines the main tuning circuit being automatically isolated methods of calculating the oscillation frequency in terms of the circuit parameters are described simplifying assumptions being mace a description is given of the design and performance of an experimental model for the range mcs 6170 internal oscillations and microwaves in transistors 6171 transistor convert sine waves to pulses a circuit using eight point contact transistors to amplify limit and differentiate a sine wave input is described the power supply unit uses junction diodes the frequency range is minimum input is pulse output maximum pulse rise time pulse width adjustable from to and output impedance of 6172 a mains supplied indicating dc amplifier with linear response a stage unit for use in conjunction with a piezoelectric transducer and a duddell oscillograph for obtaining indicator diagrams is described an electrometer valve is used as input to a first preamplifier stage from which cable connection is made to the remaining amplifier stages and the oscillograph amplifier stability is good and effects of valve aging not apparent 6173 some circuit considerations of the transistor a detailed discussion of the single stage transistor amplifier and in particular of the unity coupler condition stability criteria are also discussed since four useful varieties of a single stage amplifier exist a two stage amplifier can take different forms these are divided into four groups high power gain low terminating resistance high terminating resistance and bilateral type the latter is an emitter base base emitter circuit and is suitable for obtaining high gains 6174 a triode fm discriminator the triode is arranged to operate as a gated rectifier with the gating time and hence the rectified output dependent on the input frequency a sine wave with the straight portion extending over about one radian can be used for the input waveform for a particular circuit in which the rectified output should theoretically change by about for a frequency change for this frequency difference was about the output is proportional to input amplitude as well as to frequency 6175 minimizing contact potential in apparatus design consideration is given particularly to the design of radio equipment required to function under adverse conditions such as exposure to humid or salt laden atmosphere a table reproduced from the inter services document rcs gives the potentials of various metals in sea water against the saturated calomel electrode as a guide to the choice of metal coatings the latter may be applied by electroplating spraying or hot dippling 6176 single operated tone compensation a triode valve is used as variable element of a circuit which boosts amplifier response at both ends of the af range to compensate for the reduced response of the ear the amount of boost thus varies automatically with the input level 6177 on diffraction by a strip limitations of the integral equation and fourier lame methods of dealing with the problem of diffraction by a strip or slit are discussed the variational technique of levine and schwinger of can b used to obtain an approximate value of the far zone field in a form which is stationary with respect to small variations about is true value of the current induced in the strip a calculation using this representation and assuming as a rough approximation as a rough approximation a uniform density distribution of current in the strip gives a good approximation to the value of the far zone field the scattering cross section is then found by using the scattering theorem of papas 6178 diffraction of electromagnetic waves radiated from an arbitrarily oriented electric or magnetic dipole at an ideally conducting half plane the solving of this problem is simplified by writing maxwells equations in a general form so as to include the case of a conducting medium with a finite permeability and by including a magnetic current for reasons of symmetry the equation is solved for different boundary conditions of p in particular cases p represents components of the electric or magnetic fields or vector potentials or vector potentials t is a function of position which is zero except in a small volume element surrounding the dipole and with the usual notation for the dielectric constant angular frequency electrical conductivity permeability velocity of light and to the solutions for various orientations of the dipole are given in the form of definite single integrals which can be evaluated 6179 energy loss of electrons in passage through thin films energy loss values of electrons passing through thin evaporated films of metals and insulators are tabulated reasonable agreement with calculations of pines and bohm of april and pine of may is shown 6180 the field e and the induction d of a point electric charge in space 6181 solid state electronics a general account of the mechanism of electronic conduction in solids 6182 notes on the comparison between the study of an imperfect contact and experimental results on thin metal films continuation of investigation of the conduction mechanism in thin films of nifontoff and perrot 6183 electron ejection by slow positive ions incident on flashed and gas covered metallic surfaces 6184 liberation of electrons by positive ion impact on the cathode of a pulsed townsend discharge tube of 6185 ionization processes in the electrical breakdown of gases a brief review 6186 diffusion cooling o electrons in ionized gases measurements made during low pressure ne and ar afterglows show a reduction in ambipolar diffusion coefficient characteristic of diffusion cooling which is not observed when he is present 6187 the mechanism of secondary electron emission a simple theory based on the constant energy loss per unit path length of primary electrons accounts quantitatively for the variation of secondary electron yield below its maximum value the theory can be extended to include a bethe type energy loss at high primary energies relations between secondary electron emission and atomic structure are discussed secondary emission in insulators and semiconductors is also considered 6188 explanation of the inaccuracy of secondary electron measurements a recording arrangement used for the measurements is described a variation of the secondary electron ratio with beam density was observed in several metals this variation is probably due to the formation of positive ions at the target when this is taken into account the secondary electron velocity distribution is found to b independent of temperature in the range contrary to several other published results 6189 threshold of secondary electron emission of nickel and molybdenum the threshold is defined as the minimum energy of primary electrons for which the number of slow secondary electrons differ from zero experimental results show that it is equal to the work function within the limits of experimental error the velocity distribution of secondary electron including reflected electrons at various primary electron energies and the effect of pe treatment of mo by heating at for a period up to days are discussed and the experimental results shown graphically 6190 effective depth of secondary electron emission an experimental investigation is reported the principal conclusions are tht the effective depth of secondary electron emission is smaller in metals than in semiconductors that it is independent of the primary electron energy and that there is no direct relation between the secondary emission efficiency and the emission depth 6191 theory of plasmas in the presence of a constant magnetic field of arbitrary intensity superimposed on an oscillating electric field generalization of results obtained previously of july and back reference 6192 pressure effects of ionic currents in atmospheric air with various discharge configurations the mechanical pressures produced by steady and modulated ion currents were investigated theoretically for parallel plate concentric sphere and concentric cylinder electrode systems and experimentally for a point and plate system the agreement between theoretical and experimental results is good the investigation is of interest in relation to the ionic loudspeaker 6193 a refinement of the pauling theory of ferromagnetism the theory formulated by pauling of is modified to take into account the nonuniform electron density in ferromagnetic crystals 6194 electrodynamics without potentials by means of a more general approach based on the em field and not potential field equations of a general type are derived these contain the equations of diracs new theory of electrodynamics of as an important special case 6195 maxwells tensor without modifying the classical em field equations it is possible to replace maxwells tensor by another which gives the same expression for the lorentz force but a different and in some ways more satisfactory expression for the distribution of energy in the field 6196 self excitation of oscillations in a gas discharge at high pressures the interaction of sound and electron waves in a gas discharge plasma at pressures hg is considered theoretically the possibility is shown of self excitation of a definite range of frequencies see also of for work at mm hg 6197 group velocity continuation of previous work of theory applicable to the ionosphere and to waveguides is given 6198 the excitation of plasma oscillations a beam of high energy electrons injected into the plasma of a dc discharge from an auxiliary electron gun excited oscillations in the plasma the standing wave patterns set up for varying values of electron beam density and thickness of the ion space charge sheath being investigated by a movable probe discontinuous changes in oscillation frequency occurred as either the electron density or the sheath thickness was varied but the frequencies were in accordance with the tonks langmuir relation and wehners transit time relation of in both cases the results confirm that the mechanism of energy transfer involved is a vm process as suggested by wehner and indicate that the oscillation is a longitudinal pressure wave set up in the plasma electrons 6199 zeeman effect and line breadth studies of the microwave lines of oxygen experiments with applied fields gauss gave results in accordance with weak field zeeman theory the two important mechanisms involved are rotational resonance interaction and quadrupole quadrupole interaction 6200 absorption of uhg radio waves in the range by substituted benzenes part measurements have been made on chlorobenzene bromobenzene o xylene and m xylene at room and lower temperatures the positions of absorption peaks are reported 6201 relations between magneto optical phenomena in the visible and radio regions of the spectrum 6202 the distribution of temperature along a thin rod electrically heated in vacuo part theoretical an integral expression derived for the temperature distribution can be expanded as a convergent power series for evaluation two regions are defined region a in the middle of the rod and region b the portions outside a in the a region temperature distribution is parabolic in the b region it is practically the same as in the corresponding end region of an infinitely long rod an analytical expression is obtained for the temperat ure at the centre of a rod as a function of its length for a summary of the analysis see 6203 antenna and receiver measurements by solar and cosmic noise the sun and various intense cosmic sources of rf radiation which have been previously measured are used as calibration sources for determining aerial patterns and receiver sensitivities for radio astronomy investigations practical procedure is outlined inaccuracies are involved in evaluating background radiation contours and solar energy distribution but the technique is sufficiently accurate for checking field instruments 6204 radio evidence of the ejection of very fast particles from the sun dynamic spectra of type rf bursts fast frequency drift duration sec are discussed the observations were made using a spectroscope with a frequency range harmonic pairs are commonly observed as in the case of the longer duration type bursts previously studied of february wild et al from a comparison of the profiles for the fundamental and the second harmonic it appear that a low frequency cut off process occurs in this case also the observed properties of type bursts can be accounted for by associating the frequency drift with motion of a disturbance such as a corpuscular stream travelling outwards through the solar atmosphere several possible mechanisms are considered 6205 washington conference on radio astronomy the aim of the conference was to present a comprehensive survey of the present state of work in the field to examine some of the most critical problems and to indicate possible future lines of research summaries of some of the papers are given for a short report see science 6206 generation of radio noise by cosmic sources critical comment on of january and authors reply 6207 on the nature of the discrete radio sources investigation of results of measurements of radio noise from a source in cassiopeia shows that the noise may be due to interaction of cosmic ray electrons with the local magnetic field if the average value of the latter is of the oder of gauss the rf power received shoul then vary at leastas rapidly as below a critical frequency in the range 6208 effective radio ground conductivity measurements in the united states the results of ground conductivity determinations made at broadcasting stations at frequencies between and are presented in a series of maps more than radials being shown the degree of correlation between the effective conductivity and the nture of the surface soil is insufficient for purposes of prediction 6209 electron inertia and terrestrial magnetism analysis shows that electron inertia effects make no appreciable contribution to the geomagnetic field 6210 the areal distribution of geomagnetic activity as an aeromagnetic survey problem near the auroral zone 6211 on the dynamo theory of geomagnetic field variations chapmans expression for the current function is solved in the most general way assuming that the main component in atmospheric oscillation is semidiurnal and using th same conductivity function as chapman tables of coefficients of the current function and numerical equinoctial values of th coefficients deduced by the authors and by chapman are given the sq variations of h and v are deduced and compared with the results of observations at abinger and alibag and with chapmans analysis in these calculations the phase of the atmospheric oscillations has been taken as and results compare well with observations 6212 the lunar diurnal variations of the earths magnetic field for all elements at amberley nz based on five years observations 6213 very long sequences of geomagnetic activity and its annual variation a study was made of the recurrence tendency of geomagnetic activity for the period to two long sequences of storms were identified mainly associated with solar m regions the mean recurrence period for each of the sequences was days characteristic annual variation is attributed to the approach of the earths projection on the solar disk towards the zones of maximum solar activity 6214 magnetic storms aurorae ionosphere and zodiacal light general account of observed phenomena and review of theories which have been advanced in attempts to explain them 6215 study of atmospheric ions in a nonequilibrium system the variation with time of the concentration of small ions in the atmosphere in a nonequilibrium system has been determined theoretically and in two sets of experiments if the atmosphere is relatively unpolluted equilibrium conditions may not be restored after disturbance until a time of about minutes has elapsed 6216 the dissociation of oxygen in the high atmosphere the transition region is investigated using recent data on atmospheric transmission of solar radiation in the spectral region of the schumann runge continuum of o observational data can be represented by a complete mixing of the atmosphere which causes the vertical distribution of molecular oxygen to follow atmospheric scale height mixing and diffusing processes are responsible for a shift in the transition region to lower heights than given by photochemical equilibrium considerations thus the transition region must be associated with the mesopause airglow formation of ionosphere regions and dissociation of nitrogen are briefly discussed in the light of this theory 6217 motion of the storm d regions results of an analysis at the national bureau of standards of ionosphere data from stations for the four years do not support piggotts hypothesis of coherent motion of storm d regions of 6218 propagation of a plane aerodynamic wave of semidiurnal oscillation period through a plane ionosphere in a uniform magnetic field analysis is based on the momentum equation for the gas and the tensor equation of electric conduction derived earlier of july frequency and wave length correspond to the atmospheric oscillations caused by tidal effects of the sun and the moon the solution indicates that em damping of the atmospheric oscillations will occur at height the electrical conductivity in a horizontal and in a vertical magnetic field is expressed as a function of the neutral gas density 6219 dynamo theory of geomagnetic tides plasma theory and results of earlier analysis of july are applied in deriving a differential equation expressing height integrated ionospheric current as a function of latitude taking account of coriolis forces and assuming a velocity amplitude of for tidal oscillations at e layer height the calculated magnitude of geomagnetic tides is in agreement with recorded data in particular as regards the large tidal amplitudes at the magnetic equator the theory is consistent with the assumption that the negative particles in the e layer are predominantly electrons rather than ions 6220 ionospheric wind analysis by meteoric echo techniques the procedure for finding vector average wind of is shown to be unaffected by the presence of turbulent wind components expressions are derived for the rms values of the horizontal and vertical wind components sources of errors are discussed in detail 6221 winds in the upper atmosphere deduced from the dynamo theory of geomagnetic disturbance simple dynamo theory of winds moving along and perpendicular to the geomagnetic field is developed and various wind systems are discussed which might account for certain phases of magnetic storms a possible wind system for the main phase of a magnetic storm shows some measure of agreement with diurnal atmospheric motions deduced from radio star scintillations and auroral motions the role of such wind systems in modifying the effective transverse conductivity of the ionosphere is uncertain both the flux of x rays producing ionization and the dynamo airflow in the e region are apparently the same on days of magnetic storms as on days prior to them 6222 correlation of magnetic auroral and ionospheric variations at saskatoon part the relations between magnetic auroral and ionospheric observations are summarized with reference to the occurrence of positive and negative magnetic bays auroral light associated with positive bays occurs at a higher geomagnetic latitude than that associated with negative bays the magnetic and auroral light variations are compared to martyns theory of the aurora if the latter is accepted the conclusion is reached that most aurora is caused by positively charged particles and that the conditions described for the early phase actually exist throughout most of a disturbance part of june 6223 some results of sweep frequency investigation in the low frequency band frequency sweep measurements in the range are reported day time records show traces of three strata whose virtual heights are between and of which the lowest not always observed produces only a week echo and one sometimes suggesting that scattering is taking place at randomly located clouds night time records show an intermediate layer between the e and f layers which is erratic in appearance but seems to have continuity with the daytime e layer during sunset traces characteristic of magneto ionic splitting are exhibited for this intermediate layer polarization and virtual height records for the f layer at night are shown z and the effects of moderate ionosphere disturbances are demonstrated 6224 influence of the ionosphere on the reception of galactic radiation of frequency analysis of continuous measurements recorded at marcoussis from to april indicates that galactic radiation at is attenuated by the ionosphere the effect being due partly to the f layer and partly to the d layer the results agree qualitatively with those obtained by mitra and shain of may using a frequency of 6225 errors inherent in the radar measurement of rainfall at attenuating wavelengths 6226 radar evidence of a generating level for snow 6227 atmospheric electricity and long distance very high frequency scatter transmissions 6228 the electrical conductivity of the atmosphere over the pacific ocean conductivity measurements were made at altitudes of and and between geomagnetic latitudes of and the rate of production of ion pairs computed from the measurements agrees well with that computed from cosmic ray data 6229 propagation of a pulse in a waveguide 6230 shielding nomograph 6231 thermoelectric generator description of a paraffin lamp driven generator for use with battery type receivers the outputs are for the vibrator ht unit and for heaters tapping is also provided as being more efficient than pure metal thermd semiconductor type thermoelements are mentiono couples 6232 solutions of boundary value problems on automatic computing equipment report of an investigation in which five types of digital computer and one differential analyser were compared as regards their suitability for solving boundary value problems 6233 a progressive code digital quantizer description of an analogue to digital converter which receives information from a graph reader and gives a corresponding numerical indication several circuits are shown based on the principle of comparing the analogue voltage with the sum of a finite geometric series 6234 the manchester university high speed digital computer 6235 a mercury delay line memory unit the storage unit in the csiro digital computer is described a method is discussed of interspacing the pulses of one loop between those of another loop thus doubling the storage capacity 6236 a review of magnetic and ferroelectric computing components high speed digital storage devices may be classified as delay line or random access types with subdivisions in each case for regenerative and nonregenerative devices the more important magnetic and ferroelectric storage units are critically discussed and possible future lines of development indicated references 6237 an arithmetic unit for automatic digital computers discussion of the requirements for th arithmetic unit of a computer with magnetic drum store with particular reference to the computer for the swiss federal institute of technology operation with fixed or floating decimal point is provided for 6238 magnetic switching circuits magnetic circuits to produce the logical operations of and and or are described which may be combined to produce any switching function of any number of input binary variables the only components used are magnetic cores wire and resistors there is no extremely sensitive parameter in these circuits which must be adjusted carefully in order to ensure proper operation 6239 a simplified solution and new application of an analyser of algebraic polynomials a description is given of an analyser circuit in which complex numbers are represented by sinusoidal voltages of frequency with amplitude corresponding to the modulus and phase corresponding to the argument of the number 6240 prevention of ionization in small power transformers the ionization onset voltage is raised for a given total thickness of insulation by inserting foils in the insulation so as to split it into n sections with of the total voltage across each section design details and test results for a typical transformer are given 6241 some characteristics and limitations of capacitor and resistor components six types of film dielectric capacitors are examined with respect to their performance specifications for a new and reliable type of metallized paper capacitor at the pilot plant development stage are given a satisfactory method for power rating of precision bobbin resistors is explained 6242 stressed ferrites having rectangular hysteresis loops to obtain the rectangular hysteresis loop required in ferrite cores used in switching and storage devices the cores are stressed by encasing them in plastics which shrink during polymerization 6243 temperature fields in electrical coils numerical solutions the computation of the steady temperature fields in coils by the relaxation method is described and illustrated 6244 saturable reactors with inductive dc load part transient response part 6245 a graphical method for flip flop design 6246 switching in bistable circuits all triggering processes seem capable of description in terms of a curve with a region of negative slope points on this curve representing unstable states while points on a s positive slope represent stable states a negative resistance circuit in which the voltage is a multiple valued function of current was constructed so that details of the triggering process could be observed on an oscilloscope screen by suitable periodic sampling a slow motion representation of the transition between two states is obtained 6247 an electronic random selector criteria for recognition of random series are stated and methods for producing such series are discussed a description is given of an arrangement in which pulses are applied to a circuit which is gated periodically any pulse passing tr through the gate triggers a multivibrator which is in turn coupled to a pair of mechanical registers two such circuits make up the complete selector enabling four mechanical registers to operate use of the selector in psychical research is mentioned 6248 the transient response of transistor switching circuits transient response of the point contact transistor in a grounded base circuit is considered using a linearized equivalent circuit the required trigger voltages for both directions of switching are found experimentally to be greater than suggested y the static characteristic and to depend on trigger pulse width to a different extent for the two directions to fit these findings it is assumed that cut off frequency is high when the transistor is switched off and low when it is switched on the one shot multivibrator is discussed in the light of these assumptions 6249 a cold cathode scaling unit the five decade scaler uses dekatrons interstage coupling being by cold cathode gas filled trigger triodes the resolving time is which makes it suitable for application in conjunction with counter tubes operation under varying climatic conditions has been satisfactory 6250 the effect of minor constituents in high dielectric constant titanate capacitors additives used to modify te dielectric properties of are classified into two groups those which alter the position of the curie peak and those which lower its height and are typical of the first group while and are typica of the second the effect of composition on nonlinearity and aging is discussed see also and of january 6251 breakdown and leakage resistance investigation of metallized paper capacitors the basis of comparison between conventional paper and metallized paper capacitors is discussed experiments on units with polyester impregnants suggest that if self healing is of primary importance a pure aliphatic hydrocarbon type of impregnant will give best results 6252 applications of integral equations to the solution of nonlinear electric circuit problems the technique described gives practical results in many cases where the approximate solution of the integral equation may be effected by means of laplace transforms 6253 junction transistor circuits application of the pnp junction type transistor in single stage and cascaded amplifiers and in lf and rf oscillators is described and illustrated by eight circuit diagrams the transistor collector characteristics and operating data and typical circuit component values are given 6254 spectrum or waveform equalization the method of equalization in which signals obtained by differentiation or integration are added to the main signal of is compared with the commoner method using filters empirical design is simpler with the former method but the need for additional amplification at high frequencies n is not avoided the different requirements of communication and servo systems are indicated 6255 new effect caused by gyromagnetic phenomena theory is given of a device similar to that described by kales et al 6256 effects of harmonics on the frequency of oscillation as well as on the asymmetry of the resonance curves the nonlinear equations representing the free and synchronized oscillations are transformed into linear equations with periodically varying coefficients and complete solutions are obtained the relation between frequency variation and harmonic content is derived experimental results supporting the theory are reported 6257 the first order behavior of separable oscillators analysis is given for oscillators whose linear and nonlinear elements are separable in the first order theoretical and experimental results indicate that apart from adjustments of the linear elements the major factor for obtaining frequency stability and smooth control is the suppression of the even power terms in the amplitude characteristic 6258 quantum theory of a damped electrical oscillator and noise part the radiation resistance the results obtained in part of are extended to include damping and noise due to a radiation resistance and expressions for the mean square noise voltage and available noise power are derived which are shown to be the sm same as those previously obtained they are also extended to apply to a single mode of a cavity resonator 6259 vacuum fluctuation noise the possibility of observing vacuum fluctuations by measuring the resultant electron stream noise when an electron stream interacts with a damped oscillator is discussed an electron stream i shown to provide a means of precise measurement of the mean square noise emf for certain modes the circuit must be at low temperature 6260 block diagram solutions for vacuum tube circuits 6261 millimeter waves from harmonic generators fundamental and harmonic powers obtainable at wave lengths down to using a si crystal frequency multiplier with different types of reflex klystron have been measured three types of multiplier are compared these are a commercial si crystal mounted upright on the exterior face of the harmonic waveguide a crystal with windows cut in the face so tht the tungsten whisker is exposed a whisker and si block mounted in the waveguide arrangement is the most satisfactory for wavelengths below mm the performance of arrangement as a detector is discussed a crystal harmonic generator used with a n narrow band amplifier will furnish enough power at mm wavelength to give a dynamic range of 6262 variable frequency crystal controlled receivers and generators 6263 a modified miller timebase circuit high linearity and rapid flyback are achieved by using a blocking oscillator to charge the feedback capacitor in the miller type circuit compensation is provided for variations in the blocking oscillator characteristics a unit giving sweep durations of with either triggered or continuous operation is described 6264 transient response of glow discharges with applications 6265 lf compensation for video amplifiers part amplifiers without feedback the departure from the ideal flat top response caused by low frequency distortion can be reduced by making the differential coefficients of the output function equal to zero at the order of compensation is designated by the number of derivatives equal to zero general theory is given and is applied to some typical resistance coupled amplifiers a single rc coupled stg stage can have second order compensation and multistage amplifiers can have higher orders of compensation experimental results confirm the analysis 6266 an electronic voltage integrator a feedback amplifier integrating circuit is described the amplifier comprises a cascode connected direct coupled circuit with filament drift compensation and internal positive feedback adjustment the integrator is used with a search coil for magnetic field measurements in the range gauss accuracy is within 6267 a high efficiency high quality audio frequency power amplifier the circuit uses a type valve as phase inverter amplifier driver stage direct coupled to two output beam tetrodes operating in class b push pull with db of feedback the output transformer has a bifilar wound primary and the feedback winding is electrostatically shielded from the secondary but very closely coupled to it full power output is at frequencies design of the circuits and performance details are described 6268 the cascode as a low noise audio amplifier 6269 the influence of magnetic amplifier circuitry upon the operating hysteresis loops an analysis limited to the steady state characteristics of single phase self saturated magnetic amplifiers only resistive loads are considered 6270 high speed magnetic amplifiers units based on ramseys half wave amplifier are discussed and the development of a new series of amplifiers is described the basic type is a reversing phase input reversing dc output amplifier circuit modifications are explained for obtaining reversing dc output fr reversing dc input and reversing phase ac or reversing polarity dc output other possible modifications are indicated 6271 theory of magnetic amplifiers with square loop core materials 6272 temperature stabilized transistor amplifiers design equations are derived and nomograms presented for determining the temperature variation of the operating point of a junction transistor amplifier application of the information for temperature stabilization is indicated numerical examples are given 6273 transistors in amplifier output stages the optimum effective load impedance and the efficiency are calculated using idealized characteristic curves the results for point contact and junction type transistors in class a and in class b pushpull amplifiers are compared with the corresponding formulae for triodes and pentodes distortion the efficiency limit and circuit design are also briefly considered 6274 proposal for a new aether drift experiment comment on furths proposal of june and suggestion for an alternative experimental procedure 6275 precision determination of the velocity of light derived from a band spectrum method part from measurements of the rotational constant for by the method f exact orders and by a microwave method the value of is 6276 further experiments on the thermodielectric effect costs ribeiro effect the experiments described establish that on solidification of liquid naphthalene negative charges are expelled from the solid into the liquid phase the resultant positive charge being distributed within the solidified e dielectric see also of 6277 further quantitative experiments on the costs ribeiro effect in an investigation of the thermodielectric effect above and back reference measurements were made of the charge within a solidified naphthalene dielectric by means of a faraday cage and electrometer the relation between the charge and the mass is constant for small crystals this specific residual charge is twice the induced charge per unit mass impurities after the value of considerably 6278 contact charging between a borosilicate glass and nickel contact charging of glass spheres rolling on clean ni was studied under conditions of controlled cleanliness humidity and gas pressure the effect of a transverse electric field is important only for high surface conductivity surface conductivity surface conduction limits the maximum charge which also varies with pressure due to gaseous discharge between the sphere and the metal 6279 a chemical approach to the treatment of electronic spin in semiconductors a method due to fowler in which the electrons and the neutral and ionized donors are treated as chemical entities affords a simple approach in the nondegenerate case the results obtained agree with those of landsberg of when the occurrence of neutral donors containing a unpaired and paired electrons is taken into account 6280 theory of the anomalous skin effect in a magnetic field extension of work by euter and sondheimer to take account of the effect of a steady magnetic field 6281 the effect of relaxation on microwave measurements of the anomalous skin effect the ratio of the conductivity to the mean free path of an electron in bi t microwave frequencies estimated on on the basis of dingles theory is compared with given earlier by pippard and chambers neglecting relaxation effects this discrepancy and the discrepancy for normal metals are discussed 6282 the anomalous skin effect and the reflectivity of metals expressions derived by reuter and sondheimer of are considerably simplified numerical results obtained include calculated values of surface resistance and reactance in the microwave region for both specular and diffuse electron reflection 6283 some aspects of breakdown streamers 6284 the electric strength of air in nonuniform fields at radio frequencies measurements were made of the breakdown potential of atmospheric air between a cylinder and an axial wire over the frequency range the breakdown voltage is about below the value at and decreases at the average rate of per as the frequency is raised above this point the results are explained by a modified townsend theory the discharge occurs during the part of the cycle when the wire is positive with respect to the cylinder 6285 the secondary electron resonance mechanism of low pressure high frequency gas breakdown breakdown field strengths were measured in air and h at frequencies from to between internal electrodes separated by cm by suddenly applying a high voltage and reducing it slowly an upper breakdown curve and cut off frequency dt together define a breakdown region the secondary electron resonance theories developed by danielsson and gill and von engel are extended 6286 dynamics of corona discharge between cylindrical electrodes the screening action of the space action of the space charge is responsible for the constancy and stability of the average discharge current fluctuations are explained as a response of the system having a definite resonance frequency to the statistical fluctuations of the photoelectric current theoretical predictions are confirmed by experiment 6287 the work function of irregular metal surfaces calculation of the image potential for spherical and spherical and prolate spheroidal bosses on an otherwise smooth surface h shows that this potential might be reduced to of its value for an ideal plane surface since the image potential is likely to form a large portion of the work function for most metals the work function will be significantly reduced when the surface is rough 6288 effect of the energy distribution of electrons on the average secondary emission yield of an insulator an expression for the average yield in terms of electron temperature is calculated for pyrex th electron energy distribution being maxwellian 6289 a model for collision processes in gases part small amplitude processes in charged and neutral one component systems 6290 electron ion recombination at low pressures experiments throwing light on the nature of the fundamental processes involved are discussed the molecular ion is thought to play a decisive part the evidence is consistent with the hypothesis of dissociative recombination 6291 the tensor formulation of ferromagnetic resonance 6292 twisted magnetic fields in conducting fluids the formation of loops in the lines of force of a twisted magnetic field confined within a cylinder of radius r is discussed by the method of normal modes the condition obtained for loop formation is that the pitch of the twisted field be less than r the velocity of alfven waves in this model is also discussed 6293 diffusion after effect in weak alternating fields validity of rayleighs law 6294 on the excitation of oscillations in a thermal plasma plasma oscillations are considered for an arbitrary distribution of electron beams the fundamental equations are derived assuming a weak signal and the absence of static fields the dispersion relation derived is applied to the case of excitation of thermal plasma by an injected electron beam and the rate of wave growth is determined the numerical results are compared with results obtained by merrill and webb june 6295 the vector wave function solution of the diffraction of electromagnetic waves by circular disks and apertures part the diffraction problems 6296 determination of by a new method the method involves the determination of the excitation potential of he from the ground state to the lowest permitted singlet level the value of obtained is sec 6297 temperature distribution in a electrically heated filament a practical general solution is given for a filament of finite length heated in vacuo 6298 physics and applications of secondary electron emission the book cover practically everything of importance and should serve as an admirable guide to workers in all branches of electronics 6299 relation between the appearance of the yellow coronal line and geomagnetic activity from observations of the yellow coronal line it is possible t identify thoe solar activity centres whose passage across the central meridian is accompanied by an increase of geomagnetic activity 6300 space charge wave amplification in a shock front and the fin structure of solar radio noise the dispersion equation corresponding to the non maxwellian velocity distribution of the particles in a shock front is derived the roots indicate frequency bandwidths of space charge wave amplification decreasing with the shock strength it is suggested in agreement with cenisse and rocard of that the storm bursts of narrow bandwidth originating in shock fronts constitute the elementary fine structure components of solar radio noise bursts 6301 thermal radio emission from the sun and the source of coronal heating a statistical analysis is made of data obtained from measurements of solar radiation at frequencies between and th total radiation is separated into a component associated with sunspots and a basic component showing no such connection results indicate that sunspot radiation and the very hot regions responsible for it diminish loss rapidly than the spot area and exist for a month or more after the spot has vanished the basic component at some frequencies is much lower than previously believed s regions above the sunspots are the source of coronal energy and gases spreading from them can completely replace the corona in about four days 6302 solar radio emissions at metres wavelength during inclusive and their relations to solar activity bursts at of duration min ad of intensity over a certain minimum are analysed for correlation with solar flares the medium lag of bursts behind associated flares is about a minute but the dispersion of the time differences is such that an appreciable proportion of the bursts precede the flares secondary controlling factors seem to exist both for the solar phenomena and the related ionospheric phenomena analysis of the distribution of bursts confirms that there is a greater chance of bursts in association with flares on the eastern half of the suns disk than on the western half 6303 observation of the partial solar eclipse february at the wavelength of centimeters the diameter of the sun observed at this wavelength is greater than that of the visual disk limb brightening is observed asymmetry in the eclipse curve is attributed to a local bright region round sunspots where the values of electron density in chromosphere and corona are enhanced 6304 the distribution of radiation across the solar disk at metre wavelengths measurements were made at wavelengths of and using variable aperture interferometers an phase switching receiver systems the size of the emitting disk increases with increasing wavelength experiments with interferometers inclined at various angles to the solar axis of rotation showed the radiating shape of thesun to be elliptical the radial distance at which the brightness temperature was reduced to half was about greater at the equator than in the polar direction 6305 distribution of radio frequency brightness across the solar disk and the derivation of a model corona the derivation of a model consistent with observations previously reported above is discussed 6306 solar radio asymmetry at metres wavelength the greater frequency of observation of solar bursts at in association with flares on the eastern half of the suns disk of may be due to absorption of bursts from the western half in ionized streams this would account for the lack of evidence of asymmetry at for which wavelength absorption is much less an analysis of this asymmetry with reference to geomagnetic activity is being made 6307 intensities of discrete radio sources in cygnus and cassiopeia at measured intensities are and for the sources in cassiopeia and cygnus respectively comparison with intensities measured previously at higher frequencies indicates that in the spectrum of the cassiopeia source intensity is proportional to frequency the variation in the cygnus source being similar except at lower frequencies where the rate of increase of intensity is reduced 6308 radio emission from the perseus cluster results of observations at using radio interferometer apertures of and provide confirmation for the identification of the radio source with ngc 6309 galactic radiation at radio frequencies part discrete sources with large angular widths observation with a reflector at a frequency of with the sea interferometer at and with the azimuth interferometer at revealed the existence of a number of sources of angular width the observations are described and discussed the limitations of interference techniques are summarized part 6310 galactic radiation at radio frequencies part discrete sources at between declinations and one hundred and four discrete sources have been found individual sources are compared in position and flux density with those of previous surveys the observed distribution of sources is discussed several identifications with visible sources are suggested 6311 a comparison of the intensities of cosmic noise observed at and at the principal conclusion of this comparison is that the background radiation cannot be made up of the radiation from sources of the type observed so far although a small polar component may be due to the extragalactic sources absorption in interstellar gas has a considerable effect on the intensity variations of background radiation with direction observed at 6312 observations of the general background and discrete sources of cosmic noise a survey of a broad strip of sky centred on declination has been made using an aerial with beam width to half power of previous results concerning the background distribution of brightness have been confirmed and discrete sources have been detected the distribution of these sources is shown no correlation was found between the occurrence of scintillations and published ionospheric data but the observations are consistent with an origin of scintillations in irregularities of dimensions about km at a height of about 6313 galactic radio sources of large angular diameter preliminary results are given of measurements of the apparent angular width of sources previously observed of may 6314 wide band radio interferometer the use of a wide band amplifier with the frequency characteristic given in conjunction with an aerial system consisting of two or four aerials in line or aerials arranged symmetrically in a square results in very high resolution in the example quoted radio sources separated by an angle of ca be resolved the theory of the interferometer is given and the general form of the directional characteristic is shown 6315 geomagnetic bay disturbances and their nonuniform induced components within the earth the bay disturbance is considered as the field of a travelling dipole in the auroral zone the direction of travel depending on time of day the induced component within the earth exhibits local variations depending on the conductivity a dynamic anomaly is observed in an area in central europe the vertical component being a maximum in the north and a minimum in the south when the ionosphere current is directed southward 6316 the use of earth potential measurements for magnetic and ionospheric storm indication using the underground telephone cable system potentials are measured in directions as nearly parallel and perpendicular to the magnetic meridian as possible each of the cable circuits is over long and is provided with several earthing points at the ends the recorders are housed in the control room of the ptt station radio kootwijk 6317 radio meteorology conference in texas 6318 a preliminary survey of tropospheric refractive index measurements for us interior and coastal regions results of some recordings made between july and december using airborne refractometers at heights up to are summarized the existence of large differences in refractive index near certain cloud boundaries is confirmed see also of june crain et al 6319 atmospheric space charge comment on of january and authors reply 6320 the evaluation of ionospheric observations a critical discussion of the various methods used in calculating the height distribution of the charge carrier concentration and other parameters from experimentally determined hf curves the corrections and the estimation of errors in the calculated f layer height in the presence of an e layer and the effect of neglecting the e layer in this calculation are discussed an approximate method is indicated for taking the geomagnetic field into account 6321 semidiurnal currents and electron drifts in the ionosphere correction to paper abstracted in 6322 a subsidiary layer in the e region of the ionosphere echoes from sporadic e can be distinguished from those from a layer at km height it is suggested that the ionization in this layer results from the impact of meteors on the atmosphere and that it may therefore be called the meteoric e layer the distinctive properties may be used to extend the use of the ionosphere for intermediate distance radio communication 6323 origin of the ionospheric e layer critical discussion of theories of formation based on ionization of o by ultraviolet light and ionization by solar soft x rays the intensity of incoming radiation seems insufficient in view of absorption in case but from elwerts computations sufficient in case provided dissociation of oc occurs in a high transition layer of considerable thickness both processes may be involved but process seems the more important 6324 multiple stratification of the f layer at ibadan observations made during the period december january are reported in the f layer there is a maximum occurrence of ridges around and hours the first maximum being the more pronounced a seasonal variation is found a maximum number of ridges around and hours the first maximum being the more pronounced a seasonal variation is found a maximum number of ridges being observed when the midday minimum of f occurs early in the day a lunar semidiurnal variation is detectable during the morning hours formation of ridges is also observed in the f layer but there is little relation to those of the flayer possible phases of vertical drift velocities that could explain the observations are discussed 6325 on the f layer distribution in polar region results of an analysis of monthly mean values of and for march are summarized in a region along the auroral zone where the values are anomalously high maxima occur at noon and midnight and the region rotates round the earth with the sun the increase of apparent height of the f layer is due to wave retardation in the f layer during daytime in high latitudes 6326 a theory of distribution and variation of the ionospheric f layers a brief description is first given on the results of our recent studies which have led to the conclusions of inhibition of vertical ionospheric current enhancement of conductivity dynamo current and vertical drift of charged particles near the geomagnetic equator and suppression of daytime electron density of f layer caused by an upward drift of electrons the treatment is extended to the case of ionospheric storm accompanied with geomagnetic storm the comparison of the theoretical and observational results is made for the cases of undisturbed as well as disturbed states of f layer the agreement is generally good for undisturbed case but not quite satisfactory for disturbed case the mechanism of dynamo in the ionosphere is discussed and a hypothetical consideration concerning a wing system during a storm is given 6327 lunar radio echoes and the faraday effect in the ionosphere 6328 the enhancement of ionospheric ionization during solar flares study of the recombination coefficient in the lower ionosphere based on the decay of sudden phase anomalies at and on sudden enhancements of atmospherics gives values much smaller than those reported by bates and seaton measurements of the delay between the time of maximum flare and the times of maxima of sudden phase anomalies and sudden enhancements of atmospherics also suggest smaller values these results indicate that for any height the value of the recombination coefficient remains unaltered during a sudden ionospheric disturbance and that the sudden increase in electron concentration is due to an increase in the rate of electron production in the layer 6329 corpuscular eclipse in the f layer and its association with solar flares and m regions a survey of present knowledge on solar sources of corpuscular streams and on corpuscular velocities the drop in the f layer ion density occurring approximately five hours before the maximum of the optical solar eclipse is briefly discussed and it is suggested that in future f layer observations should commence at least seven hours before the moment of totality 6330 high multiple radio reflections from the f layer of the ionosphere at brisbane 6331 the effect of rayleigh scattering and ground reflection upon the determination of the height of the night airglow 6332 servomechanism papers six papers presented at a convention held in san francisco august with editorial trends in feedback systems nonlinear control systems with random inputs a method of analysis and synthesis of closed loop servo systems containing small discontinuous nonlinearities stability of feedback systems using dual nyquist diagram optimum lead controller synthesis in feedback control systems on the comparison of linear and nonlinear servo mechanism response predictor servomechanisms 6333 the use of steel sheet for the construction of shielded rooms 6334 self heating triode for voltage stabilization 6335 sun powers telephone brief description of a battery comprising an array of si strips each about which when exposed to sunlight gives a current of at about 6336 a versatile electronic function generator two cypes of electronic circuit for performing any desired transformation on two arbitrary voltage waveforms are described the general characteristics and accuracy of such devices when used in repetitive differential analysers are discussed 6337 transistor shift registers three different types of high speed transistor shift registers are discussed the high speed is made possible by the use of nonsaturating bistable circuits two general shift registers r are described making use of respectively one n and two transistors per stage the third register is of a specialized variety capable of shifting a single digit in addition an analysis is made of the triggering requirements of the register using a single transistor per stage 6338 waveguide switching device using gas filled tubes an arrangement for switching a single receiver between two or more channels at a relatively high rate is described the switching operation is based on detuning an oscillatory circuit consisting of a waveguide section terminated with inductive diaphragms and having a gas discharge tube located midway between the ends the hf susceptance of the tube varies with its ionization state and the tube constitutes an element of a bandpass filter analysis is given for the pass band the switching rate the electrical inertia and the noise and insertion loss due to the device results obtained with a four channel system are in good agreement with theory 6339 component design trends fixed capacitors undergo miniaturization first paper of a series describing recent developments problems involved in operating at the high temperatures resulting from reduction of the heat dissipating surface are discussed 6340 some techniques for network synthesis the synthesis of immittances with two poles and two zeros is discussed cauers continued fraction technique is generalized for use in realizing rlc network immittances design procedure is developed for a constant resistance ladder this nt network is shown to have the same field of application as the conventional rlc constant resistance bridge t but has the advantages of greater flexibility and less complexity complicated transfer functions may be realized in a chain of ladder sections having arm immittances with only two poles and two zeros 6341 analysis of network response to periodic waves the steady state response of a network to a nonsinusoidal periodic wave may be found by applying the operational calculus method of waidelich of in a simplified form the method can be used for any linear network comprising a finite number of lumped elements a set of rules for obtaining the required inverse transforms together with a table of inverse transforms for square wave inputs is pe presented and explained 6342 feedback in junction transistor circuits series and parallel feedback circuits for a single stage are reduced to a four parameter equivalent circuit for analysis cascaded transistor stages reduced in a similar manner result in either mesh or nodal derived equivalent circuits 6343 q as a mathematical parameters a definition applicable to rc networks and other systems having lumped parameters an and appropriate in cases where the q value is of the order of or less gives q in terms of circuit time constant and the differential operator 6344 ire standards on audio techniques definitions of terms 6345 thermodynamical consideration of equilibrium electrical fluctuations expressions are derived for the mean energy of electrical fluctuations in an lcr circuit maintained at a given temperature and for the spectral density of the fluctuation emf similar expressions published earlier by gorelik and ginzburg are discussed 6346 two network theorems concerning change of voltage reference terminal the first theorem describes the change in the admittance matrix corresponding to the change of the voltage reference terminal ground terminal the second theorem shows that the determinant of the d admittance matrix is invariant under such transformations 6347 the application of some semiconductors as logarithmic elements voltage dividers incorporating rectifiers to give special characteristics were described by kallmann of for circuits involving high resistances rectifiers made from other semiconductors may be more suitable logarithmic characteristics obtained using various semiconductor rectifiers are presented temperature compensation is achieved by use of negative temperature coefficient resistors the logarithmic response has been obtained at frequencies up to 6348 practical low pass and band pass minimum phase networks with equalized delay and a period transient response a minimum phase shift network with constant delay characteristic is a practical approximation to an idealized low pass filter since its attenuation characteristic in the pass band has a similar shape conditions for delay equalization are investigated for a unit step input in terms of the positions of the zeros and poles of the response function a general method of calculation for filter networks of this type is given the attenuation and group delay characteristics in a simple case are compared with those of an equivalent filter based on image parameter theory 6349 audio frequency filter with continuously adjustable attenuation characteristic a composite filter for the frequency band is described comprising two sets each of separately controllable filters with contiguous narrow frequency bands the controls are arranged so that the positions of the individual knobs give an approximate representation of the overall frequency characteristic the device is useful for investigating correcting networks and for producing special effects in broadcasting 6350 synthesis of constant time delay networks the synthesis of low pass filters to have a symmetrical transient response such as is desirable in television receivers is investigated the desired frequency response is expanded in a fourier series circuit elements corresponding to the terms of the series are constituted by sections of delay lines which are appropriately combined to give the desired overall response low pass band pass and band stop filters are considered results obtained with experimental filters are discussed 6351 punched card calculating machines as aids in the calculation of filters the use of commercial type punched card calculators for solving numerical problems involved in insertion loss filter theory is discussed and illustrated 6352 comb filters for pulsed radar use the use of comb filters for improving signal noise ratio is discussed in relation to the variation of the frequency spectrum of a radar signal with the number of pulses in the received trains the relative merits of the simple uniform type the rectangular sin type and the north type sin matched filters are compared the small gain in sensitivity obtained with type does not warrant the greater complexity of its design 6353 gain stable mixers and amplifiers with current feedback narrow band radio frequency amplifiers and mixers may be stabilized by negative feedback without increasing the bandwidth excessively a couple using current feedback is described this couple requires only a simple resistive beta circuit and may be designed such that the band pass characteristic is largely independent of the feedback experimental results are reported 6354 van der pols equation an analytic method f of solving the equation is described in which the unknown functions and of the assumed solution a sin are found by substituting the assumed solution into the integro differential form of the origin the ionic oscillator a stable device capable of delivery high output at af or rf comprises a simple gas filled valve circuit without external or internal resonators anode voltage equal for the normal ionization voltage is applied am and fm arrangements are indicated the upper frequency limit is 6355 a reactance tube controlled oscillator of unusually wide frequency sweep circuits permitting frequency seeps up to are described one for operation above and the other below 6356 quartz generators with negative feedback and an inertial nonlinearity theory is developed on lines similar to that presented by post and pit of results show that the best position for the amplitude limiting element is in a separate negative feedback circuit of the amplifier part of thetends to reduce the frequency and phase stability of the oscillator at frequencies of a few tens of kilocycles stable amplification of the order of can be obtained using a three stage amplifier with phase correction circuits stable amplification at very high and at very low frequencies is also mentioned 6357 generalized equations for rc phase shift oscillators general solutions are obtained for three and four section phase shift networks these solutions are reduced to design equations for a number of specific circuit configurations and the complete solution is given for a four section phase shift oscillator 6358 oscillator feedback networks of minimum attenuation single valve oscillators with feedback networks comprising three resistors and three capacitors are discussed optimum values for the components are determined by analysis and are plotted as functions of valve output resistance for a given value of valve input resistance both shunt r and shunt c networks are considered the former being recommended for very low frequencies and the latter for relatively high ones 6359 classification of quartz crystal oscillator circuits classification is based on quadripole representation ad two main classes are distinguished according as the circuit is represented by one or two quadripoles in the feedback line the first class includes type networks subdivided into series resonance and parallel resonance circuits and bridge type circuits variations of the a basic circuits are illustrated and formulae are derived for the properties and operating conditions the main characteristics considered are stabilization factors see of excitation conditions operating frequency and crystal loading 6360 an amplitude stabilized transistor oscillator correction to paper abstracted in 6361 effect of steepness of rise and fall of the input pulse on the response of pulse amplifiers part expressions are derived for the response of rc coupled amplifiers to input pulses of ramp form and of triangular form 6362 some experiments with miniature power triodes description including complete circuit diagrams and discussion of performance of two af amplifiers with an output of about one of which uses valves in push pull and the other four valves in parallel in a single ended output using unselected components the latter amplifier gave a more satisfactory performance 6363 selective special amplifier for a frequency of the design is discussed of a four stage amplifier for use with a capacitor pick up capacitance due to variation of external gas pressure are in the amplification is sufficient to give an output galvanometer reading for an input of across a resistance 6364 distributed amplifier for nuclear research details including component values are given of a four stage amplifier with input and output impedances of gain is over a bandwidth of pulses with rise times as short as sec are satisfactorily reproduced linearity is good up to output 6365 lf compensation for video amplifiers part negative feedback amplifiers the method outlined in part of august is applied to negative feedback amplifiers if is independent of frequency the overall response is optimum when the indicial response of the path is optimum and the order of compensation is the same if is made frequency dependent by including a capacitor in the feedback path compensation can be obtained which s one order higher than that obtainable from the path alone the method is applied to some simple circuits including cases where a coupling or a decoupling circuit is outside the feedback loop experimental results confirming the theory are reported 6366 study of noise reduction by feedback in ultra high frequency amplifiers a detailed investigation has been made to determine theoretical and practical limits for the cancellation of valve noise in rf amplifiers measurements were made on a modified planar type of disk seal triode designed to have a transit phase angle of about one radian at mcs the conditions for complete noise cancellation are determined and expressions are derived for input and output admittance available power gain and noise figure can be reduced considerably by means of feedback but w is thereby reduced at an equivalent or greater rate so that the practical application of this method is uneconomical with present valves the uncorrelated part of the induced grid noise is the most important factor in the increase in f at vhf 6367 single core magnetic amplifier analysis 6368 dissected amplifiers using negative resistance possible circuit arrangements of semiconductor devices to give hf amplification are discussed based on segregation of the amplifier properties of negative resistance and directionality an arrangement of a hexagonal ge plate with magnetic field perpendicular to its plane and with an appropriate network of resistances corresponds to a pentode amplifier 6369 transistor application fundamentals a comparison is made of valve and transistor characteristics in relation to a f amplifier circuits the design of a gramophone pickup amplifier using the twin triode and ge fused junction transistors is described circuit diagrams characteristic curves and relevant formulae are given 6370 resonant dielectric amplifier frequency response discussion of an amplifier of the type in which the capacitance of a nonlinear capacitor excited to resonance by a carrier wave is modulated by a carrier wave is modulated by a signal voltage and an amplified output is obtained by subsequent demodulation with a carrier circuit q value of the carrier frequency must be of the order of the response to be flat up to signal frequencies of 6371 detection of a radio wave by a ferrite a magneto strictive ferrite rod of mm square cross section and length mm was exposed to a uhf field pulsed at the third harmonic of the frequency of mechanical resonance of the rod the signal was detected by means of a tuned coil located at a mechanical node the detection process involves rectification of the uhf oscillation as a result of the variation of ferrite permeability with applied field and conversion of the rectified signal into a magnetostrictive vibration detectors of this type may be useful at wavelengths of cm 6372 characteristics of ultrasonic delay lines using quartz and barium titanate ceramic transducers equivalent circuit based analysis developed previously of fagen is extended to deal with metal delay media and with as well as quartz transducers calculations are made of the decrease in loss due to a decrease in the impedance of the delay medium and of the increase in bandwidth due to an increase in its impedance 6373 simplifying fabrication of printed circuits use of nitric acid in a stencil etch process reduces production time greatly 6374 comparison between luminescence and exo electron emission the mechanism and significance of exo electron emission of are investigated by studying the emission of light quanta by luminescence under the same conditions parallel effects in the two classes are tabulated and the close relation between the two is established 6375 diffraction by two parallel planes of finite length the diffracting system comprises a pair of parallel perfectly conducting planes of infinite width and finite length an incident em wave polarized perpendicular to the edges of the planes is considered the theory thus applies equally to the diffraction of a plane sound wave two integral equations are derived approximate solutions are obtained for the condition an equation is derived giving the value of for resonance of the system this is solved approximately and a formula is given for the end correction ie the difference between the resonant length and 6376 diffraction theory a critical review of progress in classical diffraction theory including references to over papers published since both scalar and electromagnetic problems are discussed the main emphasis is on diffraction by plane obstacles especially by obstacles small compared with 6377 solution of boltzmanns equation for a lorentz gases 6378 a note on the use of the titanates as thermoelectric transducers approximate calculations for a solid solution of indicate that it would not be useful as a thermoelectric transducer it seems that if materials could be produced with high permittivity and high temperature coefficient of permittivity but independent of field strength a transducer with an efficiency comparable to that of a steam engine could be developed 6379 greens functions in evaluating fields analysis based on the derivation of vector potentials from scalar potentials is extended to cases in which the field varies with time an outline is given of the method used to calculate the field due to a current in a conductor applications include the calculation of fields in waveguides and resonant cavities 6380 the magnetoresistance effect in metals at high frequencies the calculation of the effect is based on a model in which the electrons occupy two overlapping partially filled bands of normal form at low frequencies the relative change in surface resistance is independent of frequency and its variation with field strength is very similar to that observed in dc experiments at high frequencies the effect ultimately drops to zero the frequency region in which this occurs being determined by the relaxation time for normal metals it lies in the far infrared experimental results for bi suggest that the relaxation time in bi is abnormally large 6381 current voltage characteristics of a self supporting gas discharge in a transverse magnetic field continuation of previous work of march measurements were made using coaxial cylinder electrodes with axial magnetic field in argon at pressures from to below torr falling or rising characteristics are obtained according as the pressure is greater or smaller tha some thousandths of a torr at pressures above this value the discharge has the nature of a glow discharge with positive space charge at pressures below this value this value the characteristics are those of a self supporting high vacuum discharge with negative space charge 6382 study of the induced electrodeless discharge in neon induction heating theory is used to study the conductivity in the induced discharge at a frequency of 6383 on the radial extent of glow in microwave gas discharge between coaxial cylinders the glow appears in the region of maximum electric field strength close to the central wire over a radius mm the luminosity depends on the net production rate of electrons pr unit volume this rate is calculated and is shown graphically as a function of radius 6384 further research on the discharge between positiinuation of work described previously of toitot and boulloud 6385 investigation of the energy distribution of secondary electrons from single crystals of copper covered with single crystal layers of copper oxide the secondary electron energy was measured by the retarding field method the energy distribution curve is steeper towards the low energy side in the case of polycrystalline cu covered with polycrystalline cu one well defined maximum was observed in the single crystal case subsidiary maxima were also found but the evidence for these is not conclusive the results are shown graphically 6386 a reversible secondary emission fatigue effect observed in glow cathodes comprising a semiconducting layer if the usual metallic cathode in a glow discharge tube is replaced by a composite cathode having a semiconducting layer eg an cathode the self maintained discharge current decreases with time when the current density does not exceed a particular value dependent on cathode geometry an when the cell is kept in the dark recovery takes place slowly but is speeded up if the cell is subjected to infrared radiation th effect is ascribed to reversible fatigue of the emission centres for secondary electrons and the analogous effect observed with photocathodes suggests that both photons and secondary electrons originate in the same emission centres 6387 antiferromagnetism a survey paper giving particular attention to van vlecks theory and including a discussion of the superexchange mechanism papers on experimental investigations are listed by compound and by property studied nearly references 6388 fishers gyromagnetic effect observed in a body placed in a waveguide the component of magnetization produced in a ferrite perpendicular to the plane of a rotating magnetizing field may be detected in an ellipsoidal specimen placed in a waveguide excited in the h mode the theory and experiments which gave negative results were discussed by fisher on the effect can be used in determining magnetic fields at very high frequencies 6389 interpretation of the ampere experiments ampere equation for the force between current elements is unique assuming the correctness of his five postulates the general equations are here derived that apply if either the third or the fifth postulate is omitted 6390 the coulomb force and the ampere force a study of the modification of coulombs equation that will satisfy amperes experimental results 6391 a new electrodynamics a new formulation alternative to that of maxwells equations is developed from the theories of weber and of ritz the fundamental equation expresses the force on a charged particle caused by another charged particle for preliminary work see and above 6392 electromagnetic properties of plasmas in a magnetic field continuation of work reported in of assuming a constant and uniform magnetic field results obtained are discussed in relation to those of other workers in particular the matrix for the complex conductivity of an ionized gas and and the dispersion equation previous results apply only for values of gyromagnetic frequency small compared with where is the electron collision frequency and the pulsatance of the electric field 6393 magneto hydrodynamic waves in liquid sodium torsional waves in liquid na have been generated in a cylindrical vessel with the axis parallel to a homogeneous magnetic field and resonance phenomena have been investigated 6394 propagation of electromagnetic waves in a gyrotropic medium faradays law of rotation of the plane of polarization is extended to take account of the reflection and refraction at the boundaries of the medium the relation between path length and the angle of rotation is derived and results for a lyer of are shown graphically for a frequency of 6395 investigation of the transverse thermomagnetic effect the potential difference produced between faces of a conductor perpendicular to the applied magnetic field and perpendicular to the thermal flow was measured and found to be proportional to the magnetization in weak fields hysteresis is observed at saturation the potential difference remains constant a formula similar to that representing the hall effect is given the results for low carbon steel are shown graphically 6396 theory of origin of cosmic rays it is shown that a random acceleration process proposed by fermi and a physical location of the accelerating filds in radio stars proposed by unsold account satisfactorily for the main features of cosmic radiation 6397 radar determination of the heights and radiants of meteor showers the technique described by volmer of march was used for observations of the germinids and aquarids the results are discussed briefly 6398 the physical condition of the solar corona a review paper including about references 6399 probable observation of the galactic nucleus at mcs brief report of a survey of the central section of the milky way using an aerial system with a beam width of in the zone covered from to in declination and from hr to hr in right ascension a strong concentration of brightness was found near a line of galactic latitude with a maximum centred at longitude 6400 rocket instrumentation for reliable upper atmosphere temperature determination electronic telemetry equipment is described and typical curves are presented showing the variation of pressure and temperature with altitude 6401 nbs research in radio propagation 6402 electron resonance in ionospheric waves a new aspect of the investigation of travelling disturbances in the ionosphere is discussed which leads to a more satisfactory interpretation of observational data the hydrodynamic wave hypothesis of the earlier work of is retained but the observed perturbations in the electron density are attributed to a direct resonance in the electron oscillations regardless of any em fields which may be generated in the process formulae are developed for two distinct classes of possible resonant oscillations one involving and the other not involving a vertical component of propagation small scale disturbances above the f layer maximum which have been held responsible for certain radio star scintillations could be related to either set of formulae 6403 some studies on the ionospheric storm variations of are tabulated and the field current system computed 6404 simultaneous measurement of sweep frequency and of the ionosphere outline description of frequency sweep equipment designed to cover the range in four bands and used to obtain simultaneous records of the variation of virtual height and critical frequency with time sample records are shown 6405 global characteristics of the separation between the f and f layers of the ionosphere records of the separation between the f and f layers have been analysed in respect of seasonal and sunspot cycle variations the seasonal variations are similar to those observed by appleton for the height of the f layer of at at high latitude stations the variation of separation followed the trend of sunspot activity in summer but not in winter at stations close to the geomagnetic equator the separation varies inversely as sunspot activity in all seasons the observed variation with season and latitude are consistent with the view that the f and f layers belong to a common bank of ionization no simple explanation of the variations with sunspot cycle is at present possible 6406 ionization distribution in the f region the height distribution of ionization in the composite f region is calculated on the assumptions that the scale height ie the temperature increases and the recombination coefficient decreases with height in this region the recombination coefficient is assumed to vary in terms of the reduced height that is the height above f max measured in terms of the actual height as had been done earlier by ap mitra in making similar calculations the present assumption automatically takes into account the effect of rising temperature on the value of the recombination coefficient height distribution curves for high and low latitude stations are drawn for typical summer and winter conditions in the high atmosphere in the f region when the possible effect of ionospheric tidal drifts are taken into account the forms of the distribution curves and the separation between the f and f layers agree with those deduced from observations the results support the view that the f and f layers belong to a common bank of ionization produced by solar radiation 6407 ionospheric observation during the partial solar eclipse february the critical frequencies of all layers including the abnormal e layer are discussed 6408 polar magnetic storms and geomagnetic bays appendix a theory of field an current system deduced from geomagnetic observations is compared with a system calculated on the dynamo theory taking anisotropic conductivity of the ionosphere into account agreement is fairly good conductivity considerations suggest that the s current system is located at a height below km 6409 systematic investigations of the influence of geomagnetic disturbances on the daytime f layer critical frequencies a statistical analysis has been made of f layer critical frequencies observed at linden harz during the period december april and of geomagnetic observations made at wingst during the same period the geomagnetic data were arranged according to he degree of disturbance and the mean deviations of the critical frequencies corresponding to the different degrees of geomagnetic disturbance were determined dependence on sunspot cycle and on season is exhibited the significance of the results for the prediction of short wave communication conditions is discussed in detail figures are given indicating the reliability of such predictions 6410 on a change in geomagnetic declination accompanying intense sporadic e layer ionization supplement a statistical analysis revealed no relation between intense sporadic e ionization and lunar diurnal variation of geomagnetic declination in contradistinction to results for the solar diurnal variation reported in of february 6411 winds and turbulent air currents in the ionosphere predominantly horizontal linear air currents have been observed by direct and indirect methods the most frequent velocity is at altitudes between and and in the f layer between and km nonuniformity of direction is observed the results indicate that wind direction and speed depend on time of day and on season as well as on latitude the observations confirmed that turbulent currents are superposed on the linear currents in the km region but yielded no corresponding information for the f layer the occurrence of solar and lunar tides in the e layer with velocity amplitudes of and respectively was confirmed observations at the greatest possible number of stations are required to enable further conclusions to be reached 6412 horizontal movements in the ionosphere a survey of investigation methods and results under the following main headings reflected radio waves observed at closely spaced points observations of movements of large scale irregularities in the f region observations of waves from radio stairs observations of waves reflected from meteor trails observations of waves reflected from the sporadic e layer the following conclusions are reached at all levels in the ionosphere systematic as well as irregular horizontal movements are present typical velocities are of the order of there is a tendency for the velocity to increase with height the systematic movements have the form of regular diurnal and seasonal variations and show considerable consistency between observations made in the northern and southern hemispheres at heights around km the semi diurnal components of the velocity as determined by fourier analysis are found to represent a uniformly rotating velocity vector the direction of the rotation is clockwise in the northern hemisphere and anti clockwise in the southern hemisphere this is the type of movement predicted by the theory of atmospheric oscillations though the phase of the rotation is not that expected theoretically at times of magnetic disturbance the velocities of the horizontal movements are increased and this phenomenon becomes more marked with increasing height in the atmosphere at velocities as high as have been recorded during magnetic storms a brief summary of observations by non radio methods is included about references 6413 anomalous electric fields in the atmosphere the potential gradient in the atmosphere was found to depend to a large extent on the presence of clouds the formula derived which leads to results in good agreement with measurements expresses the potential gradient at any given height in terms of the known gradients at two other heights and the three heights 6414 atmospheric electricity aspects of the subject discussed include some in which significant advances have been made since publication of the authors book of and some on which work was done in germany during the war about references 6415 observation of atmospherics at very low frequencies results of observations at munich and several other places at frequencies in the range are correlated with meteorological phenomena two main types of waveform were distinguished one comprising wave trains of duration at a frequency about the other of a generally nonsinusoidal character at frequencies between and the former is associated with the presence of a temperature inversion the latter with low nimbus clouds the latter type occurred most frequently one to two days prior to the onset of increased temperatures neither type of atmospheric could be observed following the onset of fohn type weather 6416 analysis of nonlinear servos by phase plane delta method 6417 series capacitors multiply battery voltage the voltage obtainable by charging capacitors in parallel and discharging them in series is increased by using a set of capacitors of graded capacitance values and charging the first by the battery only th second by the battery in series with the first capacitor and so on the method has been used to provide using six capacitors with a battery 6418 voltage and current stabilizers for laboratory use a systematic exposition of the principal types of stabilizer divided into three main classes direct feedback and other types 6419 ac voltage stabilizers the operation of the output stage of the valve operated ac mains stabilizer is analysed with th aid of load lines and the relative advantages of various modes of operation are briefly discussed 6420 semiconductors as solid electrolytes in electrochemical systems a single shot battery and a long life cell are described and the physicochemical principles of operation outlined the former an ag agl ag s s cell gave an open circuit voltage of v at c the short circuit current was acm the latter an ag agl c cell with an emf of at room temperature can deliver a current of several hundred 6421 applications of a high speed electronic computer to a business accounting problem 6422 digital servomechanism controls shaft position devices for converting data from digital to analogue form are discussed two experimental system which convert binary digital input signals into shaft rotation angles are described the converter functions as a closed loop servomechanism in which the error sensing portion is a digital computer information can be indicated remotely with an accuracy within 6423 a one dimensional fourier analog computer the computer sums fourier series having up to terms and can be used for double and triple summations by using standard trigonometric expansions 6424 solution of second order differential equations and partial differential equations using a resistance network description of an instrument based on liebmanns design of which has an accuracy within about part in 6425 direct reading electronic correlator paper strip recordings of two functions r are read photo electrically and the electrical signals thus obtained are converted into pulses which when coincident actuate a computer the correlation delay time can be varied up to any value from a lower limit set by the recording speed 6426 statistical computers as applied to industrial control principles and circuit techniques are discussed applications described include the control of the diameter of extruded plastic cable sheating 6427 the selenium rectifier in digital computer circuits results are reported of an investigation of the birkbeck college computer with the object of replacing valves by more reliable elements where possible measurements indicate that diameter se disk rectifiers are suitable for use as shift diodes buffer isolators gating elements coincidence sensing units and decoding matrix elements in computers where the frequency of operation does not exceed 6428 a new ac network analyser for the solution of problems arising in the operation and extension of electrical power systems 6429 an analogue computing circuit for the evaluation of the ratio of two slowly varying potentials the circuit based on the miller integrator is described in detail the computed ratio is displayed as a meter deflection the use of feedback reduces the sensitivity to valve characteristic variations the error is less than of full scale deflection within wide input limits computation of reciprocals and products may be performed by means of similar circuits several possible applications of the device are mentioned 6430 the ade photo electric integrator the instrument which is in the developmental stage is capable of evaluating surface integrals of any function over a domain with boundaries not containing pooles of the function it comprises essentially a bottom lit light diffusing table with a photoplate grating and photoelectric cell arranged above the grating represents the function and an opaque mask represents the domain of integration integrals of a bivariate normal distribution function over a domain with irregular boundaries have been obtained 6431 charge carrier device as a high ohmic resistance the principle of the two arrangements described is the movement of a conductor a metal ball of capacitance to and fro at a specified frequency in an es field between two electrodes the effective resistance r of the circuit is c in the first arrangement the ball is fitted to the periphery of an insulated disk driven by a synchronous motor in the second the ball is free and its movement is controlled by an electromagnet details are given of the performance of the system operating in an electrometer circuit with balls of different materials with a ball in diameter frequency cycles minute and electrode spacing mm 6432 thermistor nomograph chart for finding values of thermistor resistance at given temperature the accuracy is nearly as good as that of a slide rule 6433 demagnetization coefficients of high permeability cores experimental determination of the dependence of demagnetization coefficients on geometrical dimensions of solid or laminated cores of rectangular cross section and solid or hollow cylindrical cores a semi empirical formula for calculating the demagnetization coefficient of cylindrical rectangular cross section and ellipsoidal cores is given and the calculated results are shown to be in good agreement with measurements 6434 an electronic ratchet when groups of nine evenly spaced pulses are applied to a decade scaler a series of output pulses is obtained with separation increasing by one time unit for each pulse group application of groups of eight pulses gives separation increasing by two time units per groups of eleven pulses decrease the separation by a single unit the instrument described comprises two decade scalers and can provide a maximum separation of time units for increasing intervals or for decreasing intervals 6435 component design trends new variable capacitors extend tuning range over different types of variable capacitor in production were surveyed an outline is given of techniques used for obtaining low minimum capacitance and high maximum capacitance adapting for operation at uhf miniaturizing and pressurizing 6436 a simple thre terminal micrometer capacitor description of a variable capacitor in which a micrometer spindle moves along the axis of a hollow cylinder which is coaxial with a cylindrical hole bored in the brass block screen typical range is from to for a movement of the spindle 6437 transistor characteristic parameters for weak alternating currents a method of representation is proposed using an impedance matrix which is completely symmetrical for all six transistor connections formulae derived for input impedance current gain etc have the same form for all the six circuits the method requires a new definition of the currents and voltages but affords the possibility of extension to multielectrode systems the setting up of matrices for complex arrangements of resistors and transistors is illustrated 6438 multilayer distributed constant delay lines 6439 synthesis of passive networks with pairs of terminals specified by their scattering matrices the method described gives results different from those of belevitch of and back references equivalent networks are represented by means of a uniquely defined regular network matrix necessary and sufficient conditions for minimum phase shift are specified in terms of matrix theory and the minimum number of elements excepting ideal transformers required in equivalent networks is determined relevant matrix theory is dealt with in an appendix the method is extended to networks violating the reciprocity principle 6440 reciprocity relations in active terminal elements it is shown by matrix analysis that under small signal conditions an active element such as a valve or transistor can be represented by an equivalent circuit comprising a triangle of resistances and a three terminal gyrator the active element is stable if one ad only one of the resitances is negative it is shown that the property of nonreciprocity is essential for an active three terminal element to be stable 6441 notes on the gyrator problem the impedance transformation properties indicated by tellegen of as characteristic of the gyrator can also exist in ordinary quadripoles the peculiar nature of the gyrator is indicated by the sign of the output current different conventions used in representing quadripole currents and voltages are discussed it is proposed that the equations should be written in a way that takes into account the terminating impedances and the internal impedance of the source 6442 solution of the field problem of the germanium gyrator analysis is presented for the hall effect gyrator described by mason et al of treated as a two dimensional boundary value problem and assuming that only one type of carrier is involved and that there is no surface recombination the efficiency is calculated as a function of electrode size shape of boundary and magnetic field strength some of the results have been checked experimentally with fields up to gauss the calculations have been carried out for even higher fields and may be useful for studying materials with higher mobilities such as 6443 impedance transformation by four terminal networks the geometrical interpretation of impedance transformations is considered in relation to the use of impedance charts and improved methods of impedance measurement 6444 intrinsic stability conditions for equivalence between a quadripole including active elements and a passive quadripole there are two necessary conditions image impedances must be passive image attenuation must exceed the value of a certain function of the phase angle of the image impedance and the image phase shift coefficient in certain important cases this second condition reduces to a simple mathematical form 6445 distortion of a frequency modulated wave passing through a mismatched quaripole analysis is based on the transfer coefficient of the network and a formula is derived for nonlinear distortion in the general case from this the percentage of odd and even harmonics generated and the upper limit of the distortion factor can be determined application of the formula in the case of transmission lines is illustrated 6446 transient response in fm correction to a paper abstracted in of august 6447 response of a low pass or band pass filter to a voltage whose instantaneous frequency varies linearly as a function of time analysis is given based on a fourier integral representation of the input voltage a formula derived for the output voltage is shown to be applicable in the case of a panoramic receiver in which the frequency is varied by in 6448 conformal mapping for filter transfer function synthesis correction to paper abstracted in of february 6449 on the filter problem of the power spectrum analyzer in an analyser for determining the power spectrum of random noise a signal derived by repeating a finite sample of the noise record is d heterodyned with another signal whose frequency is swept over the whole spectrum and the resultant is passed through a narrow filter and then detected an investigation is made of the optimum filter response for minimizing the intrinsic error associated with the finite size of the sample the lowest probable error for various types of filter is tabulated the rate of the frequency sweep must be small compared to the half bandwidth squared for the filter response to remain substantially the same as its steady state response 6450 the bridge stabilized transformerless oscillator with complex amplification factor oscillators of the type described by zaiser of with rc frequency determining circuits are discussed the effect of complex transfer factor is investigated and the conditions are determined under which oscillations at unwanted frequencies are suppressed without impairing the frequency stability of the wanted oscillation 6451 frequency stable lc oscillators literature on the subject is reviewed and attention is drawn to the chronological order of various publications simple theory is presented for the conditions governing oscillation and frequency stability 6452 the type beam deflection tubes as a complex pulse generator type is the usa designation for the type valve of and circuits for producing single double or multiple pulses with very short rise time are described 6453 contribution to the mathematical description of relaxation oscillations differences and similarities between oscillations of relaxation and of van der pol type are discussed relaxation oscillations can be represented by the van der pol equation if th self inductance term in the latter is neglected and a suitable transformation is made 6454 kilovolt delta function generator a pulse is generated in a circuit comprising two series connected hydrogen thyratrons arranged to constitute the inner conductor of a coaxial line it is passed through of cable to a delta function generator which includes a pulse sharpening gap and differentiating stub this generator reduces the pulse rise time to and the pulse width to mus pulses of ither polarity may be obtained 6455 analysis of junction transistor audio oscillator circuits 6456 a clipper with automatic mark space ratio control a rectangular wave with mark space ratio independent of the amplitude and harmonic content of the input wave is produced by controlling th bias level of the first clipping stage by means of a special feedback circuit incorporating a mark space ratio discriminator 6457 distributed amplifiers some new methods for controlling gain frequency and transient responses of amplifiers having moderate bandwidths 6458 high frequency compensation of rc amplifiers a discussion with special reference to transient response optimum values are tabulated for the circuit parameters for some typical circuits and compensating arrangements in a multistage amplifier simply compensated by means of a coil in the anode leads the rise time can be reduced to of the uncompensated value if the time constants of the stages are equal and to if the time constants are staggered 6459 design of the duplex feedback amplifier a comprehensive discussion illustrated by a detailed account of the design of carrier telephone repeater amplifiers 6460 the galvanomagnetic amplifier discussion of theoretical and practical aspects of an amplifier whose operation depends on the magnetic control of electrical resistance gauss effect such an arrangement is less noisy than magnetic or dielectric amplifiers at low temperature among metals bismuth exhibits the greatest sensitivity to this effect by using an appropriate material such as insb the principle can also be applied to amplifiers for ust at room temperature the theoretically possible gain is db at and db at corresponding values which have bee obtained with experimental units are about and 6461 reflex klystron performance from a series of measurements made while varying the anode and reflector voltages simultaneously constant frequency and constant power curves can be constructed typical curves for three modes of operation t are shown with the aid of these curves extremely pure amplitude or frequency modulation can be achieved by varying and simultaneously so that the ratio of their variations is constant the change from am to fm may be effected simply by altering the ratio the maximum frequency shift with am was about with fm a frequency swing of was obtained with constant power output of an important application of the systems described is the modulation of signal generators for measurement purposes 6462 a broadband low level error voltage detector the unbalance of a carrier frequency voltage in a bridge circuit having two inductive and two ge diode arms is used for detecting small dc or ac error signals sensitivity down to and response within are provided by the instrument which is relatively free from zero drift application to high speed multichannel sampling and to servo systems is discussed 6463 direct coupled transitron transitron arrangements are discussed in which the screen grid and suppressor grid of the pentode are connected via a resistance network various practical applications are possible as a result of a discontinuity in the characteristic circuits for detection of direct voltage changes eg amplifier gain alarm detection of alternating voltage changes eg peak suppressors and rectification of voltages exceeding a given level are considered careful design is necessary to overcome variations between individual valves but a very sharp trigger action can be produced the high sensitivity makes circuit economies possible 6464 microwave single sideband modulator using ferrites the modulator uses a ferrite rod inserted in a waveguide section and subjected to a rotating transverse magnetic field as a phase shifter a transmission type and a reflection type are described both are designed to shift the frequency of an x band signal by 6465 small transformers and inductors there has long been the need for a book which treats the design of transformers for use at both power and communication frequencies on the basis of a common systematic theory and which so closely relates the design process to fundamental theory as to enable the non specialist successfully to undertake the design of transformers for widely differing applications the author has fulfilled this need most admirably 6466 on the nature of waves critical discussion of classical theory indicating how an interpretation of the quantum theory can resolve the incompatibility of wave and particle concepts 6467 thermodielectric effect a theory is put forth to explain the electrical effects which accompany phase changes occurring in dielectrics and aqueous solutions ionic movement in the interface is treated as a transition between energy levels separated by potential barriers the height of the barriers and the value of the energy levels are supposed to be diferent for positive and negative ions such a model results in a net current flow across the solid liquid interace when the interface moves during a phase change of the system the excess electric charges thus produced constitute space charges in the solid and surface charges in the liquid see also of september and back references 6468 a new classical theory of electrons part the theory previously proposed and of is applied to a system comprising several interpenetrating streams of electricity moving in accordance with the equations of maxwell and lorentz an action principle is set up and the equations of motion are put in the hamiltonian form the hamiltonian has some similarity to that for point charge electrons but there is some discrepancy 6469 a theory of the electron further development of the theory proposed previously of 6470 the electric field of conductors arranged parallel to conducting planes intersecting at a given angle convenient formulae are obtained by considering the field as the resultant of those due to the multiple reflections of the conductor in the intersecting planes these formulae are shown to agree with those derived by the method of conformal transformation 6471 some measurements of the relative dielectric strength of gases electronegative gases including sf and were studied by measuring the breakdown voltages of sphere gaps with spacings of a few millimetres results are tabulated and discussed taking nitrogen as comparison standard 6472 anomalous electron scattering in metals a semi theoretical equation was proposed previously to account qualitatively for the thermoelectric power of metals and alloys particularly at low temperatures the consequences of this equation are now examined quantitatively in relation to experimental data on alloys of copper 6473 electron energy distributions in stationary discharges extension of previous analysis of to the case of a stationary discharge in a dc space charge field the effect of the space charge is to increase the proportion of high energy electrons this results in a higher ionization rate but the effect is not large enough to account for low maintenance potentials observed in positive columns and in microwave discharges in inert gases 6474 electron emission from cold metal surfaces at medium field strengths measurements were made of the field emisson of an fe cathode at pressures torr the emission field strength characteristic depends largely on the pre treatment of the cathode material applying schottkys equation a value of is obtained for the work function 6475 energy and temperature dependence of the secondary emission of mo the results reported by johnson and mckay of january are interpreted quantitatively on the basis of a simple one dimensional model 6476 collisional effects and the conduction current in an ionized gas a note on the approximate expression derived by westfold of january for the collision term in the current transport equation for a binary ionized gas in a strong magnetic field 6477 maxwellian approximation to the general magnetoionic theory of plasmas with an external electric and magnetic field analysis is presented to show that a maxwellian distribution of electron velocities occurs as a particular case in the theory developed previously of august and back references 6478 variation of diffusion after effect field with induction as a consequence of the different behaviour of and walls the curve representing the variation of diffusion after effect field with induction exhibits two horizontal regions this is confirmed experimentally 6479 general formulae for the theory of polarized media the classical equations of electromagnetic theory are generalized and are all derived from two fundamental formulae by a chain of definitions and identities 6480 reaction concept in electromagnetic theory a mathematical definition is given of a physically observable quantity termed the reaction which is a measure of the force exerted by one em source on another the concept is used to obtain expressions for scattering coefficients transmission coefficients and aperture impedances the advantage of using this concept rather than the variational approach is illustrated by treating the problem of scattering by a dielectric body 6481 some consequences of the theory of action at a distance in classical electrodynamics the energy taken by a free charge and by a harmonic oscillator is calculated on the absorber theory 6482 electromagnetic field of a dipole source above a grounded dielectric slab a theoretical investigation using the method of integral transforms solutions in integral form are evaluated asymptotically by the saddle point method the distant field is found to be the resultant of a spherical space wave and a cylindrical surface wave calculated radiation patterns for some particular cases with and without the dielectric slab are presented 6483 faraday effect at centimetre wavelengths a brief note on faraday effect measurements at cm at field strengths up to oersted using a pole symmetrical waveguide system not described results of measurements on and are presented graphically 6484 on the nature of the transcendental curves associated with the relativistic trajectories of charged particles analysis applicable to particles with moderate relativistic velocities at which radiation loss is negligible the equations of the e trajectory are formulated for the general case of particles injected with arbitrary velocity into crossed electric and magnetic fields the case of zero injection velocity is calculated explicitly see also below 6485 multiple element interferometer for locating sources of solar noise at the interferometer uses five aerials each with a paraboloidal reflector of diameter arranged at intervals of m the distribution of brightness observed at over the quiet sun is consistent with the conclusions that the diameter of the rf disk is about greater than that of the optical disk and the outer ring is about times brighter than the optical disk of uniform temperature about 6486 a method for the measurement of the distance of radio stars the method described depends on the absorption of the radiation from the radio stars by interstellar hydrogen at a frequency of about preliminary results are given for the two intense sources in cygnus and cassiopeia the distance of the former is parsecs that of the latter is probably between and parsecs the uncertainty will be reduced when more accurate measurements are made of the absorption spectrum 6487 on the nature of the discrete radio sources correction to paper abstracted in of august 6488 the distribution of great and small geomagnetic storms in the sunspot cycle a statistical analysis of the occurrence of great geomagnetic storms small storms with sudden commencements and small storms without sudden commencements during the last seven sunspot cycles distribution curves for and agree closely with the averaged sunspot curve for the curve has no pronounced peak at sunspot maximum but reaches a high level two years later these post maximum storms which are associated particularly with ionospheric disturbances often show a recurrence which is not observed with the ad types 6489 the aeronomic problem of oxygen dissociation the vertical distribution of o above km as determined from rocket data is discussed in terms of diffusion ad mixing processes 6490 group height calculations in the presence of the earths magnetic field a method of obtaining a theoretical curve avoiding direct numerical integration is described it is based on integral formulae involving the derivative of height with respect to electron density and obtained as special cases of the gauss christoffel quadrature formulae involving the derivative of height with respect to electron density and obtained as special cases of the gauss christoffel quadrature formula of and of july application to linear parabolic cosine and arc cosine distribution is illustrated and results are compared with exact calculations and of shinn and whale and of may shinn a different method is described for the case of layer penetration 6491 the vertical distribution of electrical conductivity in the upper atmosphere data obtained from rocket measurements are used to determine the vertical distribution of conductivity and its height integrated values for the d e and f regions the greatest conductivity value is found for the e layer around hence this region is probably the seat of the electrical currents producing diurnal magnetic variations 6492 on the law of the variation of e region maximum with the zenith distance of the sun analysis of e records obtained at calcutta for the years indicates that the value of n in chapmans formula varies between and the subsolar frequency undergoes similar variations a seasonal component of variation was almost marked in and and the mean trend of the variations follows the sunspot cycle the departures from the chapman law are attributed to changes in the height distribution of o in the transition region 6493 the sporadic e layer at kodaikanal examination of ionospheric records shows that an e layer is almost always pesent during the day two main types are distinguished a patchy type giving well spread echoes this occurs more regularly and frequently has a marked diurnal variation and resembles the constant height type observed at brisbane by mcnicol and gipps of a blanketing type occurring mostly during the afternoon neither meteoric nor thunderstorm activity greatly influences the formation of either type no correlation iis observed between f and the geomagnetic field 6494 spread f over hawaii analysis of records for the period showing diffuse and irregular echoes from the f region indicates a much greater frequency of occurrence of spread f at sunspot minimum than at sunspot maximum this difference being most pronounced in winter a marked latitude and a less marked longitude effect are exhibited 6495 f scatter at huancayo peru and relation to radio scintillations analysis of records for the period reveals marked diurnal seasonal and annual characteristics of f region scatter this effect occurs most frequently in th period four hours before to four hours after midnight and is most prevalent during local summer occurrence frequency was least during increasing by a factor of by diurnal variations correspond closely to reported characteristics of radio star scintillations annual and seasonal trends are not in simple agreement 6496 the connection between lunar height changes and lunar currents in the e layer height changes produced by vertical electronic diffusion in the presence of negative ions are considered application of the results to the e layer confirms the validity of previous qualitative conclusions of 6497 the analysis of fading records from spaced receivers fading records obtained in investigating ionospheric winds by the spaced receiver method described by mitra of and phillips o are discussed considerable variability in the records is to be expected even if the wind is constant in both direction and magnitude two particular one hour records for vertical incidence reflection from the e layer are analysed one is consistent with constant wind conditions the other requires more detailed analysis 6498 the determination of the velocity of winds from spaced dfading experiments more detailed analysis referred to in above if some assumption is made about the distribution of signal amplitude over the ground the statistics of wind variation can be deduced 6499 systematic wind measurements at altitudes of km using radio echoes from meteor trails wind drifts of ionized meteor trails were measured using a coherent pulse doppler technique at a frequency of average wind speeds and directions were obtained over hourly intervals results for september and october show semidiurnal and diurnal wind components corresponding to a clockwise rotation of the wind vector the amplitudes and phases of these components are variable a prevailing wind was also found towards the east in september and towards the west in october there is a positive wind velocity gradient of sec between and height large irregularities in the wind were noted typical records are shown and the equipment is described 6500 an apparatus for the detection of weak ionospheric echoes fm apparatus id described in which the principle of coherent integration is applied in the receiver with transmitted power of and filter bandwidth of signals are detected with attenuation of up to nepers 6501 ionospheric absorption measurements during a sunspot cycle detailed discussion of the results of the results of measurements referred to in of variation of atmospheric absorption with frequency where is the effective ionospheric reflection coefficient is accounted for by magneto ionic theory provided that where is the electron collision frequency and is the gyrofrequency corresponding to the vertical component of the geomagnetic field examination of diurnal variation shows the average value of n in the relation where is the solar zenith distance to be against the value given by simple theory possible explanations of this are considered excessive absorption on certain groups of days during th months november february is directly correlated with the occurrence of sporadic reflecting strata below e layer height noon measurements over years show a general correlation of log with sunspot number r more pronounced in summer than in winter general conclusions drawn are that the normal absorbing stratum is located in the d region and sudden disturbances associated with solar flares are probably due to increased ionization in this layer 6502 magnetic disturbances sporadic e and radio echoes associated with the aurora data obtained from simultaneous observations of visible aurora the earths magnetic field variations vertical and oblique propagation radio echoes and vhf radar echoes are examined long rang hf and vhf echoes cannot in general be correlated reflections in both frequency ranges have coincided with the appearance of low level auroral arcs which are associated with magnetic bays 6503 radio echoes during aurora saskatoon data for and of currie et al are reassessed two aerials placed at heights giving maximum resolution between corresponding to first and second lobe radiatin were used to determine whether echoes on were due to ground scatter reflected from the lower ionosphere of harang and landmark results show that practically all echoes were due to direct reflection from aurorae 6504 long range radio echoes from auroral ionization echoes believed to be from auroral ionization are consistently observed using pulse signals on frequencies and at the relatively low latitude of stanford california two types of echo are distinguished discrete of very large amplitude and diffuse of much smaller amplitude echo data show a marked correlation with visual aurorae and with magnetic activity and also indicate that reflections occur at regions well above the e layer 6505 the location of the auroral absorption zone a study of data from a chain of radio wave field strength recording stations along the meridian suggests that the auroral absorption zone coincides with the zone of maximum frequency of occurrence of visible aurora the significance of the results for radio communications across the zone is discussed 6506 the behaviour of standard cells in conditions which include the generation of appreciable current measurements made on weston type standard cells generating currents of or for varying periods of time are reported from which the voltage stability attainable under these conditions may be estimated 6507 transistors and junction diodes in telephone power plants 6508 transistor power supply for geiger counters a unit is described comprising junction transistors in a class c amplifier circuit operating from a battery and supplying at 6509 bias supplies for direct coupled circuits details are given of power supply arrangements using special transformers with low shunt capacitance thus permitting operation at above earth potentials in direct coupled amplifiers 6510 stabilized hv power supply application to millimetre wave klystrons a circuit is described in which the series stabilizer valve is inductively coupled to the error amplifier an output of at can be provided 6511 solar thermoelectric generators physical characteristics relevant to their usefulness for thermocouple materials have been determined for various metal alloys and compounds the efficiencies of flat plate type solar energy collectors in combination with such thermocouples is evaluated the value of obtained using type alloys in combination with a bi alloy was ten times as great as that obtained with commercially available chromel p in combination with constantan using concentrating lenses the efficiency obtained with the best alloy combination was the maximum economically permissible cost of thermo electric generators is evaluated 6512 leo lyons electronic office a detailed account of the installation the nucleus of which is a digital computer developed from the edsac operation maintenance and fault finding procedure are described an extensive system of marginal checking has been included punched tape read photoelectrically is used for the input errors in perforation are completely eliminated by use of a special checking device 6513 amplitude comparator for computing purposes a simple circuit is described which gives uniform output pulses for a large range of input signal derivatives low transformer output impedance is provided measures are indicated for ensuring stability when the signals are slowly varying 6514 some applications of elements with discontinuous operation in analogue computation the field of application of the differential analyser is enlarged by incorporating amplitude comparators and electronic switches solution of particular differential equations is discussed 6515 multiplier for analog computers multiplication is performed by addition of logarithms using the linear to logarithmic converter described previously of howard et al followed by a logarithmic to linear converter application to solution of nonlinear differential equations is described 6516 analogue computers in aircrew training apparatus comparison of the relative complexities of full flight simulator computers using digital and analogue methods indicates the analogue type to be more suitable operation and performance are discussed 6517 construction and calibration of a very high frequency transformer a matching device for insertion in a coaxial line consists of a pair of rings which can be slid independently along the line between the inner and outer conductors without touching either of them the frequency range for the type described is theory is developed on the basis of the equivalence of the device to a cascade connection of two loss free quadripoles 6518 component design trends fixed resistors show stability improvements a survey of available types temperature voltage and power limits are discussed composition resistors continue to be the most generally used developments in pyrolytic carbon film printed wire wound and metal film types are reported 6519 surface resistors for centimetre wave technique an account is given of the development of a method of manufacturing carbon layer resistors for waveguide attenuators and nonreflecting terminations using a colloidal suspension of graphite and an insulating base of pertinax consideration is given to the choice of medium water or alcohol and the method of application painting dipping or spraying particular importance is attached to the uniformity of the layers the resistance layer is protected by a coating of polystyrene an instrument designed for measuring the dc resistance of the layers is described measurements at dc and at are reported 6520 theory of the thermistor as an electric circuit element a study of thermistor circuits fundamental relevant physical and mathematical concepts are presented the dissipated poer rather than the thermistor temperature is taken as th basic variable the power balance equation is presented in a form introducing the thermal time constant and is used to develop equivalent circuits for thermopositive and thermonegative resistors permitting calculation of superposed variable states 6521 nonlinearity of the volt ampere characteristics of silicon carbide resistors results of an experimental investigation of the conductivity and conductivity and conductivity voltage characteristics of sic powders under a pressure of show that as the field strength increases the conductivity becomes proportional to the square root of the field strength this is probably due to an increase of the effective area of contact electron micrographs of typical sic crystal surfaces are shown results obtained using crystals graded according to size are shown graphically and are discussed from the point of view of producing a resistor with the greatest possible nonlinearity 6522 fundamental oscillations of coils and windings analysis is given based on the solution of a fredholm integral equation fundamental frequencies are evaluated for air core and iron core coils and iron core coils and the voltage distribution is discussed see also of march 6523 saturable transformers as gates use of ferrite cored units as switching elements is discussed input and output windings are wrapped on each core and control windings are wrapped around both applications include magnetic drum read out systems for computers 6524 multistable electronic circuits and decades the design of counter circuits is considered from the point of view of simplicity and reliability from this point of view it is advantageous to keep the number of internal couplings as low as possible trigger chains are used with odd numbers of triode valves alternately blocked and conducting except for one adjacent pair in the same state to ensure stability damping is required at the critical frequency circuit arrangements are shown for providing this in cases where the two adjacent valves in the same condition are both blocked both conducting 6525 a sensitive pulse trigger circuit with a stable threshold a pulse amplitude discriminator for positive or negative pulses is described in which the sensitivity is independent of contact potential variations in the valves with a threshold of stability is within the simplified circuit comprises two triodes passing steady currents and a clamping diode operated under retarding field conditions the minimum effective pulse width is about the same as that for conventional discriminators performance figures substantiate theoretical calculations of sensitivity 6526 a scaling unit employing multi electrode cold cathode tubes a complete scaling unit for counting regular of random pulses id described different methods of driving cold cathode scaling valves are considered in the method uses the amplitudes and durations of the pulses applied to all stages in the slow scaling section are controlled by a common pulse generator the unit comprises a pulse amplitude discriminator of high sensitivity a fast scaling stage with a element valve a cascade arrangement of element vales type with cold cathode gating valves and the pulse generator some routine tests for valve deterioration are outlined 6527 empirical transient formulae relations between the steady state frequency response of a network and its transient response are derived in terms of shape parameters the most important of which for the transient response are rise time overshoot and relaxation time two classes of network are considered those with a flat topped frequency response curve with a single peak at zero centre frequency and those whose frequency response curve exhibits two equal maxima located symmetrically about x zero centre frequency it is concluded that the network giving most failful reproduction of a unit step has a trapezoidal frequency response curve and that compromise is required in design as between ideal frequency response and ideal transient response 6528 nyquists criterion nyquists form of the stability criterion is deduced using well known properties of complex numbers and without using integration in the complex plane a new form of criterion the minimum phase criterion is also developed 6529 a note on the transfer voltage ratio of passive rlc networks results obtained by failkow and gerst of are generalized to include rlc networks 6530 symmetrical quadripole lattice networks determination of pass bands an attenuation bands a graphical method of determining the bands is discussed see also of leroy 6531 some passive networks under transient conditions two groups of passive quadripoles are defined by their transfer functions those approximating to an ideal delay line those producing a gaussian waveform from an input pulse of sufficiently short duration a method of synthesizing such networks given the attenuation and phase shift coefficients is based on a continued fraction expansion of the quotient of a hypergeometric function 6532 the four circuit filter with coupled circuits of equal resonance frequency the properties of the circuit are analysed and compared with those of two stage and three stage filters 6533 methods for the calculation of transient distortion based on the general properties of transfer functions theories of transients in filters developed by kupfmuller wheeler and cotte are compared cottes method of calculation is considered most suitable for the general investigation of transient distortion a definition of bandwidth is proposed it is shown that in the general case there is no simple analytical relation of the type derived by kupfmuller between bandwidth and rise time see also of 6534 universal formulae for the calculation of simple filters transfer properties and input impedance are given as functions of normalized frequency for filters with up to four tuned circuits for arbitrary ratio between source impedance and terminating impedance the calculations take account of circuit losses the formulae are evaluated and represented in curves details of the calculation are shown for a four circuit and pass filter a table is given of the most important filter circuits with the associated formulae and definitions 6535 analysis of a special purpose rc filter incorporating a periodically conducting bilinear element the circuit discussed is essentially a low pass filter incorporating a two way switch modulated carrier is applied and the switch is operated at carrier frequency so that the output is a series of amplitude modulated pulses analysis is presented based on consideration of the stepwise accumulation of charge by the capacitor and taking account of the dead time when the switch is out of contact application in the field of automatic control is mentioned 6536 band pass circuits with minimum number of coils part band pass filters with prescribed attenuation characteristic any band pass filter with the exception of the equalized characteristic impedance type can be constructed using a suitable combination of the basic filter sections described by transforming parts of the filter using the circuit equivalents given th number of circuit components can be reduced this is illustrated by a numerical example 6537 on the transformations of singularities and limit cycles of the variational equations of va der pol cartwrights solution of van der pols equation with forcing term of is shown to be incorrect in one range of the parameters the corrected solution is given in view of the correction the hysteresis effects to be expected for a van der pol oscillator with increasing and decreasing frequency are confined to a narrower frequency interval and are less varied in character than suggested by cartwrights solution 6538 wien bridge oscillator design comment on of 6539 modes of operation of a valve oscillator the operation of a tuned grid oscillator is described mathematically by the differential equation where is proportional to the capacitor voltage is the derivative of the anode current with respect to and and are constants dependent on the circuit parameters the equation is solved assuming to be small 6540 fluctuations in oscillator with inertial nonlinearity fluctuations in a valve oscillator the steady state amplitude in which is determined by an inertial nonlinearity such as a feed back system are considered theoretically and some practical conclusions are reached on the choice of circuit parameters for minimum amplitude fluctuations 6541 vertification of a descriptive theory of relaxation oscillations the conditions for oscillation previous of november are verified for the case of an oscillator using a neon lamp or a thyratron 6542 new circuits for generating pulses by means of a pulsed reactor review of circuits containing a saturable reactor with rectangular magnetization characteristic for deriving pulses of required amplitude and phase from a sine wave input the method of shifting the phase by means of an auxiliary pre magnetizing current is described pulse shapes obtainable from a square wave input are discussed and practical circuits for deriving this input from single and three phase ac are shown 6543 junction transistor pulse forming circuits analysis of integrating ad differentiating circuits using npn junction transistors practical arrangements are illustrated for obtaining sawtooth square and triangular pulses 6544 internal oscillations in transistors 6545 pulse frequency multiplication and division by delay lines analysis is given for simple arrangements of lumped element lc lines for multiplication lines with linear characteristics are suitable for division a nonlinear device eg a pentode must be included in this case the input may be sinusoidal 6546 an amplifier with low dissipation and short rise time for crt by using electron multiplier valves in an amplifier for scintillation counter pulses a gain of about and rise time of are obtained with only a few valves details are given of a circuit for a negative pulse input giving an output of about 6547 newly developed amplifiers for the sound programme chain as part of a comprehensive redesign of studio and control room equipment to be known as type b the bbc engineering division has produced a new group of amplifiers comprising gpa and general purpose level ri raising amplifiers low fixed gain amplifier for sending programme to line and for monitoring purposes compactness and standardization of construction are features the preferred amplifying valve is the double triode type or its trustworthy equivalent the type details are given of circuits construction mounting and performance 6548 design of carrier frequency amplifiers with stagger tuned resonant circuits a simple rule is derived for the distribution of the poles ad a nomogram is given facilitating the design of an amplifier with flat response over a pass band of large relative width analysis is also given for the case of response ripples within predetermined limits values of the resonant circuit elements are calculated 6549 experimental band pass amplifier a description is given of the practical design of an amplifier circuit in which the bandwidth can be adjusted and the gain varied between wide limits without shifting the centre frequency of or affecting the response curve features of the design are the capacitive coupling of the tuned circuits the neutralization of the grid anode capacitance of a type pentode by means of a specially constructed plunger type capacitor and th compensation of valve input impedance variations by a suitable cathode load 6550 a stable wide range dc amplifer description of an ac operated differential push pull amplifier for biological applications with a range from zero to and a maximum gain of about response can be controlled independently at the high and low ends o the range the dc gain can be reduced to of the mid band gain an automatic rebalancing circuit resets the zero of the amplifier at intervals of about sec 6551 amplification of small alternating voltages with the magnetic amplifier a theoretical investigation of the conditions under which saturated reactors are suitable for amplifying sall alternating voltages a parallel choke circuit with self saturation was found to be suitable and a two stage amplifier based on this circuit is described the amplification obtainable is sufficient to give a galvanometer indication with voltages down to 6552 the attainment of very high gain with unmatched transistors when a transistor is used with unmatched source or load impedance maximum gain is achieved with a particular value of the impedance maximum gain is achieved with a particular value of the impedance on the other side quadripole analysis is used to determine this optimum impedance value with grounded base or grounded emitter circuits the cut off frequency is the same as with matched impedance with grounded collector circuits the cut off frequency depends on the degree of matching 6553 certain transmission and reflection theorems established theory is used to analyse transmission and reflection of em and acoustic waves by a uniform planar distribution of cylinders reflection by a planar distribution of bosses is also considered see also of and back references 6554 step by step transition from wave optics to ray optics in inhomogeneous anisotropic absorbing media part group propagation the method of stationary phase is applied to obtain general expressions for group delay direction and velocity which are then particularized for em waves 6555 contact charging between nonconductors and metal the investigation previously reported of september was continued using spheres of fused quartz and borosilicate glass rolling n on a clean ni surface and introducing improvements in the method the surface conductivity of the glass was found to be higher than that of the quartz by three or four orders of magnitude since the charging of the two materials was of the same order of magnitude it appears that the effective work function of the glass is considerably higher than that of the quartz 6556 rigorous method for investigation of the interaction between an electron and several lattice oscillators 6557 electrothermal convection in air the effect of an inhomogeneous electric field on the thermal gradients in air was investigated using air heated electrically by a filament of length cm along the axis of a glass tube of diameter about cm results show that the field required to produce electrothermal convection is lower at high power dissipation than at low dissipation in the range the transition between gravitational thermal and electrothermal convection occurs discontinuously the potential difference between the positive filament and negative electrodes placed on either side of the filament was varied between about and interference photographs are shown and the apparatus used is described results are presented graphically 6558 theory of equations of transport in strong electric fields the transport of heat and electricity in semiconductors is considered in terms of an electron hole gas whose kinetic energy is greatly increased in a strong electric field equations for the thermal and electric currents are derived and formulae are obtained for the thermoelectric and galvanomagnetic effects these include the thomson hall nernst and nerst ettinghausen effects effects due to bipolar conduction of the semiconductor including the photomagnetic effect are also considered 6559 an analysis of the distribution of alternating current in a solid cylindrical conductor the equivalent circuit method of approach selected is designed t keep the physical basis of th problem in view at every stage of the work the expressions derived apply to a conductor of any material 6560 the theory of the anomalous skin effect in anisotropic metals the theory of the anomalous skin effect in metals is extended to a uniaxial metal crystal containing two energy bands in each of which the energy surfaces are ellipsoids of revolution about the crystal axis explicit formulae are obtained for the extreme anomalous limit giving the dependence of the surface impedance on the orientation of the crystal axis both for a plane metal surface and for a circular wire the results are evaluated numerically for tin and the surface conductivity of a circular wire is found to show the minimum observed by pippard of the parameters can be chosen to give reasonable agreement with pippards results 6561 the anomalous skin effect in anisotropic metals application of the ineffectiveness concept of leads to the same answer as a sondheimers exact method above for spheroidal fermi surfaces and for a two dimensional isotropic metal a complete solution for the general case is given in a form which illustrates the potential value of anomalous skin effect studies as a tool in determining the shape of the fermi surface of a real metal 6562 the anomalous skin effect and the reflectivity of metals if the gas of conduction electrons is subject to internal friction the resultant energy dissipation contributes to the absorption factor of metallic conductors this contribution can become predominant at low temperatures if this effect is combined with those studied by dingle of september for the case of mean free path comparable with skin depth agreement between theory and experiment is improved 6563 striated high frequency discharge the forming of striae in ne and ar at a pressure of mm hg by hf fields of frequencies and is described in symmetrical hf discharge the striae are stationary but on disturbing the symmetry eg by using electrodes of unequal dimensions the striae are set in motion their velocity in electropositive gas is of the order of the drift velocity of the positive ions both external and internal electrodes were used in the experiments 6564 theory of striae in gas discharge equations are derived connecting the spacing of striae with the radius of the discharge tube the diffusion coefficient and other parameters the calculated spacing is in good agreement with the spacing observed by dzherpetov and zaitsev above and others 6565 the hollow cathode effect and the theory of glow discharges the electric field between two plane parallel cathodes was investigated by observing the deflection of an electron beam and simultaneously noting other discharge parameters results show that the field in the two cathode dark spaces falls linearly with distance from the cathode and thus the net space charge density is constant as in a conventional discharge the dark sace length was also determined the conclusions lead to a theory of glow discharges which takes account of the effect of ultraviolet quant from the glow on the photoelectric emission from the cathodes the discrepancy between earlier experimental results showing that ions of energy of the order of cathode fall of potential arrive at the cathode and classical calculations leading to low ion energies is resolved by allowing for small angle scattering and charge transfer 6566 electrical circuit for the direct determination of the energy distribution function of secondary electrons a circuit modification of the retarding field method is described by means of which the current voltage characteristic is differentiated this results in improved accuracy and resolution as compared to numerical differentiation results of measurements on a oxide caesium cathode are shown graphically 6567 anomalous electron emission from tungsten heated by high current density pulses results of this experimental investigation using microsecond pulses with current densities up to about show that the instantaneous electron emission from w can exceed by a factor of the steady saturation emission at the melting point 6568 secondary electron emission from thoria the dependence of the secondary emission coefficient on primary electron energy and on target temperature was determined experimentally for thoria layers of thickness deposited on ta the effect of pre treatment by heating to temperatures up to is shown 6569 method of investigating secondary emission in conductors bombarded by ions several oscillographic methods are discussed an the double modulation method is described in detail the ion beam is modulated by a rectangular pulse and the secondary emission electrode potential by a lf sawtooth pulse the principal advantage of this method is the possibility of separating the true secondary ions from those produced by the heating due to the bombardment oscillograms of the current voltage characteristics of the secondary emission are shown for ta and w specimens bombarded by rb ions 6570 theory of probe in plasma part an expression is derived for the electron current into a spherical probe which is at the potential of the space in an undisturbed electron plasma the dependence of the current on the probe dimensions and the electron mean free path i is indicated 6571 dipole resonant modes of an ionized gas column a quasistatic treatment is used to show that numerous oscillation modes are possible in a cylindrical column of ionized gas with a rotationally symmetrical distribution of electron concentration of electron concentration the theory provides a qualitative explanation of the rf reflection of em waves observed by romell of approximate values of the resonance frequencies are calculated assuming a gaussian radial distribution of electron concentration some of the results may be verifiable by meteor trail echo observations an investigation is also made of the finite energy loss and phase shift shown by herlofson of and others to occur when the real part of the dielectric constant vanishes 6572 a correction of the thomson formula for the coefficient of three body recombination between electrons and ions comment on the method of deriving thomsons formula of pointing out two objections to the expression used for effective mean free path 6573 solution of magnetostatic problem for unbounded homogeneous anisotropic medium 6574 asymptotic evaluation of the field at a caustic a determination is made of the field at and near the focus when a plane em wave is incident on a parabolic cylinder the case of a reflector comprising a segment of a circular cylinder is also considered 6575 diffraction at a circular aperture a discrepancy in the results obtained by two methods of calculating the diffraction field described earlier and of is examined the first method is correct within the approximation stated the second is invalid for a small region near the centre of the aperture when the wavelength is insufficiently small 6576 theory of diffraction at a sphere taking account of the surface wave theory developed previously of is applied to the case of a sphere the main difference found is an abrupt phase change in the surface wave a as it passes over either pole 6577 diffraction of cm electromagnetic waves by cylindrical objects a brass tube and a hard rubber rrod both of diameter and length were used as obstacles in the path of a plane pulsed wave with the electric vector parallel to the cylinder axis observations were made of the diffraction patterns in planes perpendicular to the direction of incidence experimental results for the brass cylinder are in good agreement with calculations based on scalar diffraction theory the patterns for the rubber rod exhibit a pronounced peak immediately behind the rod and differ in other ways from the patterns for the brass tube particularly in the vicinity of the shadow the results are compared with those obtained by kodis of 6578 the propagation of electron space charge waves in waveguides and tubes with periodic structure 6579 method for measurement of absorption coefficients by microwave spectroscopy a technique using a modulated stark cell is described with the aid of a diagram of the experimental set up errors are estimated to be less thzn 6580 focusing electrified particles a relation is found between h th magnetic field strength and the coordinate such that the trajectories of charged particles in the xy plane pass through both the origin and a given point on the y axis the particles are assumed to have equal mass and charge h is derived in the form of a simple series 6581 physics of thin metal and semiconductor films a survey of work on formation structure and electrical properties of thin metal and semiconductor films surface states and their effect on the properties of semiconductor films theoretical work on thin metal films the present position is briefly but critically discussed and in particular the points of agreement and disagreement between experimental results and theory are noted 6582 the capacitance of an anchor ring an approximate value of where r is the mean radius is derived 6583 observations of the cm line from the magellanic clouds first observations of this neutral hydrogen line from an extragalactic source are reported 6584 the distribution of radio brightness across the crab nebula interferometer measurements were made at with aerial spacings on an axis and on a axis information regarding phase was obtained from independent measurements of the position of the source results show that brightness distribution is symmetrical and that optical and radio centres of the source coincide within of arc 6585 the motion of magnetic fields the temporal change of a magnetic field cannot b described as a motion if it involves interlinking of the lines of force it is shown that the idea of motion can be retained if the lines of force are regarded as being disconnected on a suitable surface a process is described by which magnetic flux can be generated other than at a neutral line 6586 electric field induced by vertical component of geomagnetic variations an expression is derived for the horizontal electric fiel in the earth due to a varying geomagnetic field assuming regions of unequal electrical conductivities graphs based on published experimental determinations of the electric field components and the geomagnetic field show typical hour cycles and indicate the degree of correlation between the electric and geomagnetic fields see also of 6587 an effective ground conductivity map for continental united states discussion of a map based on the sectional maps described by kirby et al of august which has been adopted by the fcc 6588 atmospheric oscillations at high altitudes and their relation to geomagnetic field variations equations developed previously of august chakrabarty and pratap are used to calculate the s variations of h ad v by assuming different phases for the atmospheric oscillations in the ionosphere layer which is the seat of the ring currents and comparing the results with observed variations of the magnetic field a phase of is found to give the best fit 6589 the action of solar particles in the ionosphere an examination is made of typical changes occurring in the ionosphere during the penetration of solar particles inside and outside the zone of northern lights and martyns extension of the chapman ferraro theory is discussed 6590 energy and duration of a sudden ionospheric disturbance a study was made of the maximum amount of energy which might be absorbed by the atmosphere down to during a sudden ionospheric disturbance assuming that the ionization is caused by lyman radiation from the sun and that all oxygen present is ionized the energy absorbed by the sunlit hemisphere is ergs 6591 symposium on ionospheric storms may the full text is given of papers presented at the symposium 6592 a theory of diurnal magnetic variations in equatorial regions and conductivity of the ionosphere e e region part the electrical conductivity of the e region is calculated in some detail for the factor by which the tidal oscillation of the e region exceeds that at ground level should be less than in oder to give the observed lunar magnetic variation the calculated lunar vertical movement of the e region is nearly in phase with that observed in south england and nearly opposite at canberra a possibility is shown that the calculated lunar vertical movement of the f region roughly agrees with that observed it is suggested that the vertical drifts of the f region near the magnetic equator may be much greter than those in the other latitudes 6593 ionospheric variations associated with geo magnetic disturbances part variations at moderate latitudes and the equatorial zone and the current system for the sp field variations of the e and f regions are studied the current system for the s field is calculated the ionospheric variations may be due to the effect of a vertical drift by the earths magnetic field and the electric field of the s current 6594 disturbances in the ionosphere during the geomagnetic stormof april analysis shows that commencement of disturbances of the f layer electron density and virtual height coincided with the commencement of the main phase of the magnetic storm 6595 characteristics of ionospheric disturbance during a sever magnetic storm data from ionospheric stations relevant to the storm of are analysed and the salient characteristics explained 6596 a radio astronomical investigation of drift movements in the upper atmosphere discussion of night time observational data of the diffraction of rf radiation from radio stars by moving irregularities in the ionosphere f region obtained at jodrell bank during the period using three receiving equipments triangularly sited and operating at the drift velocity at temperature latitudes is normally of the order of during the first half eastwards the reversal occurring around in the auroral zone the velocity is of the order of and the changes in direction are less marked results for points separated by suggest that the drift speed and directions are the same over wide areas 6597 glow of the night sky in the waveband results are reported of energy flux measurements made at the gorni observatory altitude m in september the average flux per second crossing received from steradian in the direction of cygnus varied between and units not stated referred to a wavelength of the apparatus used is briefly described 6598 observations of the electric field of the atmosphere at monaco during the partial solar eclipse of june very high values of field strength were observed after the maximum of the eclipse 6599 atmospherics due to fronts in the upper atmosphere reference to meteorological data indicates that atmospherics observed in a zone of the pacific ocean in latitude especially in autumn and winter are generated in the convergence region l of fronts in the upper atmosphere 6600 the frequency response of a certain class of nonlinear feedback systems a method is described for predicting the frequency response of feedback systems including one single valued nonlinear element followed by a low pass filter the conditions giving rise to gain discontinuity or jump phenomenon are investigated experimental results obtained with an electronic servo simulator justify the use of the analytical technique 6601 remote control of radio receivers a zero seeking servo tuning control designed for operation over a single post office telephone line is described the signal from the tuned receiver passing along the control lines maximum separation is seven loop miles for underground routes or loop miles depending on the type of cable the circuit is essentially a wheatstone bridge with two variable arms one of which is carried to the remote point along the line the detector comprises a second harmonic magnetic modulator combined with valve amplifier 6602 a stable dc source of low voltage with low internal resistance a mainsdriven source providing a direct voltage of constant to within for mains voltage variations of and current drain of uses a magnetic amplifier as an impedance transformer to provide a very low output resistance from a gas filled reference tube type long term stability depends mainly on the reference tube which has a nominal drift of per h after an aging period 6603 the design of high efficiency ratio frequency eht supplies difficulties associated with the use of air cored step up transformers for the production of high voltages are discussed designs in which these difficulties are eliminated or alleviated are obtained by using transformers with ferroxcube cores simple design procedure is outlined with numerical examples 6604 a current stabilized photomultiplier power supply stabilization is based on the series connection of two cathode followers tests on the circuit are reported voltage is maintained constant to within one part in 6605 selenium rectifier disks as voltage dependent resistors for amplification of fluctuations of a component voltage and voltage stabilization particularly amplitude limiting 6606 investigation of rectification properties of se hgse contact the experimentally determined rectification coefficient maximum occurring at is for pure se and for se current voltage characteristics were investigated for rectifiers with the hese prepared by exposing se to hg vapour or to liquid hg se crystallized at various rates and temperatures various electrode base materials and se of two different grades of purity the results are shown graphically 6607 asymmetry in conductivity of some selenides the experimentally determined current voltage characteristics of a cuse me rectifier are discussed the ratio of reverse to forward current varies between and the power handling capacity is and the blocking layer is stable even at the principal disadvantages of this rectifier are the large hysteresis effect and the de forming after prolonged storage other selenides and selenide metal combinations are briefly noted 6608 universal circle diagrams for certain radio syst systems when the q of a system eg a lecher line is nearly constant over the pass band circle diagrams similar to those previously obtained for quartz crystals of can be established 6609 transistors part discussion of transistor equivalent circuits analogies between transistors and electronic valves practical transistor circuits noise operational frequency limits part 6610 transistor oscillators detailed discussion of various transistor circuits including different types of sine wave generator relaxation oscillators and a combination of the two giving self quenching oscillations or stabilized frequency division 6611 frequency stabilization in the microwave range descriptive review of different methods including those using frequency discriminator circuits and spectral line systems 6612 production control of printed resistors factors affecting the reproducibility of resistors produced by the silk screen process are discussed those requiring especially careful control are carbon concentration squeegee speed temperature of application curing schedule and application of protective coating 6613 electronic switching elements for communications engineering a review of the characteristics of available glow discharge tubes thermistors thyratrons transistors and multi electrode counter tubes with discussion of their possible applications in telephony circuits 6614 new trigger circuits for use with cold cathode counting tubes a description is given of several trigger circuits devised for use particularly with dekatron tubes of bacon and pollard the circuits can be used in the construction of a scaling unit which can subtract as well as add the counting losses of such a unit when used on random pulses are considered 6615 high speed counter uses ternary notation the basis of the counter is a flip flop circuit modified to have three stable states by insertion of a diode coupling circuit between the cathodes a nine stage circuit is described operating reliably up to counts of per sec the indicating system may use either one or two lights per stage 6616 rf characteristics of capacitors comment on of 6617 development of vacuum capacitors vacuum capacitors are particularly suitable for hf hv operation in airborne radio equipment an account is given of the development of two types one having a capacitance of within at a peak working voltage of the corresponding figures for the other being and electrical and mechanical test methods are outlined 6618 resonance characteristics by conformal mapping the expression where is termed the resonance function it represents the impedance of the series connected lrs circuit or the admittance of the parallel connected circuit to conformal mapping of the plane on to the plane gives a figure which illustrates the meaning of the resonance function for complex frequencies typical examples illustrate the application of the figure to the parallel circuit and to one of its intrinsic generalizations the mapping of the reciprocal functions and is also considered 6619 networks with maximally flat delay corrections to paper noted in of 6620 waveform computations by the time series method the time series method greatly reduces the work of computation in the solution of waveform or transient response problems of cascade connected linear quadripoles practical procedures for dealing with time series are described and illustrated by numerical calculations relating to waveform tests on a mile coaxial cable television link with a nominal upper cut off frequency of 6621 the numerical calculation of filter circuits with generalized parameters using modern theory with special attention to cauers work corrections to paper abstracted in of 6622 the transmission range of two circuit band pass filters particularly for large bandwidths graphical methods of calculation are developed which give results with accuracy adequate for practical purposes the methods are applicable to unsymmetrical and wide bandfilters and also to narrow band symmetrical filters 6623 synthesis of narrow band direct coupled filters a general synthesis procedure is described that is based on an approximate first order equivalence between direct coupled and coupled filters the transmission characteristics computed for a cavity filter with an overall q of are in excellent agreement with measurements 6624 a frequency eliminating transconductance bridge description of a bridge circuit which completely eliminates a single frequency component n and also partially suppresses a band of frequencies whose width can be varied within wide limits by suitable choice of circuit parameters applications to ripple elimination n and to band elimination amplifiers are discussed 6625 optimum filters for the detection of signals in noise 6626 the detection of a sine wave in the presence of noise by the use of a nonlinear filter 6627 a general network theorem with applications it is proved that in a network configuration with branch currents i satisfying the node equations and branch voltages satisfying the mesh equations summed over all branches is zero using this result it is possible to prove the energy theorem and the reciprocity relation of networks and to show that if arbitrarily varying voltages are applied to a pole network at rest the difference between the electric and the magnetic energy at any instant depends only on the admittance matrix of the pole network and not on the particular network used to realize this matrix 6628 the utility factor in circuit diagrams the importance is stressed of laying out circuit diagrams so that the working of the circuit can be easily and clearly grasped the common type of drawing office diagram may look neat but usually requires to be radically rearranged to indicate circuit functions it is suggested that circuit diagrams should be drawn on the same general plan as block diagrams a standard lay out being used for common sub circuits and only lines carrying signals being included 6629 negative feedback tone control the circuit described provides independent control of bass and treble response without switching the rc arrangement on each side of a bass control potentiometer is made symmetrical so that it may be combined in the feedback line with a treble control circuit the potentiometer of which has an earthed centre tap at medium and high frequencies p is effectively shorted with both potentiometers at a middle setting response is level 6630 parallel tuned circuit periodically switched to a direct current source circuit phenomena with the switch closed open are analysed in turn linear solutions being obtained the complete solution is then obtained by matching the boundary conditions for the two cases this solution includes sinusoidal sawtooth and complex waveforms dependent on circuit parameters and switching period elimination of dissipative circuit elements simplifies the general solution with resulting clarification of the operation of the circuit tests with a mechanically switched circuit verified the theory the entire gamut of waveforms being obtained by variation of circuit parameters and switching period 6631 on the scattering matrix of symmetrical waveguide junctions fundamental properties of the scattering matrix are derived tomonagas theory for lossless resonant structures is extended to include the effect of losses the structural symmetry of microwave circuits is discussed junctions consisting of two parallel sections of rectangular waveguide with one side common being particularly considered the theory of directional couplers with such symmetry is developed an attenuator and standard matching transformer each having a directional coupler as a basic unit are described other forms of resonant coupling are discussed 6632 national electromagnetic oscillations in a rectangular cavity with walls of finite conductivity in the limiting case of infinite wall conductivity the te and tm self oscillations have the same frequency this does not hold for finite wall conductivity in which case linear combinations of the te and tm oscillations with the same frequency exist these combinations termed matched oscillations represent to a first approximation the natural oscillations of the actual resonator the determination of the characteristics of these matched oscillations is based on the solution of a simple geometrical problem from which the damping and mistuning are calculated 6633 oscillator systems including elements having inertia analysis is given for oscillator circuits both with and without valves including elements whost resistance varies with temperature 6634 amplification and bandwidth of video amplifiers the characteristics of the ideal amplifier with constant amplification and constant phase transit throughout the pass band are briefly reviewed and the principal types of amplifier are analysed with particular reference to amplification and bandwidth the theoretical maximum values of these parameters are determined for the various types and compared with the values obtained in practice and with one another arrangements using distributed amplification ad having very wide pass bands are considered briefly 6635 a mathematical analysis of a dielectric amplifier the fundamental principles of operation of dielectric amplifiers are outlined and a basic circuit with resistive load is analysed in detail it is assumed that the hysteresis curve of the dielectric is represented by a hyperbolic sine function expressions are calculated for the steady state input and output currents and the time constant of the amplifier is estimated from consideration of the transient response 6636 high gain dc amplifiers 6637 the design of a practical dc amplifier based on the second harmonic type of magnetic modulator discussion description of the development of an amplifier based on the work of williams and noble of including details of a oscillator with second harmonic distortion a low pass filter to prevent power from the oscillator reaching the dc source a phase sensitive rectifier switching and overall dc negative feedback arrangements 6638 a circuit for the limitation of discharge in gm counters a two valve feedback amplifier is used to limit the discharge to a small part of the total length of the wire full sensitivity being restored in about 6639 electrets general discussion of the properties of electrets applications in electrometers and in apparatus for detecting the presence of radioactive radiation are noted 6640 the motiton of charged particles in the magnetic field of a linear current and the electric field of a cylindrical capacitor the particle trajectories for such a system are determined under certain conditions the system may be used for focusing beams of charged particles 6641 an integrable case of electron motion in electric and magnetic field the case is considered of a two dimensional electric field with the potential given by applied together with a uniform magnetic field in the direction the path of an electron is an ellipse whose centre moves in a hyperbola the electron may drift into regions of higher or lower potential 6642 calculation of plane electron trajectories in particular electric and magnetic fields by means of complex vector loci further examples of the method previously described of include trajectories in a time variable homogeneous magnetic field circular paths in a suitable em field as for the betatron 6643 a note on the theory of semiconductors two different theories are obtained depending on whether the free energy due to the spin of electrons in impurity centres is or is not taken into account the second of these alternatives is essentially that adopted by wilson and has been used almost universally though the first which is that adopted by mott and gurney electronic processes in ionic crystals can be applied to degenerate semiconductors and is to be preferred 6644 a theory of contact noise the outlines of a theory of contact noise are presented based on the idea that it is due to temperature fluctuations in the neighbourhood of the contact detailed theory is being prepared for publication 6645 the apparent high frequency resistance of a conducting layer of finite width parallel to an infinite plane conductor opposing field and induced currents formulae are derived for the case where the conducting strip comprises a winding with a number of separate turns 6646 currents induced in a plane conductor of great width by a plane strip of small width carrying a high frequency current approximate formulae giving the variations of resistance and self inductance of the inductor 6647 thermoelectric measurements on p type silicon the thermoelectric power positive with respect to cu is about for material of purity falling to about for purity and rising again to for purity 6648 high frequency electrical breakdown of gases theory is presented which is applicable to any gas over a wide range of pressure experimental results for h r are in agreement with the theory 6649 sparking potentials in a transverse magnetic field by taking account of the distribution of electron free paths and of electron recapture by the cathode a theory is developed which is in better agreement with observation than tht of valle vol 6650 a resonance phenomenon in electrodeless hf gas discharges with superposed magnetic field experiments in atmospheres of h and ar are described which show that the resonance effect previously noted of koch and neuert is associated with a sharp drop between two peaks in the intensity of the emitted light it occurs always at the same value of the field strength 6651 dimensions and units by considering the expression for power in terms of the dimensions m l and t on the one hand and in terms of current and voltage on the other hand it follows that quantity of electricity may be regarded as having the dimensions l using this result all the other electrical magnitudes can be expressed in terms of m l and t with integral indices the separate question of the best system of units is discussed briefly the mks system fits well with the above dimensional system 6652 some post war developments in magnetism presidential address to the physical society may the extension of knowledge of the ferromagnetic domain through the work of neel and others and the systematic use of the bitter powder figure techniques is surveyed and the main resonance phenomena and experiments on the diffraction of neutrons by antiferromagnetic crystals are described 6653 diffraction of electromagnetic waves by a half plane the observed intensity and phase values of the field near the edge of a thin high conductivity sheet are compared with sommerfelds rigorous solution for an infinitely thin perfectly conducting half plane good agreement being obtained results for sheets of different thicknesses and conductivities show the importance of these factors in determining the field near the diffracting edge 6654 experimental demonstration in the laboratory of the existence of magneto hydrodynamic waves in ionized helium 6655 reciprocity of the transmissive properties of any multiple layer for electromagnetic waves a full analytical proof is given that the transmission of a perpendicularly incident plane em wave through a multiple layer consisting of any number of plane parallel absorbing or nonabsorbing components is the same in both directions if the first and last media have the same absorption index ie if if and are different the ratio of the transmission factors in the two directions is treatment is simplified by applying quadripole theory but this does not give a closed expression for the overall transmission factor the validity of the kirchhoff inversion principle is illustrated 6656 line breadths of the microwave spectrum of oxygen the microwave absorption band for consists mainly of lines around the wavelength mm with spacings of only a few hundred the intensity of the band depends on the variation of line widths with pressure this variation is expressed in terms of the line breadth parameter defined as the half width measured at half intensity of an absorption line at a pressure of atm determinations of this parameter made with a zeeman modulation spectrograph are reported and discussed and an interpretation of the self broadening collision process is developed measurements are also reported for broadening due to collisions with foreign molecules 6657 radio astronomy a general review of the subject with a description of methods of measurement and discussion of the theory of galactic and solar rf radiation 6658 solar outbursts at mm wavelength report of results obtained at the naval research laboratory washington dc with an aerial having an aperture of and correlation with observations at wavelength and with the occurrence of solar flares typical records are reproduced the mm bursts are in general of smaller amplitude and of much shorter duration than the bursts observed on greater wavelengths 6659 radio observations of the solar eclipses of september and february preliminary report of results which were confirmed during the february eclipse by observation at marcoussis near paris and at dakar french west africa see also of may 6660 radio frequency radiation from tycho brahes supernova observations at a frequency of revealed a radio source whose coordinates agree closely with those of the supernova of data for the supernovae of ad and are compared 6661 line emission from interstellar material in the radio frequency range historical review of published results including particular reference to the hydrogen emission line at 6662 on the possible relation of galactic radio noise to cosmic rays the possibility is considered that cosmic rays are accelerated in regions of the galaxy with intermediate particle density cm a conservative estimate of the magnetic fields in such regions would lead to a radio noise flux of the observed order of magnitude the observed spectrum could easily be produced 6663 occultation of a radio star by the solar corona interferometers of high resolving power were used to reduce the amplitude of the record from the undisturbed sunduring observations of the radio star in taurus as it passed near the suns southern limb a decrease of amplitude occurred on both and when the angular separation of star and sun was as great as ten times the angular radius of the visible disk the amplitude decreases being greatest when the angular separation approached its minimum value the results will be discussed in a later paper 6664 on the dielectric constant of the water in wet clay an explanation is put forward of the variation with moisture content of the permittivity of soil samples previously observed by cownie and palmer of it is suggested that relatively dry clay consists of closely packed water coated particles in an air matrix while relatively wet clay consists of particles uniformly distributed in a water increasing from the value for bound water about to that for free water about as the percentage of water is increased 6665 maxwells equations for three layered media and their application to the theory of the movement of a magnetic storm solutions of the characteristic equations for ideal and for real three layered media are given application is made to discussion of the characteristics of the marginal layers and calculation of the velocity of propagation of the elements of a magnetic storm other possible applications of the theory given are noted 6666 ionospheric disturbance of february a short account of observed variations of night sky brightness f layer limiting frequency radiocommunication with north america and radiosonde measurements of air temperature a solar origin for the disturbance cannot be assigned with certainty 6667 a self consistent calculation of the dissociation of oxygen in the upper atmosphere a model is considered similar to that previously proposed of but with the requirement of radiative energy balance abandoned and with a particular temperature distribution assumed calculations indicate a much narrower dissociation region occurring at a lower altitude 6668 the bbc ionospheric storm warning system the various data on which the bbc warning system is based are noted and a statistical review is presented of the correlation between actual and forecast ionospheric conditions in the period the accuracy of the forecasts during this period was of the order of 6669 correlation between the mean level of atmospherics and the degree of intelligibility in a kilometre wave radio link measurements made on june at the laboratoire national de radio electricite using a wavelength of are reported the signalling speed was words min and the signal strength at the receiver a vertical aerial was used and atmospherics were received simultaneously with the signal the numbers of wrong or indecipherable figures and letters received are indicated on a graph of mean field strength of atmospherics plotted against hour of day good correlation is observed 6670 the stability of a multiple linear servo system 6671 recent developments in vibrators and vibrator power packs discussion of the grade type of vibrator which is expected to give at least the hour life required for services equipment reasons are given for specializing mainly on synchronous split reed separately driven types an outline is given of extensive investigations of contact phenomena vibrator design and the circuits fed by the vibrator a range of vibrators is described with outputs from a few milliwatts to over very high conversion efficiencies have been obtained 6672 titanium dioxide rectifiers a detailed account of work carried out up to the present on the to film rectifiers previously noted of a feature of great practical importance is the improvement in performance with increase of temperature for a particular steam treated sample the forward current increased while the backward current decreased slightly as the temperature was increased up to heating to however causes irreversible damage differences of characteristics observed with different counter electrode metals are discussed a marked change of properties being noted when zn was used further investigations are in progress 6673 voltage regulators using nonlinear elements a simple method of determining the parameters of circuits providing reference voltages working o into a constant load is described and is illustrated by calculations for arrangements using either a single element or a pair of the nonlinear resistors manufactured by the compagnie generale de tsf of power limitations restrict the field of application of this type of voltage regulator 6674 how to design vr tube circuits families of supply voltage supply series resistance curves for various voltage regulator tubes are used as the basis for designing stabilized direct voltage supply circuits 6675 theory of the prediction and filtering of stationary time series according to norbert wiener digest of wieners book the extrapolation interpolation and smoothing of stationary time series with engineering applications of 6676 equipment for amplification of weak photoelectric currents description with detailed circuit diagram of equipment using a double electrometer valve mazda type the currents in which are modulated by a square wave applied to the extraction grids the photoelectric voltage being applied to the control grids 6677 changing the phase of a low frequency sinusoid description of various methods suitable for manual or automatic control or combined automatic and manual control of the phase of a sinusoidal low frequency voltage 6678 modified magic tee phase shifter for microwaves the modified unit described has the symmetrical arms parallel to each other thus allowing both short circuiting plungers to be linked to a common drive the e and h plane arms are replaced by odd and even coupling slots owing to the existence of several sources of impedance mismatch in the complete phase shifter which uses a second magic t junction a special alignment procedure is necessary 6679 basic operating principles of magnetic amplifiers 6680 low input power level magnetic amplifiers 6681 rules of similitude for magnetic amplifier systems rules are established which enable the properties of magnetic amplifier systems to be deduced from the results of suitable tests on a model the amplifier or analogue computer the method covers cases in which model and prototype have different core materials and different circuits 6682 the application of a cycle magnetic amplifier to a position indicating servomechanism 6683 a magnetic amplifier of high input impedance 6684 use of the flux charge concept in magnetic amplifier analysis 6685 a series magnetic amplifier with inductive loading analysis and discussion of the manner in which the current waveform is affected by varying the circuit resistances inductances or control voltage digest only full paper to be published in trans amer inst elect engrs 6686 a synchronizing circuit for variable input voltages description of a circuit suitable for use with a cro 6687 boroncarbon resistor characteristics further developments are described leading to the mass production of resistors with extremely stable characteristics see also and of grisdale et al 6688 shaping of nonlinear resistor characteristics feedback circuits are described which enable a wide variety of characteristics to be obtained with a single resistive element 6689 effect of pressure on the resistance of a thermistor measurements at constant temperatures from and pressures up to show that the relative diminution of the resistance of a thermistor for a given change of pressure is practically independent of temperature and is given by the formula p being expressed in kg cm 6690 all triode electronic switch the basis of the arrangement described is a gate circuit using two high triodes cathode coupled respectively to two high transconductance triodes the grids of the latter being coupled to the anodes of a multivibrator 6691 metallized paper capacitors review of the development construction and characteristics of this type of capacitor particularly those using impregnated paper test methods are noted 6692 high temperature operation of metallized paper capacitors discussion of results obtained with capacitors impregnated with aerolene a solid polyester which permits operation at without derating and up to with a derating of the capacitance value at being higher than at room temperature 6693 an electronic square law circuit for use with a graphic recorder the curvature of valve characteristics is used to produce an output voltage proportional to the square of the input voltage circuit details are given of a mean square value meter suitable for graphic recording of the output 6694 performance of ultrasonic vitreous silica delay lines 6695 the synthesis of a network to have a sine squared impulse response the method of moments of the mean moment type used by moss is applied to the problem of designing a network with an impulse response of prescribed form the method is not applicable in all cases but is particularly suitable for the design of a low pass system with not too sharp a cut off and not too oscillatory an impulse response calculation for the case of the sine squared pulse results in design data for a ladder network of inductors and capacitors with resistive terminations the discrepancy between the impulse response curve and the exact sine square curve at no point exceeds of the peak amplitude of the pulse 6696 new graphical methods for analysis and design reply to comment by schneider of on paper noted in of saraga and fosgate 6697 the transient response of rf and if filters to a wave packet summary only analysis based on fourier integral transforms is applied to two particular circuits a single stage of tuned anode coupling a single stage of tuned transformer coupling the analysis is valid for circuits of any bandwidth particular attention is paid to the build up time of a transient which for a band pass network is usually assumed to be inversely proportional to the network bandwidth the analysis shows that this assumption is correct for the tuned anode coupling circuit if the ratio of the half bandwidth to the resonance frequency is less than unity for the tuned transformer circuit however the rule does not hold good since for a given bandwidth there are many possible transfer impedances and hence transient responses the rule should therefore only be applied to circuits which its application is shown to be legitimate 6698 high q low frequency resonant filters two resonant filters are described in which a q factor is obtained by application of positive feedback normal methods used for q measurement are of little use on these circuits a method based on the relation of q to the transient response is described 6699 printed unit assemblies for tv etching and silk screening techniques and their suitability for the production of various circuit elements are discussed experimental results are quoted which show that the performance of etched coils compares favourably with that of wire wound coils 6700 etched circuits a brief note on the technograph system for producing printed circuits and components with special reference to the production of mains transformers 6701 printed circuits for home radio receivers units for valve superheterodyne sets are produced by pl ting conductors on to a plastic base in which holes have been punched previously the walls of the holes are plated at the same time thus providing connections and terminal points 6702 new developments in the auto sembly technique of circuit fabrication various applications of the technique previously described of danko and lanzalotti are reviewed new copper faced plastics are suitable for production of equipment for operating temperatures up to use of a solder resistant paint or lacquer enables joints only to be soldered in the soler dip process typical examples of circuits and assemblies produced by this method are illustrated 6703 graphical analysis for circuits containing overdriven vacuum tubes methods of approach and graphical constructions for use in analysis of circuits such as those used for pulse forming and wave shaping are described with applications to particular circuits 6704 thickness vibrations of piezoelectric crystal plates continuation of investigation noted in of the retroaction occurring in piezoelectric processes modifies not only the modulus of elasticity but also the direction of motion the influence of this secondary effect is studied and a complete theory of the mechanical electrical oscillating system is developed for plates of infinite area for plates of finite area the amplitude distribution becomes nonuniform the effect of this modification is studied in relation to the equivalent circuit 6705 a method of analysis of fundamental and overtone crystal oscillator circuits use of the method of loci facilitates comparison between the pierce miller and the pierce colpitts type of crystal oscillator circuit type is much more suitable for harmonic oscillation and very high frequencies because it requires less mutual conductance type is under certain conditions particularly suitable for frequency standards circuits with the crystal connected between anode and cathode have under certain conditions low power dissipation in the crystal conditions for frequency stability are analysed and a simple and accurate method of determining crystal parameters is described 6706 broad band coupling unit for power line carrier with associated potential device 6707 some perturbation effects in microwave cavities operating in degenerate modes theoretical investigation of the perturbation caused by introducing a metal rod into a cylindrical cavity operating in the companion modes te and tm the changes in q value and resonance frequency are different for the two modes the magnitudes of these changes as dependent on the radius and depth of insertion of the rod are considered 6708 precalculation of the mains loading in the design of high frequency generators using quenched sparks the power required to drive a hf generator of the air blast quenched spark type is determined from consideration of the generator equivalent circuit such generator are frequently used for hf inductive heating 6709 the effect of noise on the frequency stability of a linear oscillator the standard conditions for a sinusoidal oscillation are that the attenuation and net phase shift around the closed loop be zero random fluctuations are relied upon to start the oscillation if the level of oscillation is to remain finite in the continued presence of noise the oscillating loop must hav some attenuation and functions like a highly regenerative amplifier with a loop gain very nearly unity accordingly the oscillator produces not a single frequency but rather a narrow band of noise that causes instability in the magnitude and in the apparent frequency of the output thes instabilities are discussed for oscillators in which all elements are linear except for some slow acting amplitude control the bandwidth of the noisy oscillation can be predicted from easily measured system characteristics several methods of defining the frequency of the output are considered with special reference to precision measurements in general the measured frequency departs from the zero phase shift criterion and is dependent on the measuring equipment methods of minimizing instabilities due to noise are investigated 6710 the effect of long transmission lines on klystron oscillators discussion of effects occurring when the oscillator load is several wavelengths away from the valve equivalent circuits are applied to analysis of the fm distortion and of the discontinuities in the klystron characteristics experimental results are presented which corroborate the theory 6711 a hard valve pulse generator description with circuit details of a triggered generator producing pulses of width variable from to slight modifications result in a free running generator a triggered generator of pulses which is easily converted to free running with a repetition period od of ms pulses of either polarity can be used for triggering 6712 a design for a constant volume amplifier the so called constant volume amplifier is used extensively on overseas telephone circuits so that a reasonable modulation depth can be used without the risk of overmodulation circuit details are given of an amplifier which is simple to set up and reliable in operation and which uses a cathode follower circuit as a variable impedance the results obtained are comparable to those given by conventional networks using metal rectifier bridge networks 6713 a feedback pair video amplifier details are given of a circuit with a gain of frequency range and a midband output linear up to rms 6714 cathode follower as high impedance input stage if a cathode follower is used as the first stage of an amplifier in order to raise the input impedance the conductance of the grid leak between grid and cathode may not be negligible compared with the conductance of the source between grid and earth from which the signal is derived the noise performance under these conditions is examined both in terms of the cathode follower regarded as a voltage device and in terms of the noise figure which takes account of the difference between input and output impedances 6715 amplifier noise particularly in the audio frequency range noise in input stages is investigated nyquists formula is taken as starting point and only simple mathematics is used noise in resistors is dealt with by the usual device of substituting an equivalent noise voltage source in series with a noise free resistor the input circuit of a capacitor microphone is considered particularly its noise voltage is determined largely by the slope and position of the low frequency flank of the response curve noise in oscillating circuits is associated with the damping resistance formulae are given for calculating the equivalent noise resistance of valves for the same operating point a valve produces much more noise in the af range than at higher frequencies the signal noise ratio of a circuit with ideal input transformer is considered and the condition for obtaining maximum sensitivity is derived 6716 dc amplifiers with low pass feedback brockelsby of and mayr of have shown how to design a voltage amplifier of high stability and with a response curve of maximum flatness but their method has the disadvantage that the amplifier must have a particular value of loop gain if the loop gain is varied the overall frequency response will be seriously affected and the amplifier may be unstable if used as an integrator or differentiator the method is extended to cover the case of a dc amplifier with a low pass feedback network the gain of such an amplifier can be varied over a wide range without appreciable effect on the overall frequency response so that it can be used as a stable differentiator or integrator the output noise level may limit the field of application 6717 representation of experimental results by equations an analytical method is discussed for determining the form of the equation representing the measurements of a dependent variable as a function of an independent variable the accuracy with which values can hence be found for the numerical coefficients is examined 6718 representation of experimental results by equations new useful formulae methods are outlined for determining the coefficients of equations fitting a series of observed values weighted or not weighted 6719 transfer and transport of energy by resonance processes in luminescent solids experiment shows that the ratio between the efficiencies of activator and sensitizer fluorescence increases with increasing sensitizer concentration this is at variance with theory an explanation is given and a theory is developed that accounts for the temperature dependence of the energy transfer 6720 the uniqueness of the solutions in the rigorous theory of diffraction the solutions previously given by honl of not only satisfy the usual conditions but also meet the requirement that no subsidiary wave fields be radiated from the edges of the aperture so that the uniqueness of the solutions is established 6721 a simplifying technique in the solution of a class of diffraction problems considerable simplification of the treatment of diffraction problems leading to wiener hopf integral equations results from taking the transform before applying the boundary conditions this is demonstrated by consideration of the sommerfeld problem for the semi infinite plane the diffraction of small amplitude sound waves by a semi infinite rigid cylinder the diffraction of a plane em wave by a finite waveguide a vector field 6722 new direct vision stereo projection screen russian work on stereo projection screens is briefly described and a more detailed account is given of a system developed in france by f savoye see rev photographic optique this uses a rotating cone shaped grill moving round the screen thus enabling collective direct vision of stereoscopic pairs in either monochrome or colour 6723 motion of gaseous ions in a strong electric field part the theory previously given for uniform ion densities of is extended to deal with nonuniform densities errata in the earlier paper are indicated 6724 mechanism of resistance variation in a magnetic field a model with two layers having different resistances and resistivities is proposed to explain the hall effect and the variation of resistance of a material subjected to an electric field 6725 theory of the electrical conductivity of metals in a magnetic field formulae are derived for determining the resistance of metals in a transverse and in a longitudinal magnetic field taking into account the quantization of the movement of electrons in a magnetic field 6726 theory of the contact between a metal and a semiconductor for a large contact potential difference the iv characteristic for the contact between a metal and a semiconductor is calculated for the case when the contact potential difference is so great that the type of conduction of the semiconductor near the contact is altered from the electron to the hole type the calculations cover the cases of plane knife edge and needle types of contact 6727 determination of electron density and collision frequency in a gaseous discharge by microwave propagation measurements the gaseous discharge to be measured fills a section of waveguide several wavelengths long and measurements are made of the absorption and phase shift of a low power microwave signal passing through the discharge results are quoted for ar at pressures respectively of and mm hg 6728 reliability of probe measurements in hot cathode gas diodes erroneous results may be obtained due to the work function of the probe altering during the measurements particularly when investigating tubes with oxide cathodes the measurement must be made immediately after cleaning the r probe in the experiments described a cro plotter was used which took ov only some seconds to record the whole probe characteristic in contrast to results obtained by other workers no deviation from the maxwellian velocity distribution of the plasma electrons was observed over a range of nearly four orders of magnitude of probe current 6729 theory of the propagation of waves in an electron beam an approximate theory is developed for the propagation of em waves in a waveguide filled with a dielectric when an electron beam passes through it it is assumed that electrons can move freely along the waveguide in the dielectric and that they form a beam completely filling it with certain assumptions the types and characteristics of the waves which can travel in such a system are determined for various conditions the results obtained can be generalized so as to cover the case of an arbitrary transmission line 6730 the motion of electrons in the field of a uniformly wound toroid the focusing properties of the toroid are investigated theoretically in relation to beta particle or other spectroscopes 6731 secondary electron emission from certain metals under the impact of positive lithium ions an arrangement for measuring the emission is described and results are given for some metals used in electron microscopy 6732 the relation between electrical and diffusion currents a linear relation is derived between the electric current through a conducting gas in a magnetic field and the currents due to diffusion of the charge carriers in the gas from this relation the vertical displacements of the ionosphere e layer due to lunar effects are determined from the current system inferred from the lunar changes of the geomagnetic field both the amplitude and phase of the displacement are consistent with observations if it is assumed that the main lunar current flows in the lower part of the e layer and that approximately equal numbers of ions and electrons are present at the point of observation 6733 theory of the plasma in a rarefied gas when the current strength varies general equations for relatively slow processes in a plasma are applied to the calculation of the concentration of electrons and ions when the strength of the current through the gas varies the partial de ionization of the gas when the current decreases and the residual concentration of electrons and ions after the current ceases to flow are determined 6734 calculation of the leakage flux of the pendent armature relay the magnetic conductivity of the space between core and yoke is determined by application of southwells relaxation method 6735 investigation of electromagnetic waves guided by helical conductors full theoretical analysis of the propagation of em waves along helical conductors shorter versions of parts of the paper hve previously been abstracted the continuous cylinder approximation and of gives a solution in good agreement with experimental results at frequencies sufficiently low and with the action of a narrow beam travelling wave valve the second method of analysis of based on the infinitely thin wire concept leads to difficulties in calculation but has more general application and is apparently correct to the second order of approximation its application to delay lines is illustrated results obtained by the two methods are compared of and discussed with reference to experimental measurements 6736 reflection of microwaves from metal plate media experiments were made using frequencies in the cm band to verify the theory worked out by lengyel of waveguide assemblies of various depths were used with the reflecting surfaces normal to the plates for single surface measurements the absorbing wedges described by ruze and young of were used phase and amplitude of the reflection coefficient were determined for angles of incidence and for various ratios between plate separation and wavelength double surface slab measurements were also made using assemblies of parallel plates instead of square waveguides 6737 the propagation of the wave front in a dispersive medium the problem is investigated theoretically by means of the laplace transformation for the general case of a plane em wave in a homogeneous medium 6738 a soluble problem in energy bands the problem of an electron moving in a periodic simple cubic potential of the form cos x cos y cos z in investigated with particular attention to the nature of the wave functions wannier functions degeneracy of overlapping bands etc 6739 kodaikanal observatory an indication is given of the scope of the work carried on at this solar physics observatory and of results so far achieved magnetic meteorological and si seismological observations are made and the imminent commencement of ionosphere soundings is reported 6740 double doppler study of meteoric echoes both the amplitude and phase of the signal returned from a meteor trail can be determined independently by use of a twin channel doppler system details of which are presented the technique has direct application to the determination of the drift of meteor trails and to analysis of the spectra of echoes which exhibit amplitude fading 6741 final relative sunspot numbers for 6742 provisional sunspot numbers for april to june 6743 scintillation of radio stars during aurorae and magnetic storms during aurorae the rate of scintillation is four times that during normal conditions probably as a consequence of a fourfold increase in the drift speed of the ionosphere irregularities causing the scintillations more generally the scintillation rate and the speed of the ionosphere irregularities are approximately proportional to the k index of geomagnetic activity 6744 cheltenham three hour range indices k for april to june 6745 indices of geomagnetic activity of the observatories abinger eskdalemuir and lerwick july and august 6746 secular variation of the magnetic field at colaba and alibag 6747 principal magnetic storms 6748 international data on magnetic disturbances first quarter 6749 nitrogen in the upper atmosphere the probable distribution of atomic n is investigated theoretically the method of calculation adopted is a modification of that used by penndorf in investigating the dissociation of oxygen of within the height range km the predissociation mechanism suggested by herzberg and herzberg operates while in the range a dissociative recombination suggested by mitra is effective in the lower region there is a sharp maximum in the distribution curve at about km in the upper region the concentration increases monotonically with height the total number of n atoms in a vertical column of cross section is calculated to be about 6750 physical properties of the upper atmosphere over india the height temperature curve for central india from ground up to km has been constructed using data obtained from balloon measurements and sound propagation experiments the isothermal region found in the lower stratosphere over middle latitudes does not exist over india the temperature increasing steadily above the tropopause a comparison of data for india and for europe indicates that summer east winds over north india extend up to about km with strong westerly winds aloft 6751 dynamic phenomena in the ionosphere records of f layer height obtained with the rapid sweep sounder at freiburg show trace detail indicative of transient ionospheric variations various types of deformation of the trace are noted these short lived disturbances are nearly always propagated from a high level downwards 6752 an effect of the moon on the median height of the ionosphere f layer at huancayo on the magnetic equator there is a lunar effect amounting to several per cent on the median height of the f layer during local summer the effect is very much smaller in winter at freiburg in a moderate latitude the effect is extremely small if it exists at all 6753 the solar control of the e and f layers at high latitudes the monthly mean critical frequencies of the e and f layers at high latitudes vary diurnally with solar zenith angle according to a modified chapman law measurements of the seasonal latitude and solar cycle phase dependence of the e layer sensitivity to solar zenith angle and subsolar frequency are shown graphically in the auroral zone e layer sensitivity to solar zenith angle is very low but to the north of the zone it has the chapman theoretical value 6754 ionospheric refraction of radio waves from radio stars an estimate of the total ionization of the f layer can be deduced from the refraction of radiation from radio stars caused by horizontal gradients of ionization occurring during normal diurnal variations in the layer interferometer measurements of the apparent positions of four radio stars are reported and the results are compared with calculated values based on ionospheric soundings agreement is found if certain plausible assumptions are made regarding the vertical distribution of electrons about the maximum concentration level of the f layer 6755 the relation between electrical and diffusion currents 6756 a procedure for the determination of the vertical distribution of the electron density in the ionosphere description of a method based on application of the gauss christoffel quadrature formula to the numerical integration of the well known integral for true reflection height s as a function of group height the earths magnetic field and the effects of electron collisions are neglected ray theory is assumed applicable and the electron density height curve is assumed to have no maxima or minima in the region considered 6757 a method for obtaining the wave solutions of ionospherically reflected long waves including all variables and their height variation 6758 design of damper stabilized instrument servo mechanisms 6759 a transient approach to the solution of a linear servomechanism by an equivalent network 6760 stabilization of variable carrier frequency servo mechanisms 6761 highly stable power supply description of equipment giving voltages adjustable between and with loads up to the variation of output voltage is of the order of part in for line fluctuations of the dc output resistance is and the residual hum voltage a valve is used as voltage comparison standard the feedback circuit includes two pentode stages and a cathode follower stage comprising two triodes in parallel 6762 high voltage power supplies two units are described an interrupted rf oscillator with rectifier tripler and a continuous rf oscillator with rectifier doubler both give an output of about at at and both include low loss transformers with ferroxcube cores is housed in an oil filled container is larger and dispenses with oil 6763 a variable voltage stabilizer employing a cold cathode triode a circuit is described in which a cold cathode gas filled triode acts as a dc amplifier such an arrangement has desirable characteristics as a voltage stabilizer in low current circuits a portion of the output voltage of a source is compared with a reference voltage the difference being used to control the current through the parallel connected stabilizer valve so that the output voltage is maintained at a constant value 6764 ohms law for build up phenomena in the case of pole networks the laplace transformation is applied in the form of a fourier integral of the input waveform doetschs symbolic notation for asymmetrical transformations of is used and the equality sign of ohms law is replaced by the doetsch transformation sign the variation with time of a current through a complex impedance is given by the laplace transform product of the susceptance and the applied voltage spectrum application of the transformation in quadripole theory is described by formulating the quadripole equation in chain matrix form transient response parameters can be roughly estimated application of the theory to the determination of transient distortion in communication systems and to the stability testing of amplifiers is outlined 6765 pulse amplitude analysis in nuclear research various voltage discrimination techniques are discussed in detail and descriptions are given of a simple type of analyser and a moderate precision and a high precision analyser analysers are also discussed in which pulse height selection is effected either by mechanical means or by use of diode valves trigger circuits sorting ladder circuits or beam deflection techniques other types of analyser described include those in which height selection is accomplished by an expander amplifier driving a chain of discriminators by conversion of pulse amplitude to pulse duration by means of information storage devices references 6766 low cost variable phase shifter the basis of the circuit is a linear resistance potentiometer divided by tappings into four equal sections neighbouring sections being fed by a pair of transformer secondaries with voltages phase separated by the value of the potentiometer resistance is not critical providing it is large compared with the impedance of the transformer secondaries 6767 dynamics of transistor negative resistance circuits a general method is presented for calculating approximately the characteristics of nonlinear circuits the region of operation is divided into subregions within each of which the circuit may be considered as nearly linear the method is applied to analysis of a high speed switching circuit using a point contact transistor discussion of negative resistance relaxation oscillations calculation of waveforms and rise times of a regenerative transistor amplifier below 6768 matrix representation of transistor circuits transistor circuits are discussed in terms of measurable quantities only once the admittance matrix of the grounded base transistor has been determined the matrices of the grounded emitter and grounded collector transistors can easily be derived matrix representation also provides a direct method for analysis of stages in cascade 6769 transistor noise in circuit applications problems of linear circuits involving multiple noise sources can be handled by familiar methods with the aid of certain noise spectrum functions which are described several theorems of general interest in circuit work dealing with noise spectra and noise correlation are derived the noise characteristics of transistors can be described in terms of the spectrum functions for simple but arbitrary configurations of equivalent noise generators from these the noise figure can be calculated for any external circuit numerical results for a number of npn transistors are given in a table and many curves 6770 junction transistor equivalent circuits and vacuum tube analogy a comparison is made between the operating characteristics of a pnp junction transistor and a triode valve using a network to represent the transistor 6771 nonlinear circuit elements in high frequency and low frequency technology a review of the properties and applications of nonlinear inductors capacitors and resistors of many different types see also of 6772 new commercial barretters the characteristics of two tungsten coil barretters are given the resistances when cold are respectively and a current of about doubles the resistance in each case tests to determine the cooling characteristics and the effect of ambient temperature changes are described 6773 coil winding data charts give the number of turns required in conjunction with various values of capacitance for tuning over the frequency ranges and using standard formers with dust cores 6774 new bistable high speed multi purpose device operating conditions for an eccles jordan circuit using two type triode hexode valves are noted with suitable diode limiting consistent operation is maintained at pulse rates sec 6775 arithmetical counters for pulses a list is given of relevant publications with short notes indicating their scope 6776 a transistor reversible binary counter the counter is built of elementary transistor packaged units the mechanism used to achieve reversibility and the circuit for each type of building block are described 6777 transistor trigger circuits analysis is presented for transistor trigger circuits which permits prediction as to whether operation will be monostable bistable or astable oscillatory and also of the amplitude and waveform of the output practical pulse circuits for various purposes are described which are so designed that their operation is not affected by reasonable variations of circuit parameters bias voltages transistor characteristics or ambient temperature 6778 transistors in switching circuits analysis of transistor trigger circuits is based on an approximate representation of the negative resistance characteristic by three straight lines circuits using point contact transistors for waveform generation level restoration delay storage and counting are described and their properties n and limitations are discussed in detail 6779 graphical analysis of some transistor switching circuits methods are described for generating the entire input characteristics for the various terminals of a transistor and graphical methods of analysis are applied to a base input amplifier a collector to emitter direct coupled switching circuit a collector to base direct coupled circuit 6780 electronic switch a switching circuit for two waveform display with a single beam cro uses a conventional multivibrator for generating the switching voltages 6781 network analysis by repeated voltage superposition a method of analysis is described with worked out examples which reduces considerably the number of simultaneous equations to be solved for an m mesh network the method essentially involves successive applications of thevenins theorem each application reducing by one the number of meshes in the network considered with a corresponding reduction of the number of simultaneous equations to be solved a similar method has been described by tasny tschiassny of who used residual current generators at the final nodes instead of residual voltage generators in the final branches and whose method differs from the present method in other details 6782 synthesis of cascaded three terminal rc networks with minimum phase transfer functions for the realization of a particular transfer function including complex zeros the method of synthesis presented yields a network with fewer elements simpler configurations and higher level of transmission than previous methods eg of 6783 the practical significance of complex frequencies in electrical communication engineering a concise general introduction to the subject complex frequencies are complex quantities whose real part represents the gain of a system and whose imaginary part represents the frequency in the usual sense the application of the laplace transform in analysis of transmission problems is explained and the properties of the complex plane and its poles and zeros are described the use of the poles and zeros for representation of the transmission characteristics of a linear network iis considered analogues of the complex plane such as that obtainable with a stretched elastic membrane are discussed and their applications illustrated 6784 anode follower derivatives low output impedance stages characterized by anode output and feedback of the entire output voltage are derived from the basic anode follower by substitution of a vlve impedance for the shunt resistor of the feedback path or of a comparator stage for the entire input feedback potential divider and by replacement of the output valve by a series connected push pull pair these developments suggest the possibility of obtaining an anode follower analogue of each cathode follower derivative thereby increasing the number of circuit variants available for practical use 6785 applications of tensor theory to linear electronic circuits an explanation of tensor concepts and their general application to valve circuits with examples illustrating the determination of input impedance and gain of feedback cathode follower and grounded grid circuits 6786 on the approximation problem in network synthesis a method of synthesis is presented in which a desired frequency response characteristic is replaced by an approximation consisting of a sequence of rectilinear segments the method is illustrated by application to the design of attenuation equalizers with constant resistance ladder sections 6787 the parallel t resistance capacitance network analysis is given for the general case of finite source and load resistances when these two resistances are appropriately related the network loss is the same at low and high frequencies the transfer characteristic is then a circle in the complex plane this symmetrical networks is equivalent to a simple series resonant circuit as regards its transfer characteristic 6788 rc cathode follower feedback circuits when certain rc circuits are associated with a cathode follower circuit a voltage gain can be obtained over a band of frequencies a number of prototype and derived rc circuits which can be used in this way are analysed and their response curves are determined the matrices of the derived networks can be formed easily from those of the corresponding prototypes the effect of circuit termination on response is discussed and the use of these circuits as feedback elements in amplifiers is considered in some detail experiments in confirmation of the theory are mentioned 6789 resistance capacitance networks with over unity gain longmire of and epstein of have described rc circuits with greater output than input voltage a method of increasing the voltage gain by feeding the output voltage of one network into a second network is described the process cannot be extended indefinitely the voltage gain attainable being limited by the impedance increase necessary at each stage experiments confirmed the theory such networks can be used with a cathode follower to construct oscillators in which the valve gain is less than unity an experimental circuit is described 6790 response of a linear network to an input with linearly variable frequency as obtained in sweep frequency testing application of an input voltage with linearly increasing frequency to a linear network produces an output curve which for very slow frequency variation is an image of the admittance plotted as a function of frequency when the rate of frequency variation is not negligible the response curve is a distorted image of the admittance the nature of this distortion is investigated a quantitative approximation method is presented which uses the theory of functions for evaluation of an integral the result is expressible in terms of elementary functions explicit expressions are given for the dynamic corrections to be applied to the observed resonance frequencies and peak admittances the method is applied to several simple circuits in addition to the lcr circuit which has been previously treated by other authors 6791 fundamentals of filter theory and technique description of the application of the wave theory and the operating parameter theory in the design and calculation of different basic types of filter 6792 formulae for ladder filters four related sets of explicit formulae for the elements of a basic low pass filter network are presented with a common notation three of the sets have been published previously of norton of of belevitch the fourth being new all have reference to the image parameter theory due to norton and darlington of if corresponding formulae could be found for a general type of filter with response depending on jacobian sn elliptic functions they would represent a considerable contribution to filter design technique 6793 a nonlinear statistical filter a method is described for using the statistical differences between a periodic rectangular pulse the wanted signal and the envelope of fluctuation noise the interfering signal for the purpose of discriminating between the two signals expressions are derived for the density distribution probability of noise and of signal plus noise a description is given of a practical filter which was checked experimentally under conditions when the signal was completely masked by the noise both aurally and visually but could be reliably detected by means of the statistical filter possible application to secret transmission systems is discussed 6794 numerical calculation of filter circuits with tchebycheff characteristics after the method of w cauer formulae for tchebycheff type filters are derived from those previously given for filters with generalized parameters of three types of antimetrical filter are considered the formulae necessary for numerical calculation of both symmetrical and antimetrical normalized filters are derived and applied to examples by suitable frequency transformation the normal type of tchebycheff filter can be dealt with a complete set of curves is provided for evaluation of the required parameters 6795 coaxial transmission line filters analysis for coaxial line band pass filters is given based on tem mode transmission the influence of the nature and spacing of the obstacles on the bandwidth is discussed measurements on filters of various constructions support the theoretical results a te mode high pass filter is also discussed for narrow band applications this type of filter is inferior to the cavity type 6796 nonlinear filtering and waveshape multiplexing a method of providing two channels on one carrier consists of differentiating the combined signal clipping to remove one component and re integrating to restore the other the removed component is recovered by subtracting the retained component from the original input experimental circuits and waveforms obtained are illustrated the two components being respectively a sine wave and a square wave 6797 functional circuit diagrams shortened version of paper abstracted in of january 6798 transistors in airborne equipment discussion of the advantages of using transistors instead of valves in aircraft equipment 6799 slow speed circular timebase french version of paper by hardie and thomas of supplemented with references and a note on earlier types of sine cosine potentiometer 6800 printed circuitry for transistors the auto sembly technique of february danko is suggested as a simple and effective method for the production of compact transistor circuits 6801 resonance curves deviations encountered in practical circuits from the ideal conditions dealt with in elementary theory are simply explained 6802 spontaneous voltage fluctuations in a resonant circuit the rms value of voltage fluctuations of thermal origin at the terminals of a parallel rlc circuit is determined for the unusual case where the frequency range in question is not negligible in comparison with the bandwidth of the resonant circuit curves are given to facilitate numerical calculation 6803 a junction transistor tetrode for high frequency use application of suitable bias to a fourth electrode connected to the p type central section of an npn junction transistor causes a considerable reduction of the base resistance this reduction enables the transistor to be used at frequencies over ten times the normal limit circuits are given for a variable frequency tuned amplifier a band pass amplifier and a sine wave oscillator for 6804 transistor oscillators the characteristics of transistor oscillators are established by analysis in which the conductance form of the transistor equations is used the following circuits are considered transistor with frequency determining quadripole and overall feedback as in but with transformer coupling between transistor and quadripole transistor oscillator with a arrangement of three parallel connected tuned circuits 6805 low drain transistor audio oscillator description and performance of a oscillator using a western electric type point contact transistor supplied from a single battery the power drain from which does not exceed 6806 a low frequency function generator description of a relaxation oscillator capable of giving a constant amplitude output of sine square or triangular waveform in the frequency range 6807 automatic tuning control of hf generators with varying load the phase relation between the primary voltage and the secondary current of the output transformer of a crystal driven generator is used for automatic control of the tuning of the output circuit under varying load conditions control is effected via a bridge type of phase measurement unit using a pair of type eq enneodes which acts on a control unit using a pair of type pl thyratrons circuit details photographs and performance figures are given 6808 pulse duration and repetition rate of a transistor multivibrator expressions are derived for the pulse duration and repetition rate of an astable oscillatory multivibrator circuit using a point contact transistor the formulae are confirmed experimentally for repetition rates from to per sec and pulse durations from to 6809 variable inductance and its application in frequency sweep oscillators the modulation principle described consists in varying the voltage across an inductor while the current through it is maintained constant alternations of the control grid voltage of a pentode cause anode and screen grid currents to vary in magnitude developing a voltage variation across an anode inductor coupled to the inductor in the cathode circuit the current through l is maintained constant by an alternating voltage applied to the suppressor grid a frequency shift of around is attainable the use of the method for fm and frequency sweep tuning is indicated 6810 double counter fm and afc discriminator a frequency discriminator with large bandwidth and good stability comprises a pair of pulse counter circuits each preceded by mixer and pulse forming circuits with their outputs connected in series 6811 vacuum tube circuits without plate supplies the existence of thermal emf and contact potential makes circuit operation possible with out application of voltage to valve anodes a limiter a low gain amplifier a multivibrator and an oscillator circuit are described 6812 volume compression and expansion comment on of february and authors reply 6813 calculations for a power amplifier for a dc motor the design is considered of valve circuits for driving low power motors such as are often used in control or telemetry equipment 6814 transistor operation stabilization of operating points the provision of optimum emitter and collector bias currents for a transistor amplifier is discussed and a relation between the values of resistors and voltages is derived which should be satisfied if stable operation is to be achieved 6815 transistor amplifier cut off frequency the effect of the positive feedback associated with the internal base resistance of a transistor on its cut off frequency is analysed expansion of the expression for current gain in a taylor series shows that only the phase shift in is important in reducing the cut off frequency 6816 frequency variations of current amplification factor for junction transistors in a grounded emitter or grounded collector connection of a junction type transistor the effective current amplification is proportional to where is the current gain of the transistor as a result of the phase shift associated with the value of decreases rapidly with increasing frequency so that the upper frequency limit of the grounded emitter or grounded collector arrangements may be considerably lower than has been expected results of measurements of the frequency variation of for several fused impurity pnp junction transistors developed by saby below are shown graphically 6817 the reproduction of voltage pulses by means of a proportional amplifier analysis of an amplifier for nuclear physics investigations is based on laplace transformations a characteristic transmission function is introduced which completely describes the transmission properties of the amplifier and represents the combined pulse distorting influences of the individual circuit elements the transmission functions of single stage and multistage amplifiers are derived and a detailed and a detailed exposition is given of the distortion experienced by a typical exponential decay pulse optimum reproduction of such a pulse requires a particular relation between pulse duration and the time constants of the amplifier circuits improvement of time resolution involves closer restriction of this relation and greater complexity of circuits use of negative feedback offers advantages a two stage feedback amplifier is a useful unit in a large amplifier system the transmission function can alternatively be determined from the response of the amplifier to steady alternating voltage a suitable method of measurements is described 6818 a photocell amplifier for infra red spectroscopy description of a highly linear amplifier for use at a chopping frequency of gain variation is for variation of supply voltage 6819 symposium on noise general introduction discussion of the mathematical representation of noise 6820 a coherent theory of relaxation phenomena the theory presented is based on the theory of functions general formulae are derived and the particular case of elastic relaxation oscillations is discussed conditions for the occurrence of discrete and of continuous relaxation spectra are determined and a formula is derived for the distribution function of the continuous spectrum 6821 on a multiple scattering theory of the finite grating and the wood anomalies the problem is treated by applying the solution previously obtained of for multiple scattering from an arbitrary configuration of parallel cylinders both the transmission grating and the reflection grating comprising semi cylindrical bosses on a perfectly conducting plane are considered the complete expression for the scattered wave is given for the case of grating width small compared with distance to observation point and cylinder spacing large compared with the case of raddi is investigated in detail bright and dark bands in the intensity curves similar to the grating anomalies found by wood in are related to the magnitudes and phases of the various orders of scattering the theory is extended to gratings with elements other than cylinders 6822 removal of an inconsistency in the theory of diffraction in certain cases the integral equations involved in analysis of the diffraction of small amplitude acoustic or em waves give a solution which does not satisfy the boundary conditions imposed but which agrees with the solution found by other means this inconsistency is removed if different boundary conditions are imposed in the formulation of the problem this is illustrated by discussion of two dimensional diffraction of a plane em wave by a perfectly conducting semi infinite plane 6823 the rydberg constant and the atomic mass of the electron re evaluation of the spectro scopic data pertinent to the rydberg constant and the mass of the electron yields the values r and atomic mass units from microwave measurements and cm houstons and chus data can be brought into agreement with those of drinkwater richardson and williams by assuming differences in the wavelength standards used 6824 dielectric dispersion in pure polar liquids at very high radio frequencies part the effect of electrolytes in solution a description is given of measurements at mm and cm wavelengths of the absorption of electrolytic solutions of concentrations up to water and methyl alcohol being used as solvents the results obtained are analysed in terms of debyes theory of dispersion in a polar dielectric and modifications of the theory necessary to take account of the ionic conductivity of an electrolyte are indicated measurements on aqueous solutions of are discussed in relation to huckels theory of electrolytic solutions 6825 piezoelectricity ferroelectricity and crystal structure by visualizing polar crystals as a network of permanent dipole moments the piezoelectric and ferroelectric properties of dielectrics may be deduced from considerations of molecular symmetry this approach is used to clarify the relation between the sphalerite cubic and wurtzite hexagonal structures the ferroelectric feedback effect in aspects of domain formation and the interrelation between ferro electricity and piezoelectricity 6826 carriers of electricity in metals exhibiting positive hall effects measurements on samples of mo and zn made by an inertia method showed the sign of the charge mass ratio of the carriers to be negative the mean value of over measurements being within of the value for free electrons 6827 electrical discharges in gases a summarized account of six papers with discussion presented at a meeting of section a mathematics and physics of the british association belfast september 6828 high frequency breakdown in neon preliminary report of the results of measurements of breakdown fields for cylindrical cavities of heights and over the pressure range mm hg a detailed p report is to be published in the canadian journal of physics 6829 an explanation of the extremely low normal running potential of a high frequency discharge between plane plates a tentative explanation is provided by taking account in the equation of electron motion of a restoring force indicated by plasma diffusion theory 6830 chromatic losses of electrons in passage through matter an account of investigations of the velocity distribution of electrons after passage through various gases and solid materials 6831 the theory of secondary emission preliminary note to be treated in detail in a forthcoming paper 6832 antiferromagnetism a comprehensive review of the subject with references 6833 a simplified form of the relativistic electromagnetic equations maxwells equations are expressed in the form of a single four vector density equation in which the field tensor has only three distinct complex components the number of equations is reduced but all the usual classical formulae may be obtained by separating the real and imaginary parts 6834 the induction of electric currents in a uniformly conducting circular disk by the sudden creation of magnetic poles using toroidal coordinates a riemann space of two regions is constructed as in sommerfelds methods of multiform potentials and the riemann potential for a single magnetic pole is determined jeans treatment of uniform finite plane current sheets is applied to the case of the circular disk numerical results being given for a particular example 6835 hertzian waves and photons discussion of the implications in physical theory of an uncertainty relation between the number of particles of the bose einstein type associated with a wave and the phase of that wave 6836 diffraction of electromagnetic waves by apertures in plane conducting screens 6837 diffraction by an edge and by a corner conditions are given which are sufficient to ensure that the current density normal to an edge is zero at the edge and that there is no line distribution of charge on the edge an extra condition is given which makes the components of the field parallel to the edge finite the solution is then shown to be unique simpler conditions are given for two dimensional fields the agreement of various known solutions with the conditions here determined is discussed certain simple types of current and charge distribution lead to a unique solution for the diffraction by corners formed by flat surfaces 6838 propagation of electric waves in stratified and continuously variable plasmas for a plasma of sandwich structure with the denser medium inside there are two possible frequency ranges for propagation in which the phase velocity falls from the value at the lower limiting frequency to zero at the upper limiting frequency when the density varies linearly towards the interior to an arbitrarily high value the wave is strongly concentrated at the plane for which and the phase velocity tends to zero for a plasma of uniform density and natural frequency with outer layers in which density falls off linearly propagation is possible only when the more the wave is concentrated at the region and the smaller its phase velocity the nearer approaches to 6839 hall effect discussion of the hall ettingshausen nernst and righi leduc effects 6840 mean free paths of electrons in evaporated metal films estimates of the mean free paths of the conduction electrons in cu and ag films based on resistivity measurements on films of thickness from to are found to be in good agreement with values calculated from dingles theory of 6841 sunspot areas flares and filaments observed at the stockholm observatory in the years and 6842 comparison of photographs of the corona obtained at the eclipse of february with simultaneous observations by lyot coronagraphs photographs of the solar corona taken at khartoum are reproduced and discussed in relation to routine estimates of the intensity of the green corona line possible correlation of particular features of the corona with geomagnetic effects is noted 6843 the positions of six discrete sources of cosmic radio radiation 6844 a preliminary survey of line emission from galactic hydrogen report of measurements on a radiation source having the form of a band of varying intensity along the galactic equator 6845 the ionic equilibrium of the lower atmosphere and recombination theories 6846 a note on ionospheric wind measurements at report of measurements made in pennsylvania using a three receiver technique similar to that of mitra 6847 the ionization of the e layer its measurement and relation to solar eruptions criteria for distinguishing between normal and abnormal layers are discussed relatively thin layers are classed as abnormal their ionization distribution corresponds to a power law with index a definition of is given which remains valid for complex layers is the highest critical frequency of a normal layer preceding or coinciding with the first discontinuity between the e and f echoes application of this definition to the evaluation of ionosphere observations made at freiburg during and leads to greater constancy of the daily variations and monthly means of e examination of the values of e for three summer months indicates that all deviations above the monthly mean are attributable to sudden ionospheric disturbances 6848 the diffraction of galactic radio waves as a method of investigating the irregular structure of the ionosphere an account of an investigation of ionospheric characteristics by observation of changes in the diffraction pattern of radio waves from the galaxy ionospheric irregularities cause irregular changes of phase in the galactic waves passing through them observations at two stations about apart indicate that such ionospheric irregularities may have a lateral extent of and a variation of electron density of about their height is about they are most pronounced about midnight and they show little annual variation such portions of the ionosphere have a wind like motion with velocities of the order of ms the velocities are associated with periods of geomagnetic disturbances 6849 production of the e layer in the oxygen dissociation region in the upper atmosphere the probable value of the absorption cross section of for the ionization causing the e layer is calculated using the o height distribution data obtained by moses and wu of discussion indicates that the preionization by solar radiation in the range suggested by nicolet of and ionization by high energy photons emitted from the solar corona hoyle and bates of are both operative in producing e layer ionization the former produces the normal e layer and the latter is responsible for the fine structure of the e layer recently reported by naismith and bramley of 6850 a new ionosphere sounder frequency sweep apparatus covering the range is described the aerial circuit is eliminated the high impedance rhombic aerial being directly matched to the power valves the frequency range is covered in the other circuits in two wavebands each with a ratio quick waveband changing is achieved by means of carbon brushes rotating with the variable capacitors the transmitter and receiver have a common oscillator the power supply arrangements are particularly described the unit is of small size 6851 improvements to the berkner wells seaton type of ionosphere sounder 6852 high altitude research an account of methods and equipment used with rockets for investigations at heights up to miles physical phenomena observed include the ion and electron densities in the ion and electron densities in the ionosphere a description is given of a channel telemetering system transmitting at with a peak power of kw 6853 ionospheric measurements at oblique incidence over eastern australia 6854 localization of aurorae with high power radar technique using a rotating antenna radar equipment with a peak pulse power of pulse width and element yagi aerial rotating at rpm has been used since may at kiruna geophysical observatory for the location of aurorae preliminary results of the observations indicate good correlation between auroral activity geomagnetic activity and the appearance of the n layer a special type of sporadic e ionization often appearing in connection with magnetic bays the distribution in range and bearing of the recorded aurorae agrees with the simple theory that most of the radio wave scattering comes from those points where the radar beam is perpendicular to the surface of the auroral discharges the calculated height distributions of the reflection centres have maxima around km 6855 propagation of very long electromagnetic waves and the wave spectrum of lightning 6856 servomechanisms a survey design techniques discussed include frequency and time analysis and statistical methods an indication is given of problems not yet solved references 6857 nonlinear servomechanism the various factors limiting the application of the linear theory of servomechanisms are discussed the theory of filtered systems using relays developed independently by dutilh of and kochenburger is outlined and two net criteria applicable to all filtered servomechanisms are established the first criterion is concerned with the possibility of hunting taking place and includes the criteria of nyquist and kochenburger as special cases the second criterion determines the stability of such oscillations of the system 6858 a formula for an integral occurring in the theory of linear servomechanisms and control systems 6859 application of transistors to high voltage low current supplies a transistor oscillator is used to develop the hv required for such devices as geiger muller counters the oscillations have a sawtooth waveform the flyback being used for shock excitation of the hv transformer 6860 power rectifiers and transistors power rectifiers with rectification ratios as high as can be made by fusing donor and acceptor contacts to the opposite faces of a ge wafer analysis of the characteristics of such rectifiers gives results in good agreement with experimental values the properties of transistors prepared in a similar manner and capable of outputs as high as are described at present the operation of these power units is limited to about by transit time effects 6861 a high voltage medium power rectifier a description is given of the operating characteristics of pnp junction rectifiers prepared by fusing impurity metals to ge wafers the addition of cooling fins enables higher powers to be handled 6862 the nevitron mercury arc rectifier description of a new type of rectifier with the hg pool in a mo cup with external al cooling fins provided the mo cup is wetted by the hg to give a concave meniscus the cathode spot runs in a continuous line round the edge of the hg the cooling system ensures no excessive emission of vapour an auxiliary electrode lifted from the hg by means of a solenoid serves to start the arc the voltage drop across the arc is the weight of a nevitron is only excluding the ignition solenoid types with grid control have also been tested the power required in the grid circuit for full control is only one thousandth of that for a multianode rectifier 6863 improved stabilization from a voltage regulator tube by using a suitable barretter in place of the resistor usually connected in series with a voltage regulator tube a definite improvement in performance is obtained the barretter type of circuit is most useful when the load current is relatively high 6864 stabilizer for control of high direct voltages the development and performance of a stabilizer for direct voltages of the order of several thousands of volts are described the application of the stabilizer to voltages of any value using as variable resistor a large number of triode valves in series suppressing the voltage divider bridge generally used to control the regulator system is also discussed rectifier ripple can be eliminated so that a simple type of filter can be used 6865 the transbooster description of circuits in which a transductor is used for regulation of the output voltage of a rectifier fed from ac mains under varying load conditions if the transductor is connected on the dc side of the main rectifier a smaller transductor can be used since it will only have to handle the total boost voltage required to cover rectifier regulation and mains voltage variation 6866 automatic feedback control theory and applications of servo control systems 6867 compensation against effects of grid cathode capacitance in pulse height selectors the precision of the selector may be reduced by an effect due to the grid cathode capacitance of the input valve when a constant current valve is used in the cathode circuit this effect can be compensated by applying the input signal appropriately modified to the grid of the constant current valve 6868 the design of thermocouple transformers for infrared chopped beam systems description of transformer for operation at to be inserted between a thermocouple detector and an amplifier the design is such as to give at the amplifier output a signal noise ratio approaching that at the thermocouple terminals 6869 magnetic amplifiers comment on of pistoulet pointing out the existence of several french publications and patents on the subject one paper by leonard and weber dating back to and thus being considerably prior to the american paper by alexanderson and nixdorff quoted by pistoulet as the first publication on magnetic amplifiers 6870 a mathematical analysis of parallel connected magnetic amplifiers with resistive loads comment on 6871 magnetic amplifiers for industry description with outline circuit diagrams of a series of westinghouse magamp instruments with power ratings from to and examples of their application 6872 new developments in fixed resistors for electronic applications a review of the characteristics of deposited carbon metal film and borocarbon resistors and comparison with carbon composition and wire wound resistors 6873 high temperature carbon film resistors details are given of the method of pyrolysis used in the production of stable carbon film resistors with values from to and capable of operation at temperatures up to the carbon film is deposited on a porcelain base made from alumina mixed with other ingredients such as and in an alcohol binder 6874 industrial applications of semiconductors part thermistors description of the characteristics of thermistors typical forms of construction and various applications 6875 three phase transductor circuits for magnetic amplifiers various transductor connections for phase operation are described a element circuit with separate excitation and a element circuit with auto excitation are discussed in detail a theoretical and experimental comparison is made between single phase and phase circuits the latter should be used where balanced loading of the supply is sufficiently desirable to compensate for the increased circuit complexity 6876 the coupling of scale of two circuits a simple and reliable rc divider circuit is described and illustrated 6877 ultra high frequency switches and filters discussion pp the design of filters and switches for the london birmingham television relay link is described the type of switch adopted uses resonant stub lines in shunt with the main transmission lines typical performance details are given the filters are of the band stop type and consist of stub lines composed of a series of nominal line sections shunted across the main transmission line design curves are given and typical filter attenuation curves shown 6878 further data on the design of eccles jornan flip flops full text of paper presented at the aiee summer general meeting june analysis under specified conditions of the grounded cathode type of flip flop circuit including no inductors a graphical design technique is described which should facilitate the design of switching circuits using a large number of identical direct coupled circuits 6879 fixed capacitors for electronic circuits a review of the development of new types involving both new materials and new manufacturing techniques 6880 tuning stability nomograph a chart is given for facilitating calculation of the parallel capacitors required to give an overall temperature coefficient of zero in circuits using inductance tuning 6881 the calculation of energy flow using the laplace transformation laplace perseval integral is applied to determine energy flow directly from the laplace transforms of the applied force and the resultant response the method is applicable to both transient and steady states and leads directly to the most simple form of solution the method is most advantageous when the applied force possesses several discontinuities as an example the classical problem of eddy current losses in linear sheet conductors is solved in general for arbitrary excitations 6882 on transformations of linear active networks with applications at ultra high frequencies a relation similar to the star delta transformation is developed for linear circuits including valves formulae are derived for triode circuits under the results are extended to tetrodes and pentodes the method is useful for analysing the operation of uhf triodes and for determining amplifier admittances and gain 6883 response of a quadripole to discontinuous signals the phenomenon of gibbs and methods of generalized summation mathematical analysis with application to the design of quadripoles with good transmission characteristics for square wave signals 6884 tunable rc bridge network with only one variable element a circuit is described with which an output of required phase is obtained by varying either one resistance or one capacitance the magnitude of the output voltage remaining constant details are given of a stable valve generator with frequency ranging from a very low value to the circuit can also be used in phase shifters frequency meters and selective amplifiers 6885 a theory of time series for waveform transmission systems a theoretical study is made of time series suitable for application to low pass systems with a fixed upper limit to the pass band for division and inversion of time series algebraic division is not in general legitimate for time series related to bandwidth limitation although it is legitimate for certain other forms of time series more general methods of inversion are treated and an iterative method which can always be used is discussed in detail and a practical computing scheme is outlined see also of january lewis which also deals with the time series method 6886 a wide band hybrid ring for uhf the bandwidth of a hybrid ring is increased by replacing the long arm with a line and introducing a frequency insensitive reversal of phase calculations are made of input and transfer admittances insertion loss and the effect of capacitance across the loads some experimental results are given and applications to power splitters harmonic generators mixers are indicated 6887 wave filter characteristics by a direct method digest of paper presented at the aiee winter general meeting january a chart is given from which the attenuation in db can be directly determined for seven commonly used ladder filter sections the abscissae used being the number of bandwidths from the cut off frequency 6888 formulae for calculating filter circuits with flattened attenuation curves simple formulae are given for calculating tchebycheff type low pass filters with attenuation values falling between prescribed limits either inside or outside the pass band attenuation curves obtainable with filters thus calculated are shown 6889 the transient response of rf and if filters to a wave packet 6890 characteristics of the magnetic attenuator at uhf the design of the field controlled attenuator previously described by reggia is discussed and performance data are given for attenuators using various ferromagnetic materials 6891 new principle for electronic volume compression 6892 loading of quartz oscillator plates an investigation was made of the effectiveness of mechanical loading for eliminating unwanted modes of vibration and adjusting the oscillation frequency towards the value corresponding to greatest activity the loading was done by applying various amounts of woods metal to different parts of the plate surfaces for concave thickness shear mode and x cut plates improvement was obtained when the loading was applied at or near the active central area for flat or convex x cut plates with an extensional mode of vibration improvement was obtained when the loading was applied near the periphery for both types loading increased the q factor 6893 microwave cavity resonators as circuit elements the differential equation for the equivalent circuit of a double loop coupled cavity resonator is derived by using lagranges equation and maxwells equations the losses in the walls and the q of the cavity operating in the te mode are evaluated 6894 power spectrum of a nonlinear oscillator with a frequency amplitude law perturbed by noise discussion for the case where the dependence of the frequency on the amplitude is represented by the formula and the power spectrum is determined and can be represented as a single line with a superposed noise spectrum resulting from the amplitude and phase fluctuations the methods previously developed and of enable the noise spectrum to be resolved into a continuous band and a periodic line component 6895 multiple feedback oscillators the use of several feedback circuits in connection with a single tank circuit makes it possible to construct oscillators capable of operation over a wide frequency range the lc value of the tank circuit remaining fixed such oscillators and the theory on which they are based are described by m morrison in usa patent no important points of the theory are here given and two typical oscillator circuits are described in the second of these a special current transformer with a ratio is used to effect phase alteration of the feedback current the transformer with a variable capacitor across the output terminals is adjusted to provide feedback current in phase with the ac component of the anode load current so that the proper grid voltage angle is obtained for maintaining oscillation at the desired frequency 6896 constant amplitude oscillator a circuit developed by nc hekimian comprises a conventional oscillator whose rectified output is applied as a positive voltage to the grid of a clamp valve which shares the voltage dropping resistance in the oscillator anode supply lead for a more detailed account see electronics 6897 on an equation connected with the theory of triode oscillations detailed discussion of the periodic solutions of the differential equation in which the parameter is small the equation is concerned with the forced oscillations in a simple electrical circuit containing a triode van der pol has treated the case where and an extensive theory of triode oscillations has been built up for this case in practice however the graph of has a much flatter bottom than that of the function and cartwright of and of has raised the question whether this flattening will alter the performance of the circuit near resonance the main part of this paper is an attempt to answer this question an estimate is made of the permissible degree of flattening of the curve without the detuning diagram losing any of its significant properties various pertinent theorems are established and the possible periodic solutions of the equation are discussed in relation to the detuning diagram particular results include the following a if k is small enough and the value of lies in a certain small range near forced oscillations with half the applied frequency are possible two of these have amplitudes very large compared with that of the applied emf one mode being stable and the other unstable only when the graph of is asymmetrical can there be an appreciable range of values of for which subharmonic oscillations of order take place 6898 pull in of nonlinear oscillators with filtered output the effect is considered of applying a small voltage of frequency to an oscillator whose fundamental frequency has been freed from harmonics by filtering a general formula is derived which gives the maximum value of for pull in to occur for the particular case of an oscillator with a single oscillatory circuit the formula reduces to the known expression q being the quality factor of the circuit and v the voltage amplitude of the free oscillations a formula is also given for the threshold value of below which pull in is not possible 6899 an x band sweep oscillator a generator which sweeps through the frequency band in sec is described a mechanically tuned klystron is used the output level is maintained constant to within db by means of an automatic control circuit including a variable attenuator with ferrite rotator unit above which also provides am at 6900 production of standard waves with a impulse generator equipment installed at bangalore is discussed the characteristics of the generator were determined experimentally a method of setting it up to produce a desired standard waveform is described 6901 multichannel crystal control of vhf and uhf oscillators the frequencies of a number of channels are controlled by a single crystal using an oscillator whose phase is varied periodically by application of pulses the oscillator output comprises a spectrum of harmonically related frequencies whose fundamental is the crystal controlled pulse frequency a particular triode oscillator covers the range with fundamental in the range by appropriately tuning the tank circuit any desired harmonic can be emphasized by an amount up to 6902 methods of reducing the ratio of noise to signal at the output terminals of amplifiers a summarized account of earlier work by the author alone or in collaboration with a van der ziel see of and 6903 the design of amplifiers for the birmingham manchester coaxial cable description with schematic circuit diagrams of a line amplifier suitable for the transmission of line television signals on a carrier or for telephony channel groups on diameter coaxial cables a constant gain amplifier for the transmitting terminal practical difficulties which limit the performance of the amplifiers and associated transformers are discussed and possible improvements for future designs are suggested 6904 the maestro a power amplifier description with complete circuit details of a new version of the musicians amplifier with an output of a pair of rca type beam power valves operated in class ab are used with a specially designed peerless output transformer type s q power supply circuits are also described 6905 new medium cost amplifier of unusual performance description with circuit details of an amplifier with the necessary flexibility and performance for most high fidelity applications only standard readily available valves are used 6906 essential similarity and relations between amplitude and phase distortions in video amplifiers in the complex method of e representation the transmission function of a video amplifier for steady oscillations can be regarded as the sum of an ideal transmission function and an error function the error function is applied in investigating the relations between an arbitrary transmission function with superposed amplitude and phase errors and the associated distortions for the minimum phase shift condition the investigation gives an insight into the physical relation between the distortions the formulae derived are applied to determine the distortions for a sytem with a tchebycheff type transmission function these distortions are then compared with those for a system with a steady fall of amplitude near the cut off frequency 6907 the direct voltage valve amplifier effects of valve and circuit noise fluctuations of the current source and temperature changes are evaluated a review of basic amplifier circuits for measurement purposes illustrates different directly coupled interstage and output arrangements and methods of compensating the above effects methods of amplification involving modulation are noted 6908 the parallel t dc amplifier a low drift amplifier with wide frequency response the frequency response of a modulated dc amplifier is broadened by the parallel addition of a conventional ac amplifier which has inherently a response capable of being made complementary to that of the dc amplifier the result is a homogeneous design without excessive phase shift circuit details are given of an amplifier designed for use with a high speed pen recorder in the frequency range the avoidance of direct coupling renders the use of electrometer valves unnecessary 6909 feedback amplifier design discussion of the pole pattern required for a low pass amplifier with overall feedback analysis is presented for an amplifier whose gain function contains no internal zeros and for which the feedback fraction is independent of frequency a general solution applicable to any number of poles is obtained for the case of critical damping for amplifiers with maximally flat response curves of graphical solutions are given for systems with n poles where n ranges from to the synthesis of a prescribed pole pattern is considered and the method of realizing conjugate poles by feedback pairs id described 6910 two simple types of feedback amplifier for the relaying of television signals over coaxial cables discussion a method is described for applying negative feedback to flatten the gain frequency characteristic of stage amplifiers using tuned anode intervalve couplings resonant at the mid band frequency two typical amplifiers are described 6911 summarized proceedings of a conference on microwave physics oxford summaries are given of the papers presented and of the subsequent discussions 6912 diffraction of a shock or an electromagnetic pulse by a right angled wedge solutions given in a previous paper of keller and blank are used as a basis for calculating the field distribution comparison with measurements made for the acoustic case shows satisfactory agreement 6913 precision determination of the velocity of light derived from a band spectrum method detailed report of the work noted in of the value obtained for the velocity is km sec 6914 extension and more exact statement of the analogies between electrical and mechanical devices 6915 electrical and mechanical analogies an introduction to the study of general problems concerning electrical networks and mechanical systems whose operation is governed by linear laws matrix symbolism is explained by examples and a table of elementary electrical and mechanical analogues is given application of the theory is made to discussion of the characteristics of transducers such as loudspeakers and piezoelectric or magnetostrictive generators 6916 diracs new classical theory of the electron diracs new theory and is shown to arise as a limiting case for both the particle and wave theories for continuously distributed charge it is equivalent to the maxwell lorentz theory 6917 number theory and the magnetic properties of an electron gas 6918 application of the theory of numbers to the magnetic properties of a free electron gas 6919 a direct comparison of the kelvin and electron beam methods of contact potential measurement 6920 the poisson kelvin hypothesis and the theory of dielectrics a comprehensive critical review of fundamental mathematical theory electrostatics only is considered but the treatment indicates that a complete reconstruction of electrodynamic theory is essential 6921 an optical method for determining the complex dielectric constant and the magnetic permeability a method applicable in the cm and mm wave ranges is described which depends on determination of the normal incidence reflection and transmission factors of a plane parallel plate the calculation is based on the general matrix equations of the field as derived from maxwells equations 6922 the mean free path of conduction electrons in bismuth experimental results for bi single crystals are given from which it is concluded that in agreement with the suggestion of sondheimer of the mean free path of the conduction electrons in bi is much longer than in normal metals and that for electrons travelling perpendicular to the triad axis the path length is probably in the range at room temperature 6923 secondary processes active in the electrical breakdown of gases results of recent investigations indicate the complexity of gas breakdown mechanisms three cathode mechanisms and two anode mechanisms are analysed and their relative importance and the conditions for their occurrence are discussed they lead to the same type of generalized threshold breakdown condition subject to statistical fluctuations and to space charge effects this condition masks the active processes and renders analysis difficult the various factors affecting the discharge are considered n and proper methods of discharge investigation are indicated 6924 the mechanism of field dependent secondary emission an account of experiments made to test the theory that the mechanism of field dependent secondary emission is similar to that of the townsend avalanche in gas discharges special tubes were used having dynodes with a porous coating the results indicate tht the high yield of secondaries is independent of the base material the variation of secondary current with field strength was in accordance with the gas discharge equations this was confirmed by retarding field measurements of the energies and mean free paths of the secondaries the time required for the surface to become charged was determined by using pulsed bombarding currents and was found to be consistent with the theory 6925 recombination of gaseous ions recombination between positive ions and electrons and between positive ions and negative ions are considered separately since the nature of the processes involved and the experimental techniques for observing them are quite different in the two cases although there is still little information about the rate of recombination of positive and negative ions at low pressure there has been substantial clarification of the processes of electron ion recombination during the last two years due to the application of microwave techniques the knowledge of the mechanism of electron ion recombination derived from both theory and experiment is reviewed in detail and a shorter account given of present knowledge of ion ion recombination at pressures less than that of the atmosphere recombination phenomena in the ionosphere in the solar corona and in interstellar gas are also discussed briefly references 6926 antiferromagnetism and ferrimagnetism the holweck lecture may reviewing the present state of knowledge of antiferromagnetism including ferrimagnetism and describing interesting phenomena related to the magnetic properties of certain ferrites and of pyrrhotite 6927 spin degeneracy and the theory of collective electron ferromagnetism a model is discussed for which the results obtained by neglecting or taking account of spin degeneracy are identical the model can be treated exactly and leads to equations for the free energy magnetization etc which are a generalization of those of stoners theory of collective electron ferromagnetism of 6928 zeners treatment of ferromagnetism a critical review of zeners theory 6929 the theory of ferromagnetism and heisenbergs model 6930 some magnetic properties of metals part diamagnetic resonance em radiation incident on a large system of electrons moving in a constant magnetic field h in a metal is strongly absorbed near a frequency where m is the effective mass the resonance absorption is of the same order of magnitude as the absorption due to skin effect part of 6931 some magnetic properties of metals part properties of small systems of electrons a calculation is made of the magnetic properties of a system of electrons within a cylinder of very small radius with its axis parallel to the field direction the expressions obtained for magnetic susceptibility thermodynamic potential and specific heat contain a steady term which remains of significant magnitude at all temperatures together with terms periodic in the field which are significant only at very low temperatures the influence of electron spin is discussed similar calculations are made for a small spherical system 6932 the limits of total reflection part rigorous wave theory calculation the variation of intensity in the region of the critical reflection angle is calculated numerically for a particular case previously considered by ott of the curve obtained indicates a continuous variation from the region of partial to that of total reflection 6933 propagation of a wave front in anisotropic dispersive media extension of work previously noted of february to the case of anisotropic media expressions are derived for the velocity of propagation and for the field in the vicinity of the wave front 6934 determination of nuclear moments from hertzian spectra discussion of the interaction between nucleus and electron and an account of the principal methods apart from resonance methods of applying microwave spectroscopy to the determination of nuclear moments 6935 the velocity distribution of sporadic meteors part extension of the work noted in part of to the investigation of fainter meteors similar results are obtained 6936 the velocity distribution of sporadic meteors part calculation of the theoretical distributions a general method is described for estimating the field of view of any aerial system and hence of predicting the ratio of true to observed hourly numbers for particles of different velocity and flight direction part above 6937 relation between geomagnetic activity and solar radio activity a fuller account of work noted previously of denisse steinberg and zisler 6938 the representation of the main geomagnetic field and of its secular variation by means of two eccentric dipoles a model comprising two dipoles is suggested to account for the second order terms in the expansion representing the geomagnetic potential the systematic displacement of the dipoles with time explains certain features of the geomagnetic secular variation the model provides a generally improved approximation to the actual surface geomagnetic field 6939 theories of magnetic storms and aurorae the discussion of theories advanced by alfven and martyn of 6940 slide rule computes radio refractive index of air details are given of methods developed at the national bureau of standards for computing atmospheric rf refractive indices from radiosonede meteorological data using special types of straight or circular slide rule the methods give adequate accuracy for almost any conditions likely to be encountered in the troposphere 6941 ozone in the earths atmosphere general discussion of processes involved in the formation of ozone methods of measuring z ozone content and its vertical distribution in the atmosphere and variations of ozone content with meteorological conditions 6942 ionosphere review curves are given for the period showing monthly mean values month running averages of sunspot numbers and noon and midnight f critical frequencies from these it appears probable that both sunspot numbers and critical frequencies will continue to decrease slightly during 6943 recent advances in auroral spectroscopy and in our knowledge of the upper atmosphere 6944 auroral effects on television 6945 the propagation of a radio atmospheric part 6946 transients in nonlinear servomechanisms with filters continuing previous work of equations are derived for amplitude and elongation a complex function of time for the case of small damping and a new construction o for point to point tracing of the xt curve is indicated which furnishes a new criterion of stability of steady states of oscillation 6947 the pulse transfer function and its application to sampling servo systems a method of analysis of sampling in a linear system is described which is based on a sequence transformation closely analogous to the laplace transform the pulse transfer function relates a sequence of samples at the output of the system to the input sequence of pulses producing it servo systems with a finite time delay in the feedback loop are particularly considered a list of transforms is provided in an appendix 6948 the design and testing of an electronic simulator for a hydraulic remote position control servo mechanism discussion 6949 exceptionally stable regulated power supply for electrometer tubes description of a two stage regulator circuit delivering about at with the output regulated to within several parts per million for line voltage changes of drift of the output voltage is about parts per million per hour theory construction details and results of performance tests are given 6950 radiofrequency power supply brief description of a circuit designed for a maximum current output of an output voltage of being provided by means of a chain of wire wound resistors the variation of the dc output voltage measured over a period of hours was part in 6951 compensation of feedback control systems subject to saturation a theory for the design of compensating networks for feedback control systems and filters is developed the novel feature of this theory is its consideration of saturation and transient performance in addition to the usual steady state behaviour this theory is essentially an extension of the researches of wiener and lee in statistical methods for filter design saturation is handled by limiting the rms signal levels at critical points in the linear model used as the design basis for the physical system transient performance is handled by limiting the integral square errors to a set of transient test signals 6952 corona discharge tubes for voltage stabilization the mechanism of the corona discharge is briefly described by reference to the current voltage characteristic of the glow discharge tube the construction processing and performance of experimental coaxial types of tube are discussed the data presented are sufficient for the design of tubes with regulating voltages between and operating at currents up to at least such tubes can be made with characteristics stable for over hours 6953 the importance of frequency rate indication in the control of the national grid description of the construction and use of equipment indicating time error mains frequency error and rate of change of mains frequency the unit comprises a mains frequency the unit comprises a mains driven and a tuning fork controlled motor both coupled to a differential gear whose output shaft moves only when the mains frequency differs from systems of differentiators and geared counters operate the indicating instruments 6954 initial conditions in transient analysis in a paper on network theory of lee and macdonald indicated the equivalence of a charged capacitor and the series combination of an uncharged capacitor and a battery extension of this idea to consideration of inductors leads to a simple method of analysing initial conditions the method is elucidated by two theorems and examples the laplace transform treatment is used 6955 transient conditions by transformation of the fourier integrals to obtain a series development of bessel functions expressions have been derived for certain transient response characteristics these included the response of a low pass and a high pass lc ladder filter and of a homogeneous transmission line to unit step and sinusoidal voltage input when the system is terminated by its image impedance 6956 reduction of carrier frequency build up process to a complex low frequency process the laplace transform method is used by applying the displacement law the distortion of a carrier envelope due to a linear transmission element can be calculated directly vestigial as well as symmetrical sideband systems can be dealt with in this way 6957 a turns index for pulse transformer design by assuming certain ratios between core and coil dimensions which represent average values of normal practical designs it is found possible to generalize design relations so that coil and core dimensions are eliminated from first design considerations the only parameter remaining being that of the turns of the windings for a step up pulse transformer of ratio a formula is given for the number of turns on the secondary in terms of performance requirements and properties of the dielectric and magnetic materials used the formula was checked against actual values for existing transformers covering a range of pulse widths from to and secondary voltages from to 6958 a mathematical analysis of an inductively loaded parallel connected magnetic amplifier 6959 a multichannel switch for operation in a microwave circuit description of a rotating disk type of switch for cro display of a rapid succession of pulses picked up by a number of probes arranged at different points along a waveguide passing signals 6960 e c class resistors discussion of performance characteristics of highly stable resistors consisting of a thin conductive coating on heat resistant glass ratings range from to resistance change is for temperature cycles between and 6961 the design of single phase transductors 6962 a ferromagnetic scaling circuit each incoming pulse triggers the discharge of a capacitor through the primary coil on an iron wire core the maximum voltage of the pulse induced in the secondary depends on the core magnetization and thus on the number of incoming pulses on reaching a preselected level a thyratron is fired and operates a mechanical counter the core being restored to its initial state of magnetization scales of up to are stable in operation design details and theory are discussed 6963 gated decade counter requires no feedback decade counting is achieved in a system using binary type counting circuits by arranging that eight pulses are directed into one storage circuit and the next two pulses into a second storage circuit after which the systems resets itself 6964 counting pulses of various forms and occurrence intervals by electronic counters modifications to univibrator circuits are described which prevent retriggering during the recovery period or provide a retriggering characteristic permitting the recording of overlapping pulses or both 6965 maximum power in termination impedors an analytical proof that power is a maximum when the resistive component of the load is equal to the internal resistance of the source and the reactive components cancel out the principle can be extended to the case of a quadripole by reformulating the helmholtz equations 6966 the power of nonsinusoidal systems a calculation is made of the instantaneous power absorbed by a series lrc circuit with a nonsinusoidal periodic applied voltage the square of the apparent power is the sum of the squares of l all the component powers for all the harmonics including so called mutual terms involving harmonics of different order 6967 the optimum piston position for wide band coaxial to waveguide transducers matching of a coaxial line to a waveguide can be effected by means of a probe located ahead of a short circuiting piston in the waveguide matching can usually be achieved by varying any two of the following dimensions off centre distance of the probe probe length distance from piston to probe as there is theoretically an optimum piston position giving greatest bandwidth it is convenient to vary dimensions and experimental results are quoted which corroborate the theory bandwidths to the swr points were obtained 6968 a highly stable variable time delay system description with detailed circuit diagrams of delay systems in which distributed amplification is used to compensate the losses in the linear delay elements time jitter is extremely low two practical circuits have maximum delays of and per step and per step respectively 6969 theory of the compensated delay line analysis based on an equivalent ladder network indicates that for a certain compensating capacitance a constant delay can be obtained over a predetermined frequency range calculations are made for compensating rectangular plate capacitors results are presented in a graph useful for design the results are in good agreement with those of kallmann of and others 6970 synthesis of terminal pair networks to realize a quadripole ladder network comprising only reactive elements and with prescribed transfer function five general conditions must be satisfied these are discussed with particular reference to the synthesis of a ladder network consisting of a number of l sections in cascade all the sections except one comprising only inductors and capacitors a simple method of completely determining the transfer function of such a network is outlined 6971 four terminal networks a rigorous theory of passive quadripoles in the steady state is presented the general quadripole is regarded as consistent of n meshes and the equations for the system as a whole are obtained by solving the equations for the meshes iterative and image impedances are obtained as properties of a single quadripole and a suitable propagation function is associated with each pair of impedances conditions in quadripoles in two types of cascade arrangement can be deduced immediately from the equations for a single quadripole tables are included giving expressions for the image functions in terms of the iterative functions and vice versa and giving the equations of the quadripole in terms of the iterative and image functions 6972 new linear passive nonreciprocal microwave circuit component a note calling attention to the fact that the magneto optic element producing the faraday rotations previously reported by goldstein et al of and of constitutes a network element of the tellegen gyrator type se also of hogan 6973 a theorem on ideal transformer networks by applying the principle of duality to an impedance inversion network a general theorem on ideal transformation of voltage current and both voltage and current is derived provided the resistive components of reactors are sufficiently small the theorem may be applied in designing networks which can be tuned by a single control through a range of frequencies with fixed transformation ratio to give a variable transformation ratio at a fixed frequency 6974 exact amplitude frequency characteristics of ladder networks a basic theory of the low pass ladder networks is developed on similar lines to dishals treatment of the theory can be applied by well known analogies to the derived band pass high pass and band stop filters two types of desired frequency response curves are considered the butterworth and tchebycheff types general solutions are obtained for both the results are applied to many practical problems including the use of networks for coupling a valve to a resistive load or to another valve power bandwidth and gain bandwidth curves being determined for particular cases impedance matching between a generator and its load is also considered and matching networks are designed examples are also given of the design of low pass and band pass filters with either the butterworth or the tchebycheff type of response many useful design curves being given 6975 alignment and adjustment of synchronously tuned multiple resonant circuit filters 6976 manufacture of microstrip illustrated description of processes in the manufacture of microstrip components see also grieg and engelmann assadourian and rimai and kostriza of march 6977 automodulation in ferroresonance automodulation of forced oscillations in ferroresonant circuits ie circuits containing nonlinear reactive elements is considered the following examples are examined circuit with a thermistor circuit with a capacitor whose value depends on the field and on temperature an es voltmeter connected to a ferroresonant circuit the stationary operating conditions and their stability in such circuits are discussed and the depth and period of automodulation are determined the discussion is limited to cases in which the circuit is nearly of the linear conservative type and the variations of amplitude and phase are slow in comparison with the period of the external force 6978 a criterion of stability for oscillations in n mesh networks with varying parameters analysis given previously of is generalized to apply to any network in which some or all of the capacitances or inductances vary periodically conditions necessary for the growth of free oscillations having small initial amplitudes are investigated the system is represented by a determinant equation from whose roots the stability conditions are derived 6979 fixed length transmission lines as circuit elements resonant systems consisting of fixed length transmission lines with a capacitor at each end have decided advantages compared with short circuited transmission line sections for use at frequencies of the order of analysis is presented which leads to simple graphical determination of the line and capacitor parameters the analysis is extended to include interstage coupling circuits and wide band coupling of an aerial to the output stage of a transmitter numerical examples are given 6980 the measure of activity for oscillating quartz crystals in parallel resonance circuits the concept of performance index is explained this is the effective parallel resistance r of the resonant crystal shunted by a specified capacitance a method of measurement of r is described load current density should be specified when quoting r 6981 the stability of quartz oscillators supposing a a series connected crystal in a resonant lc circuit to be short circuited the relative detuning f due to the presence of the crystal is termed the stabilization factor different arrangements of meissner hartley and colpitts circuits are considered the most stable circuit is one in which f is a maximum compatible with oscillation and is independent of change in the valve interlectrode capacitance and the load current through the crystal the properties of a circuit in which the crystal acts as an inductance are similar in all respects to those of a circuit with the crystal operating at series resonance 6982 methods for improving the frequency stability of transmitters 6983 equations for the natural frequencies of coupled circuits from the quadripole viewpoint part theory previously given of is extended to the case of a six terminal network with both series and parallel connected resistance the biquadratic equation for a coupled system is expressed by two binomials one referring to the circuits uncoupled the other occupation binomial taking account of the coupling data two schemes for formulating this occupation factor and associated expressions probably cover all cases of coupling by a single resistor 6984 quartz crystal circuit with variable coupling as oscillator and discriminator the principle of the fm oscillator described is the use of two coupled tuned circuits the second of which has a crystal connected in parallel a reactance valve drives the oscillator valve which has the first circuit connected between anode and a capacitor connected to the grid with anode feed to the centre tap on the inductor the relative frequency swing attainable is from to parts in impedance diagrams for the circuit are shown the principle is also applied in a discriminator in which the centre tap of the second circuit inductor is connected through a large value capacitor to the anode side of the first circuit the coupling between the inductors being variable the centre frequency of this discriminator is largely independent of the characteristics of the rectifying diodes 6985 wien bridge oscillator design a set of curves is presented which allows direct determination of design parameters of wien bridge oscillators and selective amplifiers 6986 perturbations of filtered oscillators the amplifier of an oscillator is assumed to be filtered to isolate the fundamental frequency so that the oscillator responds to excitation by a synchronous sinusoidal oscillation an equation for the oscillator perturbations is developed which involves the partial derivatives of the gain and phase from this equation th existence of a synchronization threshold can be demonstrated for the general case when the perturbation is below this threshold frequency pulling occurs 6987 the lock in performance of an afc circuit for t the case of rc coupling between phase detector and reactance valve in an afc system an explicit relation is derived which determines the lock in condition in an afc system using a reactance valve controlled oscillator the relation involves the filter time constant the initial frequency error the phase detector constant and the sensitivity of the oscillator 6988 analysis and performance of locked oscillator frequency dividers employing nonlinear elements locked oscillator frequency dividers can be stabilized by inserting certain nonlinear elements in the oscillator circuits these elements should have a characteristic such that the voltage is proportional to an integral root of the current through them if this condition is satisfied the locked oscillator divider is almost completely insensitive to wide changes of anode voltage driving signal voltage and driving frequency the mathematical representation of the nonlinearity of the elements permits some analysis of the circuit nonlinear differential equations thyrite elements or varistors were used in experimental circuits for division by or 6989 calculation of the harmonic distortion in sinusoidal modulation of frequency or phase detailed study of a quadripole with antiresonant circuit the fm voltage applied to the input terminals of an arbitrary quadripole is expressed by a convergent fourier series an expression is deduced for the tangent of the variable phase shift introduced by the quadripole in the form of the quotient of two rapidly convergent series of bessel functions which lend themselves well to numerical calculation three parameters are involved the wave length the modulation index m and the ratio of to the qu factor of the parallel rlc circuit considered numerical calculations are made for eight cases of practical interest involving different values of m and the results given by the complete formulae for the harmonic distortion are compared with those obtained by application of the instantaneous frequency rule 6990 a ferroelectric amplifier a lf signal was applied to a capacitor with ceramic dielectric thereby causing its capacitance to vary the capacitor formed part of a tuned circuit fed by a hf voltage the resulting am hf voltage was applied to a detector circuit to recover the signal analysis for this arrangement indicates the conditions for maximum amplification with a signal frequency of hf of and load resistance a power gain of was obtained with the signal source removed and the output fed back to the input terminals sustained lf oscillations were obtained with only the hf voltage applied the oscillation frequency could be varied continuously from to by varying the value of a rf choke in the input lead and of a capacitor in the detector circuit see also of vincent 6991 distributed amplifiers mutual inductance coupled type design procedure is outlined the problems of output voltage and output matching being considered in detail a method involving over running the valves is described for increasing gain and output while maintaining the time delay constant when amplifying random pulses details are given of the construction and performance of two amplifiers having a useful bandwidth of 6992 cathode follower operation comment on of 6993 rc or direct coupled power stage analysis is performed for an rc or direct coupled output stage consisting of an ideal triode of resistance anode feed resistance r and load resistance r to determine the relations between and for maximum efficiency the formula derived is evaluated for some particular cases 6994 transistor circuits by appropriate use of transformers transistor circuits having characteristics similar to those of ordinary valves can be obtained calculations are given for several particular cases 6995 noise in transistor amplifiers conditions for obtaining optimum signal noise ratio are indicated for amplifiers using point contact and junction type transistors graphs show the dependence of noise figure on operating point and for a two stage amplifier on the source impedance of the second stage see also of march and of montgomery 6996 mathematical aspects of the quantum theory of fields part boson field in interaction with a given source distribution 6997 mathematical aspects of the quantum theory of fields part occupation number representation and fields of different kinds 6998 gravitation and electrodynamics a modification of einsteins unified field theory is proposed and its physical implications are examined 6999 further experimental investigations on the nature of light experimental arrangements are described for obtaining a photographic record of the effect of a strong nonuniform electric field on a light beam a photometric record of the variation in diffraction due to such a field the deviation of the beam which occurs when the plane of polarization is perpendicular to the direction of the field is discussed in relation to the em theory of light 7000 diffraction of electromagnetic waves by an aperture in an infinite screen an approximate solution is derived for conditions of normal incidence on a perfectly conducting screen the method is applicable where the aperture is large compared with and reduces the problem to one of scalar boundary values 7001 diffraction field of a circular aperture an equation expressing the diffracted field is derived for the case of a normally incident plane wave and a perfectly reflecting screen the equation is of the form given by stratton of but is modiffied to agree with certain theoretically and experimentally established conditions 7002 a new method of solving diffraction problems a double approximation method is indicated for dealing with various problems on the diffraction of em waves 7003 application of the methods of optics to calculations of diffraction phenomena in the centimetre wave range analysis and examples illustrating the use of kirchhoffs theory for approximate calculation of diffraction effects both for centimetre em waves and for sound waves 7004 angular momentum in diracs new electrodynamics 7005 the energy momentum tensor in diracs new electromagnetic theory 7006 diffraction by a charged filament the deflection of an electron by a charged infinite filament is considered and an equation is derived determining its trajectory 7007 interpretation of the electron inertia experiment for metals with positive hall coefficients a critical discussion of the measurements described by brown and barnett of march 7008 interpretation of em values for electrons in crystals the e values obtained by brown and barnett of march are shown to be in agreement with established theory if the mass of the holes is considered to be negative 7009 mobility in high electric fields conductivity theory is extended to the case of strong es fields all electron collisions being assumed to be elastic a relation is derived between mobility and relaxation time which is valid over a wide range of field strengths 7010 the anomalous skin effect measurements were made on a number of metals at frequencies of and at temperatures in the range the variation of rf surface conductance with dc conductivity agrees well with the theoretical prediction of reuter and sondheimer of assuming that the electrons are scattered diffusely when they hit the surface of the metal the results are used to estimate the effective value of mean free path of electrons the estimate for cu agrees well with that based on theory but those for ag and au are rather lower than the theoretical values the results are largely dependent on the surface condition of the metal the use of the two different frequencies enables the influence of this factor to be assessed 7011 the influence of the surface states of electrons on the optical properties of semiconductors and dielectrics the reflection of em waves from a plane surface with electronic surface conduction is considered for incidence angles close to reflection increases with the angle when the electric vector is parallel to the surface but decreases when the electric vector is almost perpendicular to the surface 7012 experimental verification of the relationship between diffusion constant and mobility of electrons and holes short pulses of electrons or holes were injected into single crystal rods of p and n type ge as the pulse travelled along the rod under the influence of an electric field diffusion took place resulting in broadening of the pulse a large number of measurements of pulse widths and transit times for two positions of the emitter point were made and the most probable value of the ratio of diffusion constant to mobility was derived by the method o of least squares this was found to verify the relation see of 7013 corona suppression methods physical aspects of corona discharge are discussed and its prevention by pressurization or evacuation of electrical equipment by increasing the radii of curvature of conductors and by coating with or immersion in materials of high dielectric strength is described 7014 the single electrode discharge at pressures from a few millimetres of mercury to atmospheric pressure at the frequency of experiments were conducted with discharges in air n and ar to investigate the characteristics of the torch discharge 7015 formative time lags of uniform field breakdown in n 7016 dynamics of plasma part plasma with neutral gas continuation of work noted in of to illustrate theory it is applied to investigate the influence of self magnetic field on a glow discharge 7017 longitudinal waves in an ionized medium plasma the permittivity of an electronic plasma is calculated taking account of electron motion the value found depends on the spatial structure of the field a concept of spatial dispersion is introduced the properties of longitudinal waves and their relation to transverse waves are investigated 7018 crystal structure and antiferromagnetism in haematite 7019 ferromagnetism at very high frequencies part temperature dependence of the magnetic spectrum of a ferrite continuation of work noted in of rado et al observations at and are reported by using single domain particles embedded in wax the rotational resonance was observed separately the resonance frequencies decrease with increasing temperature a theoretical interpretation is given auxiliary measurements of the spectroscopic splitting factor saturation magnetization and coercive force are described 7020 the distribution of currents in a disk rotating in a uniform magnetic field and the damping 7021 application of the calculus of variations to the determination of reflection coefficients the method previously used to determine the reflection coefficient of a potential barrier of is here applied to the vector field of em waves to determine the reflection coefficient of a stratified medium for te and tm waves 7022 the complete system of natural electromagnetic oscillations of a biaxial anisotropic parallelepiped analysis of the em field inside a rectangular cavity resonator completely filled with an optically biaxial crystal 7023 propagation in electron ion streams mathematical theory is developed for streams composed of n discrete beams the solution of the propagation equations is obtained in vector form by an extension of hansens theory and takes explicit account of initial and boundary conditions when certain restrictions are placed on the transverse boundary conditions the general solution satisfying arbitrary initial conditions can be expanded in terms of a complete orthogonal set of elementary vector solutions for this case the necessary and sufficient conditions are found for amplification and instability in the terminated and the unterminated stream the analysis is extended to a continuous velocity distribution see also of 7024 a broad band coaxial stark cell for microwave spectroscopy the cell consists of a coaxial structure long the outer conductor being of brass tube and the inner of brass rod the ends are vacuum sealed only a single wave transmission mode is possible in the operation range the application of a voltage between the conductors at some predetermined repetition rate modifies the variation of the absorption with the frequency of the rf wave field thus facilitating detection of resonance see also 7025 apparatus for zeeman effect measurements on microwave spectra 7026 the connection between transverse magnetogalvaniic effects and resistivity the magnetogalvanic rotation due to the hall effect in an isotropic conductor is expressed in terms of transverse magnetogalvanic conductivity its variation with temperature and field intensity is discussed briefly with reference to ferromagnetic and super conducting media 7027 a radar investigation of the delta aquarid meteor shower of 7028 effects of solar radiation in the upper atmosphere an account is given of the various radiations emitted by the sun and of the ionization and dissociation effects resulting from their absorption in the upper atmosphere 7029 solar enhanced radiation and plasma oscillations the dispersion formula for plasma oscillations in a static magnetic field is derived by the laplace transform method used by landau of the oscillations are unstable in frequency bands around multiples of the gyrofrequency numerical calculations for sunspot magnetic fields in the corona indicate that random fluctuations may be amplified and afford support for the explanation given by wild of enhanced radiation 7030 solar activity and the atmosphere statistical analysis of records confirms that correlation exists between geomagnetic disturbances and fluctuations of atmospheric pressure over scandinavia the hypothesis of planetary influence on solar activity is discussed assumptions regarding the mechanism of the suns influence on the atmosphere are justified by measurements 7031 the physical conditions in large sunspots deduced from their spectra the temperature electronic pressure and gas pressure at the centre of a large sunspot are determined from published spectral data 7032 provisional sunspot numbers for july to september 7033 the corona and geomagnetism discussion of available data for the present solar activity minimum shows the existence of a tendency for the central meridian passages of moderately bright regions to be followed by reduced geomagnetic activity for about three days 7034 effects of the solar eclipse of february on the ionospheric f region over equatorial africa detailed note of effects observed in ionosphere soundings at bangui these are interpreted satisfactorily in terms of the existence of two interspersed layers x and g comprising the f region the lower x disappears as ionization decreases during occultation during the reionization process which occurs more rapidly at the base of the layer than at the top the lower regions of x merge with the f layer the comparative insensitiveness of the upper layer g can be explained on the basis of corpuscular radiation 7035 on some possible mechanisms of radio stars part neither the deflection of fast electrons nor transitions of thermally excited electrons can account for the observed intensity of radiation 7036 the determination of the position of a radio star discussion of the accuracy of different methods 7037 the measurement of the angular diameter of radio stars the phase switching interferometer method described by ryle of is considered in detail and measurements made by this method are reported 7038 electromagnetic radiation from cosmic protons and the rf radiation from the galaxy calculations indicate that galactic rf radiation may be originated by the proton component of cosmic rays when the latter pass through the galactic fields 7039 a new discussion of the changes in the earths rate of rotation a detailed analysis of available information on changes in the rate of rotation of the earth since 7040 a negative experiment relating to magnetism and the earths rotation an experiment was made to determine whether a cm gold cylinder rotating with the earth produced a weak magnetic field no such field was observed the magnetometer used is described in detail 7041 the electromagnetic field of a rotating uniformly magnetized sphere 7042 the variation of the geomagnetic activity recurrence interval with the solar cycle 7043 cheltenham three hour range indices k for july to september 7044 isolation of the eleven yearly variation of the horizontal component of the earths magnetic field by linear combinations of ordinates the ev eleven yearly component is brought into evidence by using labroustes method of analysis this component has in general a minimum value years after the maximum of sunspot activity and a total amplitude of gamma exceptional results observed for certain stations are discussed 7045 on variations of the geomagnetic field fluid motions and the rate of the earths rotation brouwers results above are compared with changes with time in the westward drift of fluid moving near the surface of the earths central core as inferred from the westward drift of the eccentric dipole field of geomagnetism 7046 principal magnetic storms 7047 international data on magnetic disturbances second quarter 7048 measurement of tropospheric index of refraction fluctuations and profiles results are presented of measurements made with a direct reading microwave refractometer over the sea and coastal areas near lakehurst nj and over southern ohio for heights up to the refractometer was essentially the same as that previously described by crain 7049 some reactions occurring in the earths upper atmosphere the photo chemical reactions determining the equilibrium between n n no and no are examined the origin of the no in the atmosphere is discussed a considerable yield is necessary to balance the loss due to photodissociation this gas may be formed in the troposphere by collisions between o or o and n 7050 the height of the atmospheric electric equilibrium layer continuation of previous work by israel and kasemir the values of electron concentration corresponding to two limiting assumptions regarding dependence of recombination coefficient on pressure are compared with values deduced fro determinations of d layer ionization is found to be proportional to the cube root of the pressure the height of the equilibrium layer is about km 7051 relations between temperature and the phenomena of photochemical dissociation or ionization in the upper atmosphere particularly in the e layer a calculation of the initial kinetic energy of oxygen atoms produced by photodissociation of oxygen molecules gives a value corresponding to a temperature at altitudes between and 7052 a new early morning ionospheric phenomenon kodaikanal records indicate the cessation of ionospheric echoes some minutes to several hours before sunrise and their reappearance at about the time of ground sunrise on about of days during theflecting layer on reappearance of the echoes was km on mornings when the echoes did not disappear the new reflecting layer appeared suddenly and its height decreased rapidly to that of the overnight layer viz km 7053 investigation of the ionizing effect in the e layer near sunrise virtual height time records for signals show a sudden decrease in virtual height around ground sunrise analysis for the period jan dec shows that the difference between time of occurrence of the sunrise drop and sun rise at the reflection level is constant and independent of season absorption is considered the most likely cause of this effect calculations of absorption coefficients for o n and o give results of the right order of magnitude in the case of only ionization of o could be caused by ultraviolet radiation of 7054 the f layer at dakar and the motion of the sun the occurrence of a layer between the normal f and f layers has been reported previously of delobeau et al the results of observations for the period july to july are shown graphically and discussed curves for summer winter and the equinoxes showing the number of occurrences of the f layer for each hour of the day are of similar shape with maxima shortly after local time the curves dropping to zero at about and the seasonal curves show maxima about the summer solstice and minima at about the winter solstice similar effects thick f layer have been observed at singapore of osborne 7055 solar ionospheric tides in the f region the equation of continuity for electrons subject to the influence of a vertical drift harmonic in time has been integrated by numerical methods taking the processes of ion production and recombination into account for physica conditions representative of the f region the results of the analysis are applied to a brief discussion of the nature of the information regarding the vertical electron drift which can be derived from measured ionospheric data 7056 some practical determinations of the electron content below the level of maximum ionization in the f region of the ionosphere ratcliffes method of was applied to results of observation at slough and at singapore during and to simultaneous observations at penang and singapore during one week of july seasonal and diurnal variations of maximum electron density differ from those of the total number n of electrons in a vertical column of unit cross section in the f region up to the level of maximum ionization the variations of n show a greater dependence on the solar zenith angle diurnal variations of the latitude gradient of n near the magnetic equator are briefly discussed it apper probable that as the latitude alters the local noon value of n goes through a flat maximum in equatorial latitudes whereas the noon value of maximum electron density goes through a sharp minimum near the magnetic equator and exhibits the well known equatorial trough 7057 the differences in the relationship between ionospheric critical frequencies and sunspot number for different sunspot cycles statistical analysis of data from washington dc and watheroo australia shows significant differences for months near the equinoxes and also seasonal variations between the and cycles inconclusive results for other months are ascribed in part to the small sample size of available data for radio propagation predictions therefore only current cycle data should be used 7058 calculation of absorption in the ionospheric propagation of short waves formulae and graphs necessary for calculation of the absorption in the absence of and in the presence of the geomagnetic field are assembled and explained 7059 conductivity of the ionosphere the investigations of various workers relative to balfour stewarts dynamo theory of geomagnetic diurnal variations are reviewed and the fundamental principles involved in the production of electric currents in the ionosphere by tidal winds are reexamined three conductivities two of which are related to the hall effect appear to be involved one of these has two relatively small maxima at km height due mainly to ions and due to electrons the second has a broad maximum at thus including all the e region ionization and the third has a very pronounced sharp maximum at km discussion shows that the effective conductivity of the ionosphere over most of the earth is some twelve times greater than that deduced when the hall current is ignored and near the magnetic equator the conductivity is increased further by a factor of equations developed appear to account quantitatively for the high conductivity required by the dynamo theory and also for the increased conductivity near the magnetic equator near the equator the current system should be in a relatively thin layer centred at about km height evidence of the existence of a current sheet between the and levels has recently been obtained by singer et al in rocket experiments 7060 dynamo currents and conductivities in the earths upper atmosphere discussion of the results of rocket measurements reported previously of the observed current system would account for the exceptionally large geomagnetic diurnal variations found at huancayo and strongly supports balfour stewarts dynamo theory of the diurnal variations by taking account of polarization due to the hall effect the large discrepancy between conventionally calculated ionosphere conductivities and the value of the conductivity required by the dynamo theory using accepted values for the velocity of high altitude winds can be eliminated further rocket measurements on both magnetically quiet and disturbed days are very desirable 7061 studies of the atmospheric potential gradient no current theory f the electric field in the air particular cases arising from the theory given previously of are examined in detail using moderately advanced mathematics 7062 studies of the atmospheric potential gradient no examples of atmospheric electrical phenomena in foggy conditions from an examination of numerous records of the atmospheric electric field and the vertical current obtained at stations in lowland and mountainous regions during fog several types of characteristic reaction are distinguished these are discussed in detail 7063 theories of the aurora polaris the discussion presented deals only with theories based on the action of streams or clouds of neutral ionized gas ejected from the sun 7064 the teometry of radio echoes from aurorae 7065 the streaming of charged particles through a magnetic field as a theory of the aurora 7066 landolt bornstein zahlenwerte und funktionen aus physik chemie astronomie geophysik und technik vol astronomie und geophysik j bartels and p ten bruggencate volume eds publishers springer verlag berlin gottingen e heidelberg should be available in any library catering for meteorologists geophysicists or astronomers no book written in english contains such a useful and complete collection of information 7067 stability of control systems study of a common type of equation 7068 converting direct voltage to alternating voltage at high power description of a unit providing a supply for a radio beacon at schiphol an inverter circuit with balanced hg vapour filled thyratrons is used and the maximum continuous power output is with an overall efficiency of considerably higher supply frequencies can be provided by using thyratrons with different gas fillings 7069 use of a bridge circuit for supplying several loads independently from a common voltage source a circuit suitable for measurement purposes and adapted for both dc and ac supplies has the source arranged in one arm of a bridge and two loads respectively in the two diagonals modification to accomodate more loads is indicated 7070 design of series peaking transformers essential features of this type of transformer are the load current is arranged to be negligible compared with the magnetizing current and the magnetizing current is allowed to reach a value much greater than that required to saturate the core an easy and accurate design method is presented which does not require an analytical representation of the by bh characteristic the example of a transformer to produce a voltage pulse of about for triggering a thyratron is worked out numerically the voltage and duration of the pulse can be predicted to within about of the measured values 7071 investigations on voltage transformers a conductance diagram is developed to show directly the variation of secondary voltage and phase angle as a function of the load its application in transformer design is illustrated 7072 dc ac converter utilizing the space charge capacitance of a valve two circuits are described for converting feeble dc to ac prior to amplification for measurement purposes both make use of the variation of grid cathode capacitance with the voltage applied to the grid the first circuit using a bridge balanced for a certain value of the grid cathode capacitance so that any variation produces a proportionate deflection of a meter the second circuit uses a balanced arrangement of two valves with a differential transformer zero stability is good in both cases 7073 transistor equations formulae giving circuit voltage and current gain and impedance characteristics in terms of transistor parameters are tabulated for grounded base grounded emitter and grounded collector transistor amplifier circuits 7074 static dynamic design of flip flop circuits discussion of the design of flip flop circuits for operation from a relatively low supply voltage a desirable feature for computer elements the circuit adopted uses negative pulse triggering and a diode input circuit the minimum trigger voltage being adjustable by means of two variable resistors stability is determined by use of rouths criteria general directions for the design of flip flop circuits for low voltage operation are summarized 7075 design of low frequency constant time delay lines analysis is presented for ladder type low frequency delay lines consisting of pierce asymmetrical t sections each section having two unequal coils in series wound on a common core to give a coupling coefficient near unity a capacitor being connected from the junction of the coils to earth when properly terminated such delay lines give delays constant to within over of the pass band where many sections must be used they have the decided advantage of requiring only two components per section a double winding inductor and a capacitor 7076 transfer matrix of a four terminal passive network in terms of its image parameters the constants in the fundamental simultaneous equations relating the input and output voltages and currents for a linear passive quadripole have a particular significance and can be used to derive the transfer matrix of any passive network in terms of the image impedances this is demonstrated for the l type of network 7077 the measurement of a matrix elements of passive networks th general method of using the a matrix has previously been described of a method is here described for determining the matrix elements from measurements of the impedance looking in at the sending nd of a network the receiving end being first open circuited and then short circuited the elements so found apply only for the measurement frequency the analysis shows that networks are electrically equivalent at a given frequency when their a matrices are equal at that frequency 7078 the maximum gain of an rc network analysis is presented indicating that any desired voltage gain can be achieved at a given real frequency by using networks of sufficient complexity as represented by the degree of the corresponding formulae transfer function theory developed previously of is used the relation between the maximum possible gain and the degree of the transfer function is determined the results are illustrated by examples 7079 note on a network theorem the formulation adopted by zepler of is criticized and it is shown that his results can be obtained more simply by using the conventional impedance concept rather than his unconventional power concept 7080 waveform computations by the time series method discussion on paper abstracted in of january 7081 the synthesis of a network to have a sine squared impulse response discussion on paper abstracted in of february 7082 reduction of the loss in ferrite materials in the microwave region the loss in microwave gyrators of the type comprising a ferrite rod inside a circular waveguide surrounded by a solenoid producing an axial magnetic field has in certain cases been reduced by application of an auxiliary transverse static magnetic field 7083 filter transfer function synthesis theory is developed for circuits in which approximately constant attenuation is achieved over one or more frequency bands an electrostatic potential analogue method is used see of klinkhamer the method is applied to some examples of low pass filters 7084 a systematic procedure for the design of filters continuing previous work on the formulation of the characteristic functions of filters of tables are developed which facilitate the determination of the circuit elements of coupling free filters of various types 7085 multistage band pass filter with optimum approximation to the ideal rectangular shape of the response curve 7086 the design of linear phase low pass filters discussion general design principles are outlined and a method applicable to certain low pass filters required in television equipment is described adequate phase linearity of response can be obtained over the whole pass band only by limiting the discrimination required in the attenuation region of the insertion loss characteristic practical examples include a set of low pass filters with linear phase characteristics from zero nearly to their cut off frequencies which range from to an asymmetric sideband filter with a cut off frequency of and phase linearity from to with discrimination above 7087 how to use mechanical if filters discussion of the construction and performance of electromechanical filters using magneto strictive ni wires as coupling units between metal disk resonators a typical disk filter has a bandwidth of centred on with a transmission loss and an operating temperature from to c the size of the complete assembly is only in 7088 fundamental results and outstanding problems of network synthesis 7089 synthesis of n terminal pair e networks dissipative networks only are considered generalization of the gewertz reduced matrix e method and three methods involving auxiliary reactive networks are outlined and critically reviewed the first auxiliary reactive network method considered was developed independently by oono of and leroy of and of the second was due to bayard of and the third to belevitch of 7090 recmf exhibition preview short descriptions of selected exhibits at the exhibition arranged by the radio and electronics component manufacturers federation london april 7091 piezoelectric oscillations of quartz plates at even and half odd harmonics a number of quartz plates of different dimensions were plated with ag al or cu by various methods and tested in the same circuit results show that a quartz plate has preferred modes of oscillation at the odd and even harmonic and at frequencies mid way between these though the amplitude of the odd harmonics is very much the greater 7092 the double resonance in the secondary of a system of two circuits with inductive coupling the resonance condition is defined in terms of the primary and secondary impedances and the mutual inductance the variation of secondary current with the coupling frequency and series capacitance is determined in the case of a variable frequency with fixed coupling a graphical method is used to derive equal current curves by means of these a region can be defined within which two resonance peaks occur 7093 some exactly integrable cases of electromagnetic oscillations in two coupled cavity resonators calculations of resonance frequencies are made for cavity configurations whose boundaries coincide with co ordinate surfaces of an elliptical cylindrical co ordinate system the expressions obtained are developed explicitly for the case of weak coupling and are compared with known approximations 7094 theory of forced oscillations in electrodynamic systems the method of analysis using vector series progressing according to the eigenfunctions of the wave equation is applied to a system comprising cylindrical resonator and coaxial line the theoretical assumption underlying the method are examined and the green tensor appropriate to linear electrodynamic processes is formulated 7095 the complete system of natural electromagnetic oscillations of uniaxal anisotropic cavity resonators analysis of the field inside an arbitrary cylinder completely or partially filled by a uniaxal crystal the special cases of the circular section cylinder and the parallelepiped are treated explicitly see also of may 7096 perturbations of filtered oscillators part results previously obtained of may regarding the stability synchronization and frequency pulling of a nonlinear oscillator subjected to excitation by an external source are generalized by considering the dependence of amplifier gain on the rate of phase change 7097 nonlinear oscillators and the nyquist diagram two types of nonlinear oscillators having amplitude limiting are considered their equations become linear when a particular value is chosen for the parameter involving the amplitude a single curve can then be drawn for this particular value on the same principle as the ordinary nyquist curve other values of the parameter yield a family of curves showing the stages in the evolution of oc oscillations conditions for stable and unable oscillations are derived and the results extended to cover response to a small perturbation frequency stability and synchronization limits a brief account of part of the work was given in and of 7098 electrical and acoustic oscillation build up phenomena mathematical treatment of build up phenomena such as those investigated experimentally by trendelenburg et al of for organ pipe sounds 7099 multimesh rc networks for phase shift oscillators the required phase shift for each mesh is calculated for a terminated mesh network the values which total differ considerably from 7100 a wide range oscillator of high stability description of a beat frequency oscillator for the rf system of the birmingham university proton synchrotron of hibbard the two similar oscillators used are tuned by coaxial resonators on rubber shock mounts in a constant temperature enclose the fixed frequency oscillator operating at about a capacitor using a single plate rotor with a stepped profile serves for varying the tuning of the other oscillator via a servomechanism the beat frequency as a function of rotor setting is reproducible to within throughout the range 7101 a phase shifting pulse generator for thyratron control description with detailed circuit diagram of equipment producing positive pulses with repetition frequency that of the mains but with phase variable with respect to that of the supply voltage the phase lag is controlled by application of a small direct voltage to the grid of a high vacuum valve 7102 pulse operated time bases discussion of the basic principles and description f a practical timebase circuit of the single sweep type triggered by a delayed pulse developed from the transient or transmitter pulse to be examined 7103 timebase circuits discussion of the principles of operation of various types of timebase including an anastigmatic system and of hv generation by the fly back method 7104 the three possible types of valve amplifier circuit and applications in television receivers analysis and comparison of grounded cathode grounded grid and grounded anode amplifier circuits 7105 a selective detector amplifier for an amplifier is described for use as a detector in bridge or other measurements where a null indication is required tuning is accomplished by means of parallel t feedback networks including only resistors and capacitors noise is equivalent to an input signal of across 7106 background noise in ionization chamber pulse amplifiers two methods of particle energy measurement are considered for the charge collection method milatz and keller of have calculated the absolute limit to measurement accuracy for the amplifier circuit used for the pulse slope method initiated by sherr and peterson a slightly different limit is found circuits giving optimum signal noise rato are proposed in each case 7107 constant current audio power amplifiers the design features are discussed of a push pull amplifier using a pair of type valves in the output stage to feed a general radio type toroidal output transformer constant current operation of the output stage with resistors in the cathode leads for dc degeneration minimizes variations due to valve aging or replacement full circuit details of the amplifier and its simple power supply unit are given 7108 comments on the performance of pentode output stages except from book of the phillips series of books on electronic valves of 7109 the differential amplifier comment on of and authors reply 7110 electrically tuned rc oscillator or amplifier two variants are described of a feedback circuit including two all pass phase shifting networks tuning is performed by adding a variable amount of the output of the one phase shifter to the output of the other the variation being controlled electronically by means of a modulator circuit theoretically the tuning range is from zero to infinite frequency in practice the frequency ratio obtainable without appreciable change in gain is about 7111 fundamental problems of hf and if amplifiers for tv reception part gain and bandwidth the gain bandwidth product gb is shown to depend exclusively on the ratio of valve mutual conductance to the sum of input and output capacitances factors affecting g and b are discussed amplifier response curves are considered and the total bandwidth is deduced for amplifiers with synchronous circuits staggered tuning is discussed in detail the unit function response curves for double and vestigial sideband systems are treated and the distortion in the latter system is analysed the gain and bandwidth of quadripole coupling networks particularly the network and the double tuned band pass filter are discussed and characteristic data including gb values are tabulated for nine commonly used pentode circuits data for unit function response curves when several identical groups are connected in cascade and bandwidth factor for double tuned coupling circuits are also tabulated 7112 fundamental problems of hf and if amplifiers for tv reception part noise noise factors of amplifiers operating under various specified conditions are calculated and valve noise is discussed formulae are derived for the noise factor at metre wavelengths for four special simplified cases a general formula being given in an appendix the concept of noise reference frequency the frequency the frequency at which the equivalent noise resistance of a valve is equal to the input resistance is discussed and formulae are tabulated for both triode and pentode circuits with predominating partition noise graphs of noise factor for various cases show that above the frequency the noise factor increases rapidly the signal noise ratio is calculated from the noise factor it appears that the weakest signal that can be received reasonably well depends on the frequency on the aerial noise and particularly on the noise reference frequency of the first valve of the receiver 7113 the first boundary value problem of maxwells equations mathematical analysis of the generation of oscillations in an em system by an external source such as excitation of a cavity resonator by means of a waveguide feeder 7114 refractive index of dipolar gas mixtures at decimetre wavelengths the refractive index of mixtures of air and water vapour was measured at frequencies from to over a range of pressures using a cavity resonator method results are shown in curves discrepancies between the observations and values predicted from theory are attributed to the fact that the relaxation time of the water molecules is not negligible at low pressures 7115 capture and recapture of electrons in phosphorescence the relative importance of these phenomena is discussed and the mechanisms with which they are associated in phosphorescence decay are analysed 7116 the luminescence of phosphors in strong electric fields the account of the phenomenon of electroluminescence given by destriau see eg of is critically discussed cells used for demonstrating the phenomenon always take the form of a stratified capacitor including a layer of gas and a layer of solid dielectric of much greater breakdown strength the gas being occluded either in the electrodes or in or between the phosphor grains with such an arrangement a glow discharge occurs in the gas layer for voltages above a certain threshold and below sparking voltage it is concluded that this is the true explanation of the observed phenomenon 7117 circulation in the flow of electricity diracs new variables kelvins circulation theorems are shown to be applicable to the generalized momentum vector in the relativistic flow of electricity vortex filaments become vortex ribbons in space time and diracs variables and are identified as the parameters which characterize the family of vortex ribbons 7118 the electric potential in an electrically shielded space experiments confirm the previously observed variation of potential inside a metallic enclosure the phenomenon is attributed to the production of space charge by ionization due to spontaneous radiation from the enclosure walls 7119 the frequency dependence of the dielectric properties of dipolar substances inconsistencies in previous theories of dipolar interaction are pointed out a new theory presented is based on debyes theory of molecular relaxation and on an application of onsagers method for treating es interaction 7120 neoc the solution of the schrodinger equation for finite systems with special reference to the motion of electrons in coulomb electric fields and uniform magnetic fields 7121 motion of gaseous ions in strong electric fields amplified and extended version of papers noted in of and of february 7122 current flow in cylinders the mixed boundary value problem of the flow of current into a right circular cylinder through a perfectly conducting coaxial disk electrode at one end is solved approximately 7123 numerical calculation of the potential and field due to a uniformly charged disk various methods of calculating the potential at any point are discussed the particular advantages of the relaxation method in the most general case being pointed out 7124 new types of discharge in magnetic fields discharge phenomena described by ehrenhaft et al are explained in terms of known concepts and laws ogas discharge physics 7125 investigations of discharges in magnetic fields a note on righis magnetic rays 7126 the microwave admittance of a mercury vapour discharge 7127 theory of the discharge potential for coaxial cylindrical electrodes in a transverse magnetic field 7128 the absorption and reflection of microwave radiation by a mercury vapour discharge results of measurements at show that with increasing discharge current the real component of the complex conductivity of the discharge increases almost linearly the imaginary component which is negative increasing nonlinearly ad and less rapidly 7129 the imaging properties of electron beams in arbitrary static electromagnetic fields detailed theory of the aberrations of electron optical systems with curved axes with application to calculation of the imaging properties of a helical beam moving in the field of a pair of coaxial cylindrical electrodes 7130 the secondary emission from copper and silver films obtained with primary electron energies below values obtained for the secondary emission ratio are lower than those hitherto recorded both ag and cu having a ratio in the primary energy range ev the difference is attributed to the improved vacuum conditions used measurements of the energy distribution of the secondary electrons for primary energies show that the secondary electrons are in fact elastically reflected primary electrons 7131 electromagnetic properties of plasmas conditions for the propagation of longitudinal and transverse em waves are considered taking account of the effect of collisions on electron velocities and assuming no applied magnetic field the mobility coefficient relating the electric field to the mean velocity imparted by it to the electrons and dispersion formulae linking wavelength and frequency of the propagated disturbance are derived 7132 studies in magneto hydrodynamics a systematic treatment of the subject designed to bring out the underlying physical principles basic equations for em phenomena in a conducting liquid and their conditions of validity are discussed these are applied in specific static kinematic and dynamic problems experimental work is briefly summarized 7133 a new type of propagation discussion of the properties of magneto hydrodynamic waves in various types of conducting gluids see also of 7134 overlapping energy bands and the theory of collective electron ferromagnetism 7135 motions of material particles in the field of an electromagnet description and discussion of two different effects observed when ferromagnetic particles of order of magnitude cm are exposed to fields of strength up to oersted in the air gap of a magnet 7136 the behaviour of ferromagnetic particles in a rotating magnetic field account of an experimental investigation of the motion of ferromagnetic particles of order of magnitude cm suspended in gas at pressures between and mm hg and subjected to illumination and to a magnetic field rotating at 7137 theory of diffraction by a cylinder taking account of the surface wave maxima and minima observed by a limback in diffraction of centimetre em waves by metal cylinders are found to be due to interference between the waves geometrically reflected from the cylinder surface and the surface wave creeping round to the b ck of the cylinder quantitative calculations based on the integral equations of the diffraction theory of give results in good agreement with experiment 7138 diffraction patterns in circular apertures less than one wavelength in diameter measurements were made of the field intensity at points along the aperture diameters parallel respectively to the electric and magnetic vectors using normally incident radiation of wavelengths cm and cm the results disagree with values calculated from youngs theory in two respects viz the observations indicate a sharp increase at the ends of the diameter parallel to the magnetic vector the observed central peak for apertures of diameter near was greater than the calculated value the high intensity being attributed to multiple reflections from the edges 7139 the electromagnetic field in the plane of a circular aperture due to incident spherical waves measurements were made of the field in an aperture of diameter cm illuminated with radiation of wavelength from small radiators at various distances results are shown graphically the curves obtained can be represented approximately by a modified form of andrews equation of 7140 application of matrices to the problem of transmission through a multi layered dielectric wall the matrix methods described by watson are applied to the determination of design formulae for dielectric walls of the symmetrical sandwich type 7141 the physical conditions in sunspots deduced from their spectra discussion of the theoretical consequences resulting from the sunspot model recently proposed the vertical gradient of the magnetic field is found to be about gauss km 7142 nomograms for the computation of tropospheric refractive index charts for calculating refractive index refractive index discontinuities and vertical gradient are presented in a form convenient for use with standard radiosonde data they are valid for wavelengths cm 7143 humidity of the upper troposphere and lower stratosphere over southern england detailed report of observations made on flights during at altitude 7144 abnormalities in the ionosphere at high latitudes study of the variations with respect to time and location of the frequency of occurrence of storm s types e and d shows that the polar region may be divided into three zones the polar zone the storm belt and the polar quiet zone within the storm belt the most dense forms of storm e ionization are practically confined to an area centred near canada while the existence can be demonstrated of two centres of activity in the d region spaced apart which rotate once around the earth every hours 7145 geo morphology of f region ionospheric storms f region ionospheric storms may be regarded as manifestations of a single world wide phenomenon viz the es field of the solar diurnal current system whose local effects depend markedly on local time ad a season the theoretical chapman characteristics of the f region are normally perturbed by solar tidal electric fields of during magnetic storms the phase of the additional electric field present is such as to increase these perturbations at high latitudes and to reduce them at low latitudes though the effect may be masked by local time variations of ionization density in contradistinction to appleton and piggott of no evidence is found that any magnetic storm affects the northern and southern hemispheres differently when due allowance is made for the seasonal effect 7146 study of the ionosphere by extraterrestrial radio waves a paper surveying experimental work on the use of galactic rf radiation for investigating ionospheric refraction absorption irregularities and the effects of sudden ionospheric disturbances results are compared with theory and further lines of investigation are suggested 7147 e region during the solar eclipse of february analysis of observations of e layer critical frequencies at khartoum during the eclipse indicates tht the ionizing radiation from the solar disk is not uniformly distributed as is also the case for the optical radiation part of the u nonuniform component of the ionizing radiation appears to be divided about equally between the east and west limbs of the sun this is consistent with observations made at meudon of the distribution over the suns disk of the intensity of the green coronal line the main discrepancy between the values of the parameter proportional to the radiation flux calculated from the coronal data and from the e region measurements appears abruptly just after totality and suggests the existence of an intense source of ionizing radiation near the west limb of the sun which cannot be explained in terms of solar data available at present 7148 a study of ionospheric winds and turbulence utilizing long radio waves an experimental investigation of winds in the e layer was made during the period july march using vertical incidence pulse technique with waves of frequency the time variations of the reflected amplitudes are analysed statistically and compared with results to be expected from theory fades of duration min are most prevalent diurnal and seasonal effects are observed see also of march 7149 a high precision ionospheric sounding equipment description with circuit diagrams and oscillograms of high resolution equipment which provides pulses variable from t in duration and from to in peak power the delta aerials are of the type considered by cones of alternative terminations giving improved signal strength at frequencies during conditions of severe interference a horizontal receiving dipole is used interchangeable receivers covering a bandwidth of are provided the timebase circuit previously described of is modified to give a line raster each line corresponding to height the evaluation of resolution is discussed in an appendix 7150 effect f the geomagnetic field on the absorption of short waves in the ionosphere vertical incidence an approximate formula for the index of refraction is used to calculate the coefficient of absorption for five frequencies around the results are sensibly the same as those obtained by use of the rigorous appleton hartree formula those previously given by argence mayot and rawer or of are about higher 7151 the reflection and absorption of radio waves in the ionosphere investigations of the absorption of rf waves made in britain since are reviewed and the theory f ionospheric absorption is outlined the effects of double refraction polarization spatial attenuation dispersion ionospheric inhomogeneities and partial reflection which modify the apparent attenuation of radio waves reflected in the ionosphere are discussed and methods used to minimize absorption measurement errors due to these factors are given the experimental techniques used in routine absorption measurements being described fully detailed results of measurements of ionospheric absorption made in south east england in the period are being published separately 7152 the investigation of ionospheric absorption by a new automatic method part measurements on vertical incidence pulse signals equipment is described which automatically measures echo pulse amplitude and produces records at minute intervals of the integral of all echo pulse amplitudes received during each minute the output of a modified communications receiver blanked so as not to respond to the transmitter pulse is fed to two gated amplifiers one of which selects the echo signal and associated noise while the other deals with nose only after integration for min the difference of the output voltages of the integrators is applied to a pen recorder the integrators at the same time being reset to zero under good conditions with little rapid fading the results obtained are in good agreement with results noted by a skilled observer from a cro display of the transmitted and echo pulses wide differences are found under poor conditions with rapid fading and the results furnished by the automatic equipment are considered the more reliable 7153 measurement of the electric field of the atmosphere by means of radioactive probes 7154 boys camera study of the air discharge and the flash to ground with horizontal top 7155 air discharges and the positive charge at the bottom of a thundercloud 7156 the principle of a servo type mechanism requiring variable elements 7157 the analysis of sampled data systems the laplace and fourier transform methods of analysis for sampled data systems are unified and extended formulae representing the input output relations of such systems in the frequency domain are derived 7158 capacitance of selenium rectifiers in ac measurements on se rectifiers a temperature dependent phase shift between current and voltage is produced representation of the rectifier by an equivalent circuit consisting of a resistor and parallel capacitor affords a satisfactory explanation of this discussion shows that a negative component of capacitance is concerned which decreases with decreasing current and with increasing frequency the abnormal decrease of capacitance with high reverse voltages observed by hoffmann of is in agreement with this 7159 a corona stabilizer eht supply for proportional counters 7160 an electronic control device description of a high precision voltage regulator suitable for a rotary generator 7161 cold cathode voltage stabilizer 7162 internal alternating current resistance and reactance of conductors of circular cross section a numerical table is presented for simple and accurate calculations for solid conductors and for thin or thick tubes proximity effect is neglected 7163 vector representation in the time plane of electrical potential difference current and power varying sinusoidally in time the varying magnitudes are considered according to a method originally used by fresnel as the resultant of two imaginary vectors of equal and constant length rotating at the same rate in opposite senses the imaginary plane containing these vectors is called the time plane the impedances of a circuit to the two vector components of a sinusoidally varying current are defined and the method of representing power ie the product of voltage and current is explained 7164 a new pulse analyzer design description with detailed circuit diagrams of a single channel analyser which serves as the basic design for multichannel analysers details being given of a channel analyser positive pulses are accepted in the amplitude range plus the sum of channel widths the width and position of the channels can be changed quickly without requiring recalibration the design is simple and relatively few valves are required 7165 resistor temperature coefficients tests were carried out on four types of pyrolytic cr carbon film resistor and one type of metal film resistor several samples of each type of different resistance ratings being used the results obtained for the temperature range from to are shown graphically the temperature coefficients of the carbon film resistors are considerably lower than those of carbon composition resistors the coefficients are negative and much greater than those of wire wound resistors though this is not the case for borocarbon film resistors of et al 7166 determination of voltage current and magnetic field distributions together with the self capacitance inductance and hf resistance of single layer coils a theoretical investigation is made which is applicable to coils of intermediate lengths the number and magnitudes of the harmonics are calculated and their effect on the self capacitance is indicated experimental results obtained by other workers support the theoretical results 7167 ferrite core inductors design of inductors for communication equipment is considered particularly from the point of view of the best use of the properties of ferrites advantages of ferrite compared with metal cores for high frequency low power applications include higher q values smaller volume and greater ease of adjustment 7168 miniaturization of airborne filter chokes a calculation charts is given for chokes using mil laminations of si steel with square stack use of the chart is illustrated by numerical examples 7169 the power factor and capacitance of mica capacitors at low frequencies experimental results confirm an empirical law of the form negative and fractional for the power factor over the range at normal temperatures they also confirm a relation between frequency power factor and capacitance power factors as high as have been found corresponding to increases of nearly in capacitance over the values at higher frequencies 7170 calculation of transient phenomena in electrically short networks by means of fourier integrals fourier integrals are applied to the determination of the frequency spectra of periodic functions nonperiodic functions including step functions the results are used in discussion of the distortion and initial conditions in networks to which an impulse voltage is applied 7171 design of practical linear networks with optimum signal noise ratios a general method is described for the design of networks for which the relation between the input and output signals is represented by linear equations the frequency spectra of signal and noise being assumed known the application of the method of analysis in the design of the optimum ionization chamber amplifier is illustrated and the signal noise ratios attainable are compared with those for an rc discrimination network and a delay line clipping circuit 7172 applications of t networks adaptation of paper r by lavagnino of incorporating additional material references 7173 synthesis of transfer functions with poles restricted to the negative real axis a procedure for the synthesis of general rc transfer c functions by means of unbalanced networks is described the transfer function need not be minimum phase but may have zeros anywhere in the complex plane except on the positive real axis use is made of techniques described by guillemin of but the r problem is simplified by use also of a network theorem due to adler enabling zero shifting to be performed in two directions from within the tootal network in an example worked out network elements are used whereas the guillemin procedure would require 7174 hall effect modulators and gyrators employing magnetic field independent orientations in germanium the application of the hall effect in ge to the measurement of magnetic flux has been described previously of pearson further applications are now described to a product modulator in which the current corresponding to one signal is passed through the ge crystal while that corresponding to the other is used to produce the magnetic field and a circuit element with non reciprocal transmission properties or gyrator in these applications a crystal orientation is used for which the transverse magnetoresistance effects are zero and the variation of the hall effect coefficient with flux up to gauss is the experimental determination of this orientation is described 7175 the development of the electrical filter by k w wagners methods wagners method of filter design which is based on consideration of the filter as a ladder of matched reflection free sections icompared with methods developed by zobel cauer and others it is concluded that the principles laid down by wagner have lost none of their original validity or usefulness 7176 some designs of ladder filter results obtained and methods of calculation the principle of matching half sections and transforming impedances in designing filters with a minimum number of components is illustrated in two examples a narrow band band pass filter for and a filter with a pass band centred on formulae relating to the transformation of t type quadripoles to type and vice versa and to various types of quadripoles for impedance matching are collected in appendices 7177 uhf band pass filters a direct method is developed for designing waveguide and coaxial line filters the characteristics of a cavity filter are calculated transverse obstacles comprising sets of thin pins are shown to be better than diaphragms windows or single pins from the point of view of losses and of manufacture and adjustment cavities with q values of can easily be obtained using four pins of diameter mm design charts are given and several types of filter are described and illustrated 7178 admittance and transfer function of a multimesh resistance capacitance filter network the impedance function of an n mesh rc network is expressed as a recurring continued fraction which is then resolved into the quotient of two polynomials the admittance function being the reciprocal of this quotient the transfer function is then determined the corresponding formulae for an n mesh cr network are derived 7179 determination of the bandwidth of band pass filters for centimetre waves theory developed previously of is used to analyse the band pass filter operation of an arbitrary arrangement of coupled cavity resonators a detailed treatment is given for the system comprising two stagger tuned coupled resonators 7180 spectrum equalization the transfer characteristics of nearly all forms of linear quadripoles can be equalized as regards both amplitude and phase by adding to the response function its successive time derivatives or integrals the method may be applied to systems for which the equivalent passive quadripole is not realizable eg a scanning aperture application of the method to servo control and television is discussed 7181 uhf magnetic attenuator construction details and performance curves are given for attenuators of the type previously described of 7182 cut off attenuators for waveguide circuits an equivalent circuit analysis and report of measurements on short and long cut off sections providing attenuation respectively less than and greater than db beyond a certain length the reduction in attenuation due to reflections at the junction is constant so that calibration measurements on long sections are unnecessary 7183 reliability of airborne electronic components an analysis is made of typical failures reliability may be improved by modifications to present day components and by substitution of less vulnerable elements such as transistors and magnetic amplifiers 7184 forced oscillations with nonlinear restoring force both transient and steady state oscillations are studied the original differential equation characterized by a nonlinear term is transformed to the following first order differential equation following poincare and bendixson the singularities and the integral curves of this equation are discussed the former being correlated with the steady states and the latter with the transient states of oscillation the integral curves yield the relation between the initial conditions and the steady state solutions fundamental and subharmonic oscillations of order are investigated the theoretical results are compared with measurements made on a circuit containing a saturable iron core satisfactory agreement is found 7185 response of a series of resonant circuits to an applied emf whose frequency is a linear function of time a formula is derived for the response of two or three rlc circuits in series to an emf of unit amplitude represented by the expression where is half the frequency sweep speed the fluctuations in the response curve of a single circuit are very much reduced when several circuits are connected in series the increase of selectivity obtainable is investigated and frequency sweep speeds permissible for one two and three circuits are determined 7186 quasi degenerated modes in high dielectric cavities a theoretical and practical investigation is made of resonators comprising solid circular cylinders composed of materials such as titanates having permittivities of with or without metallization of the surfaces as a consequence of the high permittivities cavity resonator techniques can be used in the vhf range for cylinders with the ends not metallized quasi degenerate te modes can be realized tuning can be effected by inserting magnetic rods or by applying conductive disks externally a design for an aerial developed from the te mode resonator comprises a dielectric spiral coiled round a magnetic rod practical disadvantages inherent in these high permittivity dielectrics are indicated 7187 the method of analytical signals study of the synchronization of amplitude limited oscillators a method based on that of ville of is used to determine the frequency limits within which synchronization can be effected for a single tuned self limiting valve oscillator the synchronization range is given by where is the difference between the frequency of the synchronization voltage and the natural frequency of the oscillator and e is the amplitude of the oscillation in the steady state the phase angle between the two voltages varies from o for to a system with wide synchronization range is discussed this incorporates a phase discriminator whose output proportional to the phase angle between synchronization and oscillator voltages is applied to a reactance valve which in turn controls oscillator frequency and 7188 the use of admittance diagrams in oscillator analysis a digest of the available information on this technique 7189 effect of background noise on the frequency of valve oscillators ultimate accuracy of electronic clocks fuller account of work noted previously of april and back references 7190 how to design bistable multivibrators the design procedure described is intended to ensure reliable operation in spite of deviations of resistors from nominal values variations of supply voltage and deterioration of valve cathode emission formulae are given for determining th appropriate values of coupling capacitance triggering networks for dealing with pulses of different amplitude and duration are shown 7191 the effective bandwidth of video amplifiers 7192 fluctuation noise in a microwave superregenerative amplifier the theory of operation of a superregenerative amplifier is reviewed rices representation of noise current by a fourier series of and back references is used in the expression for the amplifier output a study is made of the particular conditions when a reflex klystron is used in the amplifier expressions are derived for the noise figure in terms f the klystron parameters the overs overall noise figure can be reduced by introducing beam current with its associated shot noise during the quiescent interval 7193 calculation of compensated wide band amplifiers in german and french loss of amplification with increasing frequency due to the output capacitance of the amplifier valve is compensated by including inductance in the circuit three arrangements are discussed namely parallel compensation series compensation and double compensation abacs to facilitate calculations are presented 7194 dc amplifiers with negative feedback methods are described for automatically compensating the input impedance of current amplifiers or the input admittance of voltage amplifiers details are given of the design and performance of several circuits for measurement purposes in which very high input impedance with low capacitance is achieved 7195 the wien bridge as a frequency determining element in selective amplifiers analysis of the balance condition in a bridge circuit suppressing the amplifier feedback voltage at a fixed frequency 7196 coaxial cavity tuning element for uhf the design is described of a unit which can be used in television tuners and test instruments for the band the unit consists essentially of a metal cylinder with an axial conductor having a gap at the centre to form a variable capacitor for tuning an accurately machined low loss dielectric tube separates core and cylinder and serves as a close fitting guide for the tuning plunger applications of the unit in a signal generator a frequency sweep generator a wavemeter and a grid dip meter are described briefly 7197 agc by means of miniature ntc resistors with heating element the negative temperature coefficient resistors are surrounded by the heating element and enclosed in an evacuated glass tube the resistor being included in the input circuit of an amplifier and the heating element in the output circuit to obtain efficient agc practical circuit details are given and operating characteristics of the ntc resistors are shown graphically 7198 fundamental problems of hf and if amplifiers for tv reception part feedback and practical considerations following on the theory a detailed discussion is presented of the effects in television amplifiers of fedback via the cathode grid capacitance via the anode grid capacitance via the anode cathode capacitance the necessary formulae are derived for an amplifying stage in which all three types of feedback are present x so that their interactions can be investigated theoretically the detailed discussion is however confined to systems in which only one form of feedback is present the theory is illustrated by practical examples in amplifier design 7199 filter design data for communication engineers the book is intended to supplement existing textbooks by providing charts tables and formulae in convenient form it is concerned mainly with image parameter zobel filters 7200 the relativistic electromagnetic equations in a material medium the general relativistic em equations for a material medium are expressed in the form of a single four vector density equation the field tensor has six different complex components instead of three as in the case of a free medium the classical equations are obtained by separating the real and imaginary parts 7201 transistors theory and application part energy levels in transistor electronics a simplified exposition of some of the fundamentals of quantum mechanics relevant to an understanding of transistor operation 7202 some particular features of tropospheric propogation and their analogies in wave mechanics 7203 a precise determination of the charge of the electron from shot noise the electron charge is calculated from the shot fluctuations of saturation current in a specially constructed diode connected diode connected across a tuned circuit resonant at from precision measurements of circuit parameters and the mean square value of shot noise the final result obtained is 7204 electron spin in semiconductors theory is developed showing that starting from equilibrium electron distribution expressed in terms of absolute activity it is possible correctly to take account o electron spin 7205 high frequency discharges in gases discussion of the main characteristics and the mechanism of hf discharges indicating their practical applications references 7206 field emission of electrons in discharges substantial emission of to electrons sec was obtained from cathodes of oxidized ni and w with electric fields of about cm by relating this emission to the electric field by the fowler nordheim equation the effective work function and emitting area of the source of the electrons for oxidized ni and w were estimated as about and respectively these results are discussed 7207 field electron emission and work function of crystal surfaces the field close to the surface is determined by measurements on models in an electrolyte tank formulae are derived for the density of the field emission current these are verified by field electron microscope observations on w crystals 7208 plasma in a magnetic field the results obtained by considering plasma from the electron motion point of view on the basis of kinetic theory are discussed and reconciled 7209 the relation between various types of plasma oscillation a dispersion relation is derived which applies to plasma oscillations electron and ion oscillations of the larmor type and to magneto hydrodynamic waves 7210 definition of magnetic quantities a critical examination is made of the nomenclature hitherto used for magnetic quantities and proposals are made for definitions which fit in with modern ideas without unnecessarily disturbing established usage precise definitions are given of field strength polarization magnetization susceptibility and magnetizability 7211 some magnetic properties of metals part magnetic behaviour of a cylindrical system of electrons for all magnetic fields the schrodinger equation is solved for an electron moving in a uniform magnetic field h the boundary of the system being a cylinder with its axis along the direction of the field two entirely different types of wave function are possible one type leading to the small landau diamagnetism of large systems the other to he larger diamagnetism of small systems of april taking account of the occupied states of both types the steady contributions to the magnetic susceptibility are determined for low high and intermediate temperatures 7212 collective electron ferromagnetism a generalization of the treatment and an analysis of experimental results a term involving the fourth power of the magnetization is introduced into stoners expression for the energy associated with magnetization if parameter values are suitably chosen the properties of ni show a high degree of co ordination and the magnetization temperature curves for ni co and ni cu alloys can be interpreted simply 7213 tentative theory of nonlinear electrodynamics part 7214 production of radio waves by means of the tcherenkov effect the tcherenkov effect consists in the emission of em radiation by a particle travelling through a medium with a velocity greater than that of light the essential results of frank and tamms theory of the effect are quoted and references given to accounts of experimental verifications of the theory using electrons and also protons the possibility of producing em waves in he range between the far infra red and uhf by means of the effect in a narrow channel is discussed it is concluded that intense sources of em waves should result from the ue of powerful beams consisting of packets of electrons simple arrangements should suffice for cm a and mm waves but difficulties will certainly be experienced in the case of still shorter waves 7215 a rigorous treatment of the diffraction of electro magnetic waves by a slit wave polarization components parallel to and perpendicular to the slit are considered an integral equation for the electric field strength in the slit is found by the method of levine and schwinger and of and an exact solution is obtained by developing the kernel in a power series of the product of wave number and slit width the far field intensity and the transmission factor of the slit are calculated and compared with the results of morse and rubenstein of the relation of the work to that of sommerfeld vorlesung uber theoretische physik and of groschwitz and honl is discussed 7216 the three dimensional problem of the diffraction of monochromatic electromagnetic waves the distribution of the em field in space for a given distribution of field at a boundary surface is discussed and conditions are established for the existence of a solution obtained previously 7217 the propagation of electromagnetic waves along a conical helix with variable pitch theoretical analysis expressions are derived for the reflection coefficient which may be practically zero and for the impedance characteristics 7218 galvanomagnetic effects in conductors a review of the hall effect and magnetoresistance in conductors with primary reference to metals including ferromagnetic materials semiconductors are mentioned briefly a physical survey of the whole field is first made in the second part a more mathematical treatment is given of some of the major problems involved over references 7219 hall effect correction to paper noted in of march 7220 magnetostriction discussion of magnetostriction phenomena in single crystals and in multicrystal materials three effects are distinguished form effect forced magnetostriction spontaneous linear magnetostriction 7221 on the nature of the decay of a meteor trail critical discussion of the theories of kaiser and closs of and of greenhow of and 7222 on the decay of radio echoes from meteor trails discussion shows that observed phenomena are explicable by the theories of kaiser and closs of and of greenhow of many points of disagreement between observation and feinsteins theory of and above are noted 7223 an experimental study of radio reflections from meteor trails the dependence of the echoes on the polarization of the incident wave has been investigated and the existence of resonance scattering with transverse polarization verified 7224 thermal theories of the high intensity components of solar radio frequency radiation thermal theories of the origin of enhanced rf radiation from regions which occasionally attain brightness temperatures of deg k or more are discussed none of the theories is found capable of explaining the available observational data it is concluded that all three radiation components are generated by the ordered nonthermal motion of electrons 7225 a method of analysis of the directivity of solar radio emission from sunspots 7226 an estimate of the density and motion of solar material from observed characteristics of solar radio outbursts theory previously given by feinstein and sen of is extended and applied to the observations made in australia by wild and mccready of and by wild and of the spectra o solar rf outbursts in the range of the dispersion equation equation involving the velocity of solar material erupting into a static corona and the temperature and densities of the material and of the corona enables the velocity of the material to be estimated as about with a particle density of about with a particle density of about 7227 solar and terrestrial relationships the general problem of the relation between solar activity on the one hand and meteorological geomagnetic and ionospheric phenomena on the othr is reviewed with special reference to an account by scherhag of events which he interprets as being related to an intense solar eruption on february no such flare has been reported it is concluded that no clear evidence has yet been given of a direct relation between solar phenomena and meteorological effects 7228 provisional sunspot numbers for october to december 7229 the origin of magnetic fields in moving plasma discussion indicates that diffusion effects produce sufficiently large emfs in rotating masses of ionized gas to account for the existence of solar and stellar magnetic fields 7230 effect of a large dielectric constant on ground wave propagation 7231 cheltenham three hour range indices k for october to december 7232 principal magnetic storms 7233 international data on magnetic disturbances third quarter 7234 the constants in the equation for atmospheric refractive index at radio frequencies the formula for scaled up refractivity n for air is n where k are constants the value proposed for k is derived from recent reliable microwave and optical measurements of the refractive index of dry air by barrell birnbaum et al of and essen and froome o after adjustment to allow for an average amount of co in the composition of the air k is derived from two other constants obtained from measurements of the dielectric constant of water vapour by birnbaum and chatterjee of please note additional author a table of values of the constants used by various workers from to is given with comments on discrepancies 7235 the geographical and height distribution of the gradient of refractive index charts are presented of the february and august distributions of the effective earths radius factor over the usa and of the vertical distribution of refractive index gradient for warm temperate and cold climates 7236 long delay ionospheric echoes at a report of results obtained at pennsylvania state college ionosphere research laboratory using a vertical incidence pulse transmitter with mw peak power recordings with a min exposure were made every half hour from to of the signals received on an aerial system suitable for receiving circularly polarized waves three records obtained on november showed an isolated echo corresponding to a reflection height of about km the echo only appeared on the records of the extraordinary wave similar records were obtained on two subsequent nights possible explanations of these long delay echoes are considered they may be due to reflections from a region above the height of maximum ionization of the f region 7237 on the comparative increases of the f and f ionizations from sunspot minimum to sunspot maximum the proportionate increase of ionization from the epoch of sunspot minimum to sunspot maximum is not the same for the f as for the f layer being of the order of for the former and for the latter assuming the f region to be due to ionization of atomic oxygen an increase in temperature with height above the f maximum an effective recombination coefficient decreasing rapidly with height calculations are made for three different ionosphere models the results being in each case in satisfactory agreement with observations 7238 effect of the solar eclipse of february on the ionosphere e layer in equatorial africa a report and discussion of observations of e layer critical frequencies at bangui the critical frequency of the e layer decreased suddenly at the commencement of the eclipse and was soon masked by that of the e layer a graph of the observed values of e shows that the effects of the eclipse were certainly perceptible some to minutes before the first contact a explanation of the observed effects is based on the assumption of two solar regions more active than the rest one in the corona near the western edge of the disk the other near the eastern edge 7239 electromagnetic effects in the ionosphere effects of crossed constant magnetic and alternating electric fields the effect of the crossed fields on the distribution of the velocities of the free electrons in an ionized gas is studied by means of the general equation of boltzmann collisions between electrons being assumed negligible the result obtained includes as particular cases those of dryvestyn abstracts and of chapman and cowling the mathematical theory of nonuniform gases and margenau 7240 a study of winds in the ionosphere by radio methods report of an investigation made using mitras method of the measurements were made in ottawa and later in montreal and covered a period of a year at a nominal height of km e layer the speed of the wind showed a mean daily variation of approximately half day period and about amplitude this variation can be explained on the basis of tidal oscillations in the atmosphere a variation corresponding to lunar atmospheric tides has also been detected at this level the winds in the f region appear to increase in speed with increase of magnetic activity this effect is not observed in the e region except during severe ionospheric disturbances 7241 a procedure for the determination of the vertical distribution of the electron density in the ionosphere comment on of february 7242 an ionosphere recorder for low frequencies based on hf recorder design this beat frequency instrument covers the range and uses a single loop aerial about long by ft high sample records are reproduced 7243 radio measurements and auroral electron densities simultaneous recordings of and echoes from auroral clouds were made at sakatoon a large number of echoes at were found for which there were no corresponding echoes at and the echo amplitude ratio for the two frequencies varied widely critical reflections from small volumes of intense ionization seem the most probable explanation of these observations where intense auroral display are concerned this would involve electron densities of the order of cm in small volumes of the aurora for periods of time short in comparison with the duration of the display 7244 long duration echoes from aurora meteors and ionospheric back scatter a report of radar echoes of unusual types observed in the course of the ottawa meteor research programme pulses with a peak power of were radiated on a frequency of some of the echoes were correlated with visual observations of aurora the extremely long duration min to over min of some meteor echoes was probably caused by abnormal ionospheric conditions weak semipermanent echoes duration up to or over hour are attributed to reflection at vertical or near vertical incidence from irregularities in the lower ionosphere possibly the same as those responsible for the long range propagation reported by bailey et al 7245 synthesis of servomechanisms at root locations 7246 the cockcroft walton voltage multiplying circuit the original circuit is studied by considering it as a transmission line losses are examined and formulae are developed for the voltage efficiency for a given size of capacitor and number of stages two modifications to improve voltage efficiency are discussed the first is the use of a loading coil at the hv end of the line the other is the inclusion of inductors in series with each of the capacitors 7247 improved variable power supply a modification of walkers circuit of is described which provides direct voltage outputs from to together with heater supplies inherent regulation is as good at as at 7248 hermetically sealed magnetisum copper sulfide rectifiers short note on the construction methods used for this type of rectifier which has an operating range from or higher 7249 advanced developments in metallic rectifiers discussion of improvements relative to higher operating voltage smaller size operation at high and at low temperatures and higher efficiency largely resulting from requirements of the services se rectifiers are particularly considered 7250 new rectifier tube for extremely high power and voltage levels this valve has a th w filament with catenary configuration and a cylindrical anode of ta coated with w powder its characteristics are anode dissipation rating peak current rating maximum peak inverse voltage 7251 microporous thermoplastic separators for lead acid batteries brief account of the manufacture and properties of porvic a pvc sheet material a similar account is given in plastics april 7252 addition agents for negative plates of lead acid storage batteries part pure organic compounds the best results were obtained with carbohydrates and some of the homologous phenolic compounds 7253 some applications of permanently magnetized ferrite magnetostrictive resonators for frequencies up to about magnetostrictive resonators using ferrites are very much cheaper than crystal resonators toroidal magnetostrictive elements are discussed by applying the biasing and driving fields in different directions different modes of vibration are obtained a definition is given of the coefficient of coupling between driving coil and resonator this coefficient affording an indication of the efficiency and being measurable with a q meter applications of such devices as frequency control elements in oscillator circuits and as components in various filter circuits are described 7254 a method ensuring stability and equality of channel widths in a pulse amplitude analyser the method is basically that of wilkinson of pulses of amplitudes between and are accepted and bandwidth stability for hour working periods is within 7255 the generalized transmission matrix stability criterion 7256 generalization of the nyquist diagram method for nonlinear systems methods previously explained of june are generalized to o cover the case of oscillations represented by a nonlinear differential equation of any order 7257 the design of a peaking transformer the basic principles of the peaking transformer are outlined and the design of a transformer to produce pulses of duration about from a input is discussed 7258 helical winding slow wave structures in exponential line pulse transformer a description is given of an experimental pulse transformer with integral hydrogen thyratron pulse generator suitable for use at the high impedance levels required in pulsed operation of magnetrons the transformer has an outer cylindrical shell the inner conductor consisting of a helix of constant diameter whose pitch decreases gradually from the thyratron end overall length is input impedance and output impedance 7259 steady state analysis of self saturating magnetic amplifiers based on linear approximations of the magnetization curve a method is described for predicting the output currents of self saturating magnetic amplifiers 7260 the transient response of magnetic amplifiers cases of negligible commutation discussion full paper summary noted in of 7261 a saturable core reference source for use with magnetic amplifiers 7262 terminology and equations for linear active four terminal networks including transistors a general system of terminology is developed for linear active quadripoles both nodal and loop analysis being presented definitions are given of current voltage and power amplification factors and the transformation equations are derived the results are applied to a number of transistor circuits the appropriate formulae being tabulated numerical examples are worked out 7263 a printed circuit multiconductor plug 7264 thermistor production short illustrated account of the manufacture of bead type and rod type thermistors from powdered mixtures of the oxides of ni mn and cu 7265 a new type of waveguide rotary switch a high speed waveguide switch is described which will connect two receivers or transmitters alternately to one aerial and which is particularly suitable for centimetre wavelengths the performance of a model operating at mm was satisfactory 7266 scale of ten counting unit using four double triodes description of a scale of circuit converted to scale of ten operation by means of feedback from the fourth to the second stage ge crystals being used for the feedback coupling and for that between the first and second stage 7267 a transistor reversible binary counter see of 7268 the properties of capacitors at high frequencies the variations with frequency of the capacitance and loss angle of capacitors are deduced from the equivalent circuit the frequencies considered ranging up to the television band the self resonance frequencies of paper mica and ceramic capacitors taking account of wire leads are shown by curves other curves show the variation of loss angle with frequency 7269 on linear electrical networks preliminary note of a method of analysis in terms of network admittance 7270 the calculation of carrier frequency transients by using function theory and the laplace transform method exact calculations are made without introducing any assumptions regarding the phase response of the transmission system demodulation calculations by two methods are considered as an example of use of the preferred method a calculation of the carrier frequency transients is made for the vestigial sideband if amplifier described by zimmermann of a step voltage is used for modulation in appendices the practical application of the residue theorem to transmission calculations is demonstrated and a chart for plotting transients is presented 7271 equivalent circuits using negative two pole elements calculations for three pole and multipole networks are simplified by substitution of equivalents some of which have negative values 7272 alent circuits consisting only of two pole elemeloci of complex impedance and admittance functions 7273 impedance matching with transformer sections an equivalent circuit for a transmission line transformer section is discussed which allows considerable flexibility in design and enables and effects to be easily taken into account 7274 on the approximation problem in network synthesis correction t paper abstracted in of march 7275 networks for which magnitude or phase angle of input impedance or transfer admittance remains constant as load varies the conditions are determined that must be satisfied by a network at constant frequency to obtain a particular variation of input impedance or transfer admittance when the load changes in a specified way results are tabulated for ten special cases 7276 the parameters of a four terminal network the method of analysing quadripoles in terms of image impedances and a propagation constant is compared with the method based on the general circuit constants the latter method which can conveniently be treated by matrix algebra as described by guertler of is preferred the relation between the two sets of constants is examined and typical applications are illustrated 7277 note on the iterated network and its application to differentiators an alternative proof is given of the formula for a power of a matrix recently given by pease of 7278 use of locus diagrams to determine the equalizing action of bridged t networks numerical examples are used to show the method of determining from the impedance diagram the variation with frequency of the attenuation and phase coefficients of bridged t networks of different types 7279 how to design notch networks curves are given which simplify the design of capacitor shunt or resistor shunt bridged t networks and of parallel t networks of the infinite attenuation rc type 7280 synthesis of unbalanced rlc networks each inductor of the network is assumed to have associated series resistance the method of synthesis makes use of novel features including the breakdown of a hurwitz polynomial into two others application of a network theorem to division of the network into two parts and a method of zero shifting with one pair of complex poles and being discussed in appendices the network realizes a minimum phase transfer function whose numerator and denominator are of degree not higher than the third and fourth respectively and whose poles and zeros may lie anywhere in the left half of the complex frequency plane extension of the procedure to functions of higher degree is considered briefly 7281 high characteristic impedance distributed constant delay lines for fractional microsecond pulses the delay lines described are pile wound with wire of gauge about turns in on polystyrene rods previously coated with silver paint slotted lengthwise at intervals and then insulated with teflon tape prior to winding a typical line in length and in diameter has a characteristic impedance of a delay of and an attenuation of the order of db pulse rise and fall times are about response curves for pulses of and duration are give characteristics of and lines are tabulated 7282 phase and group delay expressions for phase and group delay are obtained and the design of low pass delay networks is considered with illustrative numerical examples 7283 networks with maximally flat delay comment on of 7284 wieners theory of linear filtering wieners theory of introduces the concept of the optimum linear filter for use when signal and noise occupy the same frequency band this concept is examined without attempting to follow the complex mathematics of the original the discussion is limited to the extreme cases of zero lag and infinite lag filters which are appropriate respectively to telecommunication and automatic control systems a formula is derived for the transfer characteristic of the optimum filter for an input signal having the power spectrum with uniform random noise for the zero lag case the transfer characteristic is affected by consideration of phase frequency variations for the infinite lag case it is not for applications in which delay can be tolerated the infinite lag filter has the advantage of transmitting a much greater fraction of the input power the applicability of optimum filters is discussed 7285 improved components and materials for reliable electronic equipment discussion of improvements in components and manufacturing techniques resulting from a us signal corps research programme 7286 the national radio components exhibition review of annual exhibition in paris with descriptions and illustrations of selected items for other accounts see toute la radio and television 7287 circuitry packages for electronic computers short description of etched circuit mass produced units with projecting pin connections the basic unit comprises a transformer coupled pulse amplifier using a type miniature beam tetrode and a number of ge diodes four variants of the basic unit meet most computer circuit requirements a new computer including such units is under construction tests jacks facilitate location of defective components of individual units 7288 electrical oscillations a physical approach to the phenomena phenomena occurring in oscillator circuits are explained in terms of modulation products for an input signal of given form an analysis is made of the modulation products introduced by the curvature of the characteristic of a nonlinear resistor the characteristic being represented to any required degree of accuracy by a polynomial the operation of a negative resistance oscillator including a nonlinear resistor is explained in terms of this analysis in general the oscillation frequency deviates slightly downwards from the resonance frequency associated with the linear part of the circuit forced oscillations and synchronization are considered a vector representation is developed for transient behaviour and combined oscillations for detailed mathematical discussion see of 7289 the response of a tuned circuit to a ramp function a ramp function is defined as one whose value increases linearly up to a certain point and then remains constant response curves are shown for a parallel tuned lrc circuit subjected to a linearly increasing driving force ramp voltages with various rise times in each case curces are given for circuit q values of and 7290 three dimensional locus curves for describing the properties of electrical circuits in the jahnke emde tafeln hoherer funktionen of the fresnel integral is shown by an isometric representation of a space curve prowse of has shown that the characteristics of an oscillatory circuit can be similarly represented by a three dimensional locus curve whose projections on the three reference planes give respectively the usual circle diagram a resonance curve and an n shaped susceptance diagram wire models on similar lines are described which show the relation between impedance and frequency or between admittance and frequency for some simple and coupled circuits 7291 a new quartz oscillator for the frequency range a quartz oscillator in the form of a tuning fork is described each prong carries four electrodes arranged according to the cut of the crystal and connected so that on application of a voltage via the spring suspensions the inner and outer halvex of each prong are stressed in opposite directions in air the q factor is increasing to at a pressure of a few mm hg with thermostatic control the frequency variation can be kept to within part in 7292 electromagnetic field expansions in loss free cavities excited through holes the electromagnetic field in a loss free cavity excited through holes cannot be completely expressed in terms of the short circuit modes of the cavity satisfying the condition that the tangential component of the electric field is zero on the boundary of the cavity including the openings for a complete expansion it is necessary to add an irrotational magnetic field which contributes a term inversely proportional to the frequency to the usual admittance matrix if the cavity is presumed to include a reasonable portion of the guides feeding the openings this irrotational component becomes almost diagonal 7293 the sawtooth derivator the sawtooth derivator differs fundamentally from the conventional type of timebase generator in that the require waveform is derived from an arbitrary waveform which in its turn is derived from the signal applied to the cro in this way perfect synchronization is obtained various types of clipping and differentiating circuits are discussed and a description is given with full circuit details of practical equipment which functions entirely automatically and covers the frequency range without any switching operations 7294 oscillator with a or tbl transmitting valve details are given of the construction of a self excited oscillator using either a water cooled or an air cooled high power transmitting valve illustrations are given of the special anode grid and cathode grid circuit arrangements and of the method of coupling used for a water cooled dummy load consisting of a shorted coaxial line the power dissipated in the load about is estimated from the rise in temperature and rate of flow of the cooling water 7295 a mode of oscillation of conventional triode valves analysis shows that if certain conditions are satisfied uhf oscillations are possible in a triode valve designed for lower frequencies this was verified for a telefunken type triode which is designed to oscillate on wavelengths down to about cm the valve has two grid and two anode terminals and to these a resonant wire system was attached with a resistor and milliammeter connected between grid and earth with an anode voltage of good oscillations on a wavelength of cm were obtained the mean oscillatory voltage on the grid being about and on the anode about the calculated wavelength was about cm 7296 stability in negative feedback time bases the term double stroking is applied to a condition in which alternate scanning strokes are dissimilar this phenomenon is liable to occur during starting and may continue indefinitely in any time base where the initiation of flyback depends on the conditions existing at the end of the scan and the flyback is maintained linear the process is examined in detail for some typical circuits 7297 interesting nonlinear effects experiments show that simple circuits comprising ordinary electric lamps together with iron core transformer coils and capacitors have properties similar to some multivibrators and ring circuits applications to switching counting and delaying are indicated 7298 the gas filled triode as pulse amplifier valve an experimental investigation is reported using a special circuit to avoid permanent ignition a recovery time of can be attained with a he filled type valve for applied pulses of duration the operating threshold value of input voltage may be as low as for shorter pulses the threshold is a few volts as pulse width and height decreases the build up time for the discharge increases and the time delay of the amplified pulse is increased the gas triode is thus only appropriat in the output stage of a pulse amplifier 7299 video amplifiers with extremely large bandwidth practical designs of a cascade amplifier and one with distributed amplification are illustrated comparison of the tw types shows certain advantages of the cascade type 7300 a direct amplifier for voltages down to having low internal resistance the low voltage threshold is zchived by using a crystal contact relay and tesla transformer in the input circuit to convert the dc to ac for amplification 7301 a survey of the limits in dc amplification the effect of a change of the cathode temperature of planar dioe and triodes is calculated and the possibility of compensating this temperature effect is discussed the effect of anode voltage changes is analysed and some new compensating circuits are described which enable dynamic and in phase balance to be obtained simultaneously with a single adjustment for all balanced circuits the requirements as regards stability of the supply or auxiliary voltage are found to be nearly the same changes of valve constants with time are discussed investigation showed that the poorly defined position of the heater in the cathode sleeve of some valves seriously limited their stability 7302 harmonic distortion and negative feedback an analysis is made which takes account of the production of harmonics of order higher than the second by the negative feedback process the usual formula for the reduction of distortion by application of negative feedback is accurate if the slope of the amplifier output voltage input voltage curve does not vary appreciably over the working range if a valve with a sharp cut off is used and the input voltage is greater than the cut off value no reduction of distortion can be effected by negative feedback 7303 noise in transistor amplifiers 7304 filter design data for communication engineers a design procedure is outlined which permits rapid computation of the element values of the optimum zobel filter having a given attenuation characteristic 7305 the acousto electric effect theoretical calculations indicate that an electric current should be generated in a crystal by the passage through it of an acoustic wave in a metal the electrons concerned are at the fermi level in an n type semi conductor they are in the conduction band calculations for na and for n type ge indicate that the predicted effect should be measurable 7306 initial rise of brightness of electroluminescent substances under the action of an alternating field observed phenomena can be explained on the assumption of excitation of luminescence centres by conduction band electrons that have acquired sufficient energy these electrons reach the conduction band from electron donor levels a few tenths of an electron volt below and are then accelerated 7307 influence of electric fields on luminescence brief report of an investigation of the luminescence of a zns cu phosphor excited by near ultraviolet radiation and subjected to alternating electric fields at frequencies up to the procedure used was similar to that of destriau of 7308 effect of an electric field on a continuously excited phosphor when an alternating electric field is applied to a zns cu phosphor excited to steady state luminescence a momentary increase of luminescence is observed with a subsequent drop and a slow change to a new steady state a periodic intensity ripple of double the field frequency e being superposed switching off the field generally results in a new momentary intensity with subsequent gradual return to the initial value these effects are explained on the basis of theory given by randall and wilkins of 7309 vector potential derivation from scalar potentials digest of paper presented at aiee district meeting may definitions are given of vector potential it is shown that vector potentials can be derived from the scalar potentials included in the tables of greens functions below results are given for the field due to a thin rectangular sheet of magnetic material or a rectangular coil 7310 calculation of contact potentials a formula is derived for the contact potential between two metals from consideration of ermi energy levels and surface thermal electron flux 7311 contact phenomena continuation of investigation noted in above if the two barrier layers have the same transparency the usual formula for contact potential is found in terms of the constants of the dunshma richardson equation if the two barrier layers have different transparencies a correction term comes into play analysis indicates that by making sufficiently accurate measurements of contact potential it should be possible to separate emission constant variation due to variation due to variation of work function with temperature from that due to barrier transparency 7312 electrical fluctuation phenomena the possibility is discussed that fluctuation phenomena in insulting materials may have their origin in recombination fluctuations of the freed electrons with their positive residual charges the recombination fluctuations being related to the statistical density fluctuations of the solid and being amplified by the mechanism of electronic conduction 7313 transistors theory and applications part physical properties of electrons in solids presents a concept of the electron that fits with generally accepted explanations of phenomena in semi conductor materials that are responsible for transistor action 7314 dependence of direct sparkover voltage of gaps on d humidity and time a systematic investigation of humidity and time effects on the breakdown voltage for gaps using spheres cm in diameter standard rods in square section with square edges results are shown graphically and discussed 7315 general expression for the conductivity tensor and for the dielectric tensor in an ionized medium various applications hall effect and generalization of langevins formula for mobility a calculation to a first order of approximation is made of the distribution function for electrons in an ionized gas exposed to crossed magnetic and electric fields the rate of diffusion of the electrons is deduced and expressions are derived for the conductivity and dielectric tensors in a later paper the formulae obtained are to be discussed and compared with those established by huxley of 7316 washington conference on magnetism september the papers presented at the conference are given in full with reports of the discussions 7317 the external magnetic field of a single thick semi infinite parallel plate terminated by a convex semicircular cylinder 7318 general solutions of maxwells equations expressions are derived which are sufficiently general to cover the case of charges or currents within the volume considered 7319 diffraction by a thick semi infinite plate a method of analysis based on that previously described of february is applied to the problem of the diffraction of a two dimensional plane harmonic wave by a semi infinite perfectly conducting plate of thickness d expressions are obtained for the distant field when d has any value and the effects at the boundary of the shadow are deduced extension of the theory to the problem of diffraction by a thick plate of finite length is briefly discussed the theory is also extended to incident scalar waves whose direction of propagation does not lie in the plane perpendicular to the plate 7320 the diffraction of a dipole field by a perfectly conducting half plane a method of analysis is developed which is valid for any orientation of the dipole the dipole field is resolved into plane waves whose diffraction can be studied independently the particular case of an electric dipole with its axis normal to the half plane is investigated 7321 absorption in an electron gas mixture the influence of the collision damping on the polarization of an electron gas mixture subjected to an alternating electric field is calculated using the kinetic theory of gases and assuming the simplest type of elastic collision the nonlinear effect of the absorption is estimated to a first approximation this nonlinearity is significant for long waves propagated in the ionosphere 7322 microwave absorption spectrum of nd the frequencies of the main jk sequence of inversion lines in the nd absorption spectrum between and measured in a coaxial type of stark cell are tabulated together with values calculated from an ny type formula 7323 the faraday effect in conductors and semiconductors analysis on classical lines is pe presented for the effect on a plane polarized plane em wave of an applied constant magnetic field in the direction of propagation a formula for the rotation of the plane of polarization is derived which may possibly be checked experimentally 7324 the influence of magnetic impulses on the kinetic energy of electrons analysis is presented showing that magnetic impulses such as those caused by em waves with discontinuities in the magnetic components may produce variation of the kinetic energy of electrons z and may contribute to the destruction of atomic structures 7325 surface investigation of metals and nonmetals with exo and photoelectrons the term exo electrons is applied to electrons emitted from a surface under excitation by light of sufficiently short wavelength an exothermic process being involved a description is given of the special geiger type needle counter used in th investigation the light source with plexiglas lenses being built into the counter results obtained are shown graphically and discussed they include curves showing the decay of exo and photo electron emission from energy treated pt stretched al and gypsum and temperature variation of exo electron emission from gyprsum quartz and quinine sulphate subjected to various types of irradiation 7326 calculation of the capacitance of a circular annulus by the method of subareas an approximation method is described and applied to the determination of the capacitance and charge distribution of a circular annulus and of a circular disk the fourth approximations for the capacitance are in good agreement with the known exact values 7327 the magnetic field strength in sunspots brief discussion of the validity of formulae developed by various investigators 7328 the sunspot number series because of the lack of a truly periodic term in the sunspot number series predictions have so far been made on an empirical basis a more satisfactory representation is obtained by plotting the numbers with reversed sign for alternative year periods to give a year cycle with practically zero mean value a significant degree of correlation is found between the slopes of adjacent flanks of the successive year cycles 7329 mean magnetic field and secular variation in adelie land 7330 the lower e and d region of the ionosphere as deduced from long radio wave measurements an ionosphere model is proposed which is in reasonable agreement with experimental data during the day this locates the reflection region in the tail of the d layer around km height the ionosphere winds region in the nose of the layer centred on km and a region of minimum ionization density between the d and e layers at about km with electron density of about electrons cm 7331 the longitude effect in the f region see also 7332 ionospheric storms and the geomagnetic anomaly in the f layer graphs are shown of hourly values of the ratio of critical frequency on magnetically disturbed days to that on quiet days for wakkanai during the winter hourly values of the ratio of critical frequency at ottawa to that at wakkanai during the winter the shape of the graphs is similar indicating that the geomagnetic distortion anomaly in the f layer is such that it causes a minimum of critical frequency in the forenoon and a maximum in the afternoon for huancayo the principal anomaly is the abnormal maintenance of high f values after sunset 7333 travelling disturbances in the ionosphere diurnal variation of direction since the publication of previous papers of observations of greater accuracy and extending over a greater part of the day have provided definite evidence of diurnal variation in the direction of horizontal movement this is most marked in the month of june a graph is given which shows the median values of all directions observed for each hourly interval for all days of june in and a similar trend is noted in all three years the direction of movement changing from about at to at recent night observations suggest that there is consistently an e component of movement at night in contrast with the consistent we component in the daytime 7334 moving clouds of ionisation in region e of the ionosphere during investigations of the phase path of radio waves returned from the e layer of some echoes were observed which came from equivalent heights rather less than that of the e layer analysis supports the interpretation that the echoes came from ionization clouds moving with constant velocity in a horizontal direction histograms show tht the velocities ranged between and that the most probable duration was and the most probable height km echoes can apparently be detected only from clouds la lying within a cone of semi angle from the observing point the average horizontal dimension of the clouds being about m 7335 the heights of ionospheric winds as measured at long radio wavelengths the winds region is considered as constituting a screen capable of altering the phase and amplitude of a radio wave passing through it the field pattern at the ground is assumed to be such that information on the phase change and absorption experienced by a wave passing through the screen can be obtained from it it is also assumed that only the ordinary wave is observed and that the region concerned is of the wkb type with these assumptions theory is is developed which when applied to experimental data for signals gives the winds region height as km during the day and km at night 7336 conductivity of the ionosphere and geomagnetic tides the results of various investigations are summarized and discussed with particular reference to effects observed near the geomagnetic equator 7337 the investigation of ionospheric absorption by a new automatic method part measurements on oblique incidence broadcast signals apparatus similar to that described in part of june is used for recording the strength of a signal received from a distant transmitter by reflection from the ionosphere comparison of the vertical incidence records with simultaneously obtained oblique incidence records is expected to facilitate the investigation of winds in the ionosphere 7338 scattering and attenuation by non spherical atmospheric particles gans theory of em scattering and absorption by ellipsoids is applied to atmospheric particles if these have preferred orientations the amount of back scattered energy depends on particle shape and on orientation of the particle relative to the incident beam the effect is negligible in the case of snow if the particles have random orientations the observed scattering is independent of aerial orientation but greater for ellipsoidal shape and for water particles than for ice these theoretical considerations account well for known melting band phenomena 7339 multiple bursts of signal in long distance very high frequency propagation 7340 a phase plane approach to the compensation of saturating servomechanisms 7341 network synthesis by graphical methods for ac servomechanisms see of 7342 calculation of the attenuation in filtered oscillators a hypothesis previously used is not required in defining the dynamic characteristics of a control system a particular class of nonlinear servo mechanisms is investigated and stability criteria are discussed see also of april of may 7343 some design criteria for automatic controls the design of control systems to give optimum response is discussed in terms of the area between the graphical representation of a step disturbance and th control response curve this area and a weighted control area can be calculated directly from th system parameters and enable the necessary control sensitivies to be determined for optimum response 7344 rotary amplifiers in servomechanisms the rotary amplifier consists of a dc generator driven at constant speed the properties of this machine as an amplifier are discussed use of this amplifier as power stage for a valve amplifier in servomechanisms is described 7345 effects of carrier shifts on derivative networks for ac servomechanisms 7346 a note on the design of conditionally stable feedback systems formulae are presented which relate parameters of the loop transfer function of a conditionally stable system to the relative stability of the system transfer function the condition is determined for which the system bandwidth is a minimum when the loop transfer function is required to have a specified value at a particular frequency 7347 power supplies for transmitters present day equipment used for supplying power to small or large installations is described 7348 differential analyzer study of harmonic power generation with nonlinear impedance element 7349 a gas tube inverter with the supply voltage below the breakdown voltage investigation of the operating characteristics of simple circuits using gas discharge tubes working with direct voltages down to about 7350 development of volt selenium rectifier plates forward and reverse characteristics are given for recently developed se rectifiers in a bridge circuit results of a life test shoed a voltage drop of about the use of such plates effects a great reduction in weight compared with post war plates 7351 voltage stabilization review paper with references results of the latest work on glow discharge tubes are reported 7352 a new electrostatic influence machine description of the principles of operation the construction and performance of a rotary machine operating at atmospheric pressure and giving voltages up to 7353 diffraction patterns for solid delay lines solutions of the vector equation of equilibrium for an isotropic solid are presented for the special case of loss free sine waves examples are considered in which the distribution of a single stress component is selected to simulate the stress produced by a high frequency quartz crystal 7354 extension of the concept of the time constant examples of the application of a general expression for the time constant are illustrated in cases where the function is not exponential 7355 geometrical transformation of impedance diagrams the limited impedance range of the normal circle diagram representation of impedances is noted a second type of circle diagram can be constructed in which all possible impedance values satisfying the required conditions lie within the unit circle its construction by means of riemanns number sphere is required 7356 consideration of some factors concerning the use of audio transformers the effect on the frequency response of using source or load impedances different from the rated values is discussed methods of reducing distortion due to nonlinear core characteristics and o eliminating noise due to various causes are indicated methods of matching several impedances to a single one simultaneously are shown 7357 the input impedance and transimpedance of if transformers formulae are derived for the conventional if transformer consisting f two coupled circuits tuned to the same frequency the relation between transimpedance and input impedance variations and the form of the frequency response curve are investigated the method of constructing polar diagrams is explained and diagrams are shown for the two impedances for various values of the parameters their usefulness in the study of feedback phenomena particularly feedback from valve anode to grid is indicated 7358 dynamic characteristics of transductors or magnetic amplifiers review of the physical characteristics of transductors with low resistance control circuits and of the self excitation type 7359 the figure of merit of magnetic amplifiers 7360 magnetic amplifier with reset control 7361 transistor negative impedance converters improved converters of the general type described by merrill of are obtained by using transistor circuits in place of th original valve circuits the characteristics obtained are highly stable various practical circuits are illustrated and discussed and application in telephone repeaters are described 7362 symmetrical properties of transistors and their applications symmetry of one kind is found in the complementary characteristics of the npn and pnp types of junction transistor by using these two types in combination reduction of the number of components and other circuit simplifications can be achieved particularly in single ended push pull amplifiers symmetry f a second kind can be found in single transistors and is evidenced by interchangeability as regards operation of emitter and collector use is made of this property in switching circuits eg for clamping and modulation and for a high efficiency television deflection circuit 7363 on the magnetization of toroids with one and two air gaps a method is proposed for calculating the leakage coefficient in the case of a toroid with one large air gap and an experimental formula is derived for determining the average leakage coefficient for the cases of toroids with one air gap and with two diametrically opposite air gaps 7364 the second fundamental theorem of electrical networks an independent proof is given of a theorem which states for the norton nodal representation the relations previously proved by ingram and cramlet of for the thevenin mesh representation the nodal equations of kron as given by le corbeiller of are deduced by a method similar to that of synge the relation between the nodal and mesh theorems is discussed 7365 network transformations a method of finding an equivalent for a given network is outlined a table of equivalent networks is presented and examples of the use of the method are given 7366 the solution of passive electrical networks by means of mathematical trees a new method of solution for network problems is based on the properties of certain basic types of network termed trees and trees linkage functions defined in terms of sets of trees and trees obey laws analogous to those of kirchhoff so that relations involving voltages and currents can be expressed in terms of linkages results of the method are given in terms of admittances 7367 design procedures for pi network antenna couplers discussion on paper noted in 7368 reciprocal ladder networks the transfer impedance of a system comprising generator and load with ladder network interposed is unchanged if instead of the original network a reciprocal network is connected in reverse the reciprocal network is derived from the original one by replacing series impedances by shunt impedance and vice versa the product of the original and new impedances being in each case equal to the product of the generator and load impedances 7369 reactive t r sections resolvable into two matched half sections means are indicated for determining whether the resolution into half sections with matched terminal impedances is possible 7370 study of an electronic antiresonant circuit theory is given of a circuit which can either be used as a low pass filter or as an antiresonant circuit the operation of the circuit in the steady state in response to an applied sinusoidal voltage and in the transient regime in response to a unit step voltage is analysed as an antiresonant circuit it is more selective than a double t rc circuit its characteristics can be varied within wide limits and the values of the components can easily be calculated from the characteristics specified its high selectivity independent of the cut off frequency makes it particularly suitable for use at very low frequencies 7371 resistive bidirectional coupler a resistive t network is discussed which when inserted between a source and a load acts as a bidirectional coupler providing voltages proportional respectively to the incident and reflected waves the arrangement is applicable to measurement purposes and is used eg in the wattmeter described by ryder and mcvay 7372 resistance capacitance networks in amplifier design two types of rc network are distinguished the first of which includes all networks with a simple series or shunt capacitor this type only is considered frequency and phase characteristics are derived and reduced to simple graphical form impedance matching and loading effects are discussed typical equalizer and tone control circuits are examined 7373 attenuation equalizers the performance of various commonly used equalizer networks is discussed and a chart method of computing their insertion loss is presented 7374 minimum inductor or capacitor filters known methods are surveyed and some new methods developed for designing equivalent filter networks having fewer inductors or capacitors than a given network the particular transformation appropriate in a given case depends on whether the given filter is an image parameter type which can be split into separate m derived sections or is of a more general character the methods presented are based on the values of the network elements without reference to impedance frequency functions of the network as a whole two practical examples of application of the methods to band pass filters are treated in detail 7375 the effects of terminations and dissipation on the insertion loss of some simple ladder filters by using special terminations the selectivity of these filters can be improved and elements with relatively low values of q can be used insertion loss curves indicating the combined effects of the terminations and of dissipation in the filter elements are presented in a form applicable to low pass high pass and band pass filters of several types 7376 theory of antimetrical lattice filters the theory o a class of lattice filters with inverse image impedances is a counterpart of that for symmetrical filters these filters comprise two reactances and their inverses the frequencies at which the modulus of the reactances is equal to the he characteristic impedance correspond to the poles and zeros of the reactances in the symmetrical case calculations relative to the construction of such filters are explained and typical examples are described a high ratio impedance transformation is attainable with narrow band circuits see also of 7377 optimum nonlinear filters theory of optimum nonlinear filter is based on the consideration of a sequence of classes of nonlinear filters n such that each class in the sequence includes all the preceding classes and also includes the class of linear filters the characteristic function of the optimum filter within the class n is found to satisfy a linear integral equation of od order a detailed treatment of optimum filters of class n is given and methods of approximate realization of such filters in the form of nonlinear delay line filters and power series filters are indicated the results are extended to the case of nonstationary time series 7378 construction and calibration of an inductive attenuator a hf attenuator is described which makes use of the properties of a waveguide at d frequencies far below cut off for a frequency of the attenuation varies linearly to within between and db with the distance between the source and the output coil the attenuation can be calculated from the physical dimensions only 7379 novel valve circuits a review of valve circuits operated under unusual conditions in respect of bias anode and screen voltages and of input and coupling arrangements as in pulse squaring and gating circuits and electrometer applications 7380 a note on moving poles in nonlinear oscillating systems since poles of the complex immittance of a linear system represent the decrements and frequencies of rotating phasors in the linear time domain it is suggested that a nonlinear system might be represented by moving poles whose instantaneous decrements and frequencies are associated with phasors rotating in the nonlinear of time distorted phase space this idea is applied to the analysis of a class of nonlinear oscillation generators of the second order which is described by the differential equation o 7381 a second contribution to the solution of the rukop problem re examination of the problem of the dynatron driven series circuit and the arc driven parallel circuit abstracts nyquists stability criterion is applied to the equivalent circuit and the necessary and sufficient conditions for excitation of oscillations are determined 7382 compensation of the temperature effect in lc circuits by means of negative coefficient capacitors compensation at a given frequency is obtained by connecting in parallel with a variable capacitor a series arrangement of a fixed negative coefficient capacitor and a variable capacitor the experimental method of adjustment is described frequency variation with temperature for uncompensated settings is studied 7383 more on the rc oscillator 7384 the frequency spectrum of a pulled oscillator the conclusions reached by buchanan o are presented in a simpler and more precise form 7385 blocking oscillators the use of blocking oscillators as generators of voltage or current pulses or of repetitive sawtooth voltage or current waveforms is examined in some detail with a description of thd mode of operation of the vz various circuits considered and discussion of the factors affecting their practical design 7386 the impulse governed oscillator a system for frequency stabilization 7387 improved lock in amplifier a stable sinusoidal voltage drives a square wave generator whose output is applied to the anodes of a pair of i diodes in phase opposition the signal is applied to the anodes of a pair of diodes in phase opposition the signal is applied to the diode cathodes in equal phase the dc output voltage developed between the two cathodes is directly proportional to the signal and is largely independent of the input noise level the value of the stable voltage and the valve parameters 7388 constant current operation of power amplifiers a class a amplifier is discussed which is designed to be nearly independent of variations in valve characteristics cathode follower drivers are used together with balanced feedback and a x separate feedback phase inverter see also of june 7389 distortion in class a push pull amplifiers the distortion is expressed in terms of the derivatives of the anode grid characteristic at the operating point the effect of the cathode resistance is to increase the distortion as compared with the effect due to the load resistance alone 7390 degenerative pentode equivalent circuit analysis and discussion based on two forms of equivalent circuit of a pentode arrangement with feedback via cathode lead impedance 7391 distributed amplifier theory matrix algebra is used to analyse operating conditions in the anode line the manner in which the amplifier gain depends on grid and anode line terminations and propagation constants number of valves and grid driving voltage is indicated experimental results obtained with a six valve amplifier provide general confirmation for the theory 7392 analysis of a single ended push pull audio amplifier analysis is given for the circuit described by peterson and sinclair of linear valve characteristics and small signals are assumed some experimental results are reported 7393 bypass and decoupling circuits in audio design the amplifier equation is put into a form which expresses the gain for ideal conditions of perfect bypassing and no reactive elements with separate terms taking account of the actual reactive effects these terms are evaluated for the limiting conditions at the low and high ends of the frequency band and the real and imaginary parts are separated design of triode and pentode circuits is considered 7394 audio frequency input circuits careful design of input circuits is important especially when the input level is low fundamental factors considered include signal noise ratio of the source optimum input impedance for resistive and reactive generators noise in the amplifier valve input transformer and connecting cable characteristics 7395 a differential input stage for low frequency amplifiers an ac coupled differential input stage is described in which the ratio of in phase to anti phase gain ie the transmission factor is theoretically infinite in an actual circuit the measured value of the transmission factor was at an in phase signal level of rms the frequency range of is adequate for most applications 7396 cathode drift compensation in dc amplifiers the miller circuit has been found effective in compensating against cathode drift but it has been assumed necessary to use a load resistance large enough to make the anode current of the output valve small compared with that of the other simple analysis is presented to show that this limitation is unnecessary an improvement of the circuit based on this analysis is suggested 7397 vacuum tube oscillators intended for senior and graduate students as well as for practising electrical engineers the subject is treated mainly from the point of view of design 7398 successive differentiation of experimental curves and method of smoothing 7399 mathematical aspects of the quantum theory of fields part fields modified by linear homogeneous forces of may 7400 diracs function and its utilization in mathematical physics 7401 some exact solutions in nonlinear oscillations a rigorous analysis is made of forced oscillation mechanical or electrical systems for certain cases which are specified by the condition that the condition that the forced oscillation has a waveform similar to that of the external force the stability conditions are derived from hills equation which can be solved exactly for the present cases 7402 one to two millimeter wave spectroscopy spectral lines have been measured at many positions between mm and mm wavelength using similar technique to that previously described of johnson et al construction details of the new multiplier and detector used will be given elsewhere 7403 the mechanism of phosphorescence in crystal phosphors a summary of the results of the investigations described elsewhere in greater detail of june 7404 infinite matrices associated with diffraction by an aperture the results obtained by levine and of are discussed and it is shown that the algebraic properties of the matrix used are such as to permit determination not only of the transmission coefficient but also of the distribution of field across the aperture 7405 a note on the application of schwingers variational principle to diracs equation of the electron 7406 transistors theory and application part transistor action in germanium and silicon a simple account of the physical structure and properties of ge and si crystals part of august 7407 investigation of the potential barrier between two electrodes of the same metal with different applied potentials a theoretical investigation of the barrier transparency and tunnel effect analysis leads to formulae which for limiting cases give the known results corresponding to a rectangular or triangular type of barrier 7408 some properties of potential barriers matrices used in defining the wave function at the junction between different media are shown to be applicable for calculations relating to potential barriers of various forms 7409 the electrical breakdown of gases in nonuniform fields at low pressure breakdown voltages between coaxial cylinders were investigated for air hr h and he the results obtained support the view that the same primary and secondary ionization processes are involved as for uniform fields 7410 the reflection coefficient of positive lithium ions striking a metal surface and the energy spectrum of the secondary electrons results obtained for targets of duralumin and nickel are shown graphically see also of february for which the number should be 7411 a survey of present knowledge of thermionic emitters 7412 the zero point susceptibility of a linear antiferromagnetic atomic chain 7413 operating of the penning gauge experiments were made to check results reported by laffineur and pecker on the emission of hf waves from a gas discharge a receiver tunable over the band and fixed tuned receivers for and cm were used no radiation was detected on the last two wavelengths on the other wavelengths continuous spectra were observed with a fairly sharp peak at a frequency less than half the gyromagnetic frequency the effect of a component of electric field normal to the magnetic field is discussed 7414 longitudinal magneto hydrodynamic waves alfvens theory indicates that the velocity of sound waves in a conducting fluid will be changed by application of a strong magnetic field theory of this effect is presented for a fluid with finite conductivity and is applied to predict effects that should be obtained in propagation of sound in hg in a very strong field in sea water under influence of the geomagnetic field 7415 generalized magneto hydrodynamic formulae the formulae of magneto hydro dynamic theory are extended by the simpler methods of magneto ionic theory in which mean velocities and forces are used and nonlinearities are avoided by perturbation treatment the results are applied to the case of plane wave propagation in the direction of a primary magnetic field 7416 interaction of microwaves propagated through a gaseous discharge plasma experimental observations are reported on the interaction of and signals in discharge plasma produced in he ne ar kr xe and h gases over the pressure range mm hg pulse excitation being used the disturbing wave was pulse modulated and the wanted cw transmitted through the decaying plasma was detected by means of a cavity resonator the amplified envelope being displayed on a cro typical oscillograms showing the modification of the envelope of the wanted wave due to the pulsed disturbing wave are reproduced when a magnetic field is applied the interaction is observed at low signal levels for which no effect is found in the absence of the magnetic field see also of goldstein et al and back reference 7417 the characteristics of an electron beam entering a coaxial magnetic field the effect of nonuniformity field on the convergence of an electron beam is studied by considering a particular field configuration and calculating the path of an electron at the edge of the beam the radius of the beam is plotted as a function of distance travelled in the transition zone for different values of a parameter which is dependent on current density accelerating voltage and length of the transition zone 7418 calculation of the electrostatic capacitance of a conductor by the method of excess and deficit application to the case of the cube using a method based on a theorem due to fichera the capacitance of a cube of side a is found to be between 7419 a high resolution aerial for radio astronomy 7420 on sunspots and magnetic storms study of the correlation between active sunspots and geomagnetic storms shows that the effect of central meridian passage of active sunspots on the occurrence of storms is more evident when the activity is defined by both the spot type and the magnetic character than by the spot type alone this is particularly noticeable in the case of geomagnetic storms with gradual commencements 7421 control of geomagnetic activity by sunspots statistical analysis of the sunspots observed in and shows that as regards their effect on geomagnetic activity they can be divided into two distinct classes radio emissive spots the source of relatively dense corpuscular jets and accompanied by marked peaks of mean geomagnetic activity sunspots with no corpuscular or a radio emission sunspots with no corpuscular or radio emission causing a marked reduction of geomagnetic activity in the case of many spots of this latter type the geomagnetic activity returns quickly to normal to days after the spots pass the central meridian 7422 proposals for the statistical treatment of geomagnetic micropulsations a system of classification is suggested in which the magnitude duration and regularity of the pulsation trains are assessed semi quantitatively 7423 some characteristics of magnetic storms part magnetic storm on august analysis of data from many observatories all over the world 7424 the morphology of geomagnetic storms an extension of the analysis of d the disturbance local time inequality 7425 further notes on a new theory of magnetic storm 7426 a suggestion for the electric conductivity of the upper atmosphere from an analysis of diurnal variations of terrestrial magnetism part diurnal variations of the electric field and electrical conductivity of the upper atmosphere are deduced from the observed variations of the geomagnetic field 7427 on the auroral zone current analysis of eleven examples of auroral zone disturbance of the geomagnetic field in the second international polar year indicates that the height of the zone currents may be km or less the current intensity for moderate magnetic disturbances being of the order of a very large increase in the electron density of the d and e layers being thus indicated 7428 the mean vertical ozone distribution resulting from the photochemical equilibrium turbulence and currents of air 7429 ursigrams abbreviated codes are given for european ursigrams and modifications in the french ursigram transmissions are tabulated 7430 the continuous layer formation in the atmosphere under the influence of solar radiation the formation of ionized layers in the atmosphere under the influence of a quiet sun a disturbed sun is the influence of a quiet sun a disturbed sun is found possible in both cases if account is taken of the variation with height of the dissociation of the molecular constituents the ionization of the different constituents at various altitudes the expression continuous layer formation signifies continuous increase and decrease of the electron density with height throughout the ionosphere 7431 formation of the d layer measurements of absorption cross sections of various gases are described the results favour the assumption that absorption of solar radiation by no is largely responsible for the formation of the d layer 7432 determination of the coefficient of recombination in the ionosphere a simple method is suggested in which the recombination coefficient is determined from night time observations in terms of the gyrofrequency the mean observation frequency and the time interval between the disappearance of the ordinary and extraordinary ray echoes the value of for the f region found by this method using records of radio ceylon transmissions on is sec using vertical incidence measurements at calcutta a value of cm sec is obtained compared with cm sec calculated by the usual method 7433 a statistical study on the minimum frequency in curve for the e region of the ionosphere the diurnal and seasonal variation of the minimum frequency in the curve for the e region is investigated and also its relation to the sunspot number the diurnal variation suggests the existence below the e layer of an absorbing layer which is ionized by solar radiation the electron density in the d layer is estimated to be cm 7434 wave hypothesis of moving irregularities in the ionosphere a preliminary discussion of magneto hydrodynamic effects which may afford an alternative explanation of the motion of ionospheric irregularities usually referred to as winds in terms of the propagation of a wave like disturbance it is found that travelling atmospheric disturbances governed by pressure oscillations and gravitational forces will be accompanied by em oscillations which can under special resonance conditions become large the corresponding amplification of the associated electron motions would render such disturbances particularly susceptible to detection by radio methods gravity tends to confine the movement of these disturbances to the horizontal plane but a secondary vertical component is possible a full treatment is to be published later 7435 an analysis of electron density variations in the f layer after sunset analysis of data obtained at kokubunji taking temperature variations into account and assuming a linear law for the rate of disappearance of electrons indicates that the nocturnal variation of electron density in the f layer is explained more satisfactorily by the attachment theory than by the recombination theory the corresponding temperature variations deduced are not satisfactory for the winter months for which other factors must be taken into account 7436 critical frequency variations twelve month running averages of f are plotted against twelve month running averages of the sunspot number for two stations in the northern hemisphere two in the northern hemisphere two in the southern hemisphere and one near the equator for the northern hemisphere stations the slope of the curve is less at the higher values of sunspot number for the southern hemisphere stations the slope is constant and for the equatorial station the slope varies in an intermediate manner these differences may be related to the differences in the annual variation of f in the various regions considered 7437 effects on the f regions of the ionosphere of the solar eclipse of may observations indicated the development during the eclipse of a new layer between the f and f layers discontinuities of the f layer critical frequency and virtual height curves and of the f layer critical frequency curve were noted for a period of about min before and after the first contact estimates are made of the electron density variations involved 7438 the h t measurement of ionosphere at the time of the annular eclipse of may at wakkanai hokkaido in japan measurements were made at frequencies of and the results obtained show that the absorption in and below the e layer decreased as the eclipse approached its maximum and increased again after the maximum phase the maximum f layer electron density began to decrease immediately after first contact and continued to decrease to a minimum about min after the maximum phase of the eclipse then recovering 7439 day variations in the absorption of the d region of the ionosphere over singapore and slough apreciable variations of d layer rf absorption with a day period are found throughout the year at singapore but only during the u summer months at slough other variations of absorption of larger amplitude than in summer are found at slouth in the winter months but are not related to the solar rotation period of variations of particle radiation the bearing of these results on radio communication and on ionospheric forecasting is discussed briefly see also of 7440 measurement of ionospheric absorption the significance of ionospheric absorption is discussed and commonly used methods of measurement are examined 7441 the recombination coefficient and the temperature variation in the upper atmosphere at night the value of the f layer recombination coefficient at kokubunji near tokyo shows a marked seasonal change the maximum being in january and the minimum in june july calculation of the corresponding relative temperatures indicates that in winter some mechanism other than temperature variation must be taken into account 7442 the solar flare type variation in geomagnetic field and the integrated electrical conductivity of the ionosphere part assuming that the solar flare type of variation of the geomagnetic field is caused by anomalous increase of the electrical conductivity of the ionosphere treatment based on the dynamo theory gives a value for the integrated conductivity of the ionosphere of the order of which is in good agreement with the value deduced from ionospheric observations 7443 the solar flare type variation in geomagnetic field and the integrated electrical conductivity of the ionosphere part effect of f layer analysis of mutual inductance effects between different ionosphere layers shows that as regards the effect of layer currents on the geomagnetic field a single layer can be assumed the conductivity of which is equal to that of the various layers integrated vertically throughout the whole conductive region the previous estimate of about emu for the integrated conductivity of the whole ionosphere is thus confirmed part above 7444 the solar flare type variation in geomagnetic field and the integrated electric conductivity of the ionosphere part effect of the earth further ductivity of the earth part above 7445 the solar flare type variation in geomagnetic field and the integrated electrical conductivity of the ionosphere part the conductivity of the ionosphere over japan statistical analysis of data obtained at kakioka during gave the averaged value of te the integrated electrical conductivity of the ionosphere over japan as emu part above 7446 the shielding effect of the ionosphere analysis of the effect of the ionosphere in screening the earth from external em fields taking account of the conductivity of the earth 7447 ionospheric stations a list is given of all stations from which results of observations are regularly received at slough in a second list which replaces those previously published ionospheric stations are grouped according to the country controlling them 7448 atmospherics with very low frequency components 7449 radio research special report no characteristics of the ionosphere observed in great britain report of measurements slough and at burghead 7450 development of an absorber for electromagnetic waves theory is given relative to the design of mesh networks suitable for screening electrical equipment from em radiation within a specified frequency band 7451 power requirements for transistor circuits primary requirement for transistor power supply is constancy of voltage or current with time long life and small size are next in importance these requirements are all satisfied by rm cells of 7452 high voltage generation for television equipment and oscillographs a review of various methods described in the literature on the subject 7453 effective current and efficiency of small mains supply units with capacitively terminated rectifiers when a mains transformer is wholly or partially loaded by a capacitively terminated rectifier network the effective value of the rectifier current pulses is determinative for the copper losses and the waveform distortion for the magnetic losses effective current and efficiency curves are presented for various simple types of rectifier circuits 7454 a stabilised extra high tension rectifier for description of equipment using a triode control valve which functions as a variable resistor in the dc circuit the reference voltage is provided by a dry battery the output voltage fluctuations are only of those of the mains supply the output voltage fluctuations are only of those of the mains supply the output voltage is variable between and in four overlapping stages each subdivided into steps which can be varied continuously protective measures are described 7455 impedances of the electrolytical rectifier the impedance characteristic of an electrolyte rectifier is investigated experimentally a method for calculating an equivalent circuit of the oxide layer from the frequency dependence of its impedance is described it is concluded that rectification occurs by means of contact between p type and n type semiconducting layers 7456 voltage stabilization with series valve control analysis of the operation of equipment taking a large load current 7457 corona discharge tubes for voltage stabilization comment on of april and authors reply 7458 geometrical transformation of impedance diagrams note on the use of graphical methods and of riemanns number sphere in impedance calculations 7459 the concept of instantaneous frequency discussion shows that this concept can properly be applied to the cases of demodulation by a linear discriminator and fm of a self oscillator by variation o a parameter of the circuit but its use in other cases such as calculation of the harmonic distortion of a simple tuned circuit leads to erroneous results this is demonstrated by rigorous calculation of the distortion introduced by an lgc circuit in the anode circuit of a pentode amplifying stage 7460 theory of the magnetic amplifier with free magnetic amplifier with free am magnetization 7461 comparison of methods of analysis of magnetic a amplifiers 7462 types of magneticc amplifiers survey a scheme for classifying magneti amplifiers under three main headings with subdivisions by number and letter is proposed and discussed 7463 the figure of merit of magnetic amplifiers combination of complex number and boolean algebra is outlined which can be applied in the analysis and synthesis of networks containing switches 7464 a method of designing transistor trigger circuits a fairly general technique was developed after the war for designing circuits that would operate with valves having characteristics which varied within fairly wide tolerances without component adjustments being necessary when valves were changed a similar technique is outlined for point contact transistors this is based on valve circuit technique and particularly on the analogy between the characteristics of transistors and pentodes basic pule circuits considered include state devices timing circuits counters and relaxation oscillators their application in digital computers is reviewed in detail 7465 nonlinear condensers the properties and applications of high permittivity materials containing are discussed with particular reference to the dependence of the dielectric constant on temperature and on the voltage applied applications of capacitance with the dc bias voltage in a modulator and in a capacitor type amplifier are described 7466 the nonlinearity of titanate capacitors ferroelectric and ferromagnetic materials are compared and expressions for the specific nonlinearity are derived for both these expressions give the hysteresis loss cm referred to unity circular frequency and a reactive power of the specific nonlinearities of material with a dielectric constant of and ferrite with an initial permeability of the same order of magnitude 7467 the use of short transmission lines in ultra high frequency techniques lines of length are considered their uses as inductances capacitances and resonant circuits are reviewed numerical examples are given applications as filters and impedance transformers are described 7468 new hf proximity effect formula arnolds results of are somewhat complex a new asymptotic formula was therefore developed which is valid whenever the proximity effect is so great that the resistance of the apir of parallel conductors is more than doubled a combination of the maxwell equation and integral equation approaches is used in deriving the new impedance formula which is rigorous and very simple 7469 the equivalent q of rc networks the effective q factor of a rc phase shift network is defined as one half the rate of change of phase with frequency at the operating point for networks commonly used as frequency determining elements the effective q value is about unity but a capacitance type of r bridge t network may have a q value of 7470 design of low frequency constant time delay lines 7471 ultrasonic delay lines survey of the characteristics and operation of delay lines using fused quartz or glass rods with quartz crystal transducers 7472 a new non reciprocal waveguide medium using ferrites a narrow ferrite strip is attached along the wall of a circular section waveguide and subjected to a transverse magnetic field a difference in phase constant exists for the two directions of transmission along the guide for suitable ferrite dimensions a nonreciprocal rotation of the plane of polarization of an em wave takes place a more complete theoretical explanation is to be published the case of an axial ferrite rod with an applied axial field has been considered by hogan of 7473 semifinite terminated electric wave filters intended for s use either as channel filters or to work between a finite resistance at one end and a very high or very low impedance at the other two design methods are presented one based on the equivalent image parameter filter the other on norton and darlingtons insertion loss procedure the minimum ratio of terminating resistances lies between and for most applications 7474 a new approach to optimum filtering in filter problems if enough is known about the signal and the noise to describe them accurately by their power spectra conventional methods based on wieners original method will provide the most effective filters an alternative procedure for computing optimum filters based on description of the signal in terms of a partial sum of orthogonal functions is presented this will specify good filters with far less labour than is necessary in the wiener method and it has a wider range of practical application a table of summation orthogonal analogues of the laguerre functions which are useful in this procedure is appended 7475 synthesis of a dynamically variable electronic filter the principles of network synthesis are applied to the design of a variable bandwidth filter with an upper cut off frequency which can be varied dynamically over the frequency range kcs the bandwidth variation is automatically controlled by voltages applied to the control grids of pentodes slight changes occurring in selectivity and midband gain 7476 printed and potted electronic circuits survey and assessment of production techniques and description of some applications 7477 russian circuit notations the methods adopted for indicating the values of resistors and capacitors on russian circuit diagrams are explained 7478 a relation between susceptance slope and selectivity for oscillator design two quantities the slope of the susceptance curve computed at an antiresonance frequency the dimensionless selectivity factor q are significant in specifying the performance of oscillatory circuits the relation between the two quantities for practical resonant circuits is discussed and general conclusions are drawn relating to resonant circuit design these conclusions are applied to the comparison of the clapp and colpitts types of oscillator and to the study of the equivalent circuit of a quartz crystal operating near resonance 7479 subharmonics in a series nonlinear circuit as influenced by initial capacitor charge 7480 note on the response of an lcr circuit 7481 the transvar directional coupler the coupling element consists of closely spaced identical apertures separated by grid wires in the common narrow wall between two waveguides by changing the relative longitudinal position of the two waveguides the number of exposed apertures and hence the effective coupling length can be changed power transfer is variable between and at maximum power transfer is available at one frequency only and hence bandwidth depends on the tolerable decrease in power transfer two models with and differing only in grid wire diameter have maximum power transfer at about and respectively agreement between theory and performance is close 7482 external influences on the circuit properties of uhf resonators the q of a cavity resonator depends not only on its physical dimensions and the material of which it is made but also on the surface finish the influence of the material and its finish on the fundamental damping and resonance resistance is investigated for resonators of various types an examination is made of the degree of roughness permissible with reference to standard specifications on surface finishes effects due to variations of atmospheric temperature pressure and humidity and methods of eliminating these effects are also discussed 7483 interaction of modes in a microwave cavity resonator the minimum energy differences between the desired and undesired modes in a cylindrical resonator are calculated by considering the em field inside the resonator as due to an infinite number of harmonic oscillators expressions for the mutual energy and the coefficient of coupling between the companion modes and are derived the significance of the total energy of a micro wave cavity resonator is discussed 7484 power spectrum of a nonlinear oscillator perturbed by noise analysis of the effect of background noise in producing amplitude fluctuations if the steady state of an oscillator is disturbed recovery takes place exponentially with a time constant which is the principal factor affecting the noise power spectrum simple relations between and the circuit parameters are derived which show that for minimum noise power oscillations of large amplitude should be used without introducing too many harmonics and the phase of the feedback should vary only slowly with frequency see also of april and back references 7485 two rc oscillator circuits cathode coupled and transitron types of rc oscillator are described which operate at freu frequencies of about and respectively 7486 low power blocking oscillators information of use in final adjustment of blocking oscillators particularly as regards requirements for short rise times and narrow pulses is reviewed a linearized equivalent circuit is used to derive an explicit expression for pulse duration which gives results in agreement with experiment particularly when the grid coupling capacitor is small 7487 use of servo techniques in the design of amplitude stabilized oscillators expressions for the oscillation amplitude in terms of the stabilizing signal voltage are derived and the amplitude stabilizing system is discussed as a negative feedback loop experimental and theoretical results for a high q oscillator are compared 7488 fm transistor oscillator a titant titanate capacitor is coupled to the resonant circuit inductor of the transistor oscillator the transformation ratio being chosen at will varying the potential applied to this capacitor alters its effective capacitance and hence the resonance frequency a polarization potential is applied from a zamboni pile to keep the capacitance variations within the linear range a oscillator constructed used a junction transistor and had a power output of when supplied from a battery the titanate capacitor consisted of two series connected units a oscillator using a type point contact transistor gave similar results some form of a fc is desirable in view of the temperature variations of the components 7489 an oscillator with constant output voltage the theory and design of an uput voltage stabilizer circuit are given by a suitable choice of the values of two resistors and of the constant reference voltage the oscillator output voltage is made virtually independent of valve characteristics and circuit impedance an application to the calibration of valve voltmeters is described 7490 mechanism of the synchronization of lc oscillators the pulling effect on the phase a and frequency of an lc oscillator due to interference is considered the phase change is calculated for the case of a single interfering pulse a series of equidistant pulses and a sinusoidal voltage interfering pulses occurring at an oscillator voltage peak affect the amplitude those occurring at zero voltage cause a change in phase only these phase changes are permanent a differential equation relating oscillator voltage phase deviation time peak oscillator voltage and the magnitude of the interference current is solved and the conditions for synchrononism are obtained 7491 some aspects of mixer crystal performance a method of calculating conversion loss and conductances of a crystal mixer is presented and their dependence on terminations at the image frequency and at the sum frequency is considered experimental data from various sources support the calculations graphs showing excess crystal noise versus output frequency and mixer noise temperature versus crystal noise temperature for varying conversion loss are derived and applied together with the conversion loss data to practical calculations of optimum mixer configuration and optimum if two examples are worked out experimental confirmation of results was obtained 7492 automatic frequency control of high power klystrons a method of control is described in which a cavity resonator and two microwave crystals are used as a standing wave discriminator in a system for automatic frequency search and lock for a pulsed klystron oscillator frequency stability to within part in is achieved 7493 length of coherent microwaves generated by an electronic oscillator investigation of the noise associated with the generation of oscillations of frequency by a reflex klystron showed a bandwidth of about this is attributed to fluctuation of the electron beam 7494 the square wave generator the circuit of a multivibrator type of generator with stabilized input is shown and a complete analysis based on the characteristics of the double triode type is given 7495 a reliable locked oscillator pulse timer description with complete circuit diagram and method of adjustment of a highly stable locked oscillator pulse timer providing pulses with recurrence frequency from a input the frequency divider has previously been described of the unit has an overall phase stability to within per volt of line voltage change 7496 an analogue reciprocal function unit for use with pulsed signals a monostable multivibrator operates so that the width of the pulse generated is approximately inversely proportional to the peak voltage of an input pulse the pulse width variation is converted to a corresponding amplitude variation of sawtooth output pulses by means of a constant velocity timebase circuit 7497 calculations for a power amplifier for driving a dc motor analysis of a symmetrical class a amplifier supplying energy to a motor connected in the cathode circuit of the output stage see also of march 7498 high power audio amplifiers recent applications for a f power up to include vibration work servomechanism studies pulsed service and variable frequency power sources all of which require response distortion and noise level characteristics similar to those for broadcasting service in high power amplifiers with class b push pull output the output transformer is the largest and most expensive item in the equipment and may weigh some hundreds of pounds a new equivalent circuit is used in the design of such transformers harmonic distortion caused by the transformer is analysed and methods of improving the performance of class b power amplifiers are described a few details are given of a amplifier with a response curve flat to within from to 7499 general design considerations of a cavity type power amplifier details r are given of the construction of a single stage amplifier using a type triode valve constant current curves for class c grounded grid operation were used to determine the operating parameters of the triode a stage amplifier using and triodes is described with performance details 7500 a simple low frequency amplifier description of a tuned amplifier circuit for the range incorporating a damped phase shift oscillator with independent control of resonance frequency and q factor 7501 differential law for the intensities of electrical fluctuations and influence of skin effect an investigation is made of the form of the correlation function of the external field which expresses the thermal electrical fluctuations in a conductor and of the differential law on which nyquists integral formula is based 7502 on the temperature dependence of contact noise results of noise measurements on se and cu rectifiers and on carbon resistors over different temperature ranges between and are shown graphically 7503 subharmonic oscillations in nonlinear systems the order of the subharmonics in systems with nonlinear restoring force is closely related to the form of the nonlinearity a detailed analysis is presented for the subharmonic oscillation of order for the cases in which the nonlinearity is expressed by a cubic or a quintic function stability is discussed by means of the criterion previously given o august 7504 step by step transition from wave optics to ray optics in inhomogeneous absorbing media part equations for wave normal refractive index and polarization the transition is made by successive approximations each approximation is considered from the physica point of view and th physical significance of the equations derived is considered 7505 luminescent layers and films with polyvinyl alcohol as protective colloid and binder 7506 electroluminescence electrical and optical properties electro optical measurements are reported on electroluminescent lamps operating on the principle described by payne et al and fundamental properties of electroluminescent phosphors are studied 7507 oscillatory phenomena of arc in hot cathode discharge tube part theoretical mechanism of oscillation of 7508 space charge spread of reflected electron beams studied by a photographic method 7509 the self charge spreading of a fucused electron beam simple formulae derived from wave mechanical considerations are obtained for the upper limitems of the self charge effects ie spreading of beam and displacements of image plane and fraunhofer plane 7510 energy distribution of thermo electrons in electron beam devices experiments are described which show that the energy distribution of the thermo electrons in oscillograph tubes electron microscopes etc is not of the maxwell type the deviations from the maxwell distribution particularly in the low energy range are attributed to reciprocal dynamic effects 7511 on the theory of the ising model of ferromagnetism 7512 the two dimensional magnetic or electric field above and below an infinite corrugated sheet 7513 a conducting permeable sphere in the presence of a coil carrying an oscillating current the secondary magnetic fields due to the sphere are calculated for frequencies 7514 current element near the edge of a conducting half plane the two dimensional problem of the maxwellian field from a line source of current adjacent to conducting half plane is treated by a transform method of solution expressions in the form of contour integrals are given for the current induced in the conductor and for the radiated field 7515 the scattering of waves at an uneven surface an approximate method is proposed for calculating the field of acoustic and electromagnetic waves scattered by an uneven surface the irregularities being large in comparison with the wavelength particular cases considered include that of sinusoidal corrugations 7516 scattering of waves by a statistically irregular surface a method is proposed for calculating the field of plane waves scattered by a perfectly reflecting statistically irregular surface the irregularities being large in comparison with the wave length the method can be used for acoustic as well as electromagnetic waves 7517 quenching of afterglow in gaseous discharge plasmas by low power microwaves continuation of work noted in of september results are reported for neon of the effect on the plasma decay of applying microwave pulses at various time intervals after the production of the plasma the state of decay was determined by observing the afterglow by means of photocells and displaying the amplified photocurrent on an oscilloscope decrease of light intensity observed during the application of the pulse is most probably due to reduction of the recombination rate differences in the traces observed at pressures of mm hg and mm hg are discussed the effect may be useful for detecting the energy 7518 on some features of noise storms discussion of solar rf emission of abnormally high intensity on metre wave lengths the radiation is circularly polarized may last for several hours and is often associated with sudden bursts of nonpolarized radiation the association of such noise storms with large and magnetically active sunspots is considered 7519 time variation of the earths magnetic field at the time of bay disturbanced 7520 distribution of sc of magnetic storms the abbreviation sc is used to denote the reverse impulse preceding a sudden commencement the distribution with respect to local tim and latitude was examined from records obtained at five us stations during a period of years and also from world wide records of individual geomagnetic storms the reverse impulses appear chiefly in the afternoon with a maximum at about local time the pulse magnitude as well as its ratio to the succeeding main pulse increases markedly with geomagnetic latitude 7521 the recurrence tendency of magnetic storms data relative to storms observed at aso magnetic observatory during the period september august are analysed storms showed no recurrence tendency the rest are divided into groups each containing several storms recurring at intervals of about days 7522 correlation of magnetic m storms with the monochromatic corona results obtained at wendelstein show that a maximum of geomagnetic activity is observed days before the central meridian passage of a region of g high coronal activity or days after the appearance of bright coronal emission at the east solar limb similar characteristics are found for the minimum epochs the relation apparently holds good only when no visible or significant sunspot phenomena exist 7523 radio echoes observed during aurorae and terrestrial magnetic storms using and waves simultaneously a report of observations at tromso near the auroral zone and at kjeller near oslo the two pulse transmitters at each station had common pulse modulators so that the shape and energy of the pulses could be made identical the peak pulse power was and repetition frequency sec echoes on appeared regularly at tromso during auroral displays and in a number of cases also on study of the results led to the conclusion that the echoes were not due to direct scatter from the ionosphere but could be explained by reflection of backwards scatter from land or see via the e layer the ionization of which increases greatly during aurorae and geomagnetic storms in all cases the echoes on showed a x smaller range than those on the difference in range usually exceeding km differences between the echo patterns on the two frequencies are noted a full account of the observations will be given in 7524 constitution of polar magnetic storms analysis of data obtained in the international polar year indicates that polar magnetic storms consist of a number of elementary disturbances which occur successively the equivalent current system corresponding to these disturbances can be represented approximately by that due to an electric dipole located in the auroral zone 7525 constitution of polar magnetic storms an examination of world wide data relative to the polar magnetic storm on april confirms the conclusions noted in above 7526 annual variation of reduced density and mean temperature of atmospheric ozone in afghanistan 7527 abbreviated codes of european ursigrams part the codes here given are data on monochromatic intensity of the solar corona coron code data on e critical frequency esfre code data on f critical frequency fodeu code for hourly values symbo code for descriptive symbols for the values given terrestrial magnettism magne code ionospheric disturbance warning pertu code radio solar emission observatories soler code part of september 7528 european ursigrams correction to of september 7529 some characteristics of ionospheric storms analysis of data for the f region the frequency of occurrence of disturbances in this region is closely related to its seasonal height being greater in summer than in winter 7530 classification of f layer storms with respect to their world wide distribution and characteristics part of analysis of available data shows that there is no correlation between f layer storms and sunspot activity but close correlation with geomagnetic storms a classification of these storms with respect to their distribution over the geomagnetic latitudes is suggested based on layer height or critical frequency characteristics 7531 on world wide distributions of f hourly values of f observed at stations distributed all over the world during the period are analysed contour lines being used to indicate places with common critical frequencies diagrams are also given showing the distribution of the difference between and its monthly mean value at and at on may the distribution of for noon local time on the same date the latitude distribution o of for noon local time on longitudes and 7532 on the cause for unnatural distribution of occurrence of and observations carried out at kokubunji indicate a correlation between receiver interference and the frequency of occurrence of and 7533 a relation between f layer disturbance and geomagnetic condition a correlation is found between the daily mean value of the electron density of the f layer and the storminess of the geomagnetic field the f layer electron density appears to decrease in local summer and increase in local winter in the middle latitude regions of both the northern and southern hemispheres 7534 characteristics of ionospheric disturbances during severe magnetic storms analysis of world wide data from ionosphere stations for the period may including two geomagnetic storms with sudden commencements shows that an ionospheric disturbance coincident with a sc in a region of high geomagnetic latitude spreads down to lower latitudes in high latitudes the disturbances travel at a high velocity which is about in the vicinity of japan the intensity of the disturbance decreases with latitude the connection between the time of occurrence of a sc and disturbance of radio communication is briefly discussed 7535 studies on ionospheric storms a definite relation is found between the types of storm discussed by appleton and piggott of and the seasons in which they occur the development of ionospheric storms is discussed in some detail the need for further world wide ionospheric investigations particularly in high latitudes and at intervals less than an hour is stressed 7536 modern ionosphere sounding equipment of the netherlands ptt full description with block diagrams of a pulse equipment for the range pulse duration is adjustable from to repetition frequency is sec a complete frequency sweep can be made in either or sec two cr tubes in parallel provide monitoring and photographic facilities 7537 ccir ursi co operation exchange of information for forecasts and warnings 7538 anomalous ionization in the upper atmosphere over the auroral zone during magnetic storms the depth of penetration of and the rate of ionization by protons of extraterrestrial origin are estimated an explanation is given of the rapid variations of the geomagnetic field in and near the auroral zone 7539 the application of nonlinear techniques to servo mechanisms 7540 the transient response of a single point nonlinear servomechanism 7541 servo systems comparators 7542 compensation of a magnetic amplifier servo system 7543 synthesis of compensation networks for carrier frequency servomechanisms 7544 screening of test rooms and instruments from electromagnetic fields screens made of wire mesh metal foil and sheet and of materials with a high expressions are given for the attenuation of incident em waves experimental curves for sheet and mesh screens are given the construction of a large screened room is described and the attenuation of magnetic fields in this room for frequencies from to is compared with that of other rooms a novel type of honeycomb wire mesh strip window screen is described 7545 reactivating the dry cell discussion of the effect on cell life of repeated passage of current in the reverse direction 7546 note on the optimum input winding resistance of a magnetic amplifier employing voltage feedback 7547 transistor controlled magnetic amplifier a circuit is described in which the collector toroidal core this part of the circuit being completed via the secondary of a transformer primary coltage at and the load resistor back to the transistor base electrode with this arrangement output currents up to peak can be obtained in the load for emitter input signal currents peak complete response to a change of input signal is obtained in one cycle of the applied alternating voltage 7548 collector base impedance of a junction transistor comment on of march early 7549 transistor circuits and applications see of september 7550 theory of afc synchronization the performance of an afc system can be described in terms of three parameters the gain constant the damping ratio and the resonance or cut off frequency using these parameters expressions v for the performance under conditions of small disturbance to the input phase and for the pull in performance are derived two different types of control network transfer function being considered 7551 the characteristics and applications of thermally sensitive resistors or thermistors basic properties of thermistors are reviewed and terms used to specify their characteristics are defined outline descriptions are given of their applications in measurement control and protection circuits etc 7552 a range of and transductors for service use a survey of common transductor types is made and details are given together with particular applications of input type transductors with n mumetal or permalloy cores for supply voltages of and rms and power type units with hcr or permalloy f coe cores for supply voltages of and rms all are of the automatic self excitation type 7553 stray capacitance with high permittivity dielectrics expressions are derived for the stray es field and stray capacitance of a parallel plate capacitor the corrections for stray capacitance of circular parallel plate and cylindrical capacitors are determined 7554 control of thyratrons by small signals variations of the phase of the control grid voltage enables the power supplied by a thyratron to an external circuit to be varied continuously over a wide range the results obtained with small control voltages indicate that although signals as small as may be permissible when the thyratron forms part of a feedback system large signals should be used whenever possible 7555 a circular waveguide magic tee and its application to high power microwave transmission the magic t discussed comprises a circular section waveguide with two mutually perpendicular side arms of rectangular section spaced longitudinally at a distance this system constitutes a pair of h mode transformers the device can be used as a variable power dividing or power combining bridge and one of its main uses is for combining feedback power with power from the source at the input to a linear electron accelerator when two similar sections are joined via a rotatable coupling the resulting system is suitable for external connection via the rectangular side arms the power dividing ratio depends on the angle of rotation between the two sections other applications include use with a circular polarizer to act as a phase shifter or variable impedance 7556 a contribution to the theory of nonlinear systems a system of classification of nonlinear terminal networks is introduced and basic properties of various classes are established the system is such that each class in the sequence n contains as a member the class before it a general nonlinear network of class n is completely defined by its responses to a family of step functions with amplitudes ranging over all real values an explicit expression is developed for the response of a class n network to a specified input modes of realization and characterization of networks of class n are outlined and a procedure for determining the optimum filter of any class is ou indicated 7557 the equivalent q of rc networks comments on of october brown and authors reply 7558 response characteristics 7559 a note on the analysis of vacuum tube and transistor circuits the setting up of node equations for a network containing one or more active elements is reduced essentially t to the determination of the admittance coefficients for the passive network resulting from removal of the active elements and adding to these the corresponding admittance coefficients for the active elements the latter being obtained from tables given in the text mesh equations are obtained in an analogous way using impedance coefficient tables 7560 tolerance coefficients for rc networks a method is presented for determining the effect on network design characteristics of the use of nonideal components a set of tolerance e coefficients is derived relating percentage changes of the positions of the poles and zeros of the network function to percentage changes of the network components changes of gain or phase are then easily calculated an exact solution is obtainable only when the network contains at most three independent capacitors two theorems are proved which serve to check approximations made for more complex networks 7561 realizability conditions for the series parallel matrix and canonical series parallel circuits for reactance quadripoles 7562 spinor theory of four terminal networks a spinor can be described as a geometrical object in dimensional space having a magnitude and three eulerian angles in the application of spinor theory to terminal networks the four spinor components represent the complex current and complex c voltage the associated vector represents power and the direction ratio represents impedance applications of the spinor theory are shown but the study is restricted to steady state conditions negative resistance is not excluded from the considerations 7563 the four pole transmission matrix comment on of june and authors reply 7564 the gyrator as a terminal element a terminal gyrator forming the nucleus of any terminal network that violates the reciprocity relation is considered a method is developed which realizes such an element with any unilateral transducer such as a valve or transistor the effect of loading by parallel or series admittance is investigated 7565 the algebraic theory of linear transmission networks the theory is based on the series combination of two networks with equal numbers of input and output terminals to form a semi group the theory is developed in a series of definitions theorems and proofs fundamental properties of transmission networks are derived and principal types of network are classified by means of a factorization theorem a simple criterion for symmetry can be derived the necessary and sufficient conditions for the existence of a characteristic impedance are determined the theory provides a concise definition and a method of rigorous treatment of the general transmission line 7566 simplified solution of phase shift networks the method is particularly applicable to phase shift circuits in rc oscillators and selective amplifiers the arbitrary initial assumption is made that all reactive network elements can be treated algebraically as resistances ie as scalar quantities this enables mesh equations to be written down and solved simply the results being then interpreted in terms of the complex quantities involved three illustrative examples are worked out 7567 a simple connection between closed loop transient response and open loop frequency response the phase margin concept of the characteristics of the nyquist diagram in the vicinity of the critical point is extended to give a more generalised formula this relates the damping of the principal oscillatory mode of a closed loop feedback system to the shape of the nyquist diagram all the quantities involved can be obtained from this diagram without further mathematical analysis or graphical construction on the diagram 7568 new linear passive nonreciprocal microwave circuit component 7569 termination variation in the constant k filter the problem treated is that of finding the modification required in a conventional filter when the terminations are resistive but otherwise quite general the filter elements are given normalized values and in addition modified by factors and to correspond with the change in termination from equal values to those modified by factors and from the expressions for the insertion transfer ratio of the original and of the modified circuit by equating appropriate terms and solving a diagram is constructed relating the four factors and two numerical examples illustrate the practical application of the diagram in the design of filter half sections full section and multisection filters are treated in similar fashion the calculations being correspondingly more complex 7570 synthesis of narrow band direct coupled 7571 design of symmetrical bridge type electrical filters by the operating parameter theory design formulae are developed and tabulated for symmetrical low pass filters of degrees and for attenuation characteristics with given zeros and poles a review of the theoretical foundations is based on work by cauer of and by darlington of 7572 a unitary design system for band pass filters of the zobel and laurent types a systematic representation of the properties of band pass filters based on the wave parameter theory is followed by the development of general design formulae for band pass half sections including the zigxag filters of laurent the system is based on cauers classification of q functions supplemented by some intermediate functions 7573 a band pass filter for low frequencies description with circuit diagrams of a filter with a pass band of consisting of four stagger tuned rc amplifier circuits with inputs and outputs connected in parallel by resistor networks the filter was developed for band encephalography 7574 synthesis of poles by networks containing the minimum number of elements the method of r brune is extended to the synthesis of passive poles the procedure is illustrated for after splitting off a series resistance the number of elements in the pole can be reduced and by repeating this procedure the pole of zero order can be realized as shown 7575 the coaxial system amplifiers 7576 high frequency oscillators designed for regulation and control of aircraft vhf equipment description of a quartz controlled fixed frequency unit and a vfo with a frequency converter for the range of a quartz crystal provides check points for all harmonics of in the range of the vfo 7577 action of an unlimited train of telegraphic signals on a resonant rlc circuit the response of a series rlc circuit to a train of pulse signals is considered for three types of pulse rectangular symmetrical trapezoidal and of sine squared form analysis shows that in the steady state whatever the degree of mistuning of the circuit with respect to the signal hf the amplitude of the current varies continually with time the variations are due partly to energy dissipation during the intervals between the signals and partly to beating of the forced oscillations due to the signals with the natural oscillations of the circuit the latter effect is particularly noticeable in a very selective circuit but its magnitude is largely dependent on the degree of mistuning of the circuit see also of 7578 amplitude stability in oscillating systems as a supplement to the kryloff and bogoliuboff method of determining amplitude of oscillation in quasilinear systems a method based upon energy balance is presented from the energy balance condition a criterion for stability of oscillation is deduced for the case of one degree of freedom the treatment is then generalized to systems of n degrees of freedom 7579 quantum theory of a damped electrical oscillator and noise field quantization is applied to an electrical oscillating circuit damping effects are treated by perturbation theory quantum effects occur both in the damping and in the noise and are discussed in detail the vacuum fluctuations are shown to be observable in certain low temperature noise experiments 7580 junction transistor circuit applications the basic circuits described include amplifiers impedance changing circuits phase inverters oscillators multivibrators and sawtooth frequency sweep oscillators 7581 self excitation with disk seal valves in a grounded grid circuit a circle diagram is derived for the internal capacitive coupling between anode and cathode in a grounded grid oscillator the phase of the transconductance and the input admittance resulting from the long transit times of electrons are taken into account calculations for several circuits with external feedback are made with th aid of the diagram 7582 am fm analogy a method is described for analysing the response of a circuit to a fm signal and for determining spectral distribution based on considering the equivalent signal produced by a series of sequentially pulsed am carriers whose frequencies range between the extremes of the fm deviation the required fm response is obtained as the synthesis of the responses to these separate am signals both aperiodic and periodic signals are considered the method is particularly appropriate and gives exact results when the modulating waveform is rectangular for other cases the results are approximate 7583 the theory and design of cathode follower output stages limitations imposed on the design of cathode follower stages feeding loads with an earthy a end are noted procedures are outlined for choice of valve for a particular service and then completing the circuit design under the conditions that the specified maximum anode current and anode dissipation are not exceeded and that linear operation is achieved 7584 transistor operation stabilization of operating points correction to paper abstracted in march 7585 why fight grid current in class b modulators by using triode valves with low anode resistance and low amplification factor efficient operation of audio amplifiers can be obtained without allowing the grid voltage to swing positive grid current is thus avoided direct coupling may be used between the driving amplifier and a modulator operated in this way permitting the use of a large amount of negative feedback measured response and distortion are presented for a modulator designed on these lines 7586 a single ended push pull audio amplifier reprint 7587 analysis of a single ended push pull audio amplifier 7588 coupling of cathode followers in dc amplifiers a symmetrical phase reversal circuit is described which together with screen coupled cathode follower stages has resulted in the development of an amplifier operated from a single source giving a gain of db and having a flat response up to kcs the level of the fluctuation noise voltage is almost too low to be measurable 7589 harmonic distortion and negative feedback commets on of august and authors reply 7590 accuracy of perturbation calculated from inaccurate unperturbed wave function 7591 t axcitation of luminescence by variable electric fields primary effect reply to herwellys criticisms and description of further experiments showing clearly that luminescence due to glow discharge can be distinguished from luminescenced induced by an electric field 7592 electroluminescence a new source of light a review of developments since the discovery of the phenomenon by the author in and an account of recent experimental work see also of and of payne et al 7593 fundamentals in the behavior of electrets further mathematical development for previous work see of and back reference 7594 the resistance of an imperfect contact between two metals comparison with experimental results for thin granular films 7595 a simple varying capacitor method for the measurement of contact potential difference in high vacuum apparatus based on kelvins original method and suitable for use at a pressure of mm hg is described the value found for the contact potential difference between cu and ag films evaporated on to w sheets was the ag being positive with respect to the cu 7596 on the changes in contact potential difference of a germanium rectifier during the electrical forming 7597 breakdown of a gas subject to crossed electric fields experiments with various gases show that breakdown in a resonator subjected to voltage pulses with a repetition frequency of is not helped by application of alternating fields of frequency or perpendicular to the main field even when such fields are only a little below the value at which they would cause breakdown if acting alone 7598 formative time lags in the electrical breakdown of gases the time rate of growth of ionization currents in a uniform field greater than that corresponding to the static sparking potential is investigated theoretically curves showing the dependence of the formative time lag on overvoltage are given with an example of their use in the elucidation of secondary ionization processes operative in the breakdown mechanism 7599 microwave technique for studying discharges in gases experiments were made with a neon filled tube inserted through a pancake waveguide internal height mm the variation of the discharge dc due to the rf field being observed on a cro for various relative positions of tube and guide the frequency used was about and the rf power 7600 the control of self maintained discharge currents by illumination of the cathode the discharge characteristics of neon filled and photocells illuminated with a hg discharge lamp were obtained experimentally the magnitude of the controllable current in the townsend discharge space depends on the illumination of the cathode the driving potential applied and the value of the stabilizing resistance used 7601 discharge between positive point and plane in compressed air at gas pressures of several tens of atmospheres the spark discharge from a point may be preceded by relatively large currents which are due either to the corona effect or to a dark discharge resulting from the emission from the cathode 7602 electron emission from metals as an after effect of irradiation the emission of electrons from metals was measured after irradiation with x rays ultraviolet rays and visible rays and after glow discharge had taken effect the dependence of the secondary emission on the wavelength of the incident radiation and on the structure of the metal surface was investigated the time and temperature relation is independent of the manner of excitation which may even be produced by mechanical means the magnitude of the secondary emission depends on the state of oxidation of the surface it is further discussed how far the secondary emission depends on the nature of the metal or the nature of the surrounding gas the work function of electrons after irradiation is also considered 7603 surface films and field emission of electrons the mechanism of cold emission of electrons from surfaces covered with a tarnish film under electric fields of the order of was investigated the results obtained are consistent with the view that the electrons are extracted from the metal substrate by the high electric field set up across the thin surface film when covered with a layer of positive ions 7604 transmission of radio waves through highly ionized gases preliminary theoretical discussion of the effect of highly ionized media on the transmission of em waves with special reference to the possible use of centimetre waves in the study of the intense thermal ionization produced in a gas subject to high pressure shock waves 7605 intensity and polarization of electromagnetic waves diffracted at a slit part diffraction of electromagnetic waves at a slit is investigated under the supposition that the electric field vector is perpendicular to the slit edges magnetic case this supplements the investigation of the same problem for the case where the electric field vector is parallel to the slit edges electric case of and the combination of both cases makes it possible to calculate the intensity and polarization of the wave field for incident polarized and unpolarized radiation in the case of very narrow slits to which the fresnel kirchhoff theory is no longer applicable the electric component normal to the slit edges is determinative for the diffracted field 7606 sorption properties of thin nickel films the sorption of o and h by ni films is studied oxygen the diffraction of electromagnetic waves at a conducting circular disk and at a circular aperture in a conducting plane screen numerical results of calculations based on the rigorous theory of diffraction of meixner and andrejewski of are given these describe the characteristics of diffracted waves in the near and far fields and are valid when the circumference of the disk and the wavelength are of comparable magnitude the methods of approximation commonly used are critically examined 7607 est orption which is much greater than that of hydrogen takes place in two stages instantaneous covering of the film by a monatomic layer gradual penetration of the oxygen atoms into the film the quantity of sorbed oxygen is independent of the gas pressure but depends on temperature oxygen covered ni films have catalytic reactions with hydrogen on the other hand hydrogen films have no effect on the sorption of oxygen 7608 distribution of radio brightness on the solar disk at mcs observations during the first six months of made with interferometer equipment confirm the results obtained at the annular eclipse of bosson et al concerning the increased brightness at the edge of the disk further observations will be required to determine whether the radio brightness increases at first uniformly from the centre and then more rapidly to a maximum near the edge or whether there is a secondary maximum at the centre 7609 asymmetry in the decimetre wave radiation from the sun data obtained in australia at the eclipse of november and in khartoum at the eclipse of february are adduced in support of the conclusion that radiation from the quiet sun at wavelengths around cm is best accounted for by a model sun at wavelengths around is best accounted for by model sun having an equatorial axis polar axis ratio of see also of and back reference 7610 radio noise receivers 7611 provisional sunspot numbers for january to march 7612 solar flare effects and magnetic storms in the years there appeared to be no increase in storm probability after the occurrence of a solar flare effect except perhaps in the probability of severe magnetic storms 7613 thermal emission from the solar corona in the wavelength range cm calculations are made of the suns radiation for various models of the corona a method is developed for determining the temperature of the corona from the measured intensity distribution over the solar disk radiation from the corona may introduce appreciable irregularities in the intensity distribution failure to take account of deviations from radial symmetry may lead to incorrect interpretation of results staniers conclusions of may be effected in this way 7614 an investigation of the h regions by a radio method the distribution of brightness near the galactic plane was determined from measurements made with a radio inteferometer at and the results obtained are discussed 7615 the harmonic analysis of the earths magnetic field for epoch there is no evidence of a dipole field of external origin greater than of the field of internal origin the intensity of the latter is at present decreasing by about per century the geomagnetic poles have a westerly drift of per century the mean position of the nr north magnetic pole at present is 7616 cheltenham three hour range indices k for january to march 7617 on variations of the geomagnetic field fluid motions and the rate of the earths rotation see of may 7618 the magnetic secular variation in new zealand an account is given of the work on secular variation from to the observations are tabulated and the results are presented in the form of isoporic charts for each magnetic element 7619 relationship between radio propagation disturbance geomagnetic activity and solar noise data on ionospheric disturbance of radio communication between new york and amsterdam during the years are compared with geomagnetic character figures a general correlation s is established the maximum radio disturbance showing a mean time lag of behind the maximum geomagnetic disturbance investigation of the relation between solar rf radiation and geomagnetic storms showed that a marked increase of the radiation on at least one of the frequencies and occurred at some time during the five days preceding a storm except in the case of recurrent storms 7620 principal magnetic storms 7621 international data on magnetic disturbances fourth quarter 7622 physical properties of the atmosphere between and the calculated values of temperature pressure molecular weight density and particle concentration are in fair agreement with available experimental results 7623 the constants in the equation for atmospheric refractive index at radio frequencies see of 7624 ionospheric disturbance forecasting causes and effects of solar flare disturbances prolonged periods of low layer absorption and ionospheric storms are reviewed in an examination of the bases for predicting ionospheric storms sunspot classification is explained and the correlation of ionospheric storms with solar flare effects geomagnetic data and precursor disturbances in high latitudes is discussed in general the accuracy of predictions days in advance is disturbances ratings used in the storm warning service are given and methods of prediction adopted during sunspot maximum and sunspot minimum periods are outlined 7625 a note on the sluggishness of the ionosphere by analogy with the lr circuit a time of relaxation analogous to a time constant is obtained from the equation for the variation of ionization where n is the electron density and the recombination coefficient two methods of determining n are described and its value is calculated for the d e f and f winter layers although the value of n varies by a factor of over n is constant within a factor of about this result may be interpreted as indicating either that must fall steadily from the d to the f layer or that the physical process of electron disappearance is not merely one of attachment 7626 method of determining the true height of the ionospheric layers taking account of the effect of the geomagnetic field part application of an approximate expression for the refractive index ordinary ray case expressions are derived for the characteristic parameters of an ionospheric region assuming a parabolic law for the ionization the values of the virtual heights of the f layer for frequencies in the range are calculated and compared with the observed heights and those calculated by appletons method the correction term in the expression for the thickness of the layer shows that the effect of the geomagnetic field is such as to reduce the value of the thickness numerical results are in good agreement with the corrections indicated by shinn and whale of 7627 dynamic probe measurements in the ionosphere measurements made during a rocket flight showed a rapid rise of probe current between and height which indicated a ps positive ion electron density ratio of approximately 7628 nature and origin of sporadic e regions as observed at different hours over calcutta typical results of the experimental determination of the variation of the reflection and transmission coefficients of the e region are shown graphically and a statistical study is made of the variation of echo amplitude the amplitude distribution of e echoes from a thin layer is of the gauss type that from an ion cloud of the rayleigh type whilst in general both the steady and the scattered reflection components are present to give a rice type of distribution of the results of observations made in the early morning at sunrise in the z afternoon and during thunderstorms are discussed and several ionizing agents are suggested 7629 ionospheric storms in the auroral zone the values of f observed at college alaska are statistically analysed when the f layer in the auroral zone is sunlit the value of f usually begins to decrease just after the commencement of a geomagnetic storm this is attributed to an expansion of the layer due to heating caused by impinging corpuscles when the f layer is in darkness an increase of f is observed 7630 travelling disturbances in the ionosphere pulse measurements at have been made during the past three years at perth western australia using munros method of results agree in general with those of munro the velocities observed ranged between and km min the direction of travel in summer lies between and and in winter between and e of n with a rapid change over in the equinoctial months 7631 f region triple splitting measurements of the direction of arrival of z echoes have been made at hobart tasmania the results indicate that f region triple splitting is caused by back scattering from a rough layer the directions observed are consistent with the assumption tht reflection at the z level occurs when the angle of incidence is such that the wave normal becomes parallel to the geomagnetic field at the ordinary level of reflection 7632 continental maps of four ionospheric disturbances the changes with time of the geographical distribution of f deviations from normal are shown 7633 sweep frequency measurement of the ionosphere continuous records of f layer heights were obtained with equipment covering the frequency band in sec the records show marked discontinuities at approximately and local time the corresponding graphs of f layer heights for several stations in japan and of the geomagnetic variations at one station are shown 7634 a consideration of the mechanism of electron removal in the f layer of the ionosphere the transformation of atomic ions into molecular ions by a transfer of charge and the subsequent recombination of molecular ions with electrons are considered theoretically such a mechanism may possibly explain the attachment type of electron removal but the theory fails to give the value of the attachment coefficient and of its variation with height 7635 the collision frequency of electrons in the ionosphere theoretical analysis indicates that the electron collision frequency in the ionosphere depends on the concentration of neutral particles in the d and e regions and on the electron concentration in the f region any atmospheric model for the region above the e layer should not therefore be based on the frequency of electron collisions with neutral particles 7636 diurnal and storm time variations of geomagnetic and ionospheric disturbance analysis of records obtained at abinger and slough during a period of months shows the diurnal variations to be very complex with significant differences dependent on season and on activity level the hr component is important in both geomagnetic and ionospheric phenomena but a component is found only in ionospheric f disturbance the storm time variations of f and of horizontal magnetic force h are statistically closely linked 7637 the morphology of the ionospheric variations associated with magnetic disturbance part variations at moderately low latitudes graphs of the ionospheric variations with local time and with storm time at watheroo canberra and washington re given the local time variations are mainly diurnal the storm time variations are appreciable for about three days after the commencement of the magnetic storm and the initial shape of the curve depends on the local time of the commencement a theory of these variations is developed all ionospheric variations due to magnetic disturbance are attributed to the es field produced by the auroral regions 7638 an ionospheric disturbance index a three hourly index with a range based on the variation of the critical frequency and the height of the f layers has been developed a positive correlation of was found between the lincoln indices and the amberley geomagnetic k indices for the period between october and september the seasonal variation between the i and k indices was investigated and a comparison with radio disturbance conditions made 7639 on the variation of the f layer accompanying geomagnetic storms the universal time dependent and local time dependent parts of the variations of and during geomagnetic storms have been calculated from data for several widely separated stations the local time variations appear to be due to the s current associated with the storm no indication of a moving disturbance from the auroral zone was found 7640 storm phenomena in the ionosphere recent advances in our knowledge of f layer ionospheric perturbations accompanying a magnetic storm are summarized the diurnal control is shown and differences between phenomena at high medium and low latitudes are noted for medium latitudes the effect of a storm is to exaggerate the geomagnetic distortion of the f layer already present 7641 investigation of ionospheric absorption comment on of june and authors reply 7642 radar echoes associated with lightning echoes from thunderstorms overhead and from distant storms were observed using radar pulses operating on a wavelength of cm the echoes from a storm overhead frequently occur in pairs corresponding to reflections from cloud layers at different heights 7643 orientations of auroral displays in west central canada a seasonal variation of orientation was found by statistical analysis of observations made at saskatoon in 7644 radio reflections from aurora echoes at and werre observed when the auroral form exhibited some ray structure and then only from parts of the aurora at elevations above the horizon no echoes were recorded at mcs the echoes occur most frequently within the auroral zone the echoes some distance south of it it is suggested that echoes arise by critical reflection from centres of high electron density for echoes and cm for the echoes 7645 scale height determinations and auroras the method hitherto used for determining scale heights from auroral luminosity curves is shown to be invalid the possibility of protons being responsible for the production of aurorae is considered 7646 the southern auroral zone as defined by the position of homogeneous arcs 7647 a study of a second order sampling servo 7648 operating modes of a servomechanism with nonlinear friction 7649 considerations on discriminators in airborne servo systems discussion of performance requirements for automatic pilot mechanisms 7650 reduction of forced error in closed loop systems 7651 the standardization of symbols and the arrangement of electronic circuit diagrams arrangement of circuit diagrams to give a clear indication of the operation is advocated 7652 relization of alternating current resistance methods of realizing resistance functions by arrangements of the partial fractions or the continued fractions type are described possible arrangements are shown in two tables 7653 geometrical transformation of impedance diagrams in of september please change the last word in the abstract to described 7654 the effect of inductance on fine transfer between platinum contacts an investigation was made with pt contacts in a circuit breaking currents of the order of the circuit inductance was varied from to measurements of the volume transferred and examination of the surface structure indicate that there are two types of transfer true bridge transfer independent of inductance and short arc transfer dependent on the inductance 7655 the behaviour of metallic contacts at low voltages in adverse environments the problem discussed is that of obtaining a metal to metzl contact mechanically when the contacts are contaminated by dust or grease or are coated with films produced by absorption tarnishing or corrosion various types of contact are considered principles are outlined which provide a basis for design and testing a new technique is described for the continuous dry lubrication of sliding contacts in mechanical and electrical systems 7656 long life contacts for unidirectional currents of amperes an experimental investigation was made of fundamental physical phenomena concerned in the operation of contacts in vibratory converters the influence of voltage and current on the direction of migration of material was studied long life was obtainable with pt contacts or with contacts of dissimilar metals but on heavy duty an adequate life was obtained only with w contacts in a low oxygen atmosphere 7657 noise of metal contacts measurements were made of the small voltage fluctuation produced by the passage of direct current through ball contacts current values from to about were used and the influence of contact resistance pressure and temperature was investigated for steel copper and gold contacts a possible mechanism accounting for the results is suggested 7658 design of unequal q double tuned transformers equations and design curves are given which should simplify calculations of certain of the transformer characteristics 7659 a turns index for pulse transformer design 7660 transient conditions in a transformer supplying energy to a half wave rectifier circuit analysis is given for a simplified equivalent circuit leakage reactance and core loss being neglected experimental results confirm the theory 7661 the magnetic cross valve further details are given of the device previously described of and of its practical applications with circuit diagrams and illustrations of the power ringers converting power to and respectively 7662 on the mechanics of magnetic amplifier operation 7663 magnetic amplifiers of the balance detector type their basic principles characteristics and applications 7664 predetermination of control characteristics of half wave self saturated magnetic amplifiers 7665 bibliography of magnetic amplifier devices and the saturable reactor art a very comprehensive bibliography of published books articles and patents for the period to mid 7666 on the control of magnetic amplifiers 7667 steady state and transient analysis of an idealized series connected magnetic amplifier 7668 series connected magnetic amplifier with inductive loading 7669 the effective feedback ratio o of magnetic amplifiers 7670 magnetic amplifiers of the self balancing potentiometer type 7671 high speed magnetic amplifier 7672 transient analysis of junction transistor amplifiers in analysing transistor operation transit time effects must be taken into account this can be done to a sufficiently close degree of approximation by including in the equivalent circuit an rc network in series with an idealized delay line only simple laplace transforms are then involved in the response calculations the theory is supported by experimental results 7673 pulse response of junction transistors the case of low load resistance is considered theoretically and experimental results are shown graphically the response characteristics are discussed good qualitative and fair quantitative agreement was found between predicted characteristics and those determined from pulse and ac measurements 7674 the phase bistable transistor circuit properties of transistor switching circuits are discussed a unit is described which comprises a commutating ring of two transistors each connected as a one shot multi vibrator the two being alternately triggered by a series of clock pulses the arrangement is used in a binary counter with a clock pulse frequency of 7675 a transistors in trigger circuits a simple circuit using a single transistor is described 7676 low distortion transistor audio oscillator design details of an oscillator operating at any one of the four frequencies and and including pnp junction transistors series resistors are used to stabilize emitter currents and a tungsten filament lamp to control amplitude maximum available output is v the low noise characteristics are ascribed to the very narrow operating bandwidth 7677 the common collector transistor amplifier at carrier frequencies formulae are derived for th af operating parameters of the grounded collector common collector circuit the variation of the transistor current amplification factor with frequency is investigated the effect of operating conditions on the cut off frequency ie the frequency ie the frequency at which drops to of its af value is discussed modified formulae are hence derived which are valid up to about experimental results support the theory presented point contact npn junction and early pnp alloy transistors were studied 7678 complementary symmetry transistor circuits under normal bias conditions the current which flows in each lead to an electrode of a pnp transistor is the negative of the corresponding current in an npn transistor this is termed static symmetry the polarity of an input signal that will increase conduction in a pnp transistor is the opposite of that for an npn transistor this is termed dynamic symmetry circuits are described that use static symmetry dynamic symmetry both types of symmetry these include a stabilized direct coupled class a amplifier with a voltage gain of a pulse circuit which converts a half sine wave to pulses a class b power output circuit using four transistors with overall feedback and giving a gain of about db when working into a load and a television vertical deflection system with a class b output stage connected directly to the deflection yoke 7679 transistor theory and transistor circuits simple theory o for transistors is developed from that for thermionic valves on the basis of the duality principle and by comparison with the aperiodic retarding field valve semidynamic rather than static characteristics are obtained by biasing the collector by means of a resistor these characteristics can be converted to the usual static ones by a coordinate transformation parameters are measured by means of a transistor bridge equivalent to that used for obtaining the dyn mic characteristics of a thermionic valve the parameters found are related to the constant current values of the parameters hitherto used simple formulae are derived for the voltage and power amplification of grounded base and grounded emitter circuits use of the negative static resistance o a grounded emitter transistor for measuring the resonance resistance of oscillatory circuits is discussed 7680 push pull transistor amplifiers a description is given of a practical af power amplifier us ng point contact transistors and developed from the class b thermionic valve amplifier by appli ation of the duality principle this amplifier an deliver at harmonic distortion 7681 equivalent circuit diagrams of the transistor different representations for transistors are derived from the equivalent circuit of the nonreversible quadripole of a two valve circuit a one valve circuit with a lossless transformer 7682 transistors theory and application part equivalent transistor circuits and equations relations between transistor parameters circuit elements and performance are derived by application of kirchhoffs mesh equations for the transistor equ valent circuit part of november 7683 theory of afc synchronization correction to paper noted in of november 7684 febrication of radio frequency micropotentiometer resistance elements stable low resistance disk type resistors are required for the bureau of standards rf micropotentiometer previously described of various processes for forming thin ilm resistors are considered three methods are described by which it is possible to produce resistors are considered three methods are descri ed by which it is possible to produce resistors stable to within viz high temperature firing ev porating and plating use of disks cut from sheets of carbon film deposited on bakelite a chemi al reduction process is under investigation 7685 copper eddy current losses in coils with car onyl iron and ferrite cores the design of low loss short multilayer coils and long single layer coils is considered because core losses are much reduced with modern ferrite cores the relative importance of the copper eddy current losses s greater these losses and their dependence on the coil and core parameters are discussed in detail 7686 saturable reactors with inductive dc load part steady state operation 7687 distribution of conductivity within dielectric films on aluminium frequency and formation voltage characteristics were determined for a ac capacitor with an anodized al anode al cathodes nd electrolyte consisting of boric acid and bor tes in the range an equivalent circuit is given and a model is suggested consisting of a layer dielectric film one layer adjacent to the metal surface having low conductivity low power loss independent of frequency but dependent on the pe k formation voltage the other film with opposite properties 7688 triode transformation groups the properties of the six networks including respectively the six possible transmission paths through a triode valve of are shown to be interrelated in such a way that given the characteristics of any one o the circuits those of the remainder are obtain ble by a routine transformation process 7689 potential analog network synthesis for arbitrary loss functions a method of network design s described in which the appropriate potential problem is formulated on the basis of a given loss function by introducing continuous charge distribution on the complex frequency plane the technique of charge quantization is used to find the natural modes of the network function 7690 feedback theory some properties of signal flow graphs the equations characterizing transmission systems may be represented by networks of directed branches termed signal flow graphs the branches terminate at nodes which represent repeater stations the topology of these diagrams is studied with particular reference to feedback circuits the technique is illustrated by application to specific circuit design problems 7691 two theorems on two terminal electrical networks given that the impedance of the network is a rational function zs of the complex frequency and putting it is shown that for networks consisting of reactances only and resistances together with reactances of one kind 7692 modified exponential line as improved transforming element with high pass characteristic for a given length of exponential line there is a critical frequency above which the transformation property becomes effective at frequencies only a little above critical the transformation is only approximate this drawback can be avoided by designing the line so that the characteristic impedance does not vary exactly exponentially approximate line equations are derived for this case and practical forms of such lines are discussed the influence of constructional defects is examined 7693 a general definition of pass band 7694 rlc lattice networks a method for synthesizing open circuited lattice networks to have a required transfer impedance is based on the partial fraction expansion of the given function no mutual inductances are used and series resistance is associated with all the self inductances so that low q coils may be used a numerical example is worked out 7695 synthesis of paralleled terminal rc networks to provide complex zeros in the transfer function an improvement n the method given by guillemin of is described which required fewer paralleled networks the desired transfer ratio is converted into the sum of several transfer ratios each of which can be realized with a single ladder network a method of synthesis for these networks in terms of a common driving point admittance function is described and theory developed for their connection in parallel 7696 the dual input parallel t network the frequency of maximum attenuation in this type of circuit is a function of the ratio of the two input voltages various potentiometer drive arrangements can be used for external tuning over a wide frequency range experimental results for a circuit with dual potentiometer input are in good agreement with theory 7697 synthesis of the transfer function of terminal pair networks 7698 the possibility of defining the width of the pass band in terms of the distortion of a transient analysis using the definition previously given indicates that it is impossible to define the distortion of a transient by a single build up time 7699 an approximate graphical analysis of the steady state response of nonlinear networks an approximate graphical analysis is given for the case when one of the circuit parameters is varied gradually transients and the generation of subharmonics are not dealt with the networks investigated consist of a nonlinear iron cored inductor with a linear resistor and linear capacitor the results of the analysis can be applied to the investigation of the effects of resistive or reactive loads of magnetic amplifiers and the utilization of jump phenomena ferroresonance effects in switching devices 7700 a theorem on the impedance transforming properties of reactive networks two circle transformations derived from the impedance transformation properties of a terminal network are used to develop a circle locus theorem which considerably simplifies analysis of impedance matching networks it is applicable to any linear reactive network with any arbitrary reference impedance not lying on the reactance axis 7701 an approximate method of obtaining the transient response from the frequency response the method is based on expressing the transient response in terms of the real part of the frequency response function which is plotted on a logarithmic frequency scale and approximated by a series of straight line segments a is calculated from the slopes of these segments 7702 concerning the minimum number of resonators and the minimum unloaded q needed in a filter the number of resonator elements required to meet given specifications of filter characteristics and the lowest no load values of q which the resonators may have can be deduced from the formulae and graphs given the specifications include the accept and reject bandwidths the peak valley ripple ratio and response in the reflect band of the selective circuit both constant k and m derived types of filter are considered and numerical examples are worked out 7703 wave filter characteristics by a direct method full paper 7704 audio frequency filters using negative feedback the operation is described of a two valve amplifier with a series resonance circuit across the cathode impedance of each of the two valves and a parallel resonance circuit in the anode circuit of the first valve a band pass filter with a flat topped response curve is obtained by adjusting the resonance frequency of the cathode circuit of the second valve to be intermediate to the cathode circuit and anode circuit resonance frequencies of the first valve 7705 nonlinear multipoles a conceptual scheme is outlined which is intended to be used in conjunction with theories of oriented graphs and with machine computers for the analysis and design of nonlinear networks a system of classes of nonlinear multipoles is defined the classes being characterized by their responses to a particular set of pulses see also of september 7706 the national radio components exhibition review of a selection of exhibits in the sections allotted to valves miscellaneous components and accessories and measurement instruments at the exhibition held in paris february march 7707 printed circuits and the automatic factory discussion of the application of the auto sembly technique of february danko to u quantity production of a wide variety of electronic equipment with substantial reduction of costs and economy in skilled personnel 7708 frequency feedback discussion of a phenomenon which occurs in all resonant systems possessing a relation between resonance frequency and amplitude in such systems there may be an external feedback channel or internal feedback due to nonlinear reactors or to nonlinear resistors combined with fixed reactors as in the so called rx modulators the phenomenon shows itself in asymmetrical deformation of the resonance curve applications of the effect in a m fm conversion and in fm conversion for frequency shift reception are noted 7709 a method of evaluation of the quasi stationary distortion of fm signals in tuned interstages a graphical approach to the problem of designing low distortion f circuits making use of the normalized derivative of the phase frequency function is shown to be preferable to that using the phase frequency curve itself the principles are applied to the determination of the distortion factor of a single tuned circuit interstage and of a cascade arrangement of three stagger tuned resonant circuits 7710 transient phenomena in an oscillator circuit with variable inductance the operation of the circuit is discussed and a formula is derived for determining the variation of the current in the circuit a numerical example is given 7711 high frequency crystal units for use in selective networks and their proposed application in filters suitable for mobile radio channel selection the design of bevelled at type quartz plates for use in band pass crystal units is described the reduction of unwanted modes of vibration including thickness shear overtone modes is considered approximate electrical data for plated circular at type quartz plates with all unwanted modes reduced to a level db below the response of the main thickness shear mode are tabulated the design is considered of a crystal filter with a mid band frequency of and bandwidths of and respectively at the and points 7712 thickness vibrations of piezoelectric crystal plates addendum to work noted in of february 7713 a simple method of coupling toroidal coils theory is given of a method of coupling suitable for the low values of coupling coefficient usually required for if transformers fm discriminators and in some types of filter the coupling coils with very few turns are wound on a separate toroidal core each being connected in series with one of the toroidal coils to be coupled in a simplified version a coupling coil of one or two turns connected in series with one toroidal coil is wound on top of the other toroidal coil such a transformer may be accommodated in a cube with the toroids close together with no shield between them 7714 electromagnetic waves in hollow metal cylinders with circular cross section the object of the paper is to coordinate the treatment of the subject and to clarify some points the electric and magnetic lines of force are mapped in perspective other diagrams show the distribution of poynting vector over the cross section and the currents in the walls wave propagation in concentric lines is investigated 7715 nonlinear electromechanical systems by an extension of lienards graphical method abstracts only two or three coplanar curves need be traced for a complete topological study of the stability conditions for systems represented by equations of the types results of a detailed analysis are applied to the case of a filtered oscillator of may and of june a much shorter version of the first part of this paper was given in paris 7716 a study on the triggering of a plate coupled multivibrator by negative pulses experimental observations showed that voltage waveforms at different electrodes were markedly influenced by the form of the input pulses that triggering action depended largely on the input pulse amplitude that triggering might not take place for either very small or very large pulse amplitudes depending on circuit arrangement but larger amplitudes caused greater difficulties analysis of the circuit response to pulses of various durations and amplitudes gave results supporting the observations 7717 design of triode flip flops for long term stability description of an analytical method of design based on considerations of dc stability limiting tolerances in respect of voltage and component values being taken into account initially an eccles jordan circuit with injection diodes is considered as a general case and equations are derived expressing the operating conditions in the grid and the anode circuits solution of these equations gives appropriate key values the method is applied to three special cases and a numerical example is given 7718 wide band data transmitter a fm oscillator uses a double phantastron circuit of close and lebenbaum for a linear data recording system signals in the range can be handled with an accuracy to within full circuit details are given 7719 stable frequency dividers using thyrite elements locked oscillator frequency dividers using nonlinear thyrite elements as load impedors are described with slight circuit modifications a stable locking action is obtainable for division by any number between and no circuit adjustments are required as the valves age dividers have been constructed for frequencies up to 7720 vibrating wire high q resonator resonator units are described in which a wire of high tensile strength is stretched between long pole pieces maintaining a strong transverse magnetic field resonance occurs when the frequency of current sent through the wire coincides with the natural frequency of the system theory is given and the equivalent electrical circuit analysed with a tungsten wire mounted in vacuo a q value of has been obtained at kcs applications of such devices in filters and for frequency control are noted 7721 spurious frequency modulation in signal generators the chief cause of fm in an am circuit is the variation of valve input capacitance with modulation methods of reducing this effect are examined two circuits effective in reducing fm at vhf are described an untuned class a amplifier with grid modulation a voltage dividing network containing a crystal diode suitably biased to act as resistance 7722 valve matching using resistors desired characteristics can be obtained by including resistors in series and or parallel with a valve formulae for the effective parameters are tabulated for several simple combinations matching of ac characteristics may in practice be accompanied by reasonable matching of the overall dc characteristics a circuit is shown using the latter effect for determining resistances required for matching two valves 7723 a general circle diagram for the input admittance of a grounded grid disk seal triode the method given takes account of the transconductance and anode cathode capacitance of the triode the effect of the transconductance phase which depends on the electron transit time is shown in the diagram a numerical example is given see also of november 7724 cathode follower design charts output impedance input voltage charts are shown for commonly used valve types design procedure is outlined 7725 on the faithful reproduction of the flat top of a pulse in a high fidelity pulse amplifier the pulse amplifier analysed comprises a pentode with rc coupling circuits two methods of determining anode current and hence amplifier response are applied the one based on the overall amplification reduction due to voltages across the parallel rc screen circuit and the rc cathode circuit the other based on the superposition principle correction of pulse top distortion is achieved by the anode supply rc decoupling circuit the conditions for satisfactory correction are derived 7726 a modern broadcasting pre amplifier description of a simple stage feedback amplifier using type low noise pentodes and suitable for use with sound reproduction equipment distortion is low gain practically uniform from to and pick up of stray fields effectively negligible 7727 harmonic distortion and negative feedback authors reply to comment by kerr of november 7728 use of ferromagnetic materials in electronic tuning of radiofrequency components the change of the incremental permeability of a core of ferrite material due to a secondary superimposed magnetic field is discussed the effect is utilized in the design of toroidal inductors whose inductance can be varied by altering the current in an auxiliary winding inductors of this type are incorporated in a receiver tunable from to with a bandwidth of at and of at the power required in the auxiliary tuning coil is a variable inductor has been developed whose volume is wi weight slightly and tuning range for applied power of in the frequency band falling to in the band see also electronics 7729 the relation of the quantum theory to the theories of gravitation and electromagnetism and an application to the theory of the electron 7730 on an iterative method for nonlinear vibrations analysis of a method giving results analogous to those obtained by duffings method 7731 high frequency electrical measurements conference in washington dc 7732 a new property of dimensional fields mapping of the field inside a nearly enclosed area is facilitated by working on the correlative field whose derivation is explained an analytical proof of the correlative property based on the schwartz christoffel transformation is given in an appendix the proof is due to wr smythe for a digest see 7733 the derivation of vector potential from tables for scalar potential 7734 field strength and temperature studies of electro luminescent powders in dielectric media measurements were made on electroluminescent cells using zns se cu phosphor dispersed in a thermo plastic matrix the intensity of luminescence depends critically on the field in the phosphor and hence on its dielectric constant but does not depend on the dielectric properties of the matrix except in so far as the latter provides a means of supporting a strong field in the phosphor little change of luminescent intensity was observed when the temperature was varied from to polystyrene being used as matrix 7735 dielectric changes of electroluminescent phosphor during illumination measurements were made of the dielectric properties of electro luminescent films composed as described previously above for different values of applied voltage at and for various wavelengths and intensities of illumination the dielectric constant depends markedly on the illumination the magnitude of the variations depending critically on the applied voltage the effect exhibits a maximum at about 7736 development of the electrical resistance of thin films of platinum subjected to a relatively high direct voltage measurements made on films of different thicknesses before and after the application of voltages of or indicate that the resistance is increased decreased or unchanged depending on the amount of heat developed which in turn depends on the initial resistance and hence on the thickness 7737 on pre exponential factors in formulae for ionic conductivity in solids it if in formulae for equilibrium constants and rate constants ener y is assumed to be proportional to temperature the factor preceding the exponential term is not increased by a factor exp being a constant and boltmanns constant but by a factor involving entropy 7738 initiation of discharges at electrical conta ts the experimental investigation described deals with discharges between low power contacts w th special attention to the cases of make and break at medium voltage the discharges were found to be initiated by a cold field emission of electrons govenred by the nature of the surface tarnish layers the influence of the gas atmosphere was examined a theory of the mechanism is outlined 7739 on the nonoptical theory of focusing in rotating magnetic fields the difficulties arising in the application of optical methods to electron optics are pointed out the general theory of t e focusing action of static magnetic fields developed by grinberg which is based on nonoptical methods is applied to the case of paraxial electron beams in rotating magnetic fields 7740 measurement of secondary electron emission the sources of error in secondary electron emiss on determinations are discussed in detail retarding voltage curves obtained experimentally are analysed and a method of calculating the proportion electron current is given for the cz case w en the target and spherical collector are made of the same material for a cr ni alloy and a pr mary potential of this proportion is 7741 experiments on radiation by fast electron be ms the design of a magnet system for an undulator in which the field direction alternates periodically along th electron path of is described a electron beam from a linear accelerator was p ssed through the system light radiated by the beam was determined using a small linear accelerator with good bunching action and beam energy r diation at wavelengths below was observed peak power output was millimetre waves were also generated in the accelerator tube 7742 graphs for a rapid calculation of the work function of thermionic emission a set of graphs is given for the saturation current density as a function of absolute temperature with the work unction as parameter the use of the graphs is explained 7743 dimensional analysis units and rationalization careless manipulation of dimensional formulae can lead to fallacious results the trouble is due to the use of the multiplication sign for two different kinds of products having very different physical meanings once these are clearly distinguished and the phsy physical meaning considered at every stage in the proceedings the diff culties encountered even with rationalized units are overcome 7744 antiferromagnetism a survey paper the distinction between antiferromagnetism and ferrimagnetism is indicated the former is found mainly in simple inorganic compounds the latter in complex compounds problems discussed concern the interaction between adjacent dipoles the different possible arrangements within the various lattices the magnetic properties and the phenomena of the transition from order to disorder 7745 a theory of ferromagnetism a theory is formulated that when applied to iron making use only of spectroscopic data for the fe atom gives a value of bohr magnetons for the saturation magnetic moment per iron atom and a value of for the curie temperature these values are in reasonable agreement with the experimental values of magnetons and 7746 the calculation of the magnetizing force full details of the method described in f of 7747 the electromagnetic properties of a plane grating a plane grating is considered which consists of a number of parallel conducting planes between which electron streams pass and its waveguide properties are discussed taking into account the velocity scatter of the electrons a general solution of the problem is given for an arbitrary type o of scatter function the velocity scatter narrows the range of average velocities of the streams for which amplification is possible and displaces it towards the higher velocity values the maximum amplification is also reduced 7748 propagation of electromagnetic waves in a transp rent periodically stratified space equations derived for the general case are applied to the special case of a pile of double layers of equal optical thickness 7749 transmission of electromagnetic waves through pairs of parallel wire grids an analytical solution is obtained for the power transmission coefficient of a double grid system transmission coefficients are plotted as functions of the integrid spacing for different wire spacing and angles of tilt the curves are compared with those obtained by measurement at cm using wire of radius cm agreement is good until the wire spacing approaches reasons for this divergence are noted 7750 plasma oscillations in crossed electric and magnetic fields an idealized case is considered and the specific structure which retards the em waves is replaced by a medium with an effective dielectric constant greater thn than unity it is also assumed that the constant charge and current of the electron beam are compensated by the charge and current of ions which do not participate in the hf oscillations with these assumptions conditions are determined under which the electron beam becomes unstable the fluctuations of the velocity and density of the beam increasing indefinitely 7751 extension of fermats principle to group propagation time continuation of work noted in of it is shown by analysis that the difference between the group propagation times for two real paths joining the same two points is zero 7752 amplification of microwave radiation by substances not in thermal equilibrium methods are discussed for the production of a nonequilibrium energy distribution and the amount of amplification which may possibly be obtained by this method is calculated 7753 new techniques in radio astronomy 7754 extrapolation of sunspot climate relationships consideration of the periodicity of sunspot number variations is based on taking the maximum year as the middle one of three successive maximal years the next maximum should occur in and should be a strong one 7755 nonradiative natural oscillations of a conducting sphere so surrounded by a layer of air and an ionospheric sheath a theoretical investigation having special reference to em oscillations of the earth and relevant to the study of atmospherics the dependence of the oscillation frequencies on the air layer thickness and on the plasma properties are analysed the lowest natural frequency to be expected for earth oscillations is about oscillations of low frequencies are reflected at the inner surface of the plasma while higher order oscillations may penetrate right through the plasma and radiate into space 7756 damping of the natural electromagnetic oscillations of the system earth air ionosphere continuation of work noted in above an approximate formula is derived for the damping of the lowest frequency oscillations from which the effective height of the air layer and the effective conductivity of the ionosphere can be determined 7757 electron density in the upper atmosphere and interpretation of the hf curves of ionosphere virtual height for the case of vertical incidence and the geomagnetic latitude of rome an expression is developed for the group refractive index using appletons formula absorption is neglected the optical path of em waves totally or partially reflected or transmitted through an ionosphere layer is determined as a function of frequency for various cases the results are applied in conjunction with experimental hf curves to derive linear relations giving directly the thickness of the layer and its height above the ground cases of single and superposed layers are treated 7758 instrumentation for measuring changes in phase of ionospheric echoes changes in carrier phase of ionosphere pulse echoes are determined from a comparison of the transmitted signal stored by a memory circuit with the echo signal received the phase variation is presented in the instrument described on a cro and a continuous photographic record is obtained the equipment used is similar in principle to that of findlay of results of e region observations at have been published by davids 7759 cozi communication zone indicator a general description with block diagram of timing and indicating circuits is given of a low power oblique incidence ionosphere sounder designed to indicate skip distances and communication zones from to operation is on any one of six pre set frequencies in the range peak pulse power pulse duration and repetition frequency sec the one hop skip distance is obtained directly from the time lag of the back scatter from the ground after single reflection from the ionosphere typical oscillograms show the increase of skip distance as the carrier frequency is increased in steps from the complete series of records two at each frequency being obtained in min 7760 synthesis of feedback control systems by means of pole and zero location of the closed loop function a mathematical description of the desired frequency response based on the location of the poles and zeros of the closed loop function is given which ensures that the specifications of velocity or acceleration error constant bandwidth and relative stability will be met and which provides for acceptable system transient response algebraic manipulation yields the transfer function of the main loop and subsidiary feedback loop corrective networks required to meet the specifications 7761 servomechanism transient performance from decibel log frequency plots discussion 7762 sampled data control systems studied through comparison of sampling with amplitude modulation 7763 stability of varying element servomechanisms with polynomial coefficients 7764 an improved magnetic servo amplifier 7765 current and voltage regulators a review of the principles of various types of regulator utilizing a reference standard systems for low and high power and for direct and alternating current or voltage are considered 7766 an electromechanical ac line voltage stabilizer description of a stabilizing unit having a short recovery time comparing favourably with that of commercial electronic devices a temperature limited diode in a bridge circuit is used to detect the line voltage variations and is followed by a phase inverter and a thyratron driving circuit 7767 recent developments in the field of electric cells improvements in leclanche type cells are reviewed and the construction and properties of ag mg cells with ag cl depolarizer c zn cells with hgo depolarizer are described 7768 the silver zinc accumulator construction details are described and performance figures given types are available with capacities from to the corresponding weights ranging from oz to oz the temperature limits of operation are discussed 7769 geographic and temporal distribution of polar blackouts tabulations of hourly values of the ionospheric parameters for northern hemisphere stations have been used to derive diurnal variations in the occurrence of blackout no echo conditions contour plots are presented showing the diurnal average percentage of time during which blackout conditions prevailed the amplitude of the diurnal variation and the time of maximum frequency of occurrence changes in the contours with season and with magnetic activity are discussed 7770 ionosphere review evidence indicates that the sunspot minimum had occurred before the end of the latest sunspot cycle exhibited the asymmetry characteristic of cycles with high maximum the increasing phase lasted months and the decreasing phase about months smoothed sunspot number and critical frequency curves show close correlation the increase of muf at sunspot maximum is greatest for winter day and least for winter night frequencies over appear to have been usable for long distance communication during four winters around the sunspot maximum 7771 upward stepped leaders from the empire state building a new interpretation is presented of the observations reported by mceachron of 7772 observations on the negatively charged column in thunderclouds 7773 doppler shifted radio echoes from aurora note on the results of an experiment in which alternate pulsed and cw signals at were transmitted northward from a transmitter signals recorded at a receiver miles away with aerial beamed north showed a doppler frequency shift upward or downward correlating respectively with homogeneous and rayed structure both shifts may be recorded simultaneously 7774 very low frequency noise power from the lightning discharge present knowledge about the lightning discharge mechanism is reviewed particular attention is paid to the theory of bruce and golde of computed power spectra of a nearby cloud to ground flash and a distant daytime atmospheric are compared taking propagation effects into account of the results confirm the presence of a peak at about in the spectra of the distant atmospherics 7775 an equalizing network for carrier type feedback control systems the analysis of an active high q rlc circuit shows that it permits lag compensation of carrier type feedback control systems through direct operation on the system actuating signal the use of this circuit in an instrument type velocity servo reduces the steady state error by a factor of at least 7776 the minimum moment f of error squared criterion a new performance criterion for servo mechanisms 7777 the behaviour of a remote position control servo mechanism with hard spring non linear characteristics 7778 radioactive and photoelectric pn junction power sources an electrical power source can be made by exposing a pn junction to radioactivity or light so that the junction field separates electron hole pairs produced by the radiation expressions for maximum power optimum load resistance and efficiency are derived from an equivalent circuit and rectification theory power and efficiency increase with source current of separated charges and zeros bias junction resistance increases with energy and intensity of radiation but is limited by self absorption in the radioactive isotopes estimates of z attainable power and efficiency for silicon cells are watt cm and percent for solar radiation averaged allowing for night weather and varying angle of incidence and watt cm and percent for beta radiation from of activity curie g however lattice defects produced by beta radiation impair cell performance by increasing electron hole recombination a theoretical estimate of threshold energy for radiation damage in silicon is about about half the experimental value reported for germanium avoiding radiation damage by annealing by absorbers and by use of less energetic isotopes is discussed the y beta spectrum is given it is used in estimating damage rates in germanium which are high and efficiencies obtainable with absorbers which are low theory and experiment are compared for cells of silicon and of germanium 7779 an rf source of heater power for low level audio frequency amplifiers details are given of a simple and compact oscillator having a rated output of at 7780 a new self excited square wave transistor power oscillator 7781 transmission by sun power achieved successful communication at over a distance of about miles using a se photocell powered transistor transmitter is reported the power unit consisting of photocells illuminated by sunlight is described 7782 stabilized dc supplies using grid controlled rectifiers circuits using magnitude controlled thyratrons are discussed these are suitable for hv power supplies where the load is reasonably constant and the output voltage regulation is not required to be better than within about a unit incorporating two type miniature thyratrons can supply at 7783 wide range operation of grid controlled rectifiers a method of controlling thyratron conduction over a wide range from a dc control signal is described and the steady state characteristics of a dc power amplifier employing this method of control in a bi phase rectifier circuit are discussed and experimental results t given 7784 an alternating voltage stabilizer a unit designed to give an output of varying by for line voltage changes of frequency changes and load variations from to includes provision for correction of form factor by simultaneously stabilizing the rectified mean and rms voltages 7785 a textbook of servomechanisms 7786 an autocorrelogram computer a comparatively simple and inexpensive instrument is described with detailed circuit diagram the signal recorded on a magnetic tape is played back through two separate heads thus producing the functions and these are amplified multiplied and then integrated by a modified dc watt hour meter the computer was originally developed as a yarn cross section analyser 7787 frequency analysis of computer systems 7788 australian guided weapons analogue computer brief description of agwac whose design is based on that of the royal aircraft establishment simulator tridac the equipment is built up of plug in units bricks 7789 differential analyser the npls new analogue computer for solving differential equations brief description of a large analyser recently brought into use the machine i actuated by a motor driven shaft representing the independent variable the three principal types of mechanism used are integrators ger trains and differential gears function tables permit an arbitrary function of any variable to be inserted from the graph and also allow solutions to be obtained in graphical form setting up time is low since all units are coupled by means of servomechanisms which may be connected in any combination through a telephone type switchboard 7790 algebraic method of synthesis of multi contact relay systems a vector algebraic method of synthesis of switching circuits suitable for computers is developed theoretically 7791 note on the resistance network analogue solution of field problems f spherical symmetry results of a previous paper of april are applied to the derivation of design formulae for a resistance chain analogue for solving the equation div k grad u in cases of spherical symmetry 7792 bibliography on ultrasonic delay lines 7793 current fluctuation phenomena in current carrying sliding contacts an account is given of an experimental investigation of sliding contacts as sources of interference voltages the dependence of the noise characteristics on sliding speed and current intensity is examined most of the observed phenomena have a thermal origin several ranges of operation involving different mechanisms are distinguished 7794 odd integer magnetic frequency multipliers for various applications in the frequency f range frequency multiplication can be performed more efficiently by magnetic than by electronic equipment the operation of the magnetic m multiplier is analysed and experimental units are described for higher multiples multistage arrangements are preferred harmonic distortion can be kept low by suitable choice of core materials 7795 component design trends new relay materials improve performance tungsten carbide contacts nickel iron armatures stain less steel springs silicone damping fluids and self shielded cores are among the materials discussed 7796 flip flop counter has expanded range design procedure is indicated for counter having up to six stable states without using feedback or matrixing long term reliability is a primary objective crystal diodes are used in cross coupling networks 7797 junction transistor switching circuits a transistor experimental switching system includes blocking oscillator multivibrator flip flop gating and adding circuits 7798 a method of designing transistor trigger circuits 7799 the behaviour of polystyrene capacitors under alternating voltage experiments at are reported the main conclusions reached are heat treatment has no adverse effect on life for a given value of applied voltage the life is shortened if the voltage gradient is increased for a given ratio between applied voltage and initial ionization voltage the life is considerably shortened if ambient temperature is raised certain considerations regarding the impregnation of capacitors with mineral oil are discussed 7800 discoidal vs tubular feed through capacitors tubular and disk type ceramic feed through capacitors for filtering purposes are compared in respect of their coupling impedance and its frequency dependence the disk type is superior as regards hf performance and mechanical ruggedness the necessary improved shielding methods are described 7801 interesting applications of transistor technique circuit diagrams and photographs are presented of various applications including an af amplifier moulded inside a record player pickup arm 7802 practical circuits using transistors diagrams and descriptions of operation are given for amplifiers oscillators and switching circuits 7803 integrated microwave circuits use of a milled block constucting for producing microwave assemblies is shown to offer advantages over more usual waveguide assemblies 7804 a definition of passive linear networks in terms of time and energy 7805 thermodynamic consideration of electromagnetic cavity resonators a simple method is presented for calculating the shift of resonance frequency produced by introducing a foreign body into the cavity 7806 tunable cavity for x band oscillators a rectangular waveguide tuner for external cavity reflex klystrons is described 7807 equivalent circuit for a passive nonreciprocal network a nonreciprocal quadripole is considered comprising an ideal amplifier and phase shifter compared with the gyrator representation this method facilitates the linking of the network parameters with measurements 7808 behavior and applications of ferrites in the microwave region both reciprocal and nonreciprocal devices comprising ferrite loaded waveguides are studied the nonreciprocal effects in the latter being based on bire fringence phase shift field displacement and coupling through apertures as well as on rotation of polarization a method called point field analysis facilitates qualitative investigation definitions are given of the gyrator the isolator and the circulator performance of some experimental devices is reported 7809 an investigation of the nonlinear distortion of a quadripole using a continuous spectrum signal fo measuring the nonlinear distortion introduced by an af transmission system it is necessary to use a continuous spectrum of frequencies with a given shape of the envelope relations are derived from which it is possible to calculate the spectra at the output of certain nonlinear systems for input signals covering a continuous band of frequencies and having envelopes represented by an exponential function or a difference between two exponential functions as compared with tests using one or two spot frequencies the results so obtained are more in accordance with results of subjective listening tests 7810 the theory and design of gas discharge microwave attenuators the theory of the interaction between a dc gas discharge and an rf field is considered and expressions developed for the complex conductivity of the discharge the simple lorentz theory is shown to give values of complex conductivity not very different from those derived with more detailed analyses problems connected with the gas discharge including that of noise production are considered practical microwave attenuators developed by the authors are described in detail two main classes of device are considered devices with resonant structures and distributed devices 7811 vacuum fluctuation noise and dissipation continuation of previous investigation of the interaction of an electron beam with the field in an enclosed region an expression is derived for the observable mean squared emf and is used to calculate the fluctuations induced in the beam when interacting with a damped oscillator as the damping becomes very large the fluctuations approach zero 7812 cathode follower coupled phase shift oscillator a note on the advantages of using cathode follower amplifiers between the sections of the phase shifting network 7813 circuits for producing high negative conductance several arrangements using two triodes are illustrated negative conductances of the order of can be produced stable oscillators can be made to operate with a supply voltage of or less 7814 the regenerative pulse generator pulses are circulated repeatedly in a feedback loop including an expander and a filter being alternately shortened in the expander and lengthened in the filter and giving an output at each traversal a loop gain of unity is maintained by agc for microwave pulses the nonlinear expander characteristic may be obtained by means of a crystal microwave pulses of duration down to and dc pulses down to have been produced possible applications include communications radar and measurements were coherent pulse trains are required 7815 a versatile pulse shaper a triggered miniature thyratron circuit is described for deriving sharp pulses with uniform amplitude and duration from an input of nonuniform pulses a table shows the output waveform for various circuit arrangements and component values 7816 frequency multiplication by regenerative modulation a multiple frequency generator is discussed in which operation depends on mixing a feedback and an input voltage theory is presented for a circuit designed to produce four multiples of the input frequency experimental confirmation of the results is reported multiples up to the have been obtained with good amplitudes maximum amplitudes can be arranged to fall in desired frequency ranges even and odd multiples can be made available at separate output terminals operation is unaffected by variations of anode filament or input voltage or by phase shifts due to aging of components in the feedback loop 7817 effect of steepness of rise and fall of the input pulse on the response of pulse amplifiers the response of shunt compensated amplifier to ramp function and triangular pulses is analysed 7818 a stable and sensitive dc amplifier with high input resistance a line operated dc amplifier for automatic regulation using ac amplification and a breaker modulator has been designed with the following characteristics direct reading instrument zero drift after warming up les than peak to peak in hours test sensitivity short time stability usually input resistance and damping about sec with source resistance 7819 new amplifier has bridge circuit output the basic circuit is described and complete circuit diagrams are given of and af amplifiers the advantages of the circuit include absence of switching transients absence of dc current through primary of output transformer and low quiescent current 7820 differential amplifier design the possibility is discussed of providing good rejection of in phase signals without using a balancing adjustment or specially selected components to achieve the desired result by use of in phase negative feedback care must be taken that the feedback and input voltages are correctly combined two circuits combined two circuits are described illustrating the principles v involved both have the disadvantage of requiring floating batteries and isolated heater supplies 7821 the possibility of adjusting the internal impedance and varying the gain in amplifiers with combined current and voltage feedback the internal impedance can be reduced to and maintained at any desired level r inc independent of the gain or the amount of feedback by using a fixed amount of the total feedback to achieve the impedance reduction and apportioning the remainder so that where r and k are the current and voltage feedback factors of this remainder three commonly used circuits incorporating this feature are discusr attention is devoted to the use of magnetic amsed 7822 magnetic amplifiers and weak currents particular amplifiers for measurement purposes 7823 investigations of noise in audio frequency amplifiers using junction transistors noise factor measurements were made using various types of transistor in different circuit arrangements the influence of input termination and operating point are discussed results are presented graphically three distinct sources are identified shot noise and thermal noise are independent of frequency over the af band semiconductor noise varies approximately as noise properties of transistors and thermionic valves are compared 7824 search for a general definition of energy and of the parameters of extension and intensity a scheme of relations between energy and extension and intensity is presented which leads to definitions generally valid for all forms of energy including those as yet unknown 7825 conductivity and viscosity effects on wave propagation in piezoelectric crystals 7826 diffraction of pulses by a circular cylinder 7827 economic aspects of printed foil circuits 7828 electroluminescence with nonsinusoidal fields experiments using pulses of rectangular sawtooth exponential form were made to supplement the information obtained by applying sinusoidal voltages of piper and williams the phosphor investigated was giving green and blue luminescent bands which were examined separately measurements were made of field and frequency dependence and decay law with square pulses only qualitative observations were made with the other waveforms a theoretical interpretation of the results is advanced 7829 voltage dependence of electroluminescent brightness an equation of the form relating the brightness l to the voltage v is found to fit experimental data well a b and v being constants 7830 the two dimensional electric field of a curved sided wall or groove on an infinite plane results of a theoretical investigation are tabulated and presented graphically the calculation involves conformal transformations and elliptic integrals for complex moduli values of the latter are tabulated 7831 some properties of dielectrics with high permittivity analysis shows that for a conductor surrounded by a dielectric of sufficiently high permittivity the depth of penetration of hf current is dependent only on the constants of the dielectric formulae are derived for solid and for hollow dielectric cylinders and spheres subjected to an alternating electric field expressing the conditions under which the amplitude of oscillation of the bound electrons becomes infinite the results can be stated in terms of characteristic radii for a given material and frequency 7832 theory of electrical conduction general theory of conduction in pure metals is developed without assuming spherical symmetry for the energy levels this is applied to calculate the conductivity of the alkali metals 7833 the theory of electrical resistance of good metallic conductors reasonable values are obtained for the resistivity of the alkali metals except li by calculation based on the propagation of compression waves in an ionic continuum 7834 electromagnetic heating of thin layers of conductors or semiconductors generalizations relating to the problem of the determination of the ideal thickness formulae are quoted for the thickness of a cylindrical and of a spherical metal shell to make optimum use of the heating effect of a hf magnetic field if the metal is replaced by a material which is both a conductor and a dielectric the corresponding expressions are quite different though the ratio between them is the sam consideration is also given to the case of a cylindrical shell rotated rapidly in a uniform constant transverse magnetic field 7835 artificial increase of electrical breakdown strength of air at low pressure in the region of mcs measurements covering the pressure range mm hg using gap widths of mm and frequencies of and are reported under these conditions the superposition of a moderate direct voltage on the alternating voltage can increase the uhf breakdown stress quite considerably typical results obtained with direct voltages up to are shown graphically the effect is large enough to find practical application as an inhibitor of breakdown in electronic equipment for operation at high altitudes 7836 theory of electric breakdown in the high temperature region and its relation to thermionic emission discussion is based on consideration of the distribution of electrons over the energy states rather than the behaviour of individual electrons 7837 energy distribution of secondary electrons from magnesium and berylium alloys experiments were carried out at a pressure of mm hg with alloys and activated by heating either in a vacuum or in an atmosphere of oxygen curves showing the dependence of the secondary emission coefficient on the energy of primary electrons and of the secondary current on the voltage at the collector are plotted the mechanism of secondary emission from complex surfaces is not considered to be similar to that of the malter effect the role of the accelerating field is probably reduced here to the compensation of local retarding fields above the inhomogeneous surface of the activated layer 7838 the secondary electron emission of sodium and zinc experiments are described in which the metal to be examined was deposited on a copper target block in a valve with a guiding grid accurately aligned with a collector grid the collector potential was high enough for saturation secondary current to introduce the sodium an electrolytic method was used for sodium the maximum secondary emission factor reached a peak value of during the coating process and then fell to a constant value of ccurring at a target potential of for zinc the maximum value of occurred at a target potential of 7839 non maxwellian theory of homogeneous anisotropic plasmas using theory based on boltzmanns integegro differential equation a calculation is made of the distribution of electron velocities in an ionized gas subjected to a constant magnetic field for non maxwellian conditions explicit expressions are derived for the magneto ionic conductivity dielectric tensor hall effect deflection of an electron beam and a generalized form of langevins mobility formula results are compared with those obtained by other methods based on mean free path wave propagation is studied formulae being derived for refractive index birefringence phase and group velocities attenuation polarization and critical frequencies classical results of ionosphere theory are confirmed see also of 7840 magnetic fields in plasmas with turbulent motion when a plasma comprising electrons and ions is in turbulent motion diffusion currents give rise to magnetic fields these can be demonstrated by rotating the gases produced by burning a mixture of oxygen and propane an account is given of suitable experimental technique 7841 spin precession in a vibrating bloch wall at small amplitudes the natural frequency of vibration of the wall is derived on the basis of an effective internal magnetic field the formula obtained for a wall is identical except for a factor with that given by doring for a wall on the basis of the wall mass 7842 electromagnetism old and new comment on and of and authors reply 7843 energy of the harmonic oscillator in vacuum continuation of work abstracted previously of braffort et al the term energy of the oscillator us used to indicate the additional energy acquired by a free charge on passing into the oscillating state the energy of the harmonic oscillator in the fluctuating field of the absorber is equal to the product of its natural frequency and a universal constant 7844 electronic band structure of solids brief report of conference held at the radar research establishment at malvern in september at which criticisms of the energy band theory were advanced 7845 the isotropic component of cosmic radio frequency radiation possible sources of the isotropic component deduced by westerhout and oort of february are discussed the integrated radition from normal extragalactic nebulae is shown to be inadequate to account for the observations which may be explained on the basis of collisions between galaxies the intensity to be expected depends strongly on the cosmological theory assumed hence accurate measurements of the extragalactic component may yield information of value for distinguishing between different theories 7846 prediction of the present sunspot cycle the reliability of the prediction method presented previously is examined with reference to observed sunspot data for the period 7847 observation of the total eclipse of the sun on june at hagaby sweden and of the partial eclipse using the radio telescope at meudon observatory the curve obtained from the observations in sweden at was less irregular than that observed at khartoum in this is consistent with the lower level of solar activity at totality the residual radiation was compared with in 7848 symposium on scientific aspects of the international geophysical year the text is given of a number of papers including the following morphology of ionospheric storms pp the morphology of the aurora pp diurnal and seasonal variation of the airglow transport problems in the atmosphere evidence for winds in the outer atmosphere solar activity and terrestrial disturbances geographic basis for antarctic scientific observations 7849 homogeneous dynamos and terrestrial magnetism solutions of maxwells equations are obtained for a sphere of electrically conducting fluid in which there are specified velocities solutions exist when harmonics up to degree four are included but for a greater number of harmonics the convergence of solutions has not been proved orders of magnitude are derived for a number of quantities connected with the dynamo theory of terrestrial magnetism 7850 possible cause of disturbance of solar diurnal variation of geomagnetic field a mechanism is considered whereby currents in the ionosphere acquire a pattern such as to produce the observed s variations of the geomagnetic field 7851 infrared radiation of night sky production of infrared radiation in the upper atmosphere is discussed and the estimates given by various authors for the heights at which radiation is produced are quoted the heights coincide roughly with the d and e layers references including about to russian literature 7852 seasonal variation in the absorption of solar radiation by atmospheric ozone at microns 7853 aircraft investigation of the large ion content and conductivity of the atmosphere and their relation to meteorological factors continuation of work described previously of callahan et al simultaneous measurements of conductivity large ion concentration temperature and humidity over the altitude range are reported the results indicate that over continental areas in fair weather there exists z layer adjacent to the ground varying in height from to in which the vertical distributions of large ions and conductivity are controlled primarily at atmospheric turbulence at the upperaboundary of this layer there is a transition region about ft high in which the conductivity increases by a factor of while the large ion content decreases by a factor of above this region the large ion content is reduced to a very low value and the conductivity is determined primarily by the intensity of cosmic radiation and 7854 reviews of modern meteorology the physical state of the upeer atmosphere the composition of the atmosphere at various levels is discussed mainly as regards the constituents n and o this provides an indication of the value to be assigned to the mean molecular weight in the formula for converting scale height to temperature following the discussion of the properties of the static atmosphere the evidence for movement in the high atmosphere is reviewed and the complications to be expected in the upper levels of the ionosphere as a results of the interaction of the ionized gas with the earths magnetic field are considered 7855 determination of electron densities in the ionosphere from experimental curves an error in the argument used in the original paper of was pointed out by kelso of it is suggested that it may nevertheless be possible to provide a rigorous argument justifying the use of the curves given 7856 concentration of hydroxyl in the upper atmosphere a brief critical discussion of possible reactions and their equilibria at heights of about 7857 the physics of the ionosphere a brief survey of selected aspects of recent research on the ionosphere 7858 the anomalous equatorial belt in the f layer an examination has been made of the relation between the maximum electron density and geomagnetic latitude for y hours of the equinox day other than noon the abnormally low values of n found over a wide equatorial belt at noon tnd to disappear during the afternoon and to be replaced by abnormally high values during the evening the n anomaly disappears between midnight and these variations appear to be due to contraction of the vertical extent of the f layer during the first half of the night and an expansion prior to noon 7859 f layer regularities at ibadan analysis of records for the period december january confirms that the daily variation of n the total electron content in a column of unit cross section below the height of maximum ionization in the f layer is relatively free from anomalies exhibited by the corresponding variation of n the maximum electron density of the f layer in calculating n the non parabolic electron distribution at ibadan must be taken into account inclusion of the f layer electron contribution has no appreciable effect on the regularity of the daily variation a new method is described for deducing the recombination coefficient and the rate of ion production from the variation of n the phenomenon of sunset minimum of is discussed reasons are given for considering it a spurious effect arising from errors in the reduction of records 7860 preliminary results of ionospheric observations of the sola eclipse of june ionosphere soundings were made in the o zone of totality from a ship off the coast of southern norway a panoramic instrument was used covering the frequency range in a second instrument was used for absorption measurements at and the variation of the maximum electron concentrations for the different layers is shown graphically the recombination coefficients are estimated from the delay between the optically and the ionospherically observed maximum phase and by trying different values in the equilibrium equation expressings the dependence of electron concentration on unobscured fraction of the solar disk the recombination coefficient for a normal law is greater than or equal to for the e and f layers and over for the f layer 7861 the physics of the ionosphere report of conference held at cambridge england in september at which papers were presented and discussed summarizing existing knowledge of the subject 7862 simultaneous ionospheric absorption measurements at widely separated stations 7863 ionospheric thermal radiation at radio frequencies part further observations continuation of work reported previously pawsey et al observations were made at frequencies near over a period of about a year at a site chosen to minimize man made noise the location of the absorbing regions was deduced from consideration of pulse echo observations of the d region made on of gardner and pawsey the ionosphere temperatures deduced ranged from about to varying appreciably from day to day and being lower and less variable in winter an increase of up to during sudden ionospheric distinct disturbances is probably do due to a change of height of the absorbing region polarization measurements in september indicated that the absorbing regions were then located at a level where the temperature decreased with height 7864 effects of solar flares on the absorption of cosmic noise abnormal variations of ionospheric absorption were investigated during the course of the observations reported previously of most cases of unusually high absorption appear to be associated with solar flares observations of the increases in absorption during the resulting sudden ionospheric disturbances are compared with observations of sudden phase anomalies in waves rn waves reflected from the ionosphere a db absorption difference appears to correspond to a phase anomaly of about at the frequency considered as a method of detecting sudden ionospheric disturbances observation of the absorption variation variation is as sensitive as and more convenient than observation of phase anomalies evidence was found of a delayed increase of absorption about hours after some solar flares the magnetic records sshowed no abnormal features at these times and it is uncertain whether the excess absorption occurs within the ionosphere or outside it 7865 theoretical considerations regarding the day glow results of rocket observations made by miley et al are examined the reported great altitude and luminosity of the emissive source cannot be reconciled with the assumption that dayglow is due to direct photo action by incident solar radiation a determination is made of the emission to be expected from processes known to be operative including resonant and fluorescent scattering photo dissociation photo ionization and recombination 7866 chain process of accumulating charges in thunderclouds theoretical considerations lead to the conclusion that the build up of charge in a thundercloud follows an exponential law 7867 field intensities and charge densities in thunderclouds calculations based on the assumption that the thundercloud is ellipsoidal give the maximum field strength in the cloud as and the charge density as cm the conditions under which lightning discharges may be initiated are discussed 7868 radar echoes from lightning 7869 the wave forms of the electric field in atmospherics recorded simultaneously by two distant stations electric field variations were recorded at two stations one near uppsala the other at fotevik at the south western tip of sweden during september and the variations were correlated with thunderstorms which occurred at distances between and from uppsala in pre discharge atmospherics a quasi periodic variation was observed which corresponded most frequently to a wavelength of km the waveforms of the main discharges varied greatly with distance often in q a quasi periodic manner a unipolar form was also observed the mean waveform obtained from several hundreds of oscillograms shows five pulses reflected from the ionosphere in addition to the ground pulse waveform changes with distance travelled can only be calculated by making large simplifications numerous oscillograms are reproduced and discussed 7870 the processing and some characteristics of coaxial cylinder corona stabilizer tubes the running voltage of tubes filled with hydrogen has been found to be stable to within over and to within over h the dependence of slope resistance on pressure and current has been investigated the temperature coefficient of running voltage is about per deg c it may be possible to obtain higher current by glow discharge treatment 7871 a new type of high voltage machine a machine is described which operates on a principle related to that of the van de graaff generator with the difference that the moving belts carry not surface charges but capacitors which become charged on reaching a certain point and are then connected in series performance figures are given for an experimental model in which the capacitors are stationary and the electrical contacts are rotated 7872 wide band analog function multiplier operation of the multiplier is based on the formula the squaring is effc uaring is effected by means of beam deflection tubes with parabolic characteristics of soltes 7873 analogue computer with stepping switch drive for the solution of algebraic equations of up to sixth degree the analogy used is that between a sinusoidal voltage and a complex quantity the representation of the polynomials is effected using feedback amplifiers as computing elements the zero points corresponding to the solutions are found automatically 7874 some devices permitting study of the variable regime in the transportation of gas in pipes a particular application is discussed of the analogue computer arrangements described previously of 7875 programming a digital computer for cell counting programming a digital computer for cell counting and sizing 7876 magnetic materials for digital computer components part a theory of flux reversal in polycrystalline ferromagnetics 7877 logical and control functions performed with magnetic cores use of magnetic cores with square hysteresis loops in digital computer systems based on the single line shift register is described 7878 a technique for nonlinear function generation a method is described for converting a circuit whose output is proportional to the nth root of the input to give the nth power or vice versa a practical circuit based on a variable gain feedback amplifier for dealing with square and square roots is illustrated 7879 two new electronic analog multipliers improved types of four quadrant multipliers for deriving the product of two time functions are described one uses a double amplitude modulation scheme applying the work of sternberg and kaufman on the two frequency modulation product problem of the other uses successive phase modulation and amplitude modulation of a carrier the accuracy obtainable is discussed 7880 automatic digital computation contains discussions and original papers presented at the symposium held at the national physical laboratory in march 7881 calculation of losses in transformer cores expressions for core losses are developed which take account of the nonuniformity in the flux distribution across the face of the core plates the nonuniformity across the stack of plates is neglected 7882 the noise generated in a coil with a ferro magnetic core the discussion presented indicates that when there is no varying or alternating magnetization of the core the noise can be calculated from the nyquist formula provided that the resistance of the coil is measured using an alternating voltage of such magnitude that the magnetization process remains linear 7883 composite cores for instrument transductors the characteristics of self excited transducers are markedly dependent on the properties of the core material cores with satisfactory properties can be produced at reasonable cost by combining different materials experimental results are reported for a core comprising a mumetal bridge and a u shaped grain oriented si fe yoke 7884 auto self excited transductors and push pull circuit theory the modes of operation of transductors with parallel bridge and centre tap connections are explained expressions are derived for the sensitivity and time constant under idealized conditions an examination is made of the use of transductors in push pull pairs to obtain magnetic amplifiers with outputs whose polarity depends on the signal sense the transductors are assumed to e be of the auto self excited type with resistance loads 7885 component design trends special purpose relays gain new uses 7886 time delay in high speed ferrite microwave switches measurements indicate that for an x band switch using a rod of a particular mg mn ferrite and actuated by a current pulse of given magnitude and rise time the time delay of the switch is about 7887 study of the dielectric in paper capacitors measurements were made of the loss angle of wet and dry paper at and of the permittivity of the impregnant and of the impregnated paper from these an equivalent circuit was derived for the capacitor which can be used in estimating the quality of the paper and desirable conditions of manufacture breakdown strength measurements were also made to determine the optimum applied voltage 7888 arc arc inductance and dynatron capacitance the stability of systems with nonlinear negative resistances of arc and dynatron types is discussed analysis indicates that though the arc can have e some inductive po properties and the dynatron capacitive ones these are not essential to an explanation of the behaviour of the systems transient conditions and steady oscillation states are considered 7889 further bounds existing on the transient responses of various types of networks five theorems further to those presented previously are proved and illustrated 7890 an approximate treatment of cascaded four terminal networks an approximate expressions is derived for the nth power of a matrix the result is used in an approximate treatment of a ladder network used as a filter 7891 the approximation problem of network synthesis a review with references 7892 series resonant circuit theory expressions are derived for the fractional errors in tuning capacitance resonance frequency maximum current and selectivity at current resonance due in the case of frequency tuning to the frequency dependence of the circuit resistance and in the case of capacitance tuning to capacitor losses and coil self capacitance 7893 the mesh counterpart of shekels theorem it is shown that whereas the determinant of the admittance matrix of a network is independent of the choice of reference node of shekel the corresponding statement for the mesh determinant is not true 7894 distortion of arbitrary waveforms by resonance sections the method developed earlier for rc sections is extended to sections including an inductance 7895 extension of nonreciprocal ferrite devices to the frequency range calculations indicate that devices such as circulators of reasonable dimensions can be designed for operation at frequencies below by using static magnetic fields of intensity greater than required for ferromagnetic resonance 7896 a short slot hybrid for mm the x band junction by riblet of was redesigned for a wavelength of mm a brief illustrated note n on this junction is given 7897 resonance conditions in a sytem of two circuits with inductive coupling assuming m r l and c constant conditions are derived for the existence of one minimum and two maximum values of current in the secondary in the general and in two particular cases the results are applied to a band pass filter and presented graphically for two different parameter valuex low q values are assumed 7898 microwave filters theory of filters comprising coaxial lines and or waveguides is developed by reference to equivalent lumped constant circuits band pass and band stop filters of ladder amplifier and bridge types are discussed 7899 tunable microwave aerial diplexer a diplexer for the band is based on the use of continuously tunable resonant circuits comprising coaxial line sections short circuited at one end and having a third coaxial conductor insulated from and sliding within the inner conductor in a particular design illustrated for separation between transmission and reception frequencies the transmitted energy penetrating into the receiver is attenuated by 7900 theoretical investigation of three stage tchebycheff type band pass filters 7901 juding the quality of oscillator circuits discussion of the frequency and amplitude stability of oscillators considered as composed of a slightly nonlinear frequency independent amplifier and a linear frequency dependent feedbz feedback quadripole stability is found to depend on the rate of change of the imaginary part of the voltage transfe transfer characteristic of the feedback quadripole the use of this criterion in the design of bridge stabilized rc oscillators is illustrated measurements on and various faults of experimental oscillators are briefly discussed 7902 generation and use of single frequency pulses in electroacoustics and musical acoustics 7903 experimental investigations on multivibrators and amplifier circuits with secondary electron emission valves as described by kroebel multivibrators of the type described by kroebel of february were investigated pulse flank slopes of the order of up to pulse amplitudes of were obtained the multivibrator can be modified to act as a pulse amplifier without feedback 7904 equipment for excitation of spectra by high frequency pulses the equipment comprises a pulse generator which controls a clapp oscillator of followed by a frequency multiplier and amplifiers average hf power transferred to the discharge tube is about with peak power of the frequency is about mcs argon spectra obtained are shown 7905 transistor frequency standard this unit designed primarily for geophysical prospecting has a printed circuit base and uses transistors in all stages accuracy is within part in over the range f to f an oscillator is followed by a pulse forming amplifier and first divider stage then by two dividers in parallel whose outputs are mixed to obtain an u output frequency of cs 7906 the transient response of direct current amplifier systems dc amplifiers of the dc ac conversion type have an upper frequency response limited by the detector circuit and when negative feedback is used transients are amplified considerably more than the steady signal the form of the transient response and methods of reducing its magnitude ar discussed 7907 a long lived packaged amplifier for aircraft the development and construction of units with a probable life of hours are described selected valves are pressed into cast al wells lined with a silicone rubber paste which is hardened by a short curing process this is more effective for heat transfer than al dust or foil deposited carbon resistors and capacitors serviceable at are mounted on a phenolic board supported by the al base and wired to a recessed plug the assembled unit after testing is embedded in liquid plastic which is then solidified test figures for heat dissipation under different conditions are given 7908 amplifier stages with transitionally coupled two stage band pass filters particularly for large bandwidths the amplitude and group delay characteristics of an amplifier stage consisting of two coupled circuits are analysed for the case when the amplification is constant over a wide frequency band transitional coupling the case when the damping factors d and d of the two circuits are equal is considered first and formulae are also given for the cases of either d or d tending to zero formulae are also given for transforming a filter with indirect inductive coupling into one with direct inductive coupling design curves are shown 7909 nyquists criterion for multiple loop feedback circuits a method of deriving the stability criterion alternative to that of cutteridge of and based on conformal transformation is presented see also of january 7910 the effect of inverse feedback on input impedance formulae are given for the input impedance gain and gain without feedback of twelve single stage amplifiers and these together with the circuits and their equivalents are tabulated 7911 alteration of dynamic response of magnetic amplifiers analysis is presented indicating how a magnetic amplifier of full wave self saturating type can be made to exhibit phase lead or lag by adjusting the parameters of the feedback networks 7912 analysis of the common base transistor circuit simple equations are obtained by choosing a hybrid inverted network as the equivalent circuit for investigating the operation of the grounded base point contact transistor amplifier 7913 dc stability of transistor circuits the design of amplifiers using junction transistors is discussed with particular reference to the influence of the base to collector leakage current which increases rapidly with rising temperature for stable operation the change of collector current produced by a change of leakage current should be low circuit arrangements for achieving this are indicated 7914 the distortion of fm signals in passive networks expressions for the fundamental and first four harmonics of the output instantaneous frequency are given in a series expansion in terms of modulation frequency and modulation index the coefficients in the expansion depending on the network parameters effects of detuning are considered and detailed results for the butterworth circuit are presented 7915 the linear distortion of fm signals in band pass filters for large modulation frequencies the linear distortion of a fm signal in a highly selective band pass filter follows almost exactly the static response curve of the network provided the following conditions are fulfilled the modulation frequency is not less than two thirds of the semi bandwidth the modulation index does not exceed unity the network q is sufficiently large 7916 a ferrite frequency modulator the modulator described comprises a ferroxcube ring carrying a rf winding and located in the gap of a ni fe core carrying lf and polarizing windings it is suitable for operation over the frequency range from to uhf with slight modifications its demodulated distortion is at an oscillator frequency of and a frequency deviation and at and respectively 7917 discriminator circuit analysis theory and performance figures are given for a simple frequency discriminator circuit using an asymmetrical arrangement the conversion efficiency compares favourably with that of the equivalent foster seeley discriminator it is particularly recommended for purposes where high efficiency is of greater importance than accurate linearity over a wide frequency range 7918 a universal printed circuit the universal printed circuit board has a standard pattern of parallel wires on one side and is useful at the design stage when prototypes are required for testing since circuit changes may be made with relative ease 7919 amplitude frequency characteristics of ladder networks suitable mainly as a reference work for telecommunication engineers 7920 proposals for units for area electric displacement and magnetic field strength 7921 the two dimensional magnetic or electric field of a single isolated pole piece theoretical investigation for a pole piece consisting of a thick plate terminated by a concave semicircular cylinder conformal transformations and elliptic functions are used the variation of the field strength along the edge of the pole piece and along the external axis of symmetry is calculated and shown graphically 7922 observation of the costa ribeiro effect on the dissolution of naphthalene crystals report of experiments indicating that electric charges are developed on dissolving single crystals of naphthalene in a solvent of very low conductivity such as toluene the crystals thus treated constitute natural electrets 7923 electro fusion a new phenomenon observed in the phase changes of dielectrics under the influence of an electric field experiments are described which indicate that application of a field between the electrodes of a capacitor with the dielectric partly in the solid and partly in the liquid state accelerates the phase change in the dielectric from measurements of the current and calculation of the joule energy dissipated it is shown that this energy is several hundred times smaller than the heat necessary for the normal fusion of the corresponding mass of the dielectric 7924 field induced melting of dielectrics theory is presented relevant to the phenomena described by costa ribeiro above 7925 plasma oscillations in a periodic potential the one zone theory the plasma oscillation theory of collective electron interactions developed by bohm and pines of and back references can be applied to the problem of the cn conduction electrons in metals by modifying it to take account of the periodic potential present this modification is carried out neglecting the interactions of electrons in different zones and assuming that the effect of inter zone transitions on the collective behaviour is small enough to be treated by perturbation theory the main effect of the potential is to alter the effective mass of the electrons 7926 the electrical and thermal conductivities of monovalent metals numerical calculations for the case of so sodium using the bardeen formula for the scattering cross section and blackmans value for a longitudinal b debye temperature agree better with observation than do the simple bloch expressions but there still remain discrepancies further x study of the scattering cross section function might remove these 7927 high frequency resistance of tin and indium in the normal and superconducting state further measurements at confirm results obtained previously of grebenkemper and hagen 7928 the physical nature of a metal surface in conduction theory a discussion is presented in which the reflection of electrons striking the surface from inside is treated as a diffraction phenomenon 7929 gaseous electronics conference in new york papers presented at the conference held in october are surveyed briefly physics of plasma and ionization processes leading to electrical breakdown were among the subjects discussed 7930 study of gaseous discharges by magnetic resonance measurements are reported which indicate that the technique of magnetic resonance may prove useful for studying the characteristics of low pressure gas discharges 7931 relaxation oscillations and noise from low current arc discharges noise measurements were made on arcs using various electrode materials and gases over the frequency range the results for al electrodes in air are plotted in comparison with the computed spectrum pulses generated in the circuit formed by the series limiting resistor and the capacitance across the discharge are considered responsible for most of the noise 7932 formative time of the cathodic space charge a criterion for evaluating the formative time is based on observations of rise time and overshoot in intermittent discharges different kinds of intermittent discharges are reviewed 7933 on intermittent discharges in air at low pressure an experimental investigation is reported of the dependence of the discharge frequency on the gas pressure and electrode separation 7934 forces between parallel electron streams a simplified fundamental analysis is presented taking account of the forces of acceleration es repulsion em attraction gravitation and any local fields the results indicate that for all electron velocities up to the immediate threshold of the velocity of light the resultant force between parallel electron streams is repulsive 7935 spectroscopic studies of highly ionized argon produced by shock waves 7936 kinetic theory of weakly ionized homogeneous plasmas part a rigorous method is presented for integrating boltzmanns equation by successive approximations for a weakly ionized gas subjected to an alternating electric field and a static magnetic field the electron velocity distribution function is developed with respect to the electric field and the individual functions obtained are developed as spherical functions the method is applied to investigation of a lorentz type gas 7937 electrical conductivity of highly ionized argon produced by shock waves 7938 antiferromagnetism and ferrimagnetism of non stoichmetric compounds a simple quantitative treatment is given of the magnetic properties of a substance containing vacancies enabling the most important magnetic properties of many non stoichiometric compounds to be interpreted 7939 representation of electromagnetic fields of any frequency using the energy quantum model development of theory presented previously of wave propagation phenomena including reflection interference and diffraction are explained in terms of the energy quantum model static fields are also considered voltage current and characteristic impedance are related to mechanical quantities and an appropriate system of dimensions and units is presented 7940 cerenkov radiation from extended electron beams calculations are made of the radiation emitted by bunched beams passing close to dielectric surfaces both plane and cylindrical geometries are considered 7941 calculated diffraction patterns of dielectric rods at centimetric wavelengths calculations of the field behind the cylinder are made for the case of a normally incident wave with the electric vector parallel and perpendicular to the cylinder axis the dielectric materials considered include polystyrene lucite and tenite the diffraction pattern is only slightly dependent on the dielectric constant of the rod small discrepancies between the calculated values and values obtained experimentally of are probably due to resistive loss in the dielectric 7942 spectral investigations in the wavelength range around mm a description is given of the construction an method of operation of an infrared type spectrometer which has been used with thermal radiator and receiver to obtain absorption spectra at wavelengths over mm the spectrum obtained for water vapour over the range mm is shown as an example results obtained with hcn and are also reported 7943 variable frequency microwave cavity spectro meter molecular gas spectra at wavelengths around are investigated using a system in which a single coaxial cai cavity serves as stark or zeeman modulation cell and as frequency reference unit 7944 simplified impurity calculation the methods developed previously of march are used to investigate the case of a local perturbation in a simple cubic lattice 7945 abnormal galaxies as radio sources results of radio telescope observations at sydney indicate that galaxy ngc is probably a radio source whereas ngc is probably not 7946 observations of galactic radiation on a wave length of cm report of measurements made using the wurzburg mirror at marcoussis results are presented in the form of an isophot map of the galaxy with intensities expressed as apparent temperature in arbitrary units the cm radiation is attributed principally to ionized hydrogen a table giving the positions of localized sources includes five thought to have been observed for the first time 7947 study of solar rf radiation on around sunset and sunrise report of measurements made at paris using a parabolic mirror of diameter m graphs are presented showing the variation of refraction with solar angle and quasi periodic intensity variations observed when the angle of elevation is less than attenuation due to absorption by oxygen is observed at zn angles less than about 7948 fine structure of solar radio transients brief report of observations made during solar bursts observed at and were found to be composed of numerous discrete pips with median duration approximately proportional to wavelength the spectral width of a pip is a few per cent of its mean frequency of occurrence of the pips was greatest at 7949 aerial smoothing in radio astronomy theoretical considerations show that the aerial does not register those spatial fourier components of the true distribution of radio brightness having frequencies beyond a cut off determined by the aerial p aperture components of lower frequency are registered but their relative strengths are altered the consequences are that there are invisible distributions which produce no response when scanned by the aerial and in conducting a survey the measuring points must be closer together than half the period of the fourier component at cut off 7950 prominence activity charts prepared from observations made at m kodaikanal show the salient features of solar prominence activity during the last four sunspot cycles a preliminary examination suggests that during the maximum phase of the cycle geomagnetic activity shows a better correlation with prominences than with sunspots 7951 the emission of radiation from model hydrogen chromospheres part an improved method is presented for calculating the characteristics of the radiation field of and the lyman continuum emitted by model hydrogen atmospheres at kinetic temperratures of k a useful application of the results would be in interpreting observations of prominences and flares 7952 qualitative explanation of the commencement of some polar magnetic disturbances based on the theory of chapman and ferraro 7953 geomagnetic and geoelectric variations analysis of records of geomagnetic pulsations especially those with periods of sec indicates that they may be associated with ionospheric vibrations caused by a disturbance of the ionization equilibrium information regarding the distribution of ground conductivity is obtained from the relation between the magnetic pulsations and the associated transverse electric field pulsations 7954 the abnormal variations of the horizontal magnetic intensity t at huancayo peru the magnetic field of the ionospheric current system arising from lunar atmospheric tidal motion is calculated for various points on the earths surface the daily variation of the horizontal component at huancayo is found to be nearly twice as great as at batavia though the latitudes of the two points are nearly the same observations at a point between the geographic and magnetic equators in the northern hemisphere should help to explain this anomaly 7955 on the world wide disturbance in f region the average disturbance in the value of f during magnetic storms is separated into the short time part and the local time part d these were calculated in the cases of typical storms from data obtained from stations in the northern hemisphere both their range and phase are correlated with the magnetic activity the phase of d during the active stage of the magnetic storm is almost entirely dependent on the local time but after the cessation of activity the disturbance moves with the rotating earth see also 7956 an analysis on the diurnal variation of the terrestrial magnetism especially on the day time variation of geomagnetically quiet days 7957 vertical distribution of atmospheric ozone at longyearbyen spitzbergen 7958 the constitution of the upper atmosphere and the ionosphere research station of the institute of geophysics at genoa an outline of knowledge on the structure and electrical properties of the ionosphere is followed by a description of ionosphere sounding equipment recently put into operation and comprising pulse transmitter for the range double superheterodyne receiver and cro recorder 7959 calculation of the collision frequency in the ionosphere it is shown that if is the true reflection height corresponding to the lowest frequency of the sounding sweep and is the true reflection height corresponding to the first critical frequency greater than then provided that the distribution of ion concentration and collision frequency are known for values of up to and the absorption is observed over the range the function expressing the height distribution of collision frequency can be determined over the range by solving a an integral equation due to abel 7960 turbulence in the upper ionosphere from the experimental data at present available it is shown that the reynolds number in the upper f region level is of the order of the region may therefore be turbulent it is suggested that the high level diffracting screens which give rise to spread f r echoes and to radio star fading are caused by non laminar flow and that their non appearance during the daylight hours may be due to the inhibition of turbulence by large temperature gradients by lower drift velocities or by an increase in the kinematic viscosity 7961 motion of clouds of abnormal ionization in the auroral and polar regions a study has been made of unusual types of echo exhibited by film records of rapid succession sweep observations at several stations in northern canada three distinct types of echo are identified probably corresponding to horizontally moving e clouds clouds descending vertically from the f to the e layer and clouds moving at extremely high velocities in the e layer type echoes were observed only at stations very close t the auroral zone maximum and may be due to sweeping of the auroral ionizing agent type echoes also appear to be related to an auroral ionizing agent 7962 information obtained from ionization charts ionization charts drawn up monthly for two zones covering america and europe africa and asia are discussed the distributions observed generally confirm the theory of geomagnetic control of the f layer of appleton but some exceptions are observed there appears to be a lower limiting value for the height of the sun below which the geomagnetic control does not operate the control is effective at latitudes as high as measurements at other times besides midday are required to study the effect asymmetry as between northern and southern hemispheres is observed the north polar zone was studied in detail the auroral e zone appears to be centred on the geographic pole 7963 velocity of movement of sporadic e clouds curves of the diurnal variation of the e layer critical frequency for o four japanese stations indicate a progressive retardation of the time of occurrence of the maximum on passing from the highest latitude to the lower latitude stations a value of about is deduced for the horizontal component of the velocity of the e clouds this is of the same order as the velocity of e layer winds found by various methods 7964 interpretation of measurements on the ionosphere f layer the maximum ionization level of the f layer is often located within the lower part of the f layer so that echo sounding yields a continuous curve for the f and f layers with a more or less marked maximum or merely a point of inflection indicating the virtual height of the f layer is not clearly defined a correction is required the sign of which depends on th the theory accepted for the origin of the f layer mohlers theory of gives results in good agreement with observations 7965 lunar tides in the ionosphere f layer at dakar hourly records of and for the years have been analysed maximum variations and times of occurrence of maxima are tabulated for the different seasons the semi diurnal component is predominant except in summer during winter the tidal variations of and have amplitudes of and respectively the phases and amplitudes are considerably different from those observed at other tropical stations anomalies may be due to the circumstance that the f layer at dakar is very thick in summer the ionization maximum occurs at the equinoxes and not in winter 7966 on the meridional distribution of the minimum virtual height of the f layer results of an analysis of daily variations in from observatories indicate the presence of two periodic terms the diurnal variation which is dependent on the geographic latitude and the semidiurnal variation which depends on the geomagnetic latitude the former may be considered as the thermal effect the latter as the tidal effect in the f region 7967 the effect of the solar tides and the temperature change on the daily variation in electron density and height of the f layer the departure of the maximum electron density from the norm of a static chapman region is inversely proportional to the temperature variation except in the morning when the electron density is small the semidiurnal variation in appears even in the case when account is taken of the diurnal temperature variation only as regards the departure from the norm of the height of the result is similar to that obtained by weiss of except that it is more strongly temperature dependent there is some interaction between the temperature and the tidal effects 7968 influence of the moon on the maximum ionization of the ionosphere e layer an analysis of e variations over a period of four years observed at six stations indicates that after taking account of seasonal solar cycle and equation of time effects there is evidence of a lunar variation of amplitude centred on the full moon 7969 soft x radiation from the quiet solar corona the mechanisms involved in the production of the soft x rays are discussed and the significance of this radiation for the formation of the normal ionosphere e layer is indicated 7970 equipment for the measurement of changes of the phase path of ionospheric echoes the equipment described is built with units conventional in pulse applications and is developed from that described f by findlay and of oscillograms of ground pulse beats and echo patterns of the e and f regions are shown 7971 reflection conditions for vertical propagation in the ionosphere in the presence of collisions and of the earths magnetic field case of the e layer 7972 the development of an e region model consistent with long wave phase path measurements an electron density model iw evolved by modification of the chapman theory to include the effects of variable scale height dissociation of o and variable recombination the model is checked against phase height data for and and against values 7973 measurement of attenuation in the ionosphere 7974 the autocorrelogram of randomly fading waves 7975 statistical studies of polar radio blackouts a statistical study of high frequency radio blackouts in canada is made from records taken at several ionosphere sounding stations both vertical incidence and communication data are examined to determine the geographical seasonal and diurnal distributions of the frequency of occurrence of blackout it is found that blackouts are most abundant in the morning and that the time of maximum occurrence increases with increasing latitude 7976 the microwave properties of precipitation particles the theory of scattering and attenuation by rain snow and cloud is reviewed and theoretical results are presented in the form of equations are presented in the form of equations tables and graphs so that the radar response to meteorological particles can be calculated at six wavelengths and various temperatures particular emphasis is placed on developments since rydes comprehensive paper in published experimental results are compared with the theory all results computed from the theory are contained in tables and the attenuation by water vapour and oxygen is given in an appendix 7977 an attempt to observe whistling atmospherics near the magnetic equator according to the theory of bark hausen and eckersley the mode of propagation of whistling atmospherics is such that they should not occur near the magnetic equator a report is given of observations made at achimota over the period from december to march no whistlers were detected though other types of atmospheric were frequent 7978 closed expansion of the convolution integral a generalization of servomechanism error coefficients 7979 precision high current computer power supplies a unit supplying at uses a magnetic amplifier regulated se rectifier 7980 a portable van de graaff generator the generator described develops a maximum open circuit voltage of about and has a short circuit current of 7981 practical local calling circuit the circuit diagram of an experimental local station calling device designed for operation on the amateur band is given and discussed the unit is basically a transistor receiver which operates a calling bell via a relay power consumption is of the order of per annum 7982 directors annual report on progress in research and technology part computers and automation includes a description of the besk digital computer and notes on the industrial uses of computers and automation 7983 analogue computation in the service of industry 7984 coefficient errors in analogue computers brief analysis is presented facilitating assessment of the accuracy of individual computers 7985 the use of a reflected code in digital control systems 7986 a permanent high speed store for use with digital computers information is stored in the form of spots arranged in a co ordinate grid on a slide and is picked up by a flying spot system reliable operation should be possible with a digit spacing of if phosphors with low decay time are used advantages of the system are high storage density and commercial availability of the components 7987 system design of the seac and dyseac standard design procedures developed during the work on the seac and dyseac digital computers cover system specifications functional plans and wiring plans similarity between these design procedures and data processing procedures carried out by such computers indicates that existing computers could be used to produce the wiring plans for new models 7988 the universal relay computer of the institute for low frequency engineering at the vienna technische hochschule the simple binary scale digital computer described was primarily designed to demonstrate principles for the basic arithmetical operations and the extraction of t roots the input is via perforated tape and electromechanical relays are used both in the store and the computer parts the times required are for addition and for multiplication 7989 checking codes for digital computers 7990 a radio frequency nondestructive readout for magnetic core memories 7991 new ferrite core memory uses pulse transformers 7992 asymmetrical finite difference network for tensor conductivities an extension of the technique described by macneal of 7993 junction transistor trigger circuits the junction transistor with earthed emitter is sufficiently similar to the thermionic valve with earthed cathode to enable it to be used in conventional trigger circuits details are given of bistable monostable and emitter coupled trigger circuits multi vibrators a scale of two circuit and a blocking oscillator pulses of duration down to about can be produced power consumption is of the order of per stage 7994 rotary and slider potentiometers with variable characteristic any resistance slider position characteristic can be approximated by connecting suitable resistors in parallel with short sections of the potentiometer 7995 investigations of current noise in resistors report of noise voltage measurements over the frequency range kcs with film resistors the mean square noise voltage usually varies approximately inversely as frequency for resistors exhibiting such a frequency variation the noise is proportional to the direct voltage applied deviations from this frequency dependence are accompanied by deviations from this voltage dependence as reported by macfarlane of the behaviour of wire resistors is similar the statistical distribution of amplitude of the current noise agrees with the distribution function for thermal noise indicating that its nature is gaussian 7996 linear reactor chart design data are presented for iron core reactors with inductance unaffected by variations of dc through the winding or alternating voltage across it 7997 light sensitive neon tube circuits the decrease in the striking voltage and the slight increase in the dark current produced by external illumination in low voltage neon lamps is mac made use of in switching lf relaxation oscillator and other circuits high power illumination glow lamps may also be suitable 7998 a mathematical technique for the analysis of linear systems comment on 7999 calculation of the oscillation frequency of a quartz crystal maintained by a transistor calculations are made for high q and for low q crystals values of the frequency variation are tabulated for a range of values of detuning of the oscillator circuit connected to the transistor collector 8000 an rf resonant circuit for use at mcs circuits of inductive line type with a tuning range have been designed without metallic sliding or rotating contacts the construction may be of low loss plastic with plated or printed conductors eccentric coaxial or two wire arrangements are used 8001 understanding the cyrator an equivalent network is used to show that gyrators can be simply realized by means of current or voltage generators 8002 rlc lattice transfer functions 8003 a general theory of wideband matching with dissipative poles 8004 effect of a radio pulse signal on resonant circuits calculations are made of the time required to establish the signal in a circuit of given bandwidth and time constant it is not possible to establish any simple relation between these parameters except in the case when the signal frequency is the same as the resonance frequency the influence f of signal duration is studied the results are of importance in connection with radiotelegraphy and explain the occurrence of maxima at the beginning n and end of each signal 8005 transformation for constant impedance networks certain constant impedance networks having a restricted range of variation of loss often contain components which are difficult to manufacture the transformation which is described overcomes this difficulty at the expense of two extra resistors in the network and a small amount of frequency independent loss added to the characteristics another application is the absorption of inductor dissipation in special cases 8006 a chart for analyzing transmission line filters from input impedance characteristics use of smith chart techniques is demonstrated 8007 compilation of a filter catalogue a discussion of the desirable features of a catalogue in which all numerical data required in designing reactance quadripoles by the insertion loss method are assembled an appendix gives formulae linking the reflection factor and four insertion loss parameters values of the insertion loss parameters are tabulated for values of reflection coefficient ranging from to in unit steps 8008 novel uses of the ultrasonic light cell 8009 the generation of undamped electrical oscillations in series and parallel oscillatory circuits a formal analytical treatment showing the types of negative resistance characteristic necessary for generating sinusoidal oscillations in the two types of circuit 8010 on the extension of the principle of imaginary power balance of harmonics to circuits with continuous spectra extension of the principles given in a previous paper on the interdependence of frequency variations and harmonic content in oscillators 8011 the nonlinear theory approach to resistance capacitance oscillators exact calculations can be made using nonlinear theory based on the balance of the reactive power of the harmonics involved the analysis indicates that the frequency stability when operating near the limit conditions is generally better with rc than with cr networks 8012 the influence of grid current upon valve oscillator frequency analysis indicates tht when the intensity of harmonics in the oscillator anode and grid circuits is low the fundamental component of grid current is the main factor influencing oscillation frequency grid current harmonics have b a greater influence than anode current harmonics 8013 frequency stabilization of valve oscillators in respect of grid current amplification factor and load formulae are derived for determining the values of stabilizing reactances for series connection in the grid anode and load circuits 8014 the operation and loading characteristics of valve oscillators for dielectric heating 8015 designing stable triode microwave oscillators two circuit constructional arrangements are described using a planar triode type and suitable respectively for operation at frequencies of and 8016 perturbations in nonlinear filtered systems applications to the theory of oscillators conventional methods of studying feed back amplifier stability can be applied to separable filtered systems comprising a nonlinear frequency independent unit followed or preceded by a linear selective circuit of and back references the theory of free and synchronized modes is extended to the case of frequency division stability is investigated by introducing two different coefficients for the in phase and quadrature components of the perturbation voltage so that the system can be treated as an amplifier with two feedback loops the method is applied to determine the effect on the output of a valve oscillator due to lf modulation at the grid 8017 pulse generator using secondary electron emission valves the generator described produces positive and negative voltage pulses with duration adjustable between and sec and a rise time of about as well as cro beam brightening and sweep voltages 8018 a versatile pulse shaper 8019 transistor waveform generators design of circuits using point contact and junction transistors is considered on the basis of analogies with thermionic valve circuits experimental af tuned circuit crystal controlled and blocking oscillators are described 8020 fractional frequency generation by regenerative modulation the circuit theory is similar to that presented previously for frequency multiplication of an arrangement is described producing six frequencies lower than input as well as others higher than input 8021 a high speed waveform sampling circuit pulsed sampling circuits are discussed for obtaining a quantized output corresponding to a continuously varying input voltage a cathode follower with negative feedback is used to provide an arrangement giving sz satisfactory operation with sampling pulses of short duration and small amplitude a diode switch circuit leads from the cathode follower to the input of a sign reversing amplified between whose input and output terminals the storage capacitor is connected 8022 design for a watt high quality amplifier discussion i with emphasis on the output stage and with special reference to the application of type a output pentodes 8023 amplifiers and preamplifiers a practical discussion covering the operation design construction and testing of all types of amplifiers used in home music systems and a presentation of the interesting features of commercially available products 8024 selectivity and delay distortion in high frequency amplifiers in designing wide band amplifiers or filters a compromise must be reached between the conflicting requirements of linearity of phase characteristic maximum amplification and selectivity normalized curves for the attenuation phase and transient response characteristics of four different amplifiers with four tuned coupling circuits are presented and discussed from the point of view of design to meet specific requirements the four types of amplifier considered are those with single tuned circuits those with flat phase characteristic power law and tchebycheff 8025 parallel series amplifier high amplification stability and low output impedance are achieved in a direct coupled circuit containing only two resistances one in the common cathode lead of a parallel connected double triode the other as the anode load of the first triode whose anode is also connected directly to the grid of a third triode in series with the second the output voltage is that between the anode of the second triode and the reference voltage input under appropriate conditions amplification where refers to the slope of the double triode the operation of the circuit is analysed and its application as an amplifier for an analogue computer a voltage stabilizer or a dc amplifier is described 8026 studio amplifier design for color television distribution amplifiers with highly linear phase characteristics over a wide frequency range are obtained by using multistage feedback amplifiers with rc couplings having different time constants 8027 high speed magnetic amplifiers an alternative arrangement using a junction transistor for coupling a junction transistor for coupling is described 8028 a survey of magnetic amplifiers principles of operation and basic circuits are described and applications are indicated 8029 diode amplifier 8030 delay line subcarrier discriminator the frequency discriminator described uses a multivibrator triggered by the direct input signal and stopped by the delayed signal producing pulses whose spacing is a function of signal phase designed primarily for telemetering it is useful also for automatic correction of wow and flutter in tape recorders 8031 an electrostatic problem involving a nonlinear fluid dielectric an approximate calculation is made of the electrostatic couple on an anisotropic dielectric sphere influenced by a uniform field dielectric 8032 slit middle plate capacitors a contribution to the technique of calculation of potential fields a numerical calculation is made for a system coo parallel plates distant respectively cm z and cm on opposite sides of a third parallel plate with a slit cm wide the results are compared with electrolyte trough measurements 8033 theory of the diffusion of light by strongly piezoelectric crystals expressions are derived for the variations of electric susceptibility produced in the crystal by passage of a wz wave of thermal agitation 8034 kinetic temperature of electrons in metals and anomalous electron emission the effect of strong electric fields on metals is to raise the temperature of the electrons above that of the lattice the symmetrical part of the electron energy distribution is a ferm distribution function the asymmetric part is negligible in the cases considered quantitative estimates of the effect of the electron temperature rise on conduction and emission are briefly discussed 8035 effect of strong electrostatic fields on the resistance of tungsten wires in high vacua wires of diameter and were subjected to negative and positive radial fields of strength up to and cm respectively the resistance decreased abruptly on applying the field and increased abruptly on removing it regardless of its sign the change of resistance was proportional to the square of the field strength no explanation of the effect has been found slight increases of resistance during steady application of the field are associated with temperature increases attributed to effects of ion photo and field emission currents 8036 the theory of the magnetoresistance effects in polar semiconductors theory developed previously for conduction in polar semiconductors of is extended to deal with effects occurring in the presence of a magnetic field hall coefficient and magnetoresistance effect are shown graphically as functions of the magnetic field strength and of the temperature and degree of degeneracy of the electron gas at low temperatures the magnetoresistance effect may become very large contrary to the prediction of the free path theory 8037 theory of skin effect in constant magnetic field the surface impedance is calculated for the case of a metal surface parallel to the magnetic field an analogous treatment for a normal field was given earlier by azbel and kaganov of 8038 current distribution in cylindrical conductors of circular cross section a calculation is made of the current distribution and joule heating for the conductor in a uniform alternating magnetic field 8039 the electron avalanche and its development in the self maintained discharge a survey of the primary and secondary processes la leading to breakdown in a parallel plate system in a gas 8040 departure from paschens law of breakdown in gases 8041 breakdown processes in nitrogen oxygen and mixtures 8042 influence of insulating films on the corona current and breakdown voltage of spark gaps experiments are reported in which a point to plate discharge path was used the plate being coated with lacquer or other insulator observed breakdown voltages are in some cases lower than with an uncoated plate an explanation of the results is presented 8043 the effect of lacquer films on the ac corona on points and wires 8044 two different breakdowns between a positive electrode with small curvature and a plane experiments made using loops of different radii in combination with a plane are described 8045 some peculiarities of the current potential characteristics of positive corona discharge 8046 indication of the development stages of positive corona discharge in the atmospheric air experimental technique is described for investigating the development of the discharge by means f the various optical acoustic and electrical effects involved the correlation between these effects is demonstrated 8047 radiation of plasma noise from arc discharge radiation from cold cathode dc are discharges in air has been observed at frequencies of and the oscillation is thought to be generated by periodic electron emission from the cathode caused by a small perturbation of the potential gradient due to variation of the ion sheath potential 8048 electron resonance in gas discharges brief description f experiments in which absorption lines were observed by paramagnetic resonance technique using a cavity resonator constructed so that the gas discharge occupied the region of maximum microwave magnetic field strength the results indicate that this may constitute a sensitive method for studying the variation of concentration of free ions 8049 space charge effects in a high frequency discharge details of experimental work on the effect reported in of the current flowing in a circuit connecting the external electrodes and including a high resistance r is measured and its relation to the applied voltage and to the pd between the internal electrodes examined when r is very high discontinuities in the characteristic and hysteresis effects are observed with change in applied voltage the latter are studied in further detailed oscillograms a theoretical explanation of the results is discussed 8050 noise of gas discharge plasma measurements were made in the frequency range on a discharge in a tube containing argon and hg vapour at a pressure of about mm hg probe currents of and were used current noise was approximately proportional to as with semi conductors see also of 8051 an evaluation of plasma ion temperature measurements made by the double probe ad and other methods are reported 8052 energy distributions of field dependent secondary electrons report of an experimental investigation of the emission from thin films of a retarding field technique was used the energy distribution was found to be maxwellian with values ranging from zero to and average values of to depending on the applied field the method is useful for determining the surface potential of the emitter 8053 experiments on the behaviour of an ionized gas in a magnetic field probe measurements in a plasma comprising electrons and helium ions in a toroidal tube with a toroidal magnetic field reveal an oscillatory current which is interpreted as indicating fluctuations of ion concentration consistent with magnetohydrodynamic waves of the type described by alfven of microwave measurements on a toroidal cavity resonator indicate that the degree of diffusion control in helium at low pressure is very much less than expected from the classical theory of ambipolar diffusion of ions and electrons in a magnetic field the diffusion coefficient magnetic field curve passes through a minimum at about tentative explanations of the experimental results are advanced 8054 various ways of using cavity resonators in paramagnetic resonance note on operating conditions for greatest sensitivity in signal detection the cavity resonator not being matched to the guide cases considered are oscillator tuned to cavity resonance frequency ratio of reflected to incident power and oscillator frequency varying around resonance frequency 8055 i ifield equations for a fluid electromagnetic field system a relativistic generalization is presented of the macroscopic equations of electromagnetism 8056 cauchys problem in relation to a fluid electro magnetic field system equations derived previously above are studied by an analysis of cauchys problem 8057 reflection of a transient electromagnetic wave at a conducting surface a treatment of oblique incidence reflection from the plane interface of a dissipative medium the inversion of the laplace transforms can only be carried out in closed form in special cases series solutions are developed for the general case and numerical results are presented graphically a possible application of the results to the case of a lightning discharge waveform and reflection from a sharply bounded ionosphere is noted 8058 an integral equation governing electromagnetic waves the problem discussed is that of determining the solution of the helmholtz equation for the region outside a simple closed curve boundary at which values of u or its normal derivatives are prescribed by introducing a suitable parameter constructed by conformal mapping the problem is reduced to a new fredholm integral equation whose solution is independent of conditions inside the boundary scattering cross section is discussed 8059 greens functions for the cylinder and the sphere the investigation of diffraction of is continued the exact expression for the greens function is split into two parts corresponding respectively to the geometrical optics wave and the surface wave a semi asymptotic solution is thus obtained which is valid for quite small obstacles the surface waves are shown to be identical with the residual waves discussed by watson and by van der pol and bremmer in connection with wireless telegraphy 8060 backscattering from wide angle and narrow angle cones solutions are obtained for the diffraction of the waves radiated by scalar and vector point sources on the axis of a semi infinite cone the scalar problems are solved by the method of characteristic greens functions to yield directly various alternative representations whose different convergence properties are discussed the vector problem is solved by an application of spherical transmission line theory to evaluate the plane wave scattering observed far from the cone tip a highly convergent contour integral representation is selected and evaluated approximately for the special case of backscattering from cones having large and small apex angles the results for the large angle cone exhibit the transition from a backscattered spherical wave to a plane wave as the cone degenerates into an infinite plane 8061 measurement of microwave diffraction from a long slit in a thin conducting plane an outline is given f of technique used to produce a uniform incident plane wave results of measurements of the intensity of the diffraction field are shown graphically for longitudinal and transverse polarization of the incident wave 8062 diffraction by apertures theoretical and experimental investigations are reported of the diffraction of plane em waves by circular and elliptical apertures in plane screens integral equations are derived for the distribution over te the apertures and the aperture transmission coefficient is determined by a variational method the closeness f of the agreement between experimental and theoretical results shows that the method is capable of providing good approximations to the actual field values the measurements were made in the band using an image plane technique 8063 the edge conditions and field representation theorems in the theory of electromagnetic diffraction discussion is presented relevant to the case of a perfectly conducting screen of infinite extent with an aperture of finite area order conditions are developed which must be satisfied by the field components in the neighbourhood of the edge as a consequence of the requirement that the total energy in a finite c volume must be finite the boundary value problem is formulated as a pair of simultaneous integral equations from the solution for the edge region the functional form of the local fields can be determined without assuming a particular type of expansion an indeterminacy present in the system of local integral equations can be removed when the local behaviour of certain field components is known in detail 8064 simultaneous partial absorption reflection and transmission of a uniform plane wave by a thin metal layer simple analysis is used to derive expressions for the energy reflected transmitted and absorbed for a normally incident wave for given conductivity the absorbed energy has a maximum value of half the incident energy at a particular value of thickness the reflected and transmitted energies being then equal 8065 thermodynamical theory of galvanomagnetic and thmomagnetic phenomena 8066 spin echo memory device a proton rich sample placed in a strong inhomogeneous magnetic field of mean strength h was subjected to a pattern of relatively weak radio frequency pulses at the larmor frequency of the protons in the field h the pattern was then recalled by applying a strong rf pulse at a later time as in the spin echo technique it is shown both mathematically and experimentally that such a series of pulses varying in amplitude can be memorized by the spin system of protons for times as long as one second and then repeated preserving both shape and relative amplitude spin echoes are discussed by hahn in 8067 the distribution of temperature along a thin rod electrically heated in vacuo part time lag expressions obtained previously of february for the steady state temperature distribution are used to study the increase of temperature accompanying a small increase in heating current over a considerable region near the centre of the rod the temperature variation can be completely represented by a simple exponential law involving a single relaxation time whose magnitude can be readily calculated this method is compared with that based on the fourier expansion the latter can be adapted for general use by introducing an effective length to replace the actual length of the rod for a given temperature at the centre the relaxation time varies inversely as the ratio of surface to volume and is thus smaller for a ribbon filament than for one of circular cross section as observed by prescott and morrison vol 8068 radio astronomy in hawaii observations are being made of cosmic noise at frequencies near and using a lloyds mirror technique the interference patterns observed are discussed in relation to the nature of the sources and to ionospheric and solar variations 8069 interferometer observations of solar radiation at the distribution of brightness over the solar disk has been studied by observations at marcoussis subsequent to those reported previously of the sensitivity of the system was sufficient for reliable measurements of interference of magnitude down to the results confirm that at this frequency the suns apparent diameter is slightly greater than for the visible disk and limb brightening is present 8070 new array for radio astronomical observations of the suns brightness at equipment installed at marcoussis comprises four identical parabolic mirrors of diameter located respectively at and along an line where the four aerials are connected to a single receiver by lines of equal length the overall length of this array is as compared with for a continuous mirror to give the same ha half power lobe width the arrangement enables the first six fourier harmonics of the brightness distribution over the sun to e be observed at true amplitude 8071 the apparent specific resistance of an inclined plane stratum 8072 fundamental types of geomagnetic activity k indices obtained from observations at irkutsk geomagnetic latitude watheroo slutsk and tashkent are compared and discussed the average k indices and st variations for irkutsk are presented graphically 8073 establishment of a new process of terrestrial demagnetization period of the latest demagnetization cycles recorded for our planet analysis of figures from observatories covering the whole world indicates oscillations in the intensity of the terrestrial magnetic field since an average period of years i is inferred for the remagnetization demagnetization cycles 8074 solar corpuscles responsible for geomagnetic disturbances a qualitative hypothesis is presented 8075 annual variation of the magnetic elements 8076 note on the occurrence of world wide sscs during the onset of negative bays at college alaska sudden commencements followed by a period of storminess may have an atmosphere source which is related to sudden changes in auroral activity 8077 geomagnetic activity and sunspots analysis of observations by the method of superposed epochs shows that geomagnetic activity following the central meridional passage of certain sunspots is related more closely to their rf radiation than to their eruptive intensity 8078 correlation between the solar corona and the geomagnetism for the remarkable m regions in 8079 on the distribution of refractive index in the lower atmosphere in japan radiosonde data for heights up to are analysed contour maps show the derived distribution of effective earth radius factor for day and night in each month of the year the distribution is closely related to the movement of the air mass predicted values of field strength for over a path are generally greater for summer than for winter in agreement with observed values 8080 tidal oscillations of the lower stratosphere diurnal and semidiurnal variations of wind occurring in the lower stratosphere appear to be associated with solar tides the semidiurnal variation in the stratosphere is in phase with and of comparable magnitude to the semidiurnal variation at the earths surface the diurnal variation in the stratosphere is of similar magnitude to the semidiurnal variation 8081 viscosity in the high atmosphere 8082 widespread diurnal variations of effective slope of the ionosphere measurements have been made at seagrove radio research station nz of the bearing and elevation angles of signals received on from nandi fiji distant almost magnetically north and on from brisbane queensland distant almost magnetically west from these measurements the effective slopes of the ionosphere are found to be related at places about apart and the average diurnal variation of these slopes is determined 8083 storms in the ionosphere a general survey of existing knowledge and theories of the world wide disturbances in the upper structure of the ionosphere observed at times of magnetic storms the effects on long distance short wave communication are briefly indicated 8084 behaviour of the ionosphere at rome during the period ionosphere records obtained at rome are analysed the normal variations are established predicted values of are shown graphically 8085 movement of the f region using three spaced receivers continuous recordings were made in massachusetts during the period august december of a vertical incidence and two oblique incidence pulse transmissions the base lines for the latter being km and km in directions roughly we and nw se horizontal speed and direction of winds in the f region were determined from the time displacement of echoes at an average virtual height of average speed was and mean direction nearly parallel to the earths magnetic field monthly averages of mean direction showed a semiannual period with maximum deviation e of n around the equinoxes monthly verages of speed varying between nd sh w d n annual period with higher values in winter than in summer speed increased with height 8086 intermediate layers of ionization between the e and f layers of the ionosphere over ahmedabad n e observations are reported indicating the regular occurrence of two intermediate layers with virtual heights of km and km respectively both layers exhibit magneto ionic splitting the variation of the critical frequencies with the suns zenithal angle obeys a cos law the value of n being about true heights and thickness of the layers are determined for some cases the values of true heights are in good agreement with rocket observations 8087 geomagnetic control of the f region of the ionosphere noon values of and for march june and december of and plotted against geomagnetic latitude show the same type of geomagnetic control the equatorial dip in the f curves is more pronounced in the year of higher u sunspot activity see also of 8088 a measurement at ottawa of the change in height with lunar time of the e region of the ionosphere the method used by appleton and weekes to detect the lunar variation of height of the e region of the ionosphere has been used to determine the amplitude and phase of the lunar height variation at ottawa observations were made from october to december a sinusoidal variation of height of amplitude and period was observed the maximum height occurred about six hours after lunar transit this result differs in phase by six hours from that observed in cambridge in 8089 continuous radar echoes from meteor ionization trails preliminary results are presented of experiments giving support to the view that meteoric ionization is the most important factor in extended range chf propagation 8090 interpretations of radio reflections from the aurora report and discussion o of measurement made at ithaca ny pulse radar experiments at show that reflections occur only during aurorae having ray structure the transmitted beam must be directed roughly normal to the rays echoes are complex cw signals at various frequencies between and showed a rate of fading roughly proportional to frequency ie much higher than the fading rate for normal ionospheric conditions observations are interpreted as indicating that echoes are due to scattering from numerous auroral columns of ionization fading is due to wind like motion of these columns other interpretations are critically discussed reasons are given for the possible occurrence of auroral reflection at f region as well as e region levels 8091 more about vhf auroral propagation radio amateur reports of auroral propagation at since indicate an extended communication range along ew direction rather than ns automatic recordings at show a predominance of auroral reflection around and am est an unexplained dip in the diurnal curve at midnight a marked seasonal trend and a decrease in occurrences from to in cw and radar experiments at college alaska in echoes came from far north of the auroral zone with ranges above km and never from the south reflections probably oy occurred at heights of angles of elevation were low no matter where visible aurorae occurred 8092 variations of the terrestrial magnetic field in hungary in russian english french and german the text of this survey is given in hungarian russian and german 8093 three examples of electrical servomechanism engineering servo mechanism system design problems treated by graphical methods which are explained include regulation of the output voltage of a constant speed independently excited dc generator and two cases of motor speed control 8094 component design trends metallic rectifiers approach infinite life developments in cu se si ge and rectifiers are surveyed new designs give reduced size and longer life together with higher operating temperature output current and reverse voltage ratings 8095 highly stable medium voltage direct and alternating sources for test purposes a review of methods of stabilizing supply voltages up to about and a note on methods of measuring small changes of alternating voltage see also of 8096 a cascode amplifier degenerative stabilizer description of stabilizers with modified cascode shunt amplifiers having gain 8097 generation of high voltage by charge transport on rotating insulator surfaces 8098 computer for universal application brief description of deuce a commercially available computer developed from the ace it has punched card input and output systems mercury delay lines for short term storage and a magnetic recording drum for long term storage the total floor space occupied by the equipment is by in 8099 an outline of an electronic arithmetic unit discussion of the design of a digital computer unit capable of performing and checking the operations represented by a b d c 8100 pulse switching circuits using magnetic cores design theory is presented for nonstorage uses of cores with rectangular hysteresis loops in digital computers to facilitate determination of the sense of the em processes a method of representation due to mayer is used in which the magnetic circuit elements are replaced by elements of a mirror system devices for eliminating output voltage on shuttling the core are discussed operating frequencies are attainable references 8101 a statistical method for solution of the laplace differential equation using electronic computers an electrical analogue of the galton board is used in which the rolling balls are replaced by pulses and the pins by pulse storage units 8102 analogue machine for calculation of the complex index of a body from its reflection coefficient a resistance network is discussed by means of which the phase shift of light reflected by a body can be calculated if the reflection coefficient is known for all wavelengths the refractive index can hence be determined 8103 the function of basic elements in digital systems the three basic elements of digital computers are a bistable element for storing a digit a gate for controlling the passage of a digit a diode for controlling the direction of passage a unit in the form of a beam deflection valve has been designed including a bistable element together with two gating elements see also below 8104 the geometric transformation of impedance diagrams an extension of the work of briner and graffunder of to the general case for a correction to the earlier paper see dec 8105 barkhausen noise from a cylindrical core the method used by krumhansl and bayer for calculating barkhausen noise of is simplified by considering an exciting field with a sawtooth rather than a sinusoidal waveform 8106 the variation with current and inductance of metal transfer between platinum contacts continuation of investigation described previously of warham curves of the net transfer are given for currents and inductances in the ranges and respectively four different types of transfer termed bridge short arc long arc and reversed short arc may be involved the results indicate that the life of pt contacts could be improved by controlling the effective circuit inductance at break to about 8107 analytical approach to the variable turns ratio autotransformers 8108 high frequency amplification using transistors measurements were made on transistors type oc and oc in the grounded base connection to assess them for use in narrow band if amplifiers the voltage feedback effect may lead to instability hence neutralization is essential at the higher frequencies the stage gain is reduced mainly by the base resistance and the collector barrier capacitance 8109 theory of equivalent circuits for junction transistors an equivalent circuit is discussed which differs from that of pritchard of only in respect of the arrangement of the current and voltage sources a simplified equivalent circuit including a triode valve is also presented 8110 the frequency dependence of transistor quadripole parameters the grounded base connection only is considered oertels equivalent valve circuit above is a satisfactory approximation up to a frequency about half that of cut off but a proper description of rf performance requires the addition of a base resistance and leakage conductance to the basic equivalent circuit measurements on a type oc transistor show satisfactory agreement with theory 8111 field theory of wave propagation along coils expressions are derived for phase and group velocities and surge impedance in air cored and iron cored coils and transformer windings theoretical and experimental data for frequencies up to are compared 8112 the design of coils for the production of high magnetic fields design curves are presented for coils of rectangular cross section for producing intense transient magnetic fields using energy obtained from a bank of charged capacitors 8113 a reversible binary counter a multivibrator type counter performs addition or subtraction depending on application of a control signal to a two gate system interposed between consecutive counter stages the control signal may be obtained from a multivibrator circuit similar to the counter stages applications in digital analogue conversion and in an interpolator are discussed 8114 transistor choppers for stable dc amplifiers two fused junction transistors driven at power frequency are used in a switching circuit for converting weak dc input signals into proportional square wave ac signals 8115 multi electrode counting tubes applications other than straightforward counting operations are discussed for decimal counting tubes of various types the design of a pulse amplitude analyser using trochotrons and dekatrons in a matrix system is outlined the life of the tubes is comparable to that of ordinary valves 8116 investigations of laboratory production of printed circuits for communication equipment a brief report is presented on the practical aspects of very small scale production of printed circuits using the simplest tools only th electrical and mechanical properties of different chassis materials are tabulated as well as the properties and the treatments required by seven different conducting materials applications described include the production of components an amplifier a rc oscillator and a heterodyne receiver for the frequency band this receiver contains no inductive components see also of 8117 piezoelectrically activated low frequency mechanical resonators discussion of resonators comprising plates or bars carrying two relatively small piezoelectric crystals the parameters of the equivalent electrical quadripole are determined for flexural modes of some circular chladnis plate type resonators application to stabilization of sinusoidal oscillators is briefly described 8118 on the physical realizability of linear nonreciprocal networks the necessary and sufficient conditions are given that a matrix with arbitrary complex number elements be the impedance admittance or scattering matrix of a physical linear reciprocal network a canonical form for non reciprocal network synthesis is presented which applies to any linear n terminal pair n port system at any fixed frequency if the network i is passive the only circuit element required in addition to lossless inductors capacitors transformers and positive resistors is the gyrator if the network is active negative resistors and gyrators must be used in addition to conventional passive elements some discussion of matrixes with frequency variable elements is also given 8119 transient responses with limited overshoot the problem is considered of designing a system transfer function such that in the response to a step function input the overshoot shall be limited and consist largely of the principal mode of oscillation a method is stated by which the size of any real term in the response may be calculated relative to the maximum value of the principal model graphical conditions are given restricting the permissible pole and zero positions in certain cases when this ratio is specified the procedure is illustrated by examples 8120 design of parallel t resistance capacitance networks formulae are derived for networks having a transfer characteristic symmetrical with respect to resonance frequency and a minimum loss for a prescribed frequency discrimination 8121 symmetrical quadripoles operated as asymmetrical transformers a theoretical investigation is presented of the behaviour of passive linear quadripoles in asymmetrical operation the analysis is based on introduction of the characteristic iterative impedance multisection band pass filters with different output and input impedances are built up with sections which have similar frequency characteristics and phase constants but geometrically graduated impedances a numerical example is given of a transformation for the frequency band 8122 the initial transient behaviour of filters with characteristic amplitude response the distortion of a step voltage input by butterworth type and tchebycheff type filters is analysed calculations are made for all pass equalizing networks for the former type 8123 a note on time series and the use of jump functions in approximate analysis the response of filters to jump function inputs is investigated jump transfer functions and serial operators for common types of filter are tabulated the method is compared with that described by tustin 8124 the matrix approach to filters and transmission lines use of matrices provides a direct and flexible method of treatment a simple graphical procedure is indicated for investigating filter characteristics 8125 a new method of determining correlation functions of stationary time series 8126 the transient response of rf and if filters to a wave packet 8127 a novel microwave attenuator using germanium the device comprises a thin rectangular slab of ge set obliquely across a waveguide with current leads attached to the two ends and a magnetic field applied parallel to the face of the slab so as to control the concentration of current carriers as described by weisshaar and welker of attenuation of db was obtained with a pulsed control current of 8128 the hybrid ring a hybrid circuit for very high frequencies input admittance and coupling attenuation are calculated as functions of frequency good agreement with measured values is obtained methods of increasing bandwidth are discussed and a practical arrangement is described for the band using a construction similar to microstrip 8129 suggestions on constructing oscillators the operation of various valve and transistor oscillators is analysed fixed and continuously tunable oscillators pulse generators and two frequency oscillators for special applications are discussed 8130 the generation of millimetre waves theory is presented for spark generators experimental evidence generally supports the theory useful results can only be obtained with sparks in oil 8131 ultra low frequency oscillator a cr circuit using resistors and polystyrene capacitors of moderate values is described for obtaining oscillations at frequencies down to the effective value of the resistance is increased by use of the cathode follower effect 8132 parallel network oscillators general principles are discussed of electronically tunable wide band oscillators having two signal paths with their outputs added and a common feedback path the tuning is performed by differentially controlling the gain in the two paths eg by push pull modulation particular arrangements described include a twin triode circuit using an artificial transmission line network giving a tuning ratio and a four valve circuit with lead and lag networks giving a frequency range nearly independent of centre frequency amplitude constancy stability waveform and noise are examined 8133 a simple quartz crystal oscillator driven by a junction transistor the transistor is connected with grounded base and the quartz crystal is operated in its series mode the frequency range is up to about and the output power up to about 8134 four decade frequency divider division of any frequency from sub audio to by any whole number up to is accomplished by a direct reading divider using binary counter circuits 8135 design of coaxial cavities for valves with planar electrodes the cavities form the double coaxial line structure used in conjunction with a disk seal type valve for grounded grid operation as amplifier or multiplier a graphical method of design is presented which involves only functions of the characteristic impedance once the operating mode has been chosen criteria are explained for determining the diameters of the two cavities for optimum response for higher mode operation the response can be improved most easily by the introduction of a suitable discontinuity three types are considered the occurrence of spurious resonances is also discussed 8136 design of hf and if amplifiers for multi channel fm links bandwidth required is determined from the side band amplitudes for given modulation index and from the permissible distortion expressions for involve the derivatives of the amplifier response curves and are tabulated for single stage circuits and two stage band pass filters the computation for multistage circuits is shown to involve the same derivatives under ideal conditions second harmonic distortion would be eliminated by exact tuning to the central frequency and third harmonic distortion sufficiently reduced by using symmetrical filters with a coupling coefficient in practice tuning is not exact but second harmonic distortion can be kept at a tolerable level by adjustment of the pass band response at the alignment stage valve capacitance variations are allowed for in the shunt circuit capacitance neutralization can practically eliminate the effects of feedback via grid anode capacitance criteria for the choice of if are explained 8137 circuit design factors for audio amplifiers close regulation of the anode supply of a cathode follower driver stage in a power amplifier is achieved by using a regulator triode operated by a diode connected to the driven grid circuits discussed include improved versions of williamson and ultralinear amplifiers 8138 design for a watt high quality amplifier part details are given of the circuit lay out and performance of an amplifier with an output stage of two type el high slope pentodes in push pull with partial screen grid loading part of july 8139 a new circuit for balancing the characteristics of pairs of valves a more detailed account of the work described previously of april 8140 vx band receiving amplifier a regenerative klystron amplifier is described suitable for use in a microwave television receiver having a gain at with a bandwidth of 8141 problems of magnetic pre amplifiers the topics discussed include the quality the effect of core shape on the magnetization characteristic effect of characteristic of valve or semi conductor rectifier on amplification and effects of incomplete magnetic decoupling of input circuit 8142 representation of physical quantities in formulae tables and coordinate systems a comprehensive discussion covering both fundamental physical principles and typographical aspects 8143 a new system of logarithmic units 8144 proposal for a new aether drift experiment a method of greater sensitivity than essens of uses a resonant cavity to produce a phase change in a signal form a fixed frequency oscillator 8145 derivation of the laws of relativistic electro dynamics for a vacuum from the energy quantum model theory developed previously of june is extended to include the case of systems in motion 8146 wave mechanics theory of electron optical image formation part 8147 electrostatic averaged boundary conditions for wire mesh a brief review is given of the existing methods for determining the screening effect of a mesh and a general derivation is proposed of the boundary condition for a mesh by the method of averaging the field the results obtained are applied to the determination of the screening effect of an earthed uniform spherical mesh with respect to a charge or a dipole placed at the centre and also to the determination of the effective potential in a triode see also below 8148 the field due to an infinite dielectric cylinder between two parallel conducting planes if the cylinder radius b is sufficiently small compared with the other dimensions involved the change of capacitance due to its insertion between the plates can be made proportional to where k is the dielectric constant of the cylinder for a conducting cylinder k is put equal to infinity applications include the measurement of the departure from uniformity of threads 8149 the ionic conductivity of dilute potassium chloride solutions at centimetric wavelengths measurements on solutions in the concentration range normal at a frequency of indicate the existence of a strong dispersion region at concentrations below normal which may be explained in terms of the perturbations by the applied field of a shell of water molecules surrounding the ion at a mean distance of 8150 the dielectric constant of free and bound water at microwave frequencies an attempt is made to assess and summarize results obtained by the authors and by other workers on the dielectric dispersion of water the water molecules in the temperature range from to water in hygroscopic salts aqueous gels and thixotropic gels estimation of hydration is also considered references 8151 the theory of the reflectivity of metals the reflectivity of an ideal metal for infrared radiation is calculated by a quantum mechanics method results agree with those obtained by dingle of using classical methods the diffuse reflection wave functions correspond more closely than the specular reflection wave functions to the actual electronic wave functions as indicated by experimental results 8152 skin and spiralling effect in stranded conductors discussion an analysis is made to determine the ac resistance and internal reactance of stranded conductors with or without a magnetic core at power frequencies assuming current density constant in individual strands the spiralling of strands tends to reduce skin effect data calculated for standard copper conductors with parallel and spiralled strands are listed 8153 theory of breakdown of inhomogeneous dielectrics 8154 formative time lag studies with high frequency discharges pulse techniques were used to study phenomena in coaxial cylinder and parallel wire systems in the frequency range where the discharge changes from corona type to one which completely crosses the gap the breakdown voltage drops about above the critical frequency 8155 space charge effects in a high frequency discharge part further discussion of results of experiments previously reported of cathode disintegration phenomena various shapes of characteristic and factors affecting the direction and magnitude of the emf are considered 8156 field emission and surface phenomena brief report of a symposium held at pittsburg in november 8157 delayed electron emission from metals measurements were made on a w foil substituted for the usual photocathode in a multiplier cell emission was excited by bombarding with electrons and measurements were started min after the bombardment the foil being simultaneously heated at a controlled rate the emission temperature curve passed through a maximum between and emission was eliminated by prolonged heating at but was restored by exposing the foil to the atmosphere at and abrading it the results support theory advanced by nassenstein of january 8158 electron emission from metal surfaces after mechanical working measurements were made on various metals in gas at a pressure of about torr using an electron multiplier the surfaces were abraded with a steel brush within the vessel emission time curves are shown for pb ca al and na the activity of the elements is correlated with their position in the periodic system oxidation may be the cause of the emission but no explanation of the mechanism is yet available 8159 on the escape mechanism of secondary electrons from insulators starting from the boltzmann transport equation and with certain simplifying assumptions theory is developed which takes into account the interaction of secondary electrons with lattice vibrations traps and occupied donor levels at high trap densities the secondary yield for high primary energies is inversely proportional to the square root of the trap density at low trap densities yield is independent of trap density expressions for the temperature effect for high primary energies are derived for polar and nonpolar insulators results for the first case have been confirmed by experiment 8160 antiferromagnetism the nature of the spin coupling in the antiferromagnetic oxide mno is discussed on the basis of a simplified mode the coupling between magnetic ions whose charge densities interact i with an intervening nonmagnetic ion but not directly with each other is described as the result of the polarization of the nonmagnetic ion 8161 representation of electromagnetic field by retarded potentials applications considered include a boundary problem and the equation of motion of electron gas in vacuo 8162 electromagnetic and acoustic scattering by a semi infinite body of revolution theory developed by kline of is used to determine the scattering of a plane wave incident along the axis of a perfectly reflecting body for the case of a paraboloid the solution of the em problem is obtained exactly in closed form the results are compared with those obtained from consideration of current distribution as in below 8163 electromagnetic and acoustical scattering from a semi infinite cone calculations of scattering cross section for em waves incident along the axis of the cone are made by the physical optics method based on current distribution and by the f exact method based on the appropriate field equations the solutions are practically identical for cone semi angles close to zero or the corresponding comparison is also made for acoustic waves 8164 studies of the diffraction of electromagnetic waves by circular apertures and complementary obstacles the near zone field measurements have been made of both magnetic and electric field strengths with diffracting apertures of diameter up to and normally incident waves experimental techniques for illuminating the aperture and probing the field are described wave lengths around cm afford a satisfactory compromise between reasonable overall dimensions on the one hand and reliability of measurements on the other results are shown graphically the predicted uniformity of the tangential magnetic field in the aperture plane is confirmed 8165 nonlinear theory of space charge wave in moving interacting electron beams with application to solar radio noise consideration of the exact equations for interaction between two neutralized electron beams indicates that steady state space charge waves can be propagated in such a medium the period of the wave depends on the amplitude and phase velocity the oscillation is simple harmonic for small amplitudes but deviates progressively from this condition as the amplitude increases beyond a critical amplitude whose value depends on the phase velocity the oscillation waveform becomes discontinuous the theory is used to estimate the relative intensity of the second harmonic component in solar rf outbursts reported by wild et al analysis based on theory of radiation from oscillating plasma leads to a value for the rf flux of the order of magnitude of that observed 8166 electrodynamic averaged boundary conditions for wire mesh equations and are derived which form a system of boundary conditions relating the averaged tangential components of the electric and magnetic fields on the surface of the mesh to the e averaged surface density of the current in the mesh the results obtained are illustrated by calculating the reflection of a plane wave from a plane uniform mesh and by determining the screening effect of a spherical mesh with respect to a small turn of wire carrying a current and located at the centre of the sphere 8167 the refractive index of water and aqueous solutions of sodium sulphate at metre wavelengths using the first method of drude the determination of the dependence of the refractive index of water on wavelength and temperature was extended to metre wavelengths and a temperature range from to similar investigations were also carried out to determine the dependence on concentration of the refractive index of s aqueous solutions of the main conclusions reached are the refractive in both cases increases linearly with temperature there is no anomalous dispersion at metre wavelengths for a given temperature the refractive index of a solution increases with concentration 8168 application of molecular beams to radio spectroscopic study of rotation spectra of molecules molecular beams may be used to obtain narrow spectral lines of width about and the rotation spectra of materials in the solid state quantitative estimates are made of the possibility of detecting the rotation transition in molecules at a frequency of using a spectroscope with a waveguide absorption cell and of the transition using a cavity resonator instrument see also of january 8169 growth of thin films an attempt is made to explain qualitatively the mechanism of growth on the basis of frenkels theory of absorption a summary is given of the most important parameters which may affect the structure of the film before during and after deposition 8170 investigation of the natural frequencies and natural oscillations of imperfect crystal lattices 8171 electromagnetics a treatment of maxwells theory and some of its applications suitable as a reference book for research workers mathematical functions entering into the solution of wave equations are dealt with in an appendix 8172 microwave spectroscopy includes chapters on spectroscope technique and design on measurements on gases liquids and solids on nuclear properties on molecular structure and on further possible applications of microwaves 8173 the diffusion of ionized meteor trails in the upper atmosphere the variation with height of the duration of radio echoes from meteor trails is discussed for the experimental conditions involved echo duration decreases approximately exponentially with increased height in agreement with diffusion theory the diffusion coefficient is between and in agreement with estimates based on rocket determinations of upper air density 8174 collision processes in meteor trails momentum loss cross sections for impacts between meteor atoms and atmospheric molecules are calculated the values of the ionization cross section derived from them are in agreement with those derived earlier by bates and massey the diffusion of ionization in a meteor trail is also discussed in relation to known mobilities of positive ions in gases 8175 nonlinear theory of space charge wave in moving interacting electron beams with application to solar radio noise 8176 character of solar noise observation equipment installed at hiraiso radio wave observatory principles of measurement and accuracy of equipment installed in march are discussed routine observations started in august the path of the sun is followed by a beam aerial system rotated every eight minutes with manual adjustment daily for change of declination during one minute in every eight the receiver input is connected to a noise generator for calibration purposes the double superheterodyne receiver has a bandwidth of about kcs results are compared with data from other stations 8177 solar electrodynamics the reduction in conductivity of an ionized gas by a magnetic field and the effect of a polarization electric field are discussed the theory has a bearing on conditions in the solar atmosphere above sunspots and on tidal oscillations in the ionosphere 8178 geophysical aspects of solar flares report of a discussion held at the royal astronomical society in november results of research on the geomagnetic and ionospheric effects of the flares were surveyed 8179 the irregular structure of the outer regions of the solar corona records obtained in of the radiation from the radio star in taurus of machin and smith and results of measurements made in june using aerials of greater directivity cannot be explained in terms of absorption or large scale refraction effects in the solar corona or large scale refraction effects in the solar corona but are consistent with a scattering theory an estimate is made of the size and the electron density of the coronal irregularities in the range of distance where is the solar radius the irregular structure may represent an extension of the visible coronal rays 8180 recent progress in the theory of the main geomagnetic field 8181 particularly large chromospheric eruptions and geomagnetic activity further analysis of observations indicates that geomagnetic activity related to the appearance of certain eruptions can be distinguished from that related to the central meridional passage of certain sunspots of july 8182 ion production rate in an atmosphere of exponentially rising temperature with height an expression is derived for the height distribution of the ion production rate assuming that temperature varies exponentially with height and also depends on the solar zenith distance results are similar to those of chapman for heights up to about in the f region the maximum rate of ion production and the height at which it occurs vary anomalously with solar zenith distance 8183 mechanisms of creation of i nospheric inhomogeneities results of approximate calculations indicate that a negative temperature gradient of about deg cm or greater at a height of about could result in thermal convection current such as would produce inhomogeneities and high velocity winds in the ionosphere the temperature at km is assumed to be about 8184 studies on the sunrise effect in regions e and f to be effective in causing ionization in a night time layer solar radiation must pass above the day time height of the layer the observed delay in time of sunrise effect is due therefore to the difference between the night time and day time heights of the layer considered observations made at calcutta over the period are in reasonable agreement with the theory 8185 absence of bifurcation in the e layer results of rocket measurements of electron concentration see eg of april seddon et al are adduced as evidence of absence of the bifurcation reported by lien et al 8186 further remarks on bifurcation in the e layer 8187 horizontal movements of ionization in the equatorial f region results of measurements at singapore during the period september april show the existence of a regular semidiurnal sinusoidal variation in the ew velocity component at the equinoxes around the december solstice during the mornings the movements were irregular no correlation with virtual height was found nor any regular ns movement 8188 origin of the f layer the splitting of the f layer into the f and f layers is considered to be be due to a thermal effect the maximum temperature occurs in the region of maximum ion production but since the density of gas in this region is a minimum higher electron concentrations will occur above and below it the region of maximum ionization lies in the lower half of the f layer and hence the f layer will be thinner than the f layer the formula derived for the height distribution of the electron concentration shows that the thermal process could lead to splitting of an ionized layer and also explains the secondary nocturnal maximum of the peculiarities of the equatorial layer described by osborne are briefly discussed 8189 nomenclature and conventions used in analysis of ionospheric data it is proposed to classify the layers according to their thickness a critical thickness is introduced to define the difference between normal layers which are always thick and abnormal thin layers caused by transitory phenomena the term critical frequency may be used of thin layers if account is taken of the intensity of the echoes characteristics directly determined and those found by extrapolation should be distinguished revised lists of characteristic symbols and code letters are given in appendices 8190 relations between the critical frequency of the ionosphere f layer at freiburg and solar activity centres during the years analysis is made separately for night time and day time observations no significant variation of f layer critical frequency was associated with the passage of those sunspots giving no rf radiation on passage of sunspots giving rf radiation the night time critical frequency suffered a significant reduction while the day time value was not significantly affected this night time effect is in concordance with observations of ionospheric absorption reported by davies and hagg of june 8191 ionospheric behaviour at khartoum during the eclipse of february observations indicate that the e and f layers behave as chapman layers having constant effective recombination coefficients of and respectively assuming a nonuniform distribution of the sources of ionizing radiation on the suns disk the positions and relative intensities of these sources and the frequency of the radiation are indicated the f layer records suggest the existence at the time of the eclipse of two component layers a lower one corresponding to the normal post sunrise f layer having a high and an upper one which is a later development of the lower having a low changes in d layer absorption confirm the asymmetrical distribution of sources of ionizing radiation there is no evidence of an eclipse effect on e ionization nor for a corpuscular eclipse in the f layer 8192 an apparatus for recording time delays between radio fading characteristics the equipment is designed for the study of ionospheric winds of and records time delays in the range with an instrumental accuracy of about 8193 sporadic e propagation 8194 dsir ionospheric absorption measuring equipment main design features are described of pulse transmitting and receiving equipment used at slough since highly stable operation is essential pulse duration is variable between and the frequency range is and a peak power output of is adequate for observer reception phombic delta and folded dipole transmitting aerials have been used the receiver is a superheterodyne with extra higigh gain and dynamic range and with provision for attenuation varying continuously up to about db double doublet and folded dipole receiving aee been used the display unit is a conventional cro 8195 collisional deactivation and the night airglow a possible reaction of the oxygen is indicated to explain the observed spectrum of the night airglow 8196 the earths exterior atmosphere and the counter glow the counter glow as related to modern geophysical theories with seven recent russian papers collected and translated by er hope theory based on observations suggests that a gaseous tail resembling that of a comet stretches away from the earth in the direction away from the sun a valuable contribution to the literature of upper atmosphere research 8197 asymmetrical servomechanisms servomechanisms in which the nonlinear element has an input output characteristic asymmetric with respect to the origin are considered even if the input signal is a pure sine wave the output will have a dc component that cannot be filtered out by the linear element the general feedback loop equations are reformulated and the new conditions of stability considered a temperature control device is treated a as an example 8198 feedback control systems the following papers are included quick methods for evaluating the closed loop poles of feedback control systems discussion correlation between frequency and transient responses of feedback control systems p coulomb friction in feedback control systems discussion describing function method of servomechanism analysis applied to most commonly encountered nonlinearities optimization of nonlinear feedbacks a relative damping criterion for linear systems errors in relay servo systems discussion effects of friction in an optimum relay servomechanism backlash in a velocity lag servomechanism determination of the maximum modulus or of the specified gain of a servomechanism by complex variable differentiation abstracts of others papers appear separately 8199 some saturation phenomena in servo mechanisms with emphasis on the tachometer stabilized system analytical methods of dealing with frequency response and transient response are described and various saturation effects are explained 8200 relative stability of closed loop systems the equivalence of a transfer function plot and a plot of the laplace transform of transient response is illustrated and the application of transform plots in the analysis of linear systems is described 8201 a differential analyzer study of certain nonlinearly damped servomechanisms advantages of the system described by lewis of over corresponding linear systems are illustrated and modifications to improve its operation are suggested 8202 limiting in feedback control systems study of the effect of limiting on system performance in terms of the frequency response 8203 open loop frequency response method for nonlinear r servomechanisms a graphical representation similar to a nyquist diagram is developed for indicating frequency response characteristics and for the synthesis of linear filters 8204 the synthesis of optimum transient response criteria and standard forms eight mathematical criteria for optimum transient responses are critically examined and the clear superiority of the minimum integral of time multiplied absolute value of error is demonstrated the application of this criterion results in the selection of standard forms which are presented in tables see also of january 8205 approximation of transient response from frequency response data a relatively short method is described involving an point graphical integration which gives accurate results for linear feedback systems with a closed loop transfer function of fifth order or below 8206 bibliography on feedback control a s classified list of references up to relating to the theory and application of feedback systems a list of relevant periodicals is also given 8207 control of metal build up in minimum pressure sensitive contact systems a review of designs aimed at reducing spire type metal transfer on contacts with gaps of and operating on pressures down to 8208 highly regulated rf voltage supply a rf output voltage of rms maximum with low harmonic content is obtained by using a crystal controlled pentode oscillator at the fundamental frequency with positive feedback regulation of the output is achieved by means of a negative feedback loop incorporating a high gain dc amplifier which supplies the oscillator screen grid voltage 8209 silicon power rectifiers for ac line operation used as half wave rectifiers with capacitor input filters typical alloy junction units rated for maximum rms input give output at a typical full wave rectifier with choke input filter will deliver ma at or at room temperature heat dissipating mountings are discussed 8210 rectifier filter characteristics approximate calculations are described for the design of half wave rectifiers with capacitor input filters and of full wave rectifiers with capacitor choke input filters the method gives results within about of measured values 8211 determination of frequency characteristics of automatic control systems using mikhailovs curves in russian 8212 aircraft prot ction rom thunderstorm discharges to antennas 8213 the effect of reactive components in the measurement of grounding circuits discussion of results of measurements of earth resistance using ac in the range and 8214 gating multipliers analogue computing equipment on lines proposed by goldberg of is described economy of materials is achieved by careful design of the switching circuit and by neutralization of the parasitic capacitances of the valves an accuracy to within one part in at a mean gating frequency of i is obtained 8215 a simplified method for the design of logical conversion matrices diode matrix m networks are discussed a numero graphical method is explained for converting from one numbering system to another possible applications for programming sequence control are suggested 8216 an analog electronic correlator for acoustic measurements the correlator described is of the class operating directly on the input signals ie using no carrier the magnetic drum time delay system described in of is used 8217 photoelectric reader feeds business machines ordinary print is scanned by a photocell and the resulting signals are coded and recorded on punched cards or tape for input to computers 8218 magnetic recording applied to digital computers the basic considerations involved in the design of the magnetic storage drum used in the cuba machine are discussed optimum dimensions of pole faces for recording and reproducing heads are calculated and design curves are given 8219 contact metals and relay contacts properties and comparative investigations a detailed experimental investigation is reported of the relation between contact resistance and the changes occurring at the contact surfaces current carrying current free and sparking contacts are discussed photographs are shown of contacts of various metals after service 8220 optimum shape coils analysis is presented for designing a coil to produce a required field at the centre of a cylinder with a minimum expenditure of power 8221 calculation of magnetic field strength in cylindrical coils expressions are derived for the axial component of the magnetic field using the fact that the field strength at a given point is proportional to the difference of the solid angles subtended by the end faces of the coil the expression for the solid angles is obtained in the form of a difference of two double series this can easily be evaluated approximately tables and graphs are given together with numerical examples illustrating the method the case of a multilayer coil is included 8222 parallel ferroresonant feedback type trigger circuit consisting of an ac winding on a ferromagnetic core shunted by a capacitance with auxiliary windings for excitation and polarization may be adjusted to present two and in certain conditions three stable states curves are given showing the influence of the various parameters 8223 a design method for direct coupled flip flops design procedure is described securing independence of valve characteristics and achieving stability with resistors and supply voltages which may vary by given percentages from the nominal values switching speed for given stability is a function of the supply voltages 8224 reversible dekatron counters bidirectional coupling in multistage counters is achieved without the use of gating circuits by providing the dekatrons with separate terminals for the two transfer electrodes between the ninth and zero cathodes 8225 the charging and discharging of nonlinear capacitors correction to paper abstracted in of 8226 bounds existing on the time and frequency responses of various types of networks 8227 tensor analysis and linear network theory 8228 transducer design for ultrasonic delay lines the suitability of quartz and transducers is considered for use in conjunction with and bonds between transducer and delay medium to widen the pass band a relative bandwidth of can theoretically be obtained using a transducer composed of with and with a bond to a fused silica delay line using quartz transducers a relative bandwidth of was obtained experimentally with a plastic bond and of with a solder bond theory based on equivalent circuits is given 8229 the ultra bandwidth finline coupler the finline coupler is a recently developed microwave circuit element with which it has been possible to assemble hybrid junctions directional couplers and polarization selective couplers capable of operating over bandwidths of at least three to one in frequency constructional details and experimental d results are given 8230 effect of surface roughness on losses in microwave resonant cavities measurements of value were made on a cylindrical mode cavity specially designed so that the internal surface could be treated in various ways eg by plating or polishing the magnitude of the discrepancies between the measured values and those calculated for a perfectly smooth surface depends on the dimensions of the surface irregularities and is very small when the surface unevenness is no greater than the skin depth 8231 the excitation of circular polarization in microwave cavities a matrix method is used to study the effect of transition pieces and differential phase shifters on waves propagating in guides with two degenerate orthogonal modes three different methods are discussed for generating circularly polarized waves in a cavity coupled to the side wall of a guide the preferred arrangement uses a square guide with incident wave polarized along one transverse diagonal and reflected wave polarized z along the other and a circular coupling window centred in the width of one wall at an appropriate distance from the reflecting end 8232 an approximate graphical analytical method for plotting the frequency characteristics of a linear system from its transient characteristic the method proposed is based on the approximation of the area under the given curve by a sum of triangles it is of importance in the design of automatic regulation systems 8233 transient response calculation approximate method for minimum phase shift networks the well known method of linear segments for the calculation of zero pole locations of the transfer function corresponding to a given attenuation characteristic is extended by allowing the zeros and the poles to assume complex instead of only real values 8234 matrix algebra as a sequel to the quaripole theory presented by cutteridge of special procedures and applications involving the general parameter matrix of passive quadripoles with bilateral circuit elements are discussed 8235 electrolyte tank for solving network problems 8236 synthesis of a network for a prescribed time function the moment generating function method and the time series method are discussed they yield physically realizable networks under general conditions three particular types of response are considered as illustrations 8237 design of low pass ladder networks to work between unequal resistances discussion of conversion data to enable formulae established in an earlier pp paper of to be used ror cases of unequal terminating resistances curves are presented relating the ratio of input and output branch resistances to the ratio of input and output decrement for up to five branches see also of february 8238 band pass filters using strip line techniques practical details are given of materials and dimensions for uhf filters and for matching them to coaxial lines typical units have mid band insertion loss with attenuation at off mid band frequency 8239 tchebycheff type band pass filters with arbitrary number of circuits extension of the method developed by dishal of undercoupled as well as critically and overcoupled circuits are dealt with 8240 coaxial resonator filters from an analysis of an equivalent band pass circuit an expression is derived for insertion loss in terms of the loaded and unloaded q factors and the electrical design parameters are related to the dimensions of the coupling loops the insertion loss characteristic of n identical resonators in tandem is determined by considering shunt susceptances equally spaced along a transmission line an alignment procedure and arrangements for frequency multiplexing are described 8241 microstrip applied to band pass microwave filters impedance measurements are made by connecting the microstrip line through a network to a waveguide or a coaxial slotted line characteristics deduced are phase velocity is constant over a wide range of frequencies wavelength in microstrip is greater than the value corresponding to a transverse em mode between infinite parallel plates approaching this value asymptotically for very wide strips the dominant mode propagated is not a pure transverse em mode the characteristic impedance of a microstrip line is approximately equal to the reciprocal of the product of capacitance per unit length and phase velocity the design of resonant sections by placing obstacles such as posts at proper distances is discussed in detail 8242 theory of noisy quadripoles analysis is based on equivalent circuits in which the original quadripole is depicted as noise free all noise sources being transferred to a separate noise quadripole connected in front of it the noise figure is found from the equivalent noise resistance the equivalent noise conductance and a complex correlation admittance methods for the experimental determination of the elements of the noise quadripole are outlined 8243 on asynchronous action an analysis is made of quenching and excitation of oscillations by an external oscillation of unrelated frequency the excitation depends only on the transfer of the position of equilibrium across the bifurcation point in the stability diagram and is hence observed only in hard systems whereas quenching can occur in hard and in soft systems 8244 cathode follower coupled phase shift oscillator 8245 a graphical sinusoidal analysis of a nonlinear rc phase shift feedback circuit frequency response curves are discussed of af oscillator circuits including nonlinear eg thyrite resistors in the feedback loop over a part of the frequency range the voltage function is triple valued the method used involves the graphical superposition of the voltage resistance characteristic of the nonlinear resistor on that of the parallel circuit 8246 the realization of a given transfer coefficient feedback amplifier systems the design of feedback amplifiers using rc networks is discussed in general terms and in relation to analogue computers low frequency filters servomechanisms etc 8247 harmonic distortion in sinusoidal frequency modulation case of an amplifier stage comprising pentode valve and tuned transformer formulae are presented for calculating the harmonics and the total distortion present in the demodulated voltage numerical calculations are performed for five different sets of values of two important circuit parameters 8248 electrical integration methods following brief theoretical discussions of the rc miller and wiegand hansen of integrators a new quasi exact integrator circuit is described and both an approximate and an exact theory are given the errors inherent in the various methods are discussed and graphs for their estimation are given 8249 design of choke magnetic amplifiers with complex load the design of transductors is considered from the practical point of view the characteristic curves of four core materials of russian origin are given to illustrate the method the design of a transductor with an amplification factor of working into a load is worked out in full 8250 an amplifier based on the hall effect the dc or ac signal is fed to a suitably matched coil wound on a laminated magnetic core having a narrow gap into which is inserted a thin rectangular slice of single crystal insb dc is passed through the slice and the hall emf is picked up and applied to a matched load high values of power gain are theoretically possible an upper frequency limit is set by core losses for comment by hm barlow and authors reply june 8251 feedback stabilized transistor amplifier loading of the feedback network is avoided by the use of an emitter coupled differential amplifier in the first stage a three stage amplifier using ge transistors gives an overall gain of independent of the transistors used si junction transistors give more stable operation at high ambient temperatures circuits and component values for typical amplifiers are given 8252 cubic distortions in ring modulators translations of paper abstracted in of 8253 an electronic phase shift tube for microwave frequencies the transmission of microwave radiation through an electron gas supported by a gas discharge plasma situated in a waveguide structure is discussed for the case in which the electron collision frequency is much less than the microwave frequency and an expression is derived for the phase shift arising from the change in guide wavelength a gas discharge phase shift tube has been developed on this principle and efficient action obtained by using the negative glow region of the discharge the performance of the tube is discussed in detail 8254 electrical fluctuations and thermal radiation text of a lecture giving a broad nonmathematical review of theoretical work on thermal fluctuations noise with particular reference to the uhf region 8255 fundamental electromagnetic quantities anomalies involved in the generally accepted dual system of electric and magnetic quantities are discussed a threefold system comprising magnetism conduction electricity and dielectric electricity is proposed as an improved basis 8256 study of some problems of electrostatics elementary electrostatic phenomena are deduced from the simple electronic theory of metals the phenomena of conduction in homogeneous metals and from metal to metal contact potentials and the peltier effect are examined the treatment is essentially nonmathematical 8257 survey of researches in physics in hungary part short surveys by different authors are given on several subjects including research on ferromagnetics magnetic moments of atomic nuclei and the force on polarized media 8258 extension of frohlichs general theory of the static dielectric constant to dielectrically anisotropic materials 8259 applications of the piezoelectric equations of state application of the general linear piezoelectric equations of state of to plates and thin bars particular stress and strain systems are considered a uniform notation is introduced for the elastic and piezoelectric constants used the relation between dielectric constant at constant stress and at constant strain is investigated electromechanical coupling factor is discussed 8260 the resistance of an elliptic plate formulae for the resistance are derived in the form of infinite series capable of numerical evaluation to any degree of approximation for two different electrode arrangements 8261 dependence of the electric strengths of liquids on electrode spacing measurements have been made on hexane heptane and tetradecane using electrode spacings of the electric strengths are found to vary inversely with the logarithm of the separation as predicted by theory 8262 constriction of the positive column of a glow discharge at high pressure 8263 the growth of electrodeless discharges in hydrogen 8264 electrical breakdown at very low gas pressures a discussion in terms of atomic collision data of problems involved in the interpretation of an observed anomaly in the variation of breakdown strength with pressure and in the estimation of the pressure at which breakdown would occur if it were due solely to ionizing collisions in the body of the gas 8265 studies of externally heated hot cathode arcs part plasma density distributions in the anode glow mode analysis of the plasma density distributions indicates that the anode glow mode can exist only if the emission capacity of the cathode is at least twice as great as the anode current this is supported by experimental evidence part 8266 experimental investigations on electron interaction certain observations in low pressure gas discharges and in magnetrons suggest an electron interaction effect several orders of magnitude in excess of the theoretical values based on binary encounters only the validity of the theory was tested by experiments in which a carefully colimated electron beam was shot through a charge cloud the scattering of the beam being directly observed both plasmas in thermal equilibrium and pure electronic space charges were investigated in both cases the degree of scattering observed is less than five times the value predicted by theories neglecting simultaneous multiple collisions hence the latter cannot account for the observed anomalies 8267 on the measurement of the average time delay in secondary emission the time delay of the secondary emission is measured by comparing the duration of short bursts of primary emission with the duration of the corresponding bursts of secondary emission the primary bursts are produced by deflecting a beam across an aperture at high speed while the secondary beam is scanned over eg a fluorescent screen the duration of the secondary pulses is longer than that of the primaries by an amount which depends on the accelerating voltage 8268 fundamental wave functions in an unbounded magneto hydrodynamic field 8269 particle transport electric currents and pressure balance in a magnetically immobilized plasma an analysis of a plasma immobilized by a magnetic field shows that each kind of charged particle has a general drift perpendicular to the gradient of the field but that there is no corresponding electric current density there is an exact cancellation arising from the gradient of the larmor radius the current density which is present arises exclusively from the particle density gradient and is not associated with any drift of matter 8270 antiferromagnetism a survey of theoretical and experimental aspects the spin wave approximation is useful especially for lattices of higher dimensions and for larger magnitudes of spin this method can be easily generalized eg so as to take second neighbour interactions and dipole forces into account great mathematical difficulties are involved in the refinement of the theory to apply to higher temperatures and the calculation of higher order quantities such as the fluctuations or the short range order over references see also of 8271 statistical models of ferrimagnetism a theoretical discussion of the properties of some idealized ferrimagnetic crystals the lattice being considered divided into two sublattices 8272 a short modern review of fundamental electro magnetic theory further discussion on of january 8273 diffraction of electromagnetic waves by a metallic wedge of acute dihedral angle an investigation is made of the field produced by reflections within the space included between two plane condductors set at an angle experimental and theoretical results are given for angles of and discussion indicates that the field pattern for angles which are integral fractions of can be computed on the basis of geometrical optics 8274 the diffraction of a non monochromatic electromagnetic wave by a slit and a grating a general solution is derived from kirchhoffs solution results of calculations and measurements are in good agreement over the range in which kirchhoffs solution is applicable 8275 elliptically and circularly polarized electromagnetic waves a general discussion of the subject and its applications in radar technique with extensive bibliography see also of august 8276 absorption of cm microwaves in some aromatic and aliphatic compounds in the liquid state 8277 microwave spectroscopy of gases recent developments in the field are outlined measurements have been made at wavelengths down to about 8278 distribution of radio brightness across the andromeda nebula measurements made with the helix aerial and improved receiver at the ob ohio state university are reported the frequency used was 8279 evidence of limb brightening of the sun at cm wavelength 8280 the sun in two dimensions at cm 8281 distribution of radio frequency brightness across the solar disk at a wavelength of cm results of three investigations see also and above indicate appreciable limb brightening contrary to results reported by stanier of there has been a marked change of brightness during the sunspot cycle the radial extent of the distribution is greater at the equator than at the poles 8282 magnetic field of the sun the principles of operation of babcocks zeeman effect solar magnetograph are described and some experimental results obtained are shown in the form of magnetograms the general magnetic field strength is oersted of polarity opposite to that of the earth large local bipolar and unipolar fields have been observed and are shown in several of the magnetograms the field distribution varies from day to day and fluctuations of the order of oersted are believed to occur in local fields with periods of about min the unipolar fields are probably the sources of corpuscular emission which produce geomagnetic storms with a day recurrence period 8283 some observations in bratislava during the solar eclipse on june relative measurements were made of the total radiation fig radiation in the red yellow and ultraviolet bands the air temperature detected intensity of broadcast transmissions from bratislava and the level of cosmic radiation the maximum in fig occurred about min before the minima in figs and 8284 scientific programme of the international geophysical year an outline is given of comprehensive investigations planned in various branches of geophysics and allied subjects including geomagnetism the aurora airglow solar activity and ionospheric phenomena 8285 theories of the earths magnetism 8286 a semi annual periodicity in the beginnings of recurrent magnetic storm series 8287 a note on the world wide distribution of the sporadic e ionisation a discussion based on data obtained during from ionospheric sounding stations of them in n america in geomagnetic mid latitudes the prevalence of e clouds is greatest in local summer daytime in the northern auroral and the equatorial zones no seasonal variation is apparent in the auroral zone there is a daytime belt of intense e ionization and in the equatorial zone one at night time these belts have different characteristics and appear to have different causes very marked variation with longitude has been noted 8288 a particular feature of the f layer at lwiro central africa observations over the period january may indicate that at the equinoxes the f layer rapidly drops sometimes to below km towards midnight by an apparent contraction following an equally rapid expansion often coinciding with the of measurable thickness corresponding to a night time e layer 8289 on radio measurements at jabalpur during the solar eclipse of june 8290 some geomagnetic effects in the equatorial f region o observations at ibadan nigeria during show that the midday minimum of the maximum concentration of ionization exhibited on magnetically quiet days disappears and is replaced by a maximum as the degree of magnetic disturbance increases the total ion content below the height of maximum ionization varies similarly perturbations due to magnetic disturbance have both diurnal and semidiurnal components difficulties in the application of martyns theory of are discussed and certain modifications are suggested 8291 on a new method of determining the height of the nightglow nightglow observations taken at two wo stations separated by a distance comparable with the height of the layer observed will show correlation over a period if both stations observe the same point the height of the point can hence be deduced observations taken during two successive nights give a height between and for the origin of the radiation 8292 equipment for lightning research on monte san salvatore the equipment has been appreciably augmented since the previous report of 8293 the significance of a nonterrestrial magnetic field in neutral stream theories of the aurora the hypothesis that a neutral stream of ions travels from the sun with a velocity of in a magnetic field of strength fits observed data on aurorae and magnetic storms 8294 on the electric field theory of magnetic storms and aurorae the electric field theory is further developed by taking into account the inertia of the beam of ionized gas emitted by the sun the initial as well as the main phase of storms can be accounted for see also below 8295 model experiments on aurorae and magnetic storms experiments on a magnetized sphere of were performed to check alfvens theory above although a proper scaling down is not possible some confirmation of the theory was obtained in particular the space charge accumulated in the discharge region discharges along the lines of magnetic force photographs of the discharge patterns produced at various electric and magnetic field strengths are shown and discussed 8296 radio reflections from aurorae part observations made with a meteor survey apparatus confirm the conclusions drawn previously of january the mean velocity of the reflecting regions changes from westwards at with diffuse echoes to eastwards with discrete echoes there is a diurnal minimum of echo frequency between and when the reflecting regions appear to be at rest and echoes are absent from to ut correlation is observed between the radio echoes the occurrence of visual aurorae and magnetic activity 8297 time scale and gain influence on servo performance the criterion previously applied in determining normalized transfer function coefficients of august can also usefully be applied in the selection of optimum gain or time scale for second or third order servo mechanisms 8298 the use of correlation techniques in the study of servomechanisms 8299 the dynamic behaviour of servomechanisms using thyratrons if the response of the servomechanism is linear the self inductance of the motor armature may be ignored in calculating the transfer constant of the system for discontinuous operation in continuous operation it must be taken into account a method of calculating the transfer function is presented for the general case of nonlinear operation but the formulae involved are cumbersome and an experimental approach may be preferable 8300 the economics of the transistor dc transformer hv supply units using power junction transistors are compared with conventional hv sources 8301 electrical properties of titanium dioxide rectifiers results obtained are similar to those reported earlier by breckenridge and hosler of the conversion efficiency of a bi tio rectifier remained constant during operation for at and during most of the test at but decreased rapidly during operation at failure occurring after the spread of the rectification characteristics of rectifiers is presented graphically a well as the distribution of peak dynamic current voltage characteristics in specimens 8302 a precision direct current stabilizer a dc stabilizer is described which delivers stable to a few parts in a degenerative feedback system is used with a contact modulator amplifier self oscillation being prevented and the frequency response improved by an auxiliary ac feedback loop facilities for monitoring the stability are provided 8303 a voltage stabilizer for a radio frequency extra high tension set the voltage to be stabilized is applied across a bank of resistors and a fraction is balanced against a rf reference voltage the difference being converted in a circuit comprising two valves type to a signal which is amplified rectified in a phase sensitive circuit and applied to control the screen voltage of the main oscillator curves show the variation with load current up to for nominal output voltages of and kv 8304 heavy duty high stability dc power supplies series valve stabilizers are considered as a simple step by step development of the cathode follower by shunting a resistor or barretter across the series valve substantially constant loads of several amperes can be stabilized to per cent full circuits are given of two typical units providing outputs of and watts with efficiencies of and per cent respectively the latter includes a device providing audible warning when supply voltage variations exceed the range stabilized automatically 8305 the use of an electron velocity analyser to stabilize a direct voltage source to a few parts in a million a degenerative feedback stabilizer circuit is used in which the signal to the feedback amplifier is obtained by accelerating a beam of electrons by the voltage to be stabilized and measuring the velocity by deflection in a fixed magnetic field much larger signals can be obtained in this way than by use of the usual resistance type potential divider 8306 electronic computers for the businessman a survey covering commercially available digital computers important characteristics are tabulated 8307 storage devices for high speed calculators a survey covering thermal optical sonic delay electrochemical cr tube ferroelectric capacitor magnetic drum magnetostriction and magnetic core devices 8308 a proposed modification to the csiro mark computer the suggestion is put forward that a facility be built into the machine for distinguishing between machine commands and interpretive or hyper commands so that the former are performed directly while on receipt of one of the latter control is directed to the head of the interpretation routine with simultaneous storage of the link datum to enable return of control to the nedt programme command after performance of the hyperfunction this would result in a considerable gain in speed see also and of 8309 automatic square rooting a computation method is described with examples and an indication is given of the type of additional circuit required in computers of the leo type of pinkerton et al the square root of a digit number is obtained in 8310 multiple coincidence magnetic storage systems in existing magnetic matrix storage systems a given location is selected by applying to two intersecting wires a current equivalent to one half of the selecting field this situation is generalized so that any core is selected by energizing wires each with a current equivalent to of the selecting field the advantages gained are in the correspondingly smaller fields applied to the nonselected cores or alternatively in the faster switching times obtainable by applying a total field greater than the coercive force to the selected core specifically a storage matrix is illustrated in which the cores are toroids etched from a continuous sheet of magnetic material 8311 a computer for solving some problems in connection with travelling wave particle accelerators 8312 digital computer plug in units and associated equipment basic circuits etched on small boards are plugged into standard contact receptacles of which are combined in a sub rack assembly complete with power wiring 8313 the unit step the unit pulse and the dirac operator the unit pulse is identified as the derivative of the unit step and the identity between the unit pulse and the dirac function is demonstrated by considering the establishment of a direct current in a circuit with finite inductance but vanishing capacitance 8314 stamping metals by etching the process briefly described consisted of printing the pattern of the desired circuit or part on a flat metal sheet or strip with an acid resistant ink and then etching away the unprotected metal the printing can be performed by a photographic lithographic or silk screen process 8315 resistors for radio interference suppression in otto cycle internal combustion engines 8316 directly coupled transistor circuits switching circuits using surface barrier and alloy junction transistors are described in many cases the only other circuit components required are resistors rise and fall times of about and respectively are obtained applications in digital computers are mentioned 8317 further analysis of transmission line directional couplers the conditions for infinite directivity in transmission line directional couplers derived by firestone of january are discussed more general conditions are derived valid for any degree of coupling 8318 frequency aging of high frequency plated crystal units the aging process is discussed in terms of contamination of the quartz crystal the influence of various production methods is examined data obtained with units in metal and glass enclosures are presented graphically 8319 the effect of temperature and acoustic impedance of vapours on the electrical constants of quartz measurements were made of the equivalent resistance of a crystal vibrating in vapours of various organic liquids at a given temperature the equivalent resistance depends on the pressure as the temperature increases the equivalent resistance decreases the rate of decrease depending on the particular vapour 8320 tunable temperature compensated reference cavity a design is discussed based on separation of the tuning and temperature compensation functions temperature compensation at fixed frequency is discussed first and the conditions for variable frequency are then deduced experiments indicate that a cavity with a double nosed construction can be made satisfying the theoretical requirements over a or band analysis is presented with reference to an equivalent circuit 8321 active ladder network analysis a computationally economical method is developed in which the voltage appearing across the final rung of the ladder is expressed as a function of the individual randomly distributed sources of emf by a reduction process involving successive applications of thevenins theorem to all the meshes the method is illustrated by examples 8322 representation of the general linear four terminal network and some of its properties non reciprocal networks are considered equations are formulated in terms of power and impedance a method of representation is developed based on introduction f a circuit element called the anti reciprocal transition in series with a reciprocal network power attenuation and matching are investigated a new criterion for classifying networks as passive or active is proposed a grounded emitter transistor amplifier is discussed as a particular application of the theory 8323 the design of quadripoles in the case of symmetrical quadripoles by writing where and are the impedance parameters defined earlier of general expressions are derived by a matrix treatment for the current and voltage in a ladder network in which the characteristic impedance term z occurs in the first degree 8324 synthesis of passive quadripoles it is shown that any passive a quadripole can be constituted by combining a two terminal network with a t or network the whole comprising four two terminal physically realizable networks with complex impedance 8325 a new method for investigating linear quadripoles z a treatment based on representation of impedance transformations by displacements on the surface of a sphere known graphical methods are made accessible to a purely geometric treatment by the method of projection problems of networks satisfying kirchhoffs laws can be solved with compasses and ruler 8326 impossible behaviour of nonlinear networks the following proposition is discussed an isothermal electromechanical system whose primary resistors are quasi linear cannot convert direct current to alternating current a resistor is said to be quasi linear if the voltage drop across it is a function only of the current and if the differential resistance is positive 8327 note on the kramers kronig relations this explicit form of the relationship between the real and imaginary parts of a physically realizable network function is correlated with the alternate conventions available for such problems the transformation from a linear frequency scale to a logarithmic one is simply effected by considering the mellin transforms of the appropriate functions 8328 some gyrator and impedance inverter circuits the design of feedback amplifiers to provide impedance inversion is considered negative impedance elements may be included to compensate for the residual impedances in the inverter when this is done the circuit exhibits gyrator properties measurements on a high stability amplifier with a series resistance of in the input lead indicated that accurate impedance inversion was obtained for load resistances from to 8329 nyquists and thevenins theorems generalized for nonreciprocal linear networks theory of nonreciprocal networks such as those including ferrites is developed taking account of internal noise sources the system ca be treated as the combination of a source free network together with a set of correlated noise current or noise voltage generators modifications of the treatment are indicated for dealing with cases whee the actual noise sources are at different temperatures as in the problem of determining the noise correlation between two receiver channels connected to a gydetermination of the frequency and phase characteristics of a network for a given at enuation curve a modification of the graphical method developed by baum of is described for deriving a realizable attenuation characteristic approximating to the given one 8330 a derivation method for designing two and three element filter structures a summary of fundamental principles with specific examples of two and three element design using loss free elements with no mutual inductance the h n and associative derivations and an extension of zobels m derivation are treated also the lc derivation involving interchange of la and c application of nortons transformation is illustrated 8331 the noise power bandwidths of iterated low pass rc filters the noise power bandwidths of n section low pass rc filters are calculated exactly from the transfer function for n to an asymptotic expression is derived for the band width when the number of sections is large and then the bandwidth is inversely proportional to n 8332 the periodic solutions of a nonlinear differential equation of the second order with unsymmetrical nonlinear damping and a forcing term the differential equation considered gives a closer approximation to the behaviour of valve oscillators than the van der pol equation and demonstrates the frequency deviation associated with the presence of higher harmonics 8333 study of the relative frequency fluctuations of two reflex klystrons stabilized by different methods in connection with projected experiments of the michelson type it was desired to ascertain whether a variation of due to modulation could be detected in the frequency of oscillations modulated at a study was made of the inherent frequency fluctuations of klystron oscillators and of methods for limiting them with particular reference to the stabilization of supply sources alternative electronic methods involving use of waveguides and cavity resonators were used to stabilize the frequency of the beat between the two klystron oscillations one of which was modulated filters of bandwidth were used to improve this stability results are compared with those of pound of and essen they indicate that it should be possible with present day techniques to detect a frequency variation of the order of in 8334 phase stabilization of microwave oscillators description of a circuit incorporating a single stable feedback loop that has been used to stabilize the frequency of a type band klystron by locking it to a harmonic of a quartz controlled oscillator any phase modulation in the klystron is detected in a phase discriminator the resulting signal is amplified in a differential dc amplifier and applied to the klystron repeller electrode 8335 phase fluctuations in a valve generator the effect of shot noise on an oscillator operating in the steady state is considered theoretically the intensity and the statistical properties of the shot current are independent of the feedback circuit and can thus be represented by a separate noise current generator in parallel with the oscillator analysis is presented on the basis of such an equivalent circuit 8336 frequency stable lc oscillators critical comment on of and authors reply 8337 analysis of the relaxation period of a multivibrator the analysis takes account of positive grid swing and appreciable shunting capacitance comparison of values obtained from the theory with experimental results indicates that the method is satisfactory 8338 a semiconductor diode multivibrator a circuit is described using one double base diode see eg of together with one ordinary diode and only three resistors and one capacitor 8339 significance of the mandelstam condition in the oscillations of a neon lamp theory presented previously of is generalized for relaxation oscillations to occur three conditions must be satisfied simultaneously including the mandelstam condition which requires that the energy of the system shall remain constant at the discontinuity this condition can be satisfied using a rc circuit but not using a rl circuit 8340 isocline diagrams for transistor circuits the method described for the graphical analysis of transistor negative resistance oscillators is based on nonlinear mechanics and does not necessitate approximation of curved transistor characteristics by straight lines voltage and current trajectories can be obtained by a simple construction which also indicates the rate of change of the voltages and currents during the course of cycllic or transient phenomena 8341 nonsaturating pulse circuits using two junction transistors junction transistors are found to be fast enough for pulse applications if the collector voltage is prevented from reaching zero switching times can be achieved with available types the required limiting action is effected by introducing diodes which terminate the switching transients by their breakdown a two transistor binary counter is described 8342 a decade frequency divider a divider developed for use with a quartz crystal clock consists basically of a chain of eccles jordan binary pairs whose overall division ratio has been reduced by means of feedback a complete circuit diagram is given 8343 method of reducing zero f error and drift in breaker type dc amplifiers thermal emfs in the input transformer are cancelled y by using a double pole double throw input chopper and connecting a high quality capacitor in series with the winding 8344 low frequency decoupling of cathode and screen grid of an amplifier valve a method is described for using the smith chart to determine the falling off at the upper and lower ends of the af response curve due to the decoupling capacitors 8345 distortion and power in aperiodic amplifiers using ideal screen grid valves calculations are made for class a ab b and c operation assuming a parabolic or nearly parabolic vl valve characteristic a determination is made of the input waveform required to give a pure sinusoidal output the effect of negative feedback is studied operation with sawtooth or square pulses is discussed 8346 the band pass distributed amplifier general expressions are derived for the gain of a distributed amplifier with any number of valves coupled by identical filter sections the analysis indicates that reduction of band edge peaks is more difficult for band pass than for low pass amplifiers choice of suitable filter networks for the band pass case is discussed and some experimental results are presented for a valve amplifier with a pass band from to 8347 design of wide band rc amplifiers discussion of multistage amplifier with inductive equalization in the anode circuit the effect of negative feedback in the cathode line is examined 8348 active error feedback and its application to a specific driver circuit feedback amplifiers are discussed in which the feedback signal is nominally equal to the input the difference which is proportional to the distortion or error in the output is amplified in s a separate circuit and reinjected with the proper polarity to reduce the output error analysis is given for a cathode follower circuit incorporating this principle the arrangement is especially suitable for driving the grid of an output valve highly positive experimental results support the theory 8349 the transistors part applications amplifier oscillator and switching circuits are discussed 8350 linear properties of the transistor formulae and charts for various transistor circuits are presented 8351 internal feedback and neutralization of transistor amplifiers 8352 tensor analysis of transistor feedback circuits theory is presented for the grounded base circuit the coefficients of the impedance matrix for the back coupled circuit are obtained by multiplying those for the original circuit by certain characteristic tensors derived from the relation between the currents in the original and in the back coupled arrangements particular conditions examined include current feedback positive and negative voltage feedback and other arrangements involving two feedback paths applicability of the duality principle is discussed 8353 a linear capacitance change circuit capacitance changes produced by mechanical displacement modulate the frequency of a franklin oscillator which drives a nonode fm discriminator sensitivity is and the output is linear between and about references are given to measurements of mechanical and other quantities by means of a capacitance change 8354 crystal diodes in voltage dividers in particular for increasing the linearity and slope of static and dynamic characteristics hf voltage dividers are discussed comprising a diode in series with a passive element the voltage division ratio being varied by suitably controlling the diode applications to reactance valve fm circuits are described 8355 transistor audio amplifiers only junction transistors are considered 8356 sharpening of observational data in two dimensions the problem considered is that of recovering true distributions from smoothed observed distributions this involves the solution of a linear integral equation several methods of solving the equation are examined and a technique for the application of polynomial solutions is presented the effect of random errors in the observational data is taken into account wherever possible 8357 representation of the modes of motion of an undamped linear oscillating system with two degrees of freedom the general solution of the differential equations for a system comprising two coupled mas points corresponds to the superposition of two natural oscillations but a better idea of the phenomenon is obtained by considering the motion as a single oscillation modulated in phase and in amplitude this approach is illustrated graphically 8358 polarization effects on the brightness waves of electroluminescence the observed cyclical variation of brightness of electroluminescent systems excited by sinusoidal fields is shown to be related to polarization effects of the type discussed eg by jaffe in connection with semi conductors 8359 theory of thermoluminescence 8360 polarization of light by aspherical ferro magnet particles in a uniform magnetic field part experimental investigation with smoke 8361 calculation of the elementary electric charge from the energy quantum model by extending the theory developed previously of august and back reference a value of esu is obtained for the elementary electric charge this differs by from the established value for the electron the difference being mostly due to the approximations used 8362 nets composed of parts of circles for the approximate solution of field problems 8363 dielectric layer with spherical cavity in homogeneous electrostatic field the special case of a cavity with centre equidistant from the two faces of the layer is considered mathematically a method is indicated for solving the problem when the cavity is not centrally placed 8364 calculation of internal field in relaxation polarization in polycrystalline dipole type dielectrics 8365 skin resistance of a transmission line conductor of polygon cross section a theorem is presented according to which a conductor whose cross section is a polygon that can be circumscribed on a circle has the same skin resistance as a conductor of the same material having the said circle as its cross section see also of 8366 calculation of the ac resistance of a solid conductor with rectangular cross section the joule effect losses are calculated starting from maxwells equations ad making assumptions corresponding to those for the case of a circular cross section the results are compared with those obtained by investigating penetration depth 8367 statistical description of assemblies with collective interaction parts a critical review of literature on the subject is presented two types of assemblies of electrons and ions are distinguished those with a finite number of discrete beams with definite velocity and those with thermally disordered motion with or without superimposed beams investigations of the first type of assembly lead to satisfactory results the difficulties encountered in dealing with assemblies of the second type are due to neglecting the limitations of the models used the model of the dispersed charge carrier assembly presented by twiss of is then considered and the concepts of collision and the collision zone are discussed 8368 phenomenological theory of townsend breakdown in dielectrics 8369 high frequency gas discharge plasma in hydrogen the microwave field strength required to maintain a hydrogen plasma in the steady state is calculated from theory based on a solution of the boltzmann transport equation the results are in satisfactory agreement with measurements made in a resonant cavity at different values of pressure and plasma concentration 8370 theory of high frequency discharge in gases at low pressures calculation of electron distribution function the electron distribution is obtained by resolving boltzmanns equation by a method of successive approximations considering both elastic and inelastic collisions the electron temperature corresponding to a maxwellian velocity distribution is derived and the general form of evolution of electronic density is given 8371 role of positive ions in high voltage breakdown in vacuum 8372 microwave and metre wave radiation from the positive column of a gas discharge radiation intensity measurements were made at and on a ne discharge by inserting the ps positive column in a resonant cavity and comparing the cavity output with that of a known noise source the rf power per unit bandwidth is expressed in terms of where is boltzmanns constant and i the equivalent noise temperature and is comparable with the temperature of the electrons in the discharge the departure of from the value corresponding to a maxwell or druyvesteyn electron velocity distribution is investigated 8373 resonance type secondary electron multiplication electron multiplication by means of an hf field applied between a pair of parallel plates with secondary electron emission rate greater than unity is considered theoretically and a relation is derived between the hf amplitude the length of field lines and the phase at impact required for avalanche multiplication expressions ar also obtained for the starting and cut off voltages calculated results are in good agreement with experimental results see also of 8374 delayed electron emission in metals continuation of earlier work f of results of experiments on w indicate that delayed emission centres are imperfections in the lattice of the oxide surface film these imperfections act as traps which can be emptied by heating to about and destroyed by heating to 8375 kinetic theory of weakly ionized homogeneous plasmas part the second order approximation to the electron velocity distribution function relating to the energy exchanges between an applied electric field and the plasma in a lorentz type gas is developed the resulting expression contains a divergent term corresponding to a nonstationary state in which the electron gas continually heats up the quality factor q of the plasma is calculated the derivation of certain formulae used in part is given in an appendix 8376 longitudinal plasma oscillations part a theoretical investigation is presented in which the effect of motion of ions is taken into consideration 8377 longitudinal plasma oscillations part the equations derived in part are applied to the investigation of the dispersive properties of the plasma for the case of hf oscillations lf oscillations and high electron drift velocities results show that in the propagation of longitudinal waves in discharge tubes the motion of ions is frequently of importance formulae are derived for the dependence of the space periodicity and the damping coefficient on the discharge parameters 8378 recombination between electrons and positive ions a bibliography of reference is critically examined nearly always recombination takes place by an interaction involving at least two atoms direct recombination of an electron and a positive ion in a plasma involving the radiation of excess energy is relatively rare 8379 theory of apparatus for observation of nuclear magnetic resonance 8380 a postulational approach to electromagnetism 8381 interaction of moving charges with wave circuits when a charge moves along a nondispersive transmission line it induces forward and backward wave components in the line for unaccelerated motion there is no radiation unless the charges moves with the speed of an unforced wave for small accelerations both radiation to the line and electro magnetic inertial effects caused by changes in the energy of the fields will be observed the electro magnetic mass at velocities greater than the wave velocity is negative large accelerations can be handled by numerical computation in the case of dispersive circuits the charge radiates at frequencies for which the phase velocity of the circuit is equal to the velocity of the charge this radiation is identified with cherenkov radiation similar radiation takes place when a charge moves through a plasma 8382 cerenkov radiation of electrons moving parallel to a dielectric boundary analysis is based on an eigenfunction expansion of the em field the process may be interpreted as an excitation of surface waves 8383 relation between the intensity distributions over radiating systems and their directivity characteristics fourier transform analysis is used to show that contrary to fischers result the directivity characteristic of a linear or plane radiator of finite dimensions is uniquely related to the amplitude distribution over the radiator the theory is extended to the consideration of propagation media with local inhomogeneities acting as secondary radiators and an investigation is made of the relation between distribution of inhomogeneities and the directivity characteristic of the scattered radiation 8384 study of the electromagnetic field in the vicinity of a reflecting surface analysis is given for the general case of a plane incident wave with elliptical polarization if the reflecting surface is an infinite plane the reflected wave is also plane modifications of the reflected wave by other types of reflecting surface are mentioned 8385 simultaneous partial absorption reflection and transmission of a nonuniform plane wave by a thin metal film the theory developed for uniform waves of is extended to nonuniform waves such as those propagated in waveguides appropriately modified expressions for th energy components are obtained by taking account of the guided wave phase velocity conditions with a set of parallel films are discussed a film of thickness such as to absorb of the incident energy can be made totally absorbing by setting up standing waves at the back surface 8386 the interaction between an obliquely incident plane electromagnetic wave and a electron beam part the investigation reported is relevant to the operation of mm wave generators and to phenomena occurring in the solar corona analysis is presented for magnetic field vector and electric field vector of the incident wave perpendicular to the electron beam the general solution for an arbitrarily polarized wave is obtained as the sum of the two separate solutions when the axial phase velocity of the wave is equal to the beam velocity the beam behaves like a metal reflector coupling between different modes in the scattered wave and in the wave inside the beam is taken into account this coupling vanishes if the wave is incident normally or if the beam is in vacuum resonance occurs at certain values of beam velocity 8387 direct measurement of the ellipticity of the rf cotton effect by the quarter wave method measurements were made using a circular waveguide of diameter with an aerial at one end connected to a klystron and a rotatable probe at the other end two copper pins of lengths mm and mm respectively are fixed mm apart in an axial insulator rod making angles of and respectively with the direction of the electric field the variation with wavelength of the plane of polarization and of the degree of extinction obtainable are shown graphically it is shown that the wave is elliptically polarized by inserting a quarter wave unit to produce a linear polarization 8388 electron spin resonance absorption in metals part experimental measurements were made on li na k be mg al pd and w over the temperature range using a cavity resonator technique at frequencies of and the dimensions of the specimens were in some cases large and in others small compared with skin depth the results are compared with those predicted by dysons theory 8389 electron spin resonance absorption in metals part theory of electron diffusion and the skin effect 8390 inversion spectrum of ammonia as a result of an investigation over the frequency range lines have been found and lines remeasured 8391 theory of molecular oscillator and molecular power amplifier theory is given of a device similar to that described by gordon et al of january the condition for self excitation is stated and expressions are given for the frequency amplitude and maximum power output of the oscillator and for the power amplification factor and the condition for linear amplification of the amplifier 8392 a conductivity type molecular beam detector an iodine molecular beam can be detected by observing the change in conductivity due to introduction of impurities in a cu film detector the detection threshold of this device which is briefly described is about molecules cm 8393 observations of a variable radio source associated with the planet jupiter a variable source of radiation on was observed on nine records out of a possible obtained during the first quarter of the derived position of the source corresponds to that of the planet jupiter 8394 monochromatic character of bursts of solar rf radiation bursts of solar radiation in the region were recorded simultaneously by two receivers tuned to frequency bands about apart analysis of the observations indicates that the average effective bandwidth of all bursts is about and that of high intensity bursts ie with intensities more than above the average is about a note on similar work was published by e blum 8395 correcting for gaussian aerial smoothing 8396 results of observations of scattering of rf waves by electron inhomogeneities of the solar corona results similar to those reported by machine and smith were obtained in observations of the occultations of june and the observations were made at wavelengths between and in interferometer base lengths of and were used at giving beam widths of and respectively rapid amplitude changes were noticed those associated with changes within a few seconds are believed to be due to the relativistic motion of electron inhomogeneities those of the order of a few minutes to corpuscular streams 8397 on an interplanetary magnetic field arguments are presented for the existence of an interplanetary magnetic field f intensity not exceeding g such a field would explain the observed cut off in the primary cosmic ray momentum spectrum and time delays in solar terrestrial phenomena 8398 radio echo observations of meteors in the southern hemisphere results are presented of observations at adelaide using apparatus similar to that described by aspinall et al operating on a frequency of and by robertson et al operating at for measurements of shower radiants and upper atmosphere winds respectively 8399 solar rf radiation at cm wavelength the total emission at depends on both total area and position of sunspots the variation with distance of the sunspots from the centre of the disk is expressed by a darkening factor whose value has been determined directly by observing the passage of groups of spots and by assigning trial values and comparing the resulting value of total emission with observations results by the two methods are in agreement consideration of absorption variations to be expected in consequence of variations of sunspot position indicates that the darkening must be partly due to the change of geometric form of the emitting areas 8400 the sunspot cycle bc to ad analysis of available records indicates that the mean period of the fundamental sunspot cycle is years the length of the length of the cycle varying in the opposite sense to auroral activity there is also a long term cycle with a period of years 8401 solar prominences and geomagnetic disturbance an attempt by statistical analysis of solar data to identify the solar m regions with the large prominences observed at intermediate and high solar latitudes gave negative results 8402 observations of the infrared radiation during the solar eclipse of june in tashkent results presented graphically show the changes during the eclipse of the fraction of the total incident flux contained in the infrared band curve 8403 time relationship of small magnetic disturbances in arctic and antarctic 8404 solar terrestrial time delays the observed delay of about hours between the meridian passage of a sunspot or flare and the onset of an associated magnetic storm or aurora is shown to originate in the deflection of the ion streams involved by either a solar magnetic dipole of moment or an interplanetary magnetic field of intensity or a combination of the two 8405 seasonal variations of the intensity of bands due to oh and o molecules in the atmosphere in the luminescence of the night sky 8406 post twilight and nocturnal variations of intensity of oh ad o bands in the near infrared luminescence of the night sky 8407 first investigation of ambient positive ion composition to by rocket borne spectrometer measurements were made in the range atomic mass units amu the most prominent ion peaks found at altitudes between and km on the ascent were at and amu from to km ions of and amu persisted 8408 the influence of the sunspot cycle on the f transmission factor an analysis of results obtained over a period of eight years by a number of stations north and south of the equator shows that the influence of the sunspot cycle on the height of the f layer exhibits a seasonal and a diurnal variation with a maximum effect in the afternoon noon and midnight values of the f factor cannot be taken as representative of day and night 8409 a note on radio field strength observations made at ahmedabad during the total solar eclipse on june 8410 instrumentation for the continuous measurement of certain ionospheric echo characteristics details are given of the receiving system associated with the equipment described by jones of a crossed loop aerial picks up both the direct and the reflected waves from the transmitter about km away the elliptically polarized echo is resolved into components which are appropriately combined and displayed in succession on a cro examples are shown of continuous photographic records obtained the resolution of split echoes is facilitated by suitably varying the cro beam intensity 8411 a panoramic ionospheric recorder for the study of travelling disturbances in the ionosphere a description is given of a recorder covering the frequency range in or sec this is achieved by heterodyning an oscillator which is continuously variable from to with a pulsed oscillator and amplifying the resultant pulsed signal to provide the transmitter output the same variable oscillator is used in the superheterodyne receiver a block diagram of the recorder is given and typical records are shown both single records on mm film and continuous records on mm film moving at or in min can be made using cr tubes with long and short persistence screens respectively 8412 modern ionosphere sounding equipment of the netherlands ptt part high power slow sweep equipment is described the tuning mechanism comprises a set of simultaneously and continuously variable coils and capacitors covering the range in on band sweep time is pulse output power is about pulse repetition frequency is usually a special camera with continuous film transport is used 8413 a note on factors affecting the interpretation of observations of transient echoes from the ionosphere 8414 notes on correlation methods for evaluating ionospheric winds from radio fading records a method requiring only six values of the correlation coefficient obtained from fading records at three receiver stations is developed the theory is extended to include elliptical constant correlation contours in the horizontal plane data obtained during february indicate that the correlation ellipse shows a preferred orientation and that fading associated with random changes in the ionosphere is as important as that associated with drift 8415 results of lightning measurements during the years on monte san salvatore electrical magnetic and optical measurements made with the equipment described previously of september are reported and discussed 8416 nature of ball lightning energy considerations indicate that ball lightning can be sustained neither by a chemical process nor by a nuclear process it is suggested that the luminous ball could be produced in a weakly ionized gas by a resonance process the energy required to increase the ionization and then to maintain it inside a sphere of diameter d being supplied by rf waves with d the centre of the sphere would coincide with a maximum of the wave interference field the rf waves could be due to an oscillatory process in the ionized atmosphere excited by a lightning discharge the proposed mechanism also explains bead lightning the absence of influence of wind on the position of the luminous ball and the waveguide effect of chimneys explosive and quiet types of decay are associated respectively with rapid and slow changes in the rf field strength at the end of the phenomenon observations in the decimetre region during thunderstorms and experiments on the artificial production of ball lightning are suggested 8417 radio observations of the aurora observations during the period by means of transmissions over n america mainly at indicate that the ionization aurora occurs with greatest frequency near the equinoxes as does the visual aurora 8418 silicon solar energy converters theory of operation of the si junction photodiode is given and compared with experimental data si is shown to be the most efficient semiconductor available for conversion of solar energy a design is discussed in which the radiation is incident on the n layer the thickness of the p layer is required to be low to give low resistance but not so low that minority carriers recombine before diffusing to the junction resistance at the metal contacts must be kept as low as possible conversion efficiences of have been attained possibilities are indicated of improving the efficiency by use of nonreflecting coatings or auxiliary mirrors and lenses 8419 regulated dc power supplies at low voltages a valve stabilized unit with dc output at or at is described as well as a unit using ge junction rectifiers the limitations of cold cathode tube stabilizers are discussed 8420 review of electronic computer progress during 8421 a commercial electronic calculator the main features common to three business accounting machines are briefly described the method of performing the four basic arithmetic functions is illustrated by worked examples 8422 a miniature analogue computer the computer described is capable of solving linear differential equations of orders up to the tenth and is intended for preliminary design investigations and educational purposes 8423 electrical analog computing machine for solving linear equations and related problems a computer for solving equations with ten variables by a new iteration method is described in addition to the solution the machine gives the largest eigenvalue of the matrix of the linear system 8424 a high speed permanent storage device a digital computer storage system is described using a magnetic core matrix of in combination with the threaded core system used in the bell computer model the capacity is about a million bits 8425 linear algebraic computation by multi winding transformers theory is presented of transformer circuits fol solving simultaneous equations and inequalities the reduction of errors due to transformer imperfections is discussed the practical aspects are illustrated by a problem involving checking the compatibility of ten inequalities with six variables the present device is similar to that described by mallock and 8426 a transistor digital fast multiplier with magnetostrictive storage the multiplier is operated at a basic frequency of and comprises timing waveform generator arithmetic unit and storage system except for the use of junction transistors in the amplifiers associated with the storage system point contact types are used throughout out of a total of point contact transistors junction transistors and crystal diodes three point contact units have failed in seven months of daily operation no selection of transistors is required the total power consumption is 8427 the solution of plane stress problems by an electrical analogue method it is shown that the h biharmonic equation which airys stress function has to satisfy can be solved by an electrical analogue comprising two resistance networks in cascade 8428 three dimensional electrical analogue models for studying drainage by free surface filtration 8429 transistor amplifiers for analog computers 8430 the cold cathode gas diode an outline is given of technique used to improve the diode characteristics involving aging by application of voltage pulses basic circuits using these diodes as computer elements for gating storage etc are described 8431 language translation by electronics novel application of digital computing machines 8432 the single layer solenoid as an rf transformer design curves are presented for air cored transformers inductances of coupling coefficients of and inductance ratios of are covered directly 8433 the radio frequency coaxial resistor using a tractorial jacket design of resistors for the reflection free termination of coaxial lines is discussed using an approach based on treatment of a short length of the resistor as a conical coaxial line the resulting profile of the jacket is a tractrix detailed analysis indicates that with this configuration the field satisfied the boundary conditions better than with an exponential jacket the most important design parameter is the ratio length diameter for resistances values of this ratio between and are satisfactory the difficulty of obtaining uniform distribution of resistance over the surface of the resistor may be a limiting factor in the accuracy of the termination 8434 high value organic film resistors stable resistors of resistance are prepared by coating a dispersion of eg colloidal carbon in gelatine on a glass support and mounting the unit in an evacuated enclosure 8435 production characteristics and applications of nonlinear resistors 8436 a shifting register using ferroresonant flip flops an arrangement is described in which the information can be shifted in either direction depending on the polarity of the shifting pulse consideration is given to design for operation with supply frequencies in the mcs range 8437 a two state light activated circuit element using germanium a bar of n type germanium with a potential difference across its ends and a suitably biased point contact near the middle will show double base diode action the point contact diode will conduct or cease to conduct according as one end or the other of the bar is illuminated both states being stable when the light is removed in practice the bar is divided near the point contact and the two parts are connected by copper wire to ensure that holes generated in one section recombine before they are swept into the other 8438 etched foil printed circuits discussion with particular f reference to photomechanical methods of production 8439 a theorem on the decomposition of the derivative of the operational impedance of a two pole network 8440 dynamic measurements on piezoelectric resonators with very strong electromechanical coupling the equivalent circuit used as the basis of measurements on quartz crystals is not suitable in conditions of strong electro mechanical coupling such as exist in ferroelectric crystals at the curie point the complete equivalent circuit for longitudinal resonance in such conditions includes a number of parallel branches whose contributions to the total piezoelectric current correspond to the coefficients of a fourier representation of the oscillation mode results given by the theory are compared with observations of the oscillations of a rochelle salt resonator 8441 tuning of a rectangular parallelepiped cavity resonator with a circular metallic post a relation is derived between the resonance frequency and small displacements of a post projecting into the resonator using a perturbation formula due to slater of the calculation is carried out to the first order for a rectangular cavity operating in the mode the result is compared with a similar relation for a right circular cylinder whose length is varied by a plunger completely closing one end 8442 quantum effects in the interaction between electrons and high frequency field part reported an analysis of the effect of the interaction on the motion of the electrons the effect on the field in the resonant cavity is now analysed the value of the field strength differs from the classical value by a small amount due to the wave properties of the electrons the dispersion in the field is evaluated and the number of electrons required in a bunch to produce a field comparable to the dispersion is calculated for typical experimental conditions the highest frequency at which this requirement can be met is of the order 8443 collapsed toroidal springs as contact elements in microwave cavities 8444 on extraordinary phenomena in a nonlinear forced oscillation the nonlinear forced oscillation represented by is discussed transforming the equation to the variational form the ritz method is applied to obtain the solution in the form of a fourier series in which extraordinary points of two different kinds are distinguished this method is applied to find the jump voltage of a circuit containing an iron cored reactor 8445 investigation of coupled electrical circuits with constant lumped parameters under variable conditions part analysis involving the inverse laplace transform is presented for determining the current in the secondary circuit numerical examples are given 8446 a note on the application of determinants to the solution of linear network problems 8447 coaxial cavity filters for multiplexing of radio relay systems essentially full text of paper to be published in filters are discussed comprising cascaded coaxial line sections the selectivity attained permits a frequency separation as low as between a transmitter and a receiver operating on a common aerial and a separation as low as between transmitters or receivers 8448 transient response of band pass filters analysis for multistage band pass amplifiers with parallel rlc coupling circuits is based on consideration of the characteristic values of the individual circuits 8449 a band pass filter with active elements the design of a filter amplifier is described in which impedance inversion and loss compensation are achieved using two npn junction transistors type in an arrangement based on the valve circuit described by harris of the centre frequency of the filter is and the bandwidth is and at the and points respectively a complete unit shown includes a third transistor with grounded emitter connection and gives an overall gain of db 8450 loss and phase of simple equalizers approximate computations are performed using the first one or two terms of a rapidly convergent power series expansion 8451 the noise figure of linear quadripoles and amplifier valves 8452 on subharmonic synchronization of nearly linear systems analysis is presented for a slightly nonlinear oscillator driven at a frequency near a multi le of its natural frequency the system corresponding to the equation where the forcing term is of the order of unity conditions for obtaining a response at angular frequency are investigated by expanding y in a series in 8453 symposium on fluctuation phenomena in microwave sources 8454 a twin t rc oscillator the design of a oscillator similar to that described by francini and zaccheroni of is briefly discussed performance characteristics are presented graphically the frequency is variable over a limited range 8455 a triggered timebase for oscillographs a triggered sawtooth generator is described 8456 transistors generate multiwaveforms the use of junction transistors as nonlinear network elements is illustrated by a discussion of the design of a regenerative degenerative oscillator 8457 approximate calculation of the relaxation process and time delay in the multivibrator calculations are presented based on representation of the valve characteristic curves by third degree polynomials a delay of about sec between the initiation of instability and the commencement of the anode pulse is found for a particular circuit using type ef pentodes 8458 a new method for generating relaxation oscillations with a gas filled triode large amplitude relaxation oscillations can be generated by applying a small hf voltage to the grid of a gas filled triode in which the grid is connected to the cathode via a high resistance the waveform of the relaxation oscillation depends on the parameters of the circuit in parallel with the anode to cathode path and on the excitation frequency and the frequency of the relaxation oscillation can be varied over a wide range 8459 a transistor oscillator a high stability portable oscillator uses a single point contact transistor and a quartz crystal resonator in a wien bridge circuit the frequency variation is for supply voltage variations of or more 8460 a guide to the design of sinusoidal oscillators using junction transistors oscillators based on series and parallel resonant circuits rc phase shift networks negative resistance effects and control crystals are included 8461 contribution on the problem of frequency dividing dividing circuits for both pulse and sinusoidal signals are discussed details are given of a simple locked in oscillator giving division factors up to a self starting regenerative divider and a divider with controlled oscillator a laboratory model of which gives division factors in a single step 8462 contribution on the problem of feedback a review of methods for analysis and design of feedback amplifiers 8463 all pass amplifier in a five stage amplifier for the frequency range having an overall gain of high frequency attenuation is reduced by using the parasitic capacitances of the valves ar as elements in a high pass filter 8464 the design of stagger tuned double tuned amplifiers for arbitrarily large bandwidth 8465 asymmetry zero drift errors in magnetic amplifiers 8466 transistor amplifiers for analog computers high and low gain transistor m amplifiers for servo use are described effects of power supply variations and temperature coefficients are shown 8467 temperature compensation in a low consumption transistor amplifier the circuit design is developed for a two stage amplifier for the frequency range giving a stable distortion free output of with an ambient temperature variable over the range by suitable choice of circuit elements compensation is obtained without increased power consumption and the amplifier characteristics may be made independent of the actual transistors used 8468 unilateralization of junction transistor amplifiers at high frequencies neutralization of the inherent internal feedback of the junction transistor is provided by applying external feedback practical circuits are illustrated and their performance characteristics discussed 8469 carrier leak in rectifier modulators of the shunt type carrier leak is the term used for the unbalance carrier frequency component in the modulator output an experimental investigation is reported of factors affecting the attainment of very low leak levels from to below carrier level and of the possibilities of dc balancing of the rectifier bridge square wave and sinusoidal signals are considered the results indicate that control of carrier leak adjustment by use of a dc meter is likely to be practical the effect of carrier generator impedance is discussed some details are given for a modulator with no transformer very low leak levels are attainable by correct relative j adjustment of the two coupling capacitors 8470 a new aether drift experiment results of the experiment referred to previously of are reported a cylindrical cavity resonator used to control the frequency of an oscillator at about was mounted with its axis horizontal and was rotated in a horizontal plane the frequency of the oscillator was compared with that of a quartz standard at intervals of of the rotation 8471 some aspects of standing wave patterns general analysis is given for the production of standing waves and three dimensional patterns obtained by plotting the wave equations are presented for various cases 8472 specific directions of longitudinal wave propagation in anisotropic media analysis relevant to piezoelectric oscillations is presented trigonal hexagonal tetragonal and cubic crystals are considered and the directions of propagation of purely compressional waves are determined 8473 electroluminescence a survey of existing knowledge of the physical process involved with numerous references 8474 recommendations of iec international electrotechnical commission technical committee electric and magnetic magnitudes and units full text of paper to be published also in communication and electronics recommendations made at the meeting i september are reported 8475 plasma oscillations in metals the effect of the energy band structure on the plasma frequency is analysed 8476 theory of anomalous skin effect an exact expression is derived for the surface impedance for the case of arbitrary dispersion of conduction electrons assuming an infinitely long mean free path the conclusions are the dependence of the impedance z on the angle between the normal to the surface and the crystallographic axes is determined by tensor the frequency dependence of the impedance and the relation between the real and imaginary parts of z are independent of the form of the dispersion relation the derivation of equation for is independent of the interaction of electrons with the lattice and hence may be used in the determination of the fermi surface 8477 influence of inhomogeneity of a plasma on its resonance frequency nonuniformity of the electron concentration in the plasma may give rise to variations of in the resonance frequency this explains the langmuir relation and experimental results the effect of damping is however negligible as are also magnetic effects 8478 high frequency ionization coefficients in neon argon mixtures 8479 electrical breakdown of air at small and medium overvoltages experimental results indicate that values of pressure distance about torr cm breakdown due to overvoltages of to is produced by a townsend ionization mechanism rather than by the electron avalanche build up of a channel as described by raether at overvoltages the latter process is operative 8480 electrical breakdown in high vacuum report of an investigation using gaps shorter than cm between tungsten electrodes in most cases of breakdown field emission currents from small irregularities on the cathode cause evaporation of metal from the anode the breakdown occurring in the resulting vapour 8481 noise from hot cathode discharges experiments with mercury vapour tubes in which anode glow disturbances were eliminated show that low frequency noise in an unsaturated discharge is due to a coherent random fluctuation of the whole plasma probably caused by fluctuations of the cathode sheath under certain conditions another effect was distinguished which may e be due to fluctuations of sheaths on the probes used or on the tube walls 8482 work function of tungsten single crystal planes measured by the field emission microscope 8483 wave mechanics treatment of electron and ion beams with curved axis 8484 velocity analysis of thermionic emission from single crystal tungsten the energy distribution of electrons emitted in various directions from the w filament was analysed using a special tube in which the electron trajectories were bent by a magnetic field the observed distributions were the same for all directions ad were not maxwellian variations of true work function over the temperature range were measured for several crystallographic directions the results are discussed in relation to values of the richardson emission constant found by other workers 8485 possibility of defining a scalar magnetic potential inside currents and application to the design of magnetic electron lenses the system considered is a thick solenoid various equivalent magnetic shell systems and the corresponding magnetic potential distributions are discussed 8486 electromagnetic theory of moving matter conceptual difficulties arising in connection with the didactical presentations of classical theory are discussed using an alternative approach to that of hammond of january 8487 the angular momentum of the electromagnetic field 8488 observations on an energy relation in magneto hydrodynamics 8489 correlation of amplitude and phase fluctuations in wave propagation in a medium with random inhomogeneities the two problems noted in of april are treated more fully the value of the correlation coefficient r between amplitude and phase fluctuations at the receiving point is given by equation and reduces to for small distances and to in for large distances where is given by where and is the dimension of the inhomogeneities the autocorrelation coefficient for amplitude fluctuations o at points and is plotted as a function of in curve that of phase fluctuations in curve the curves refer to the case when d and lies between and 8490 theoretical and experimental study of electromagnetic scattering by two identical conducting cylinders the scattering of a cylindrical tem wave by two parallel identical conducting circular cylinders is developed as a special case of a theoretical analysis which treats the scattering by an arbitrary array of cylinders only the case with the incident e vector parallel to the axes of the cylinders is considered and attention is focused on the mutual effects present when the cylinder diameter and spacing are comparable to a wavelength the approximations made in the theory are tested experimentally using microwaves in a parallel plate region significant departures from the results of the independent scattering hypothesis as predicted by the theory have been confirmed experimentally 8491 diffraction of electromagnetic waves by circular plate and circular hole rigorous analysis is presented using the method of expansion by the hypergeometric polynomial total scattering cross section transmission coefficient current in the disk field in the hole ad field at a distant point are shown graphically as functions of where and is the radius 8492 microwave diffraction by apertures of various shapes results of an experimental investigation of the near zone diffraction field of circular elliptical and slit apertures are presented in general these results are consistent with theory presented previously 8493 the scattering of a scalar wave by a semi infinite of rod of circular cross section analysis indicates that for a wave incident along the axis of the rod and assuming zero variation of field with distance at the end surface corresponding to the case of sound waves incident on a rigid rod the scattering coefficient is for where k is the wave number and a is the radius of the rod graphs show the variation of the average pressure amplitude on the end of the rod and of the scattering coefficient over the range the average pressure amplitude on the end of the rod for other angles of incidence is calculated an expression is derived for the scattered field when the field at the surface is zero corresponding to the case of an aerial when only the component of the electric field parallel to the axis of the rod is considered 8494 scattering of a plane wave from a circular dielectric cylinder at oblique incidence analysis is presented for the general case the solution indicates that the scattering field includes a significant cross polarization component which vanishes at normal incidence the results are applicable to scattering by ionized columns such as meteor trails 8495 polarization of electromagnetic waves basic relations of polarized em waves are expressed in vector notation use is made of the vector of refraction m defined as the product of the refractive index and the real unit vector of the wave normal 8496 nonlinearity of propagation in ferrite media measurements are reported emphasizing the need to take account of nonlinearity effects when designing microwave ferrite devices for use at high peak power levels the results are applicable for conditions remote from gyromagnetic resonance 8497 magnetic resonance for arbitrary field strengths discussion is presented for a paramagnetic gas assuming that strong collisions are the only important factor apart from the applied magnetic field and that the latter comprises a circularly polarized component in the plane perpendicular to the constant components 8498 interpolation scheme for energy bands in solids 8499 the distribution of temperature along a thin rod electrically heated in vacuo part end losses the correction for end losses is calculated for some typical physical properties which are functions of powers of temperature t or both as in thermionic emission the calculated corrections for a long w filament agree closely with those computed graphically by worthing the corrections for medium length filaments such as used in hf power valves are practically the same as those for a long filament heated by the same current 8500 electrodynamical theory of thermal radiation a theoretical note on thermal electrical fluctuations phenomena in cavity resonators and waveguides are considered 8501 radio astronomy a brief survey of techniques results and applications 8502 a radio survey of the great loop in cygnus some details are given of a radio source discovered as a result of a survey made at jodrell bank at a frequency of 8503 new modulation system of radio reception of weak signals and its application in the design of a radiotelescope of extremely high resolving power features of the systems described by vitkevich of and mills and little see eg of were combined to give a high resolution a swinging aerial beam is obtained by varying the electrical lengths of the feeders the system is explained with the aid of a block diagram 8504 a solar noise outburst of january outbursts of noise were observed at ottawa with an interferometer type receiver at a frequency of on and january a study of the vertical incidence ionosphere records indicates that storm conditions with spread f echoes low values of f increased absorption and blackout followed the outbursts auroral displays were reported from parts of canada and the us during the period 8505 change of radio signal strength during solar eclipse june 8506 a simple sensitive saturated core recording magnetometer 8507 the vertical distribution of atmospheric ozone determined by baloon ascents measurements made with an automatically recording ultraviolet spectrograph are reported 8508 d layer ionospheric echoes at macquarie island echoes from d layer heights have been recorded at the australian station on macquarie island geomagnetic latitude i since operation started in echoes are of similar type to those observed in tropical latitudes and occur on most days of the year on a few occasions each month echoes persist throughout the night the highest frequency at which echoes are received usually increases from below at first appearance within an hour after ground sunrise to above at noon decreasing to below at disappearance during the hour before sunset strong d echoes remain on occasions when other daytime echoes are absent due to high absorption the effect may be peculiar to island observatories 8509 the effect of vertical ion transport on the night time e region anomalous behaviour of the night time e layer and the formation of the night time sporadic e layer may be explained by vertical ion drifts not necessarily tidal 8510 on anomalous variations of maximum electron density and its height in the region of the ionosphere an examination of world wide observations during periods of sunspot maximum and minimum suggests that anomalous behaviour of the f region is mainly controlled in low and middle latitudes by geomagnetic factors and in higher latitudes by geographic factors the fall in the level corresponding to maximum electron concentration over the magnetic equator may be accounted for by vertical electron drifts whose magnitudes are deduced seasonal anomalies in f may be explained by variations in the height distribution of the particles from which the ions in the region are produced 8511 on latitudinal distributions of diurnal and semi diurnal components of of the ionosphere results of an analysis of world wide observations for december and june are given in a series of histograms 8512 on the solar lyman d beta radiation and the ionosphere solar lyman radiation i will be absorbed by atomic oxygen in the ionosphere with emission of a radiation observation of such radiation originating in the r region would be a criterion for the validity of the ionospheric model 8513 geomagnetic distortion of the f region on the magnetic equator calculations based on an atmospheric model inferred from rocket observations and using the dynamo theory of the earths magnetic field show that the diurnal variation of the vertical electron drift due to the es field is sufficient to account for the observed distortion of the f region over the magnetic equator the presence of the f layer is also accounted for changes following the sunspot cycle may be caused by a slight shift of the phase of the drift 8514 studies on the disturbances in f layer associated with geomagnetic disturbances f layer disturbances associated with geomagnetic storms consist of two components which is effective only in the earlier stage and is dependent on longitude and which begins simultaneously with the f storm and gradually grows to large amplitude hours later variations with latitude and season are plotted from world wide data for the period the disturbances follow the trend of geomagnetic activity except for in winter the effect of sunspot activity is shown 8515 diurnal and seasonal wind variations in the upper atmosphere results are presented graphically of observations of winds at altitudes of made at jodrell bank between september and november the measurements were based on radio reflections from meteor trails of greenhow four distinct wind components were distinguished with semi diurnal periodicity of amplitude rotating clockwise with diurnal e periodicity of prevailing winds of towards the east in summer and winter and towards the west in spring and autumn turbulent winds of the order of with occasional wind shears of over height differences of a few kilometres 8516 electrostatic field changes due to lightning discharges report and analysis of extensive observations at distances in this range es effects are dominant over induction and radiation effects 8517 the development of lightning discharges the observations reported in above are discussed and thd theories are advanced regarding the nature of lightning processes 8518 the location and shape of the auroral zone observed characteristics of aurorae and examination of data for the polar year support the view that an electrically neutral particle stream coming from the sun is resolved into positive and negative components on encountering the earths magnetic field the two components following opposing spiral tracks into the auroral zone 8519 noise power radiated by tropical thunderstorms lightning discharge phenomena are reviewed and an expression is derived for the average electric field due to a stroke the power at the source corresponding to the noise field strength measurements of which were reported previously of january is hence evaluated over the frequency range the noise power varies as discharges within the cloud or into the air are the main noise sources 8520 an alternating voltage source of high stability at standard frequency description of a three phase constant voltage source provided by a synchronous generator with quartz clock controlled frequency developed for testing ac precision instruments 8521 filters for rectifier equipment the design is discussed of series tuned lc filters in parallel with the output of a multiphase rectifier for attenuating unwanted harmonic voltages the design of a series reactor for limiting the rectifier output current is also briefly considered 8522 application of germanium power rectifiers commercially available power supply units are described with ratings such as at and at 8523 electronic voltage regulators relatively simple circuits giving a high degree of stabilization have been designed at the national bureau of standards using beam power series valves with separate screen supplies a power supply unit is briefly described containing four regulated sources and giving outputs of and 8524 an ac voltage stabilizer high regulation factor short response time low e weight and frequency independence are achieved in a valve regulator with a carbon pile variable resistor control element and local as well as overall feedback in the form described the regulator is suitable for supplying filament current for a large number of valves 8525 high speed electronic analogue computing techniques an investigation has been made of the upper limits of speed conveniently attainable in various basic operations performed with a particular differential analyser with multidimensional displays and electronic programming a very large increase in information capacity is attainable in problems requiring systematic search processes for their solution 8526 a mercury delay line storage unit 8527 magnetic memory device for business machines description of a device combining the short access time of a magnetic drum and the larte storage capacity of the tape record 8528 synchronizing magnetic drum storage speed synchronization to an acoustic delay line is obtained by a time difference discriminator which controls the drum speed an accuracy within is achieved with a line voltage variation 8529 square law circuit a device for use as a multiplier in a analogue computers consists of a source producing a negative going triangular waveform which is superposed on a positive going input signal applied to a diode the average value of the output voltage is proportional to the square of the input voltage 8530 photoelectric transformation of mathematical functions solution of equations an arrangement comprising a mirror galvanometer in combination with an appropriately shaped diaphragm and a photocell is used to generate a current when the current flows through the galvanometer elaboration of the arrangement to generate complex functions is discussed 8531 binary adder tube for high speed computers 8532 interesting new developments in the components istray reactances in power and instrument transformers saturating reactor magnetic pulser design 8533 the transfluxor a magnetic gate with stored variable setting the transfluxor is a device comprising a magnetic core with two or more apertures the core material having a nearly rectangular hysteresis loop switching and storage operations are performed by controlled transfer of the flux from leg to leg of the core the operation of a two aperture device is described in detail 8534 transistor binary number store for pulse operations 8535 the design of hard valve binary counters the method of design takes account of tolerances on component values valve characteristics and supply voltages and indicates modifications necessary when se diodes are used in place of hot cathode diodes for interstage coupling it is valid at a counting speeds up to several 8536 the relation between standing wave ratio and bandwidth in wide band compensation of a reactance calculations are made for two different equivalent circuits representing a resistance accompanied by inherent reactance the swr obtained when the compensated resistance is connected to a loss free line with purely resistive characteristic impedance is used as a criterion of the compensation the results are expressed as irrational algebraic functions which are presented as bandwidth curves simple relations are derived between the permissible swr and the bandwidth 8537 the folded tree the problem of constructing circuits to perform certain functions such as switching functions is treated by representing the circuits by vertex diagrams of which the folded tree is a particular form 8538 revolutionary new oscillator amplifier 8539 effects of impurities on resonator properties of quartz 8540 calculation of the oscillation frequency of a quartz crystal maintained by a transistor the calculation presented previously of july is extended to the general case where it is required to determine both the influence of the maintaining system on the frequency and the possibility of aligning this frequency with a given reference frequency formulae are derived based on the use of capacitors in series and in parallel with the crystal 8541 theory of imperfect waveguides the effect of wall impedance 8542 wide range electronic tuning of microwave cavities analysis is presented for tuning by introducing into the cavity an electron beam with its direction parallel to the magnetic field so that spiralling of the beam is produced measurements are reported indicating that the tuning range is much greater for a cavity containing z a gas at low pressure than for an evacuated cavity 8543 series resonance with nonlinear capacitor a graphical method is used to explain multiple resonance and hysteresis in a circuit tuned by a capacitor with a dielectric 8544 unambiguous choice of arrow direction for currents and voltages in quadripoles with applications to directional quadripoles and gyrators it is recommended that the positive direction of the voltage arrow should always point from positive to o negative charge with quadripole diagrams the output current arrow should poin away from the quadripole simplifications of network analysis resulting from adoption of this convention are indicated 8545 conditions for aperiodicity in linear systems the necessary and sufficient conditions are derived when expressed in terms of the coefficients of the characteristic equation they take the form of a number of simple determinantal inequalities which are closely analogous to the rough hurwitz stability criteria 8546 definition of the ideal transformer and the ideal gyrator by their impedance transforming properties the fundamental difference between the two networks is that the input impedance of the ideal transformer is directly proportional to the load impedance while for the ideal gyrator the proportionality is inverse the ideal gyrator can be completely defined as a passive linear loss free quadripole with frequency independent transforming properties 8547 a new method for investigating linear quadripoles part continuation of work abstracted in of october a distinction is made between elliptic hyperbolic parabolic and loxodromic quadripoles 8548 two network theorems for analytical determination of optimum response physically realizable network characteristics 8549 how to design if transistor transformers design curves are given for single and double tuned units providing matching of collector and base impedances while meeting bandwidth and minimum insertion loss requirements 8550 symmetrical lattice filters the calculation and field of utility of standard types of lattice filter are discussed and permissible approximations are indicated classification based on image parameters is proposed on the lines of the system used in a previous paper on ladder filters 8551 note on antimetrical lattice filters with successive reactances of alternate sign a simplification of the treatment given by oswald of january 8552 notch network design curves are given facilitating the design of bridged t band stop filters operating between equal impedances 8553 the period and amplitude of the van der pol limit cycle the amplitude and period of the limit cycle of the van der pol equation are found for all values of by joining graphically the results of solutions about and 8554 limit cycle period of nonlinear oscillation the problem is discussed with reference to previous work on the solution of the van der pol equation a formula is derived for the limit cycle period which is applicable both for small and large values of corresponding respectively to quasi sinusoidal and relaxation oscillations results obtained from various formulae are compared in a table 8555 the design and performance of a simple vlf oscillator using a wien rc network for frequency control the oscillator covers the range in finite steps with a maximum output of into a load 8556 secondary emission valve pulse generator with cathode output a positive feedback circuit giving a very low output impedance is used capable of producing pulses of amplitude with rise time about by using a pentode as cathode load it is possible to obtain a wide variety of pulse waveforms the arrangement gives a better performance than the ordinary blocking oscillator 8557 investigation of the time delay in the triggering of a pulse in a monostable multivibrator results of experiments indicate that a monostable multivibrator may be used as a pulse amplifier in applications where waveform distortion is unimportant with pulse voltages above the multivibrator used showed time delays of less than and these were independent of pulse width over a wide range the gain obtainable is about time delays in a free running multivibrator are of the order of to sec this is shown theoretically to be due to the stray capacitances present 8558 triggered microsecond sweep generators hard valve balanced output and single ended sweep generators are described using miller integrator feedback for linearization both are capable of providing a sweep in applications in high speed photography are indicated 8559 a time delay device using transistors pulse shaping and counting circuits are described in which junction transistors are used for switching in conjunction with magnetic cores with rectangular hysteresis loops the number of pulses required to saturate the core is such that long time delays can be produced published also in communication and electronics 8560 high frequency pulse counter a circuit based on the secondary emission valve pulse generator described in above 8561 all magnetic audio amplifier three cascaded magnetic frequency triplers are used to provide a carrier from a line frequency used with a carbon microphone and a two stage magnetic amplifier the system gives and audio output power of with linear operation over the range cs 8562 wide band frequency divider a circuit for operation at frequencies up to based on the secondary emission valve pulse generator described in above 8563 design of low pass amplifiers for fast transients the proposed synthesis of an interstage coupling network for wide band low pass amplifiers is based on darlingtons design method of some practical details are given of a amplifier experimentally determined phase and amplitude characteristics are presented graphically oscillograms of the transient response are shown details are also given of the design of a phase correction network 8564 the mechanism of subharmonic generation in a feedback system analysis is given for nonlinear feedback systems using the description function method subharmonics are produced as a result of mu modification of the response of the nonlinear element by the input signal conditions are derived for the absence of subharmonic oscillations theoretical and experimental results for a particular unit with an approximately cubic characteristic are in agreement 8565 disc seal circuit techniques a survey of amplifiers and oscillators using disk seal valves and of associated microwave measurement methods 8566 on distributed amplification the response characteristics of a distributed amplifier can be improved by making the delay characteristics of the anode and grid lines different this technique being termed staggering the improvement is illustrated y by photographic records of the responses of experimental amplifiers 8567 filters with very narrow pass band variable on the principle of the fabry perot interferometer analysis is given for a narrow band rf amplifier with n equal stages each comprising a valve and a three mesh cr phase shift network maximum gain is obtained at a frequency slightly different from that for which the phase shift is a relative bandwidth of is attainable with stages 8568 note on the design of wide band low noise amplifiers methods of reconciling the design requirements for minimum noise factor and those for adequate bandwidth are discussed the problem can be solved by equalization using either feedback or complementary networks some measurements on an experimental grounded cathode amplifier with feedback are reported satisfactory performance with bandwidths up to about appears possible 8569 figure of merit in magnetic amplifiers the figure of merit discussed is the ratio of power amplification to amplifier response time it is useful as a basic for the comparison of amplifiers which are linear over the working range and have equal rated output powers 8570 transistor operating points a theoretical and experimental investigation is reported of the relation between the junction transistor noise and gain and the collector to base voltage the results are used in the design of a high gain low noise amplifier 8571 automatic gain control of transistor amplifiers satisfactory agc circuits can be designed based on variation f either emitter current or collector voltage v the required control power is very low if the variation of is produced by varying the base current distortion may become a serious problem 8572 transistor equivalent circuits 8573 transistor equipped light weight programme input amplifier type an amplifier for a portable sound recorder is described in the pre amplifier the microphone is matched to the first transistor via a transformer by use of current feedback in the first stage it is possible to connect without attenuation capacitance microphones with terminal resistance the second stage includes a feedback circuit providing equalization up to kcs the final stage is designed for an output of mw shifting of the working point due to internal heating is reduced by use of a special stabilizing circuit 8574 millimicrosecond pulse techniques a survey with an excellent bibliography 8575 note on carpet graphs description of a method description of a method developed at the national physical laboratory for presenting information concerning three variables in a single combined graph 8576 theory of electroluminescence on the basis of the threshold value of the field necessary to excite luminescence the following three possible mechanisms are discussed direct ionization of impurity systems by the field acceleration of conduction electrons or valence band holes to velocities sufficient to produce excitation by inelastic collisions injection of charge carriers 8577 empirical relationships with the munsell value scale a discussion relevant to the establishment in colour television of an equal step grey scale 8578 the specification of colours based on measurements with the trichromatic colorimeter 8579 a general mathematical treatment applicable to certain electrode systems formulae are developed for a basic system of two coaxial dielectric cylinders of different homogeneous and isotropic media containing an embedded line charge these are applied to determine the field in a circular cylinder electrode system the result being expressed as series converging reasonably rapidly other electrode systems considered are a semi infinite strip an elliptic cylinder and a parabolic cylinder 8580 on the theory of plasma oscillations in metals the effect of the crystal lattice on plasma oscillations is investigated on the basis of quantum mechanics see also of 8581 application of the method of generating function to radiative and nonradiative transitions of a trapped electron in a crystal see also 8582 measurement of the statistical time lag of breakdown in gases and liquids 8583 the direct current associated with microwave gas discharge between coaxial cylinders part measurements made by a double probe method give results in good agreement with theory 8584 investigation of high frequency discharge by method of probes the methods used by banerji and ganguli were compared experimentally the results obtained in the two cases were similar a study was also made of the temperature concentration of electrons and potential along the axis of the discharge tube at various pressures between about and mm hg of and at frequencies of the order of the distribution was found to depend on the gas pressure the diameter of the tube and the hf field strength results are presented graphically 8585 retrograde motion in gas discharge plasmas a phenomenon observed in cylindrical diodes operating in the ball of fire mode of is discussed 8586 diffusion in moving striations a digest is presented of a thesis developing a diffusion theory of striations and testing the theory with experimental results reported by pupp 8587 field measurements in glow discharges with a refined electron beam probe and automatic recording 8588 interpretation of field measurements in the cathode region of glow discharges 8589 self focusing streams a restatement of the theory of magnetic self focusing of streams comprising a mixture of ions and electrons see also of 8590 the theoretical possibility of separating beams of charged particles having different polarizations in a magnetic field it is shown that a separation of beams such as is obtained in the stern gerlach experiment can theoretically be obtained also in the case of charged particles 8591 electron emission and other phenomena on freshly disturbed metal surfaces a general account of the effects and methods of observing them using an open ended geiger counter or a photographic plate 8592 a note on the diffusion in a gas of electrons from a small source 8593 experimental investigation of the motions of electrons in a gas in the presence of a magnetic field the aim of this investigation was to verify the theory given by huxley and 8594 secondary electron emission report of colloquium held at the institute of physics in march 8595 secondary electron emission by primary electrons in the energy range of to experiments were made using a primary beam from a small linear accelerator after passage through a magnetic analyser and targets of various metals the secondaries comprised two groups one with energy mainly and the other possibly elastically scattered with high energies curves show both the total secondary emission and the high energy component as functions of primary voltage for various target metals for a gold target the energy spectrum of the low velocity secondaries is investigated another graph shows the high energy components plotted against the atomic number of the target metal some experiments with insulator targets are briefly reported 8596 a demountable vacuum system for secondary emission studies 8597 the growth f of an electron avalanche retarded by its own space charge the calculation presented shows how the ionization coefficient and the total multiplication in the avalanche vary with the distance travelled when the positive ions formed have an appreciable effect the time taken for an avalanche to develop is also calculated the cases of constant field at electrodes and constant potential between them are considered assuming plane parallel geometry 8598 passage of charged particles through plasma a phenomenological approach is used to examine the behaviour of a dispersive plasma and determine its response to an external disturbance in particular that created by a moving point charge the validity of this approach is discussed an analysis is made of the field and the polarization charge density produced by an incident particle and the effectiveness of the plasma in stopping the particle 8599 microwave study of positive ion collection by probes the electron density in a plasma is determined from the shift in resonance frequency of a cavity in which a discharge is maintained the results are used to verify theory of positive ion collection by negatively biased or double probes experiments were performed in h ar and he at pressures from to mm hg agreement between experimental and theoretical results is good at the lower pressures at high pressures the probe collected about twice the current predicted by theory 8600 a short modern review of fundamental electromagnetic theory 8601 magneto hydrodynamics report of a royal society discussion held in may 8602 tatolectromagnetic field equations for a moving medium with hall conductivity the well known equation representing the electromagnetic field in a moving isotropic conductor is adapted to treat the case of an anisotropic conductor such as an ionized gas moving in a strong magnetic field by introducing a tensor conductivity the modified equation is used to analyse astrophysical problems including the propagation of magnetohydrodynamic waves 8603 the motion of ionized gas in combined magnetic electric and mechanical fields of force transient electric and mechanical forces uniform in space are applied to a gas in the presence of a steady magnetic field the current transport equation for the anisotropically conducting medium is used to determine the subsequent motion of the gas the internal electric field and the current density these are damped oscillatory functions leading to a steady state there is a close connection between the effects of the electric and mechanical forces a steady internal electric field perpendicular to the magnetic field cannot exist unless accompanied by a mechanical force the relationship between the two is examined 8604 cerenkov radiation and its applications 8605 reflection at arbitrary incidence from a parallel wire grid the analysis presented is valid for any direction of polarization angle of incidence or value of wire conductivity 8606 on the scattering of spherical waves by a cylindrical object analysis indicates that the ratio of the amplitude of the scattered field for a spherical incident wave to that for a plane wave is equal to where is the distance of the source and that of the observer from the cylinder axis 8607 revolutionary new oscillator amplifier short simplified description of the maser name derived from microwave amplification by stimulated emission of radiation see also of 8608 a microwave spectrometer and its applications to some organic molecules stark modulated microwave spectrometer operating in the frequency range is described in detail circuit diagrams are given spectra of several asymmetric top molecules have been investigated 8609 some magneto optical phenomena connected with the molecular resonance of gases at micro wave frequencies the production of birefringence and faraday rotation is discussed quantitatively with particular reference to nh 8610 magneto hydrodynamics 8611 new science of radio astronomy a review of research methods and results based on an address delivered to the american association for the advancement of science 8612 the spatial distribution and the nature of radio stars data obtained from a survey of radio stars by shakeshaft et al to be published in are analysed the results indicate an apparent increase in the spatial distribution density with distance in all directions a reasonable interpretation of the results cannot be provided unless most of the stars are assumed to be outside the galaxy 8613 an alternative identification of the radio source in the direction of the galactic centre an attempt has been made to determine the distance of the radio source observed eg by from the absorption by interstellar hydrogen at the results suggest that this source is considerably closer than the galactic nucleus 8614 radio emission from jupiter brief report of reception at seneca maryland of radiation on a large cross aerial was used of the type developed by mills see of the effect in a broadcast receiver was similar to tht with thunderstorm interference see also of october 8615 radio waves from the planet jupiter and a cosmoggonic hypothesis the reported observation of radiation at about of october burke and franklin is discussed in relation to theories concerning physical conditions on jupiter it is suggested that saturn may also emit radio waves but with lower intensity theoretical considerations indicate that astral heat and light may be a direct effect of the gravitational force 8616 meteor radiation ionization and atomic luminous efficiency a theoretical paper empirically constructed tables are presented for calculating the radiation from meteors 8617 corpuscular streams solar emission of particles giving rise to variations of the geomagnetic field of is discussed if the stream of particles is borne in the wake of a shock wave with a velocity of the order of complete transport of material from the sun to the earth need not be postulated the steep nature of the shock front is consistent with the sudden commencement of magnetic storms 8618 provisional determination of the mean length of the year sunspot cycle analysis of available data shows that during the past centuries the duration of the year cycle has fluctuated between five and eleven year cycles the mean being year cycles taking the mean duration of the year cycle as years this corresponds to a range and a mean value years 8619 solar flare and magnetic storm effects in cosmic ray intensity near the geomagnetic n pole phenomena observed during and following the solar flare of july are discussed if the observed increase in cosmic ray intensity was due to charged particles from the sun the trajectories must have been strongly affected by factors other than the geomagnetic field 8620 measurement of soil conductivity by the wave tilt method description of the experimental arrangement and report of results obtained in the vicinity of delhi 8621 geomagnetism this special number commemorates the golden jubilee of the alibag observatory the papers presented include the following the contrast between geomagnetic s and l at huancayo characteristics of polar magnetic storms ionospheric magnetic fields during marked decreases in cosmic rays magnetohydrodynamic waves and solar prominences auroral activity at medium latitudes solar radiation in the far ultraviolet and some related geophysical phenomena on the emission of electric currents from the sun sunspots and geomagnetic variation magnetic storms and solar m regions the dynamo action of the diurnal atmospheric oscillation recurrence tendency of geomagnetic activity during the current sunspot minimum some remarks on the equatorial electrojet as revealed by the analysis of solar flare effects geomagnetic records at colaba and alibag on days of solar eclipse some others are abstracted individually 8622 apparatus for measurement of the intensity of the terrestrial magnetic field an adaptation of the device described previously of august 8623 notes on the theory of magnetic storms a non mathematical account is given of the model problems and their solutions by which chapman and ferraro have sought to illustrate some aspects of the theory of magnetic storms these problems are here used to develop a qualitative solution of the motition of an infinite neutral ionized plane sheet of gas or of a succession of such sheets towards a unidirectional magnetic field whose intensity decreases as an inverse power of the distance from an axis to which the sheet is parallel the gas in the centre approaches to a minimum distance from the axis and then recedes again the gas far to either side moves onward with little distortion between these central and outer parts there are two strips of the sheet whose ions and electrons separate from each other under the influence of the magnetic field partly because these strips become much extended and reduced to low density some charges are deviated away to infinity others are captured by the field and build up a westward electric current to which is ascribed the main phase of a magnetic storms 8624 the relation between the geomagnetic field and range disturbance in various latitudes analysis of observations leads to a theory of the mechanism of magnetic disturbances intermediate between the classical theory and tht advanced by nikolsky of the true storm time effect is greatest at the equator an additional effect comprising instantaneous response to and recovery from the disturbance is greatest in the auroral zone the effect on the ionosphere at high latitudes is briefly considered 8625 assembly of the international union for geodesy and geophysics rome the text is given of papers most of them in english dealing with the structure of the atmosphere and especially with research by means of rockets since 8626 dissociation of oxygen in the upper atmosphere the content of the atmosphere at heights between and was determined by measuring the transmission of solar radiation in the wavelength band from to using an ultraviolet photon counter in a rocket at the concentration was indicating that of the atmospheric oxygen was still undissociated 8627 determination of the true distribution of electron density in the ionosphere part a survey leads to the conclusion that existing methods of investigating the electron density distribution are either too inaccurate or too complicated for routine use 8628 resonance absorption of sunlight in twilight layers calculations are made relevant to the determination of the thickness of the atmospheric sodium layer which appears to be located at a height between and 8629 new representation of the longitude effect in the ionosphere f layer the representation is based on a chart with geographic latitude as abscissa and magnetic latitude as ordinate on plotting the positions of existing ionospheric stations the need for stations in certain regions is demonstrated particularly for stations with south geographic and north magnetic latitude 8630 simultaneous fluctuations of the f layer ionization at two widely spaced observation stations observations of short term variations of f at graz in austria and at capetown in s africa during january are compared correlation factors up to were obtained for values observed at the same universal time but the correlation decreases rapidly as the time difference between the measurements increases the results support the view that the ionizing radiation itself undergoes short term fluctuations 8631 the ionospheric f layer over india in minimum sunspot year a summary of observations made at various stations in india 8632 a singular echo trace observed in ionograms from the kerguelen islands station traces have been obtained indicating reflections from a layer at a height of in summer and in winter corresponding to the temperature maximum region at the upper boundary of the ozone layer the results are in agreement with those of major of november 8633 investigation of vertical movements of the f layer calculations based on observations of the rate of fading of signals and simultaneous independent determinations of e layer vertical movements confirm that the vertical drift velocity of the f layer at morning and evening is greater than that of the e layer 8634 diurnal variation in auroral activity an analysis of amateur radio contacts during the period using vhf transmissions incident obliquely to the ionized aurora is compared with results obtained by radio soundings at normal incidence auroral activity shows a strong maximum at hours local time with of the total occurrences between and hours 8635 radio astronomy intended primarily for physicists and astronomers 8636 meteor astronomy a comprehensive up to date survey indicating the importance of radio techniques 8637 the sun the solar system vol chapters on the various aspects of the subject are contributed by acknowledged leaders in the field to produce a reference book for the specialist and a useful survey for the nonspecialist 8638 the physics of the ionosphere a collection of papers presented at the physical society conference held at cambridge england 8639 the response of remote position control x systems with hard spring nonlinear characteristics to step function and random inputs 8640 the adjustment of control systems for quick transien response a theoretical investigation indicates that for a large class of linear systems the error due to a transient disturbance is dependent on only one system parameter the settling time constant and that the quickest approach to correction is obtained when the system is adjusted so as to be quasicritically damped the adoption of quasicritical damping as a design criterion for stability is recommended 8641 the integral of error squared criterion for servo mechanisms 8642 silicon alloy junction diodes for power supply applications characteristics of low power and high power si diodes are presented and various applications indicated 8643 large storage binary to decimal converter a digital converter is described which will handle binary digit numbers with a maximum input speed of bits 8644 isabel iso status accumulating binaries using extraordinary logic an improved logical arrangement of a decimal counter based on bistable elements is described the advantages over usual methods are described and the performance of various circuits using this method is given 8645 input and output devices for computers the following papers were presented at a symposium held in london the transport of paper tape in digital computation a high speed tape reader a new cards per minute card reader high speed printers 8646 analysing magnetically detected stepper servo motors 8647 a vacuum evaporated random access memory the basic multiple layer magnetic film structure described is shown to have valuable properties in coincident signal switching applications including low magnetic turn over time and extremely small cell volume 8648 a special purpose analogue digital converter for use in analysing tape recordings f of time multiplex telemetry signals one channel is analysed at each playback and known transducer nonlinearities and drifts of gain and level are compensated 8649 thermistors their theory manufacture and applications 8650 line equations for an inhomogeneous line system of cylindrical symmetry and their application to circuit elements examples considered include the calculation of the skin effect of cylindrical wires the frequency response of disk type and wound capacitors and the impedance of a sintered ta electrolytic capacitor 8651 the realization of switches for both current directions using junction transistors some practical transistor arrangements with and without diodes are described 8652 static switching a transistor nor unit output only when all inputs absent is shown to be suitable as a basic element for building switching systems 8653 the practical significance for communication technique of the relation between hilbert transformation and harmonic analysis conformal mapping is used to show that the hilbert transformation can be reduced to a harmonic analysis which would simplify attenuation and phase calculations practical methods of carrying out the transformation are outlined 8654 vibration of quartz crystal plates the theory of mindlin of is extended to the case of crystal plates of nonuniform thickness 8655 design and performance of ultra precise quartz crystal units techniques are described for producing crystal resonators with a frequency stability within about part in and a of for periods up to month the frequency stability compares favourably with that of atomic frequency standards 8656 on the electrodes of gt cut crystal units used for the frequency standards the physical properties and method of fabrication of electrodes for crystals used in primary frequency standards are described a maximum q is obtained when the gold sputtered electrode has a thickness of advantages of annealing are discussed 8657 temperature compensation of coaxial cavities 8658 increasing the frequency stability of homogeneous cylindrical cavity resonators the effect of temperature fluctuations and atmospheric conditions on the resonator dimensions and the characteristics of the dielectric are investigated to determine means of minimizing frequency variations 8659 how to design broadband microwave cavities design criteria for rhumbatrons of cylindrical and prismatic form are given with a numerical example for each type 8660 analysis of all pass networks part general remarks and classification 8661 the theory of the realization of linear quadripole networks with prescribed effective transfer function in the presence of lossy circuit elements summary by the author of the results contained in a more extensive paper published in chinese 8662 the differences between single and periodic transient processes in low pass transmission systems the differences are calculated for square pulse waveforms and ideal transmission systems corrections can be made to obtain approximations applicable to practical low pass networks 8663 synthesis techniques for gain band width optimization in passive transducers the technique produces from the idealized gain bandwidth constraints which ensure matching to a given load a set of functions specifying the equalizer along the fixed transducer is synthesized from these functions examples illustrating the technique are given 8664 an analogue device for problems of filter development the equipment described is used for the design of filters from given operating characteristics other applications such as filter correction and filter design for pulse waveforms are outlined 8665 ladder networks with tchebycheff characteristic ladder networks without poles are considered with tchebycheff transfer function for inputs from a generator with finite internal impedance or from ideal current or voltage generators design formulae are tabulated 8666 an alternative approach to the realization of network transfer functions the n path filter a t me varying network consisting of n parallel transmission paths each containing input and output modulators is described and analysed some practical applications are discussed in detail and experimental verification is presented 8667 low frequency wave filters employing thermistors a general review of thermistor properties and small signal performance is presented together with results of measurements at very low frequencies and response curves of simple filter circuits 8668 realization of a comb filter for the detection of pulse signals in noise the use of comb filters in radar systems is discussed and the results obtained on an experimental filter system with up to seven pass bands are given 8669 the correction of phase distortion in rc networks near cut off frequency examples of phase correcting networks and optimum design conditions are given 8670 mechanical filters english summary 8671 band stop filters a method of achieving resistance compensation is bandstop filters is described performance curves and normalized component values are calculated for a pole filter 8672 high selectivity with constant phase over the pass band a relatively simple frequency inversion process is described for compensation of phase shifts in filters resulting in a constant output signal phase 8673 equivalent networks of generic multipoles a nonreciprocal four terminal networks can be realised by an equivalent circuit which contains only one reciprocal three pole element 8674 a new automatic frequency regulation system brief description of a system for stabilizing the output of a k band klystron the error signal is derived from a phase comparison of a driving signal with the rectified microwave signal reflected from a dimension modulated reference cavity the resonance frequency of the cavity is controlled by a driven rochelle salt crystal 8675 automatic phase control theory and design systems with a sinusoidal reference signal are analysed and the results verified experimentally 8676 variable program triggering source a transistorized unit for use with instrumentation cameras is described which generates pulses at an adjustable constant rate or at a rate which is variable for a selected period between predetermined initial and final rates 8677 a special trigger circuit the bistable transistor circuit with common emitter resistance analysed earlier of has characteristics similar to those of the schmitt multivibrator circuit two variations of the circuit component values are considered corresponding to saturating and nonsaturating conditions 8678 high speed scalers using tunnel diodes a simple reliable scaler with resolving time is described 8679 a cascode trigger circuit using a pnp and npn transistor a monostable circuit preceded by a diode pump integrator acts as a frequency dividing stage 8680 variable ultrasonic water delay line the unit described produces a delay variable from and stable w to within the bandwidth is at 8681 the noise figure of several amplifiers in cascade 8682 parametric devices and masers an annotated bibliography march 8683 parametric diodes in maser phase locked frequency divider abstract 8684 contribution to the study of parametric amplifiers an analysis of parametric amplifier operation in terms of feedback loops expressions are derived for the insertion gain noise temperature and bandwidth of different two and three frequency arrangements which can be generalized for a four frequency system 8685 the transmission of signals of any form by means of a degenerate parametric amplifier formulae are derived for the response of a degenerate parametric amplifier comprising an antiresonant circuit with frequency dependent admittance in parallel with a nonlinear capacitance diode 8686 theory of diode parametric amplification 8687 the reactance type straight amplifier as a low noise preamplifier stage in the uhf range the signal and noise response of a cascade connected amplifier is investigated which consists of a diode reactance preamplifier see of followed by a conventional triode amplifier results are given of measurements on an experimental circuit using a signal frequency of with pumping at 8688 the dc pumped quadrupole amplifier a wave analysis 8689 a contribution to the theory of the transmission of amplitude modulated frequency modulated or amplitude and frequency modulated carriers in linear systems part the standard method of calculating the distortion of fm signals in linear systems which is based on an asymptotic series is critically reviewed and its limitations are considered 8690 photovoltaic effect derived from the carnot cycle an expression for the maximum power derivable from any photovoltaic device is developed in terms of the incident light intensity measured in units of black body radiation 8691 velocity distribution of electrons in a strong electric field a method is developed for determination of a nonstationary solution of the boltzmann equation in the case of strong electric fields 8692 field emission through dielectric layers a summary is given of the results of field emission experiments on the absorption of inert gases on tungsten and a mechanism is described accounting for some of the phenomena encountered 8693 the spatial and time fluctuation of coulomb energy in the low concentration impurity conduction 8694 electron scattering in high magnetic field electrical conductivity in a strong magnetic field is calculated for the case of scattering by delta function impurities collision broadening is neglected and the scattering by an individual centre is solved exactly rather than by perturbation theory 8695 microwave breakdown of air in nonuniform electric fields two cases are treated theoretically a rectangular microwave cavity and a similar cavity with a hemispherical boss one of its walls the theoretical predictions are compared with breakdown measurements in air 8696 high frequency breakdown of air kinetic theory is applied to the ionization breakdown of air surrounding an aerial on a high speed vehicle breakdown voltage altitude curves are given for and 8697 electrical and thermal currents in a slightly io ionized gas a general solution is given of the boltzmann transfer equation for electrons under the influence of ac and dc electric fields a magnetic field and a temperature gradient 8698 nonlinear effects on electron plasma oscillations a nonlinear term in the boltzmann equation is considered as a perturbation and the results are examined to investigate the validity of the linear approximation 8699 forces on charged particles of a plasma in a cavity resonator two types of confining force are considered the mathieu force due to the electric field acting directly on electrons see boot et al and the em force resulting from the interaction of the electron current with the magnetic field component of the em wave 8700 radio frequency forced oscillations in nonuniform plasmas a theory of periodic rf oscillations in a plasma is given neglecting electron ion collisions and temperature variations small signal approximations are derived which are applicable to plasma confinement problems 8701 plasma resonance in a radio frequency probe measurements of the dc component f the electron current to the rpobe show a resonance increase at the electron plasma frequency 8702 negative electrical conductivities the complex electrical hf conductivity of a plasma in a magnetic field is calculated on the basis of boltzmanns equation and the occurrence of negative values of the real part of is discussed 8703 oscillations in a plasma in a weak magnetic fiel oscillations of two types were observed in a discharge tube these are interpreted as the plasma type oscillation and the cyclotron resonance oscillation 8704 oscillations of an inhomogeneous plasma in a magnetic field mathematical analysis of small oscillations of a hot plasma confined by a magnetic field shows that there are two types of wave a slow drift wave characteristic of an inhomogeneous plasma and a magneto acoustic wave if certain relations obtain the drift current can cause amplification of the oscillations criteria for an instability of this kind are derived 8705 transport properties of plasmas in a strong magnetic field 8706 compression waves in a plasma in a static magnetic field 8707 ion charge exchange reactions in oxygen afterglows measurements made by a linear accelerator mass spectrometer of the decay of ion concentration after a pulsed discharge are discussed with reference to electron loss processes in the upper ionosphere 8708 summarized proceedings of a conference on some aspects of magnetism september 8709 generation of phonons in high power ferromagnetic resonance experiments magneto elastic waves are produced by coupling between spin waves and elastic vibrations 8710 combinational scattering of electro magnetic waves in ferromagnetic dielectrics raman type scattering by oscillations of the magnetic moment is predicted the extinction coefficient for the scattered radiation is calculated 8711 the influence of the conductivity of the surrounding medium on the input impedance of a current loop using focks solution for the field of a low frequency current element lying on the surface of a conducting medium the input impedance of a current loop is calculated by the method of induced emfs 8712 shielding of transient electromagnetic signals by a thin conducting sheet the screening effects of an imperfectly conducting sheet against the transient field of a vertical magnetic dipole with a ramp function excitation are investigated 8713 megavolt electronics cherenkov coupler for the production of millimetre and submillimetre waves cherenkov radiation at the watt level can be produced and beamed by passing a high harmonic electron beam through a mm hole in a large specially shaped teflon cone the measured radiated power shows good agreement with theory 8714 field of a charged particle in a moving medium energy losses of the charge due to cherenkov radiation and excitation of plasma waves are determined 8715 wide band absorbers for electromagnetic waves the construction is described of shaft type absorbers suitable for metre waves measurements of reflection coefficient as a function of frequency and angle of incidence are discussed and the possibilities of reducing the depth of the absorber and of extending the absorption range to lower frequencies are mentioned 8716 the diffraction of electromagnetic waves by a circular cylinder in a homogeneous half space a solution is obtained for the distortion by a cylindrical inhomogeneity below the surface of the earth of an em field produced by a point source 8717 scattering of electromagnetic waves from an infinitely long magnetized cylindrical plasma the magnetically contained plasma is characterized in terms of its macroscopic dielectric tensor and the scattering problem is solved analytically numerical results are given 8718 scattering of radiation by a plasma more complete analysis than that given by hershberger of is necessary 8719 on electromagnetic radiation in magneto ionic media a wave matrix is defined the zeros of whose determinant are the propagation constants of the ordinary and the extraordinary plane waves 8720 doppler effect in an electron plasma in a magnetic field a note on the complex doppler effect occurring in an anisotropic or gyrotropic medium 8721 propagation of microwaves through a magnetoplasma and a possible method for determining the electron velocity distributions a study of propagation of circularly polarized waves parallel to the magnetic field giving special attention to the extraordinary ray 8722 boundary conditions and ohmic losses in conducting wedges 8723 modulation effect corrections for moments of magnetic resonance line shapes 8724 electromagnetic pressure on a charge moving in a magnetic field the radiation pressure on an oscillating particle is considerably greater than that on a free charge the problem is considered in a nonlinear approximation and the equations of motion are discussed 8725 spin configurations a direct and a fourier method are outlined for determining the configurations of ordered spin arrangements 8726 net electric charges on stars galaxies and neutral elementary particles 8727 the spectrum of the cygnus and cassiopeia radio sources below the steerable radio telescope and and the transit radio telescope at jodrell bank have been used as an interferometer to measure the ratio of the intensities of the cygnus and cassiopeia radio sources from to the ratio remains constant at results are compared with those obtained by other workers 8728 the new radio astronomy centre of the university of signey general information is given about the mills cross radio telescope which is to be erected at the new centre 8729 radio detection of the planet saturn brief report of the detection of cm radiation from saturn using an x band ruby maser in a modified dicke type radiometer system installed on an ft paraboloid a peak aerial temperature of was obtained indicating an equivalent black body disk temperature of 8730 observed variations in the amplitude scintillations of the cassiopeia radio source observations over a period of four years are analysed daily variations are presented as functions of solar and sidereal time ad the effect of the solar cycle is studied 8731 anomalous winter absorption of radio waves measurements made at cambridge england of the absorption of cosmic radio noise on a frequency of show that the average midday absorption in winter is about twice as great as in summer an attempt is made to relate this abnormality to the winter anomaly in absorption of reflected waves if certain assumptions are made it can be shown that on the majority of days in winter the absorbing electrons are largely concentrated at a height of about km 8732 ionized gas and high energy electrons in the vicinity of the earth and in the interplanetary space examination of results obtained by the three soviet cosmic rockets relating to the van allen belts the variation of ion concentration with distance from the earth and the dependence of the trap collector current and the potential of the container on the electron current at given ion concentrations are shown graphically 8733 calculations of cosmic ray trajectories near the equator 8734 electrons of the van allen radiation flux calculations show that electrons in the radiation belts cannot be produced by neutron decay from the cosmic ray albedo the acceleration of trapped electrons by em fields is briefly discussed see also of 8735 rapid reduction of cosmic radiation intensity measured in interplanetary space simultaneous observations in pioneer v and on the ground demonstrate that the forbush decrease is of solar origin takes place in interplanetary space and is not related to the presence of the earth or its magnetic field 8736 solar cosmic rays and soft radiation observed at kilometres from earth a summary of the cosmic ray and soft radiation effects observed during march april using a space probe and ground observations 8737 observations of solar cosmic rays near the north magnetic pole 8738 comparison of solar cosmic rays injection including and may 8739 observations of solar flare radiation and modulation effects at balloon altitudes july 8740 propagation of low energy cosmic ray particles associated with solar flares the propagation mechanism is examined using data obtained during the period june may 8741 cosmic ray intensity variations and the interplanetary magnetic field the characteristics of the variations can be explained in terms of a dipole type of field generated by current systems in the solar corona 8742 low energy solar cosmic rays and the geomagnetic storm of may 8743 the effect of the initial phase of a magnetic storm upon the outer van allen belt a theoretical study of the motion of a charged particle trappin a magnetic dipole field and in a compressed dipole field the latitude shift of the trapped radiation during magnetic storms is found to be small 8744 experiments on the eleven year changes of cosmic ray intensity using a space probe it is shown that the mechanism responsible for the changes is heliocentric and the region in which the changes occur is located principally outside the earths orbit 8745 investigation of interplanetary ionized gas high energy electrons and solar corpuscular radiation by means of three electrode traps for charge carrying particles installed on the second soviet space rocket between and from the earth electron streams of electrons cm sec and energies were recorded protons with energies of at heights owere also noted 8746 development of multiple radiation zones on october present observations made at about altitude during a magnetic sotmr using counters carried on explorer 8747 outer radiation belt and solar proton observations with explorer during march april a preliminary summary of observed counting rates which includes rate time plots for typical passes some of the fluctuations in the outer belt during the observation period are referred to briefly 8748 detection of electrons in the upper atmosphere by the third earth satellite electrons of energies were detected by means of two fluorescent screens covered with thin al foil of different thickness used in conjunction with photomultipliers the flux increases sharply with decreasing energy at high latitudes the night time energy flux reaches a few tens of ergs cm sec sterad 8749 penetration of fast charged particles from the outer atmosphere into the ionosphere in streams of oscillating particles trapped in the earths magnetic field the directions of motion will show pronounced spatial anisotropy due to absorption effects in the lower layers of the atmosphere 8750 the outer radiation belt and aurorae space probe observations are found to be in good agreement with a proposed unsymmetric model for the outer radiation belt see also of 8751 correlation of an auroral arc and a subvisible monochromatic arc with outer zone radiation on november 8752 a southern hemisphere survey of the radiants of sporadic meteors results are given of a new survey with higher resolution equipment see of than that used for the earlier survey of weiss good agreement is found with the results obtained by hawkins in the northern hemisphere 8753 effect of the solar activity on the earths rotation a linear relation is shown to exist between sunspot activity and were cst is atomic time this result is discussed in relation to the influence of solar activity on variations in the speed of rotation of the earth on its axis 8754 the structure of the electrostatic field in the free atmosphere from the evidence obtained during international geophysical year investigations an examination of the spherical capacitor hypothesis with reference to the variation of the electric po ential with height and time of day 8755 measurement of the atmospheric electric field in the free atmosphere the results of radiosonde measurements up to about height are compared with measured and calculated field strength data of other authors 8756 geomagnetic storm sudden commencement rise times if the sudden commencement of a magnetic storm is interpreted as the impact of a solar plasma front on the geomagnetic field its rise time usually a few minutes depends on the different transit times of hydromagnetic waves propagated to the earths surface from different poin s on the boundary of the field 8757 a note on harmonic analysis of geophysical data with special reference to the analysis of geomagnetic storms the effect of the earths rotation on the determination of magnetic disturbance variations ds and dst is discussed 8758 radio astronomy observations of the second soviet space rocket a report of observations of radio signals from the rocket which reached the moon at min sec on september signal intensity measurements were made using an interferometer technique 8759 on mr king heles theory of the effect of the earth oblateness on the orbit of a close satellite an examination of the relations between parameters used by king hele of and the more usual osculating orbital elements 8760 on the motion of a satellite in an asymmetrical gravitational field a theory for the inclusion of the effects of tesseral harmonics in the motion 8761 angular motion of the spin axis of the tiros meteorological satellite due to magnetic and gravitational torques the equations of motion including the two torques have been solved and the calculated and observed directions of the spin axis are in close agreement 8762 perturbations in classical mechanics a method similar to quantum mechanics time dependent perturbation theory is described which might be useful in the calculation of satellite orbits and plasma stability 8763 us meteorological satellite cameras photograph cloud cover description of the tiros satellite and associated tracking and interrogation equipment see also of and report on its launching and initial orbits 8764 weather radar observations from an earth satellite a survey of the problems involved in designing a weather satellite the use of radar in the satellite is discussed and also the problem of handling the data on the ground and in the satellite 8765 a method for measuring temperature directly in the upper atmosphere with a rocket borne magnetic mass spectrometer gas temperature is determined from the variation of the flux of neutral particles entering the instrument 8766 on the problem of an effective recombination coefficient in the ionosphere discussion of possible chemical exchange reactions operative in establishing ion balance in the ionosphere 8767 changes at kokubunji tokyo a statistical analysis of data recorded during the period and a study of their relation to ionospheric absorption atmospheric noise and other geophysical effects 8768 a statistical theory of ionospheric drifts a statistical study of the fluctuations in plasma density is used in an attempt to interpret drift velocities it is assumed that the ionization is transported by a turbulent flow in the neutral air under the action of the magnetic field and the dynamo electric field the application of the theory to different heights in the ionosphere is examined 8769 observations of sudden ionospheric disturbances observed phase changes for reflected waves of frequency are possible due to an increase in electron density extending to above the e layer maximum measurements of the absorption of cosmic noise transmitted through the ionosphere show that an increase occurs at heights as low as km or even 8770 use of the incoherent scatter technique to obtain ionospheric temperatures if the ionization above the f peak is in diffusive equilibrium its density decreases exponentially with height with a scale height proportional to the temperature of the neutral gas electron density profiles obtained by the incoherent scatter method at are consistent with a temperature of about between and 8771 f region travelling disturbances and sporadic e ionization a statistical study shows an association between f region travelling disturbances and increases in e ionization at sydney for about one disturbance in increases by approximately in some min after the appearance of the disturbance and returns to normal min later 8772 damping coefficient of vibrating electrons a druyvesteyn distribution is substituted for the assumed maxwellian distribution in the derivation of the damping coefficient of vibrating electrons the consequences are discussed 8773 formation of the sporadic e layer in the temperate zones an extension of work described earlier of to include regions where the gyro frequency of the ions is less than their collision frequency 8774 further observations of radio stellar scintillation results are described which support those of spencer of concerning the elongation of ionospheric irregularities the size of the irregularities is estimated and a change in dimensions with elevation of the radio source is observed 8775 electron density distribution in the upper ionosphere from rocket measurements seven flights between and having maximum heights of are discussed the electron distribution above the f layer maximum agrees well with that given by chapman theory 8776 a variable atmospheric density model from satellite accelerations an empirical expression is derived which relates atmospheric density and scale height h to satellite orbital elements and solar rf noise flux f from this can be obtained as a function of f height and solar zenith angle tables of and are given for and for two values of f and 8777 the determination of ionospheric electron content from satellite doppler measurements part method of analysis theory is given which is based on measurements of the slopes of the differential doppler and the doppler curves obtained from observations of the transmission at and from sputnik a semi empirical formula is derived for the total electron content 8778 the determination of ionospheric electron content from satellite doppler measurements part experimental results the results of observations made from september to december are presented a winter to summer variation of in total midday electron content was observed the diurnal variation showed an increasing content towards evening although the content below was decreasing day to day variations correlated well with during the summer 8779 the electron content and distribution in the ionosphere addendum to of 8780 use of logarithmic frequency spacing in ionogram analysis an improved method for the reduction of ionograms to electron density profiles 8781 an improved automatic method for measurement of ionospheric absorption pulses are transmitted at vertical incidence at a rate f one per second and the mean echo amplitude over an interval of about one minute is recorded 8782 some characteristics of ionospheric back scatter observed at an investigation of the e and f layers by the incoherent back scatter technique using either vertical or oblique incidence is described the spectra of radiation scattered from different heights and an electron density profile from are shown 8783 faraday rotation observations of the electron content of the exosphere the moon echo observations of various workers are summarized the ratios obtained for the ionospheric electron content above to that below are tabulated 8784 radar lunar investigations at a low geomagnetic latitude the theory and results are presented for polarization rotation observations of pulsed radar transmissions at reflected from the moon the diurnal variation of total electron content of the ionosphere is shown 8785 symposium on the exosphere and upper f region the text is given of papers presented at the symposium held in washington dc may some of the papers are abstracted separately others are listed below the exosphere and upper f region structure of the earths exosphere whistler dispersion and exospheric hydrogen ions electron densities to earth radii deduced from nose whistlers comment on models of the ionosphere above f radio wave scattering by an ionized gas in thermal equilibrium 8786 a sounding rocket measurement of electron densities to kilometres doppler measurements were made at and above the f layer peak the electron density decrease indicates a scale height of at and a linear gradient in scale height of from to km 8787 radio propagation measurements using the explorer satellite coherent signals at and were emitted by the satellite the results gave electron densities of about at above the earth this is higher than expected and may have been influenced by an intense geomagnetic storm or by the need to make large corrections 8788 the electron density distribution derived from whistler data and faraday fading observations an interpolation law allows satellite observations to be combined with whistler data 8789 elf electric fields from thunderstorms from an assumed cloud to ground discharge model calculations of wide band vertical electric field variations indicate a small decrease with distance up to a relation to and a relation beyond km radiation field spectrum analysis over the frequency range indicates that below long discharges produce more energy than short discharges and that intercloud discharges may produce as much as cloud to ground discharges conclusions are supported by experimental evidence 8790 the thunderstorms of september lightning discharges and atmospherics report on visual observations made at slough and an analysis of records taken by lightning flash counters at slough and other stations in the vicinity of the storm 8791 direct measurement of particles producing visible auroras a large amount of auroral light is produced by electrons with energies 8792 large scale auroral motions and polar magnetic disturbances part a polar disturbance at about hours on september a detailed study of a particular event suggests that both the westward auroral electrojet and the eastward auroral motion are produced simultaneously by a southward electric field the origin of which is discussed over references 8793 the height and geometry of auroral radio echoes at jodrell bank echoes at have been obtained only from regions where the line of sight is within of perpendicularity to the local magnetic field lines at a height of about see also of et al 8794 analysis of smooth type atmospheric waveforms over traces are analysed in an attempt to resolve previous conflicting results of and of caton and pierce the precise nature of observations necessary for the accurate analysis and reliable detection of deviations from simple theory is indicated 8795 guiding of whistlers in a homogeneous medium the velocity of energy flow of whistlers as a function of wave normal angles is computed results differ from the longitudinal value except at very low frequencies or very small angles 8796 electromagnetic signals from nuclear explosions in outer space x rays produced by a nuclear burst in outer space cause polarization currents in the medium which if distributed anisotropically will emit em radiation a rough calculation indicates that a detectable signal is produced at a range of from a burst of x ray energy equivalent to ton of high explosive the signal power varies as the square of the electron density so this effect may provide a sensitive measure of the electron density in outer space 8797 bomb excited whistlers reasons are given for the possible excitation of whistler modes by c nuclear explosions and characteristics of the signals to be expected are discussed 8798 audio frequency electromagnetic radiation in the auroral zone spectrograms of the energy in the frequency range were recorded in n sweden during the winter and early summer of the energy is low during the day and high at night and the ratio is greatest in the range no clear cut correlation with magnetic indices could be found except during some geomagnetic disturbances the main contribution to the energy probably originates in atmospheric noise from thunderstorms but magnetic fluctuations may be important at lower frequencies 8799 analysing magnetically detected stepper servo motors digital test equipment for evaluating the performance of a motor used for digital analogue conversion is described 8800 recording accuracy in magnetic tape recording the accuracy is defined on the basis of information theory and he capacity of a magnetic tape communication channel is calculated taking account of signal noise ratio and undesirable am and fm effects 8801 photovoltaic effect produced in silicon solar cells by x and gamma rays 8802 on the realization of a highly stable direct current power supply with a wide range of output voltage the principle of operation of a stabilized power supply incorporating two feedback loops is described the properties of the circuit are deduced from transfer functions 8803 designing transistorized voltage regulators a detailed analysis of the design of a dc series regulator with temperature compensation 8804 high speed adding system a new system is described which increases the adding speed by obtaining the carries of all digits in a one step operation 8805 a digital computer store with very short read time each binary cell is formed by two sets of windings coupled or not coupled by a linear ferrite a unit store has been constructed 8806 a parallel arithmetic unit using a saturated transistor fast carry circuit an addition time over digits of ns is achieved 8807 multipliers and dividers i ac computers thermionic valve and transistor divders and multipliers are described in which the exponential shape of the small signal characteristic is used to combine a dc and an ac signal 8808 the differential analyser and its realization in digital form 8809 high speed light output signals from electroluminescent storage systems the effect of phosphor afterglow pr digit on read out time appears to limit the number of matrices to about 8810 a compu er storage matrix using ferromagnetic thin films details are given of the construction and performance of a storage system using the coherent rotational mode of magnetization reversal in thin films of a newly developed alloy on an substrate 8811 a magnetic core buffer store for use with a card punch or line printer the store accepts data from a computer and provides a series of parallel outputs suitable for printer or card punch square loop magnetic cores are used and the decoding and parity check circuits are described 8812 ferrite core memory systems with rapid cycle times the normal cycle time of for square loop ferrite cores is reduced to a system suitable for a store of words of digits with a cycle time of is developed 8813 a class of optimal noiseless load h sharing matrix switches a scheme for constructing a matrix switch with a reduced number of input wires is given see also below 8814 new developments in load sharing matrix switches 8815 the parametron and its application in data processing systems ferrite core and diode parametrons are reviewed and applications are discussed 8816 transistorized magnetostrictive delay line stores two types of storage system for operation at are described their delay times are and respectively see also supplement 8817 the assessment of the reliability of magnetic tape for data processing a method of tape testing based on a theory of the origin of observed signal drop out distribution permits batch testing and assists in the design of tape handling systems and in the calculation of reliability 8818 a magnetic read head with output signal independent of tape speed each head is double consisting of a variable reluctance reading head and a conventional writing head one unit comprises eight double heads and can be used with standard tape in computer output and editing equipments the reading head is adequate for normal packing densities over a wide range of tape speeds down to zero 8819 self resonance of ceramic miniature capacitors methods of measuring the resonance frequency are discussed and the characteristics of various types of miniature ceramic capacitor at frequencies in the range are investigated see also of 8820 a review of the present state of networks synthesis part comprehensive review of synthesis methods 8821 two terminal rc networks and theoretically related topics a derivation of the properties of the principal minors f successive orders of the nodal determinant of a lumped linear rc network see also below 8822 perturbation theory of resonant cavities a detailed derivation is given of the perturbation formula for the frequency shift on introducing a sample of ferrite or dielectric material into a resonant cavity 8823 on the theory of strongly coupled cavity chains 8824 the rutile microwave resonator the use of a rutile crystal as a microwave resonant cavity is described this is of a sm much smaller size than the equivalent metal walled cavity 8825 measurement of bandwidth of microwave resonator by phase shift of signal modulation 8826 determining component variation for gradual transition between dissimilar impedances the problem is attacked by a recursive method needing a minimum of numerical precision the application to an acoustic absorption system is considered see also 8827 remarks on the additions to kupfmullers transient transient formula kupfmullers formula for low pass filters is generalized and an analogous formula valid for all pass delay circuits with optimally flat response is derived 8828 the performance of filter networks consisting of equal half sections formulae are given for the open circuit impedance of an n section network from which the transmission characteristics can be derived calculations for various simple filters are included 8829 a tuning fork filter an introduction to the use of a tuning fork filter as a circuit element and a complete description of a particular unit its derivation and the correlation between theory and measurement 8830 linear slope delay filters for compression design considerations are summarized for filters having linear change of delay time with frequency over a narrow band 8831 the normalization of electrical integrating and differentiating circuits 8832 on the switching time of subharmonic oscillators the time necessary to change the phase of an idealized subharmonic parametric oscillator by is calculated for various values of pump power and switching power 8833 qualitative investigation of a new oscillator circuit analysis of a triode oscillator circuit with good frequency stability by mathematical treatment and an analogue differential analyser 8834 transistor beta phase shift oscillator a new oscillator circuit is described whose performance is analysed theoretically and confirmed by experiment 8835 pulse shaping with variable capacitance diodes small signal and analysis is carried out for variable capacitance integrating and differentiating circuits 8836 multiple coincidence circuit a general purpose transistor coincidence circuit accepting up to five input signals with three simultaneous outputs is described it features a special discriminator which operates on the leading edge of the input signals or the passage through zero on the trailing edge the discriminator bias can be varied over a wide range without affecting the circuit recovery time 8837 high speed counter requiring n carry propagation the method depends on forming complements but the need for complementing the entire register is eliminated 8838 highly accurate phantastron delay circuit a transistor circuit incorporates compensating arran ements to cancel sources of timing error the final circuit provides a delay of with an accuracy within and 8839 the laws of summation for tilt rise time and overshoot particularly in amplifier circuits the time function parameters of pulses applied to cascade connected quadripoles are calculated an improved summation law for the rise time is derived 8840 the representation in pulse form of the noise of amplifiers the noise characteristics of pulse amplifiers are derived without reference to the reference spectrum as a function of the pulse response of the amplifier 8841 amplifiers with quasi constant gain various methods are considered whereby the overall gain of an amplifying system may be held approximately constant despite variations in the parameters of the amplifying units incorporated in the system 8842 ultralinear cathode follower six valves are use in a white follower circuit to give unity gain an output impedance of and intermodulation distortion 8843 flux resetting characteristics of full wave magnetic amplifier affected by the metallic rectifier quantitative relations between rectifier and flux resetting characteristics are investigated by a technique in which the effects of nonlinear forward and reverse characteristics of the rectifier are separated by means of mechanical synchronous contacts 8844 a high power transistor magnetic dc t amplifier the amplifier uses a transistor chopper two transistor amplifiers and a magnetic amplifier the circuits described give a high gain high power output and high input impedance 8845 transistor wide band amplifiers the design of rc coupled multistage amplifiers is considered only the earthed emitter configuration is suitable for this application 8846 atomic hydrogen maser self sustained emission at the atomic hydrogen hyperfine transition frequency has been observed increased interaction times with the radiation field mean values up to and correspondingly narrowed resonance widths have been obtained by retaining the atoms in a storage box with suitable walls stimulated emission has also been recorded and the magnetic field independent hyperfine transition used to observe field dependent zeeman transitions by a double resonance method 8847 parametric amplifiers a review of nonlinear reactance circuits amplifier characteristics are calculated and compared with experimental results 8848 an analysis of four frequency nonlinear reactance circuits 8849 shock waves in nonlinear transmission lines and their effect on parametric amplification the propagation of a periodic signal on a transmission line with a nonlinearity in the distributed capacitance is examined the signal is deformed during its propagation and em shock waves are generated the subsequent growth and decay of the shock are analysed 8850 a wide band uhf travelling wave variable reactance amplifier 8851 low noise electron beam amplifier 8852 new microwave tube devices fawshmotron using the fast electron waves 8853 negative resistance amplifier design 8854 negative resistance distributed amplifier operation f the amplifier is described in terms of iterative sections 8855 the properties and design of ring modulators treatment on the basis of quasilinear quadripole theory of experimentally determined characteristics and design parameters of ring modulators 8856 mechanical modulator uses variable capacitance 8857 the pin modulator an electrically controlled attenuator for mm and sub mm waves abstract 8858 explicit form of fm distortion products with white noise modulation an extension and correction to of medhurst 8859 first order terrestrial ether drift experiment using the mossbauer radiation a one way test of the special relativity and contraction theories is proposed which would obviate the cancellation of first order terms observed in two way tests 8860 electric polarizability of a short right circular conducting cylinder calculations to an accuracy of approximately five significant figures are carried out for cylinders with radius half length ratios of and the results are applicable to the design of artificial dielectrics 8861 method of solving a class of axially symmetric problems in the theory of potential and application to the design of electron optical lenses a class of problems arising in the calculation of es fields with rotational symmetry is considered if the systems satisfy certain conditions they can be treated by a method of successive approximations which are obtained by solving a plane es problem 8862 a note on the theory of space charge limited currents the experimental results of branwood and tredgold of january with are explained by a simple model in which there are thin layers of uncharged traps at the surface of the dielectric which are uniformly distributed in space and of one energy depth the bulk of the material contains no traps 8863 the role of cold electron emission due to field effect in the maintenance at the cathode of an electric discharge in a highly rarified gas the hypothesis of electron emission at the cathode under the influence of the space charge due to positive ions is proposed and supported by preliminary experimental results 8864 oscillation caused by electron sheath breakdown relaxation oscillations of frequency were investigated by inserting a highly charged probe into the dark plasma of a hot cathode gas discharge tube 8865 electron energy distributions in plasmas hydrogen the method given in part is applied to the study of the mechanism of striation structure in hydrogen discharges 8866 rotary magnetic polarization in plasmas application to the measurement of electron density vol 8867 measurement of the electron density of a plasma in evolution experimental apparatus a general description of apparatus for measuring electron density in the range electrons 8868 investigation of a plasma column continuously fed and subjected to an electromagnetic field conditions for the existence of non centred maxwellian solutions equations of density 8869 potential distribution between two plane emitting electrodes part thermionic engines all potential distributions can be represented by a two parameter family of curves the parameters depending on the electrode temperatures potentials and work functions the computed results show clearly th relative influence of these quantities on the potential minimum between the electrodes 8870 equivalence of the critical concentrations in the ising and heisenberg models of ferromagnetism 8871 ferrimagnetic resonance in three sublattice systems 8872 hodac sets of eigenvectors for volumes of revolution 8873 on the cherenkov effect for a charge moving above an interface mathematical analysis relating to the em radiation due to the movement of c charged particle and a modulated beam of charged particles in the proximity of a dielectric 8874 on the cherenkov radiation of dipole moments moving along an axial channel in a dielectric the radiation field is calculated for a magnetic and electric dipole moving in a dielectric if the radius of the channel then the radiation of the electric dipole moving perpendicularly to the axis increases by a factor of compared with the radiation in the dense medium of the dielectric 8875 diffraction of a pulse by a resistive half plane the two dimensional diffraction problem acoustic or em in which the incident pulse front is parallel to the edge of a half plane is solved by assuming dynamic similarity in the solu ion relations between the problem and the three dimensional problem which arises when a plane pulse is incident obliquely at the edge of a resistive half plane are discussed 8876 the diffraction of electromagnetic waves mathematical treatment of diffraction and scattering at the surface of a conducting circular cylinder 8877 diffraction of electromagnetic waves at a paraboloidal screen of finite dimensions axially symmetric fields theoretical treatment of diffraction at a thin ideally conducting paraboloidal segment 8878 diffraction by an imperfectly conducting half plane at oblique incidence the exact solution has been obtained for the problem of a plane wave incident at an oblique angle on a metallic half plane the analysis requires the solution of coupled wiener hopf integral equations for the electric and magnetic current distributions excited on the surface of the half plane 8879 diffraction of an electromagnetic plane wave by a metallic sheet a new generalized technique is developed for the o solution of the problem of the diffraction of an e polarized plane wave incident at an oblique angle on an imperfectly conducting half plane the solution obtained shows complete agreement with that of senior 8880 aperture fields in the diffraction by a slit a description of measurements at using a parallel plate device of the field distribution over apertures of width and 8881 the various statements of kirchhoffs principle and their application to the diffraction diagrams of electromagnetic waves the various approximation methods based on kirchhoffs principle are applied to the case of microwave diffraction at a diaphragm and a reflector disk particularly for oblique incidence comparisons are made with experimental results reflection at mirrors with dimensions of the order of a few wave lengths is considered with regard to the calculation of surface utilization and reflection cross sections references 8882 transmission coefficient for a system of parallel slits in a thin plane screen an extension of earlier work on the scattering of em waves to include more than two parallel slits in a perfectly conducting screen 8883 dielectric constant of a dense electron gas theoretical investigation of dispersion and absorption of em waves in a dense electron gas 8884 propagation constants for electromagnetic waves in weakly ionized dry z air data are given for dry air at ionospheric temperatures in the presence of a magnetic field the magnitude and energy dependence of the electron collision frequency are also derived 8885 electromagnetic fields of axial symmetry bounded by a cone and a sphere the radiation field of a floating magnetic current ring in a space enclosed by spheres and cones is calculated this solution is extended to certain limiting conditions of direct bearing on em radiation from aerials in free space 8886 some properties of three coupled waves 8887 induced and spontaneous emission in a coherent field theory developed in parts dealing with the interaction between the em field in a cavity resonator and a number of two level molecules is generalized to include a gaussian spread in the molecular frequency 8888 microwave emission from an optically pumped atomic system preliminary results are reported of an experiment in which the microwave emission at about from an optically pumped cs cell has been directly detected 8889 recording rf spectrometer for nuclear quadrupole zeeman spectra circuit details are given of semiautomatic apparatus in continuous operation for recording chlorine resonances in the region 8890 a simple spectrograph for nuclear paramagnetic resonance description of modifications to the bloch spectrograph which simplify decoupling problems 8891 sensitivity of microwave spectrometers using maser techniques expressions ar derived for the reduction in the coefficient of minimum detectable absorption in a microwave waveguide when molecules in an excited state are added along the waveguide the application of this principle to a cavity spectrometer is discussed 8892 atomic hydrogen maser 8893 an instrument for the investigation of interplanetary plasma a faraday cup is described for use on a deep probe to measure the density and the magnitude and direction of the bulk velocity of the positive ions 8894 amplitude scintillation of radio star at ultra high frequency observations of cygnus a at over a month period are described and show short term and seasonal fluctuations of scintillation rate as well as some correlation with geomagnetic effects 8895 evidence for the solar corpuscular origin of the decametre wavelength radiation from jupiter some correlation was found between and emissions from jupiter between april and august and the occurrence of geomagnetic disturbance about nine days earlier some events were associated with solar flares 8896 new limits to the diameters of some radio sources observations using a base line of have shown that at least seven sources have major features smaller than three seconds of arc with extremely high surface brightness 8897 relation between the position and the sense of polarization of solar radio storms observations of solar storm centres made with the great interferometer t nancay at have been related to measurements of polarization made at nera netherlands at results show that the radiation from storm centres in the northern solar hemisphere has a predominantly right hand polarization and that from the southern left hand polarization 8898 solar bursts of type and their relation to flares recordings of bursts made by radiometer and radio spectrograph at freiburg and other observatories are analysed and their relation to flares observed in the same period is studied 8899 the radiation belt produced by neutrons leaking out of the atmosphere of the earth the composition of the radiation belts is compared with that expected for a neutron decay source it seems that the inner belt is produced only by neutron e decay in the outer belt the electrons of energy greater than are probably produced by neutron decay but those of lower energy probably come froom outside the belt 8900 the solar daily variation of the cosmic radiation world wide neutron monitor observations during the international geophysical year 8901 effects of short term world wide modulation of the primary cosmic radiation on observed daily intensity variations 8902 observations of the van allen radiation regions during august and september 8903 latitude and altitude distribution of geomagnetically trapped protons a theory is derived for a geometrical injection coefficient of trapped protrons of cosmic ray origin calculated distributions resemble contours obtained experimentally 8904 diffusion of particles in the earths radiation belts fluctuations in the geomagnetic field may cause diffusion of particles across the field the distribution of particles predicted by a theoretical study of diffusion is compared with observations using pioneer 8905 geomagnetic fluctuations and the form of the outer zone of the van allen radiation belt the suden compression of the geomagnetic field associated with the initial phase of a magnetic storm causes electrons to diffuse radially across the geomagnetic field it is estimated that a particle at will diffuse a distance in about years 8906 charged particle variations in the outer van allen zone during a geomagnetic storm fluctuations in the particle fluxes and local magnetic field were observed by explorer at km during the geomagnetic storm of august and found to be correlated the numbers of low energy particles decreased and high energy particles increased the results are consistent with the theories of dessler an parker of 8907 a study of variations of corpuscular radiation observed by satellite exsilon near japan observations in august and september are related to the electron shell of the argus explosion the lowering of mirror points by coulomb scattering and the influence of corpuscular radiation on the ionosphere are examined 8908 radar methods of measuring the cislunar electron density six related techniques for measuring the integrated electron density between the earth and the moon are discussed these are based on the determination of the group retardation suffered by low frequency radar echoes very high peak power pulse technique or very high equipment stability cw technique would be required to measure absolute radar range but this difficulty can be avoided by sending a reference signal with the measuring signal the effects of path splitting electron blobs and lunar surface irregularities are considered 8909 a lunar and planetary echo theory a lunar radio echo is divided into a specular component and a lambert scatter component based on a model of the lunar surface the theory is compared with experimental data on the shape and frequency spectrum of reflected pulses 8910 propagation of solar cosmic rays through interplanetary magnetic field type polar blackouts are closely associated with solar flares which are accompanied by type noise outbursts the delay before the commencement of the type blackout is about hours for flares in the east sector of the sun and about hours for flares in the west the difference is ascribed to a regular distortion of the outer solar magnetic field the commencement of the geomagnetic storm is not dependent on the solar longitude of the flare 8911 the gross character of the geomagnetic field in the solar wind the field may be deformed into a tear drop shape by the interplanetary pasma it is emphasized that the asymmetry of the deformed field ought to be considered in space investigations 8912 note on the geometry of the earth magnetic field useful to faraday effect experiments a study of the factor cos sec where and are the angles between a ray and respectively the earths field and the vertical 8913 audio frequency fluctuations in the geomagnetic field an examination of recordings at three locations widely spaced in latitude indicates that equatorial thunderstorms are the major sources of fluctuations in the frequency range 8914 geomagnetic observations at halley bay 8915 results of scientific investigations made by soviet sputniks and cosmic rockets report presented at a meeting of the american rocket society washington november 8916 payload design for a lunar satellite a description of the experiments planned and the equipment ad methods used in the able vehicle 8917 on geomagnetic observations with the aid of the first soviet cosmic rocket the results of the investigation show that the rate at which the intensity of the magnetic field decreases with e height is greater than the calculated one a graph indicates this variation for heights between km and 8918 osculating elements derived from the modified hansen theory for the motion of an artificial satellite musens development of the hansen theory for the motion of an artificial satellite can also lead to an expression for the velocity vector and osculating elements as well as for the gravitational perturbations 8919 an algorithm applicable to numerical integration of orbits in multi revolution steps 8920 variations in the orbit of the echo satellite minitrack observations of the echo satellite show that owing to the suns radiation pressure the perigee distance and eccentricity of the orbit are varying at rates which are in good agreement with the theoretical rates the observations also lead to a value for atmospheric density at a height of km 8921 evidence of satellite induced ionization effects between hemispheres signal enhancement over a mile path is correlated with reflection from ionization caused by sputnik this occurred both when the satellite was in the northern and the southern aurora zones and an explanation for this is advanced 8922 some studies of bifurcation of the ionospheric f layer into f and f ionograms recorded at frequent intervals at cambridge in and show how the f layers develop at sunrise on quiet and disturbed days and at different seasons 8923 a pre sunrise phenomenon and the presence of negative ions in the f region of the ionosphere increases of f layer electron density which occur about two hours before ground sunrise might be due to photodetachment of electrons from negative ions 8924 a test of a procedure for easy estimation of representative monthly electron density profiles for the ionosphere the profile produced from the mean of the daily virtual height curves is well within one standard deviation of the mean of the individual profiles 8925 a study of observed spread f examination of a large number of ionograms shows the effect of using different receiver gain settings and reveals a night f phenomenon the degree of spreading varies with magnetic dip 8926 the possible importance of nitric oxide formation during polar cap ionospheric absorption events polar cap absorption is attributed to an increase in abundance of the probable ionizable constituent of the d region a possible mechanism depends on the production of n atoms by cosmic ray particles the ionization of must occur above alternative theories of polar cap absorption involving photodetachment of electrons from ions require the ionization to be much lower 8927 ionospheric disturbances following a solar flarethe perturbations of and following the great flare of september are shown on polar projection maps the charts differ significantly from those of obayashi and hakura of for the same period the disturbance during the geomagnetic storm forms an elliptic ring with the e concentrated in crescent shaped areas inside it the results are discussed theoretically 8928 back scatter experiments during the total eclipse of october th eclipse perturbations could not be clearly separated from those due to other disturbances 8929 eclipse effects on the f layer at sunrise an analysis of electron density variations during the solar eclipse of september which took place near sunrise in maryland usa z about of the ionizing radiation may have originated outside the solar disk 8930 eclipse effects on the flayer observed at cambridge on june variations of during the solar eclipse of june are discussed about of the ionizing radiation may have originated outside the solar disk 8931 a connexion between p and the f region the diurnal variation of geomagnetic micropulsations of the type near the equator is inversely related to the diurnal variation of the true electron density at km the interpretation of this result is tht the source of p oscillations lies above the ionosphere 8932 determination of electron density in the ionosphere from the rotation of the plane of polarization of radio waves emitted by a rocket rocket investigations on the august at heights up to km at frequencies of and are rp reported a graph shows the variation of electron density with altitude 8933 reducing interference in ionospheric sounding a special circuit is described for separating the desired pulses from interfering cw signals 8934 solar corpuscular radiation and polar ionospheric disturbances typical examples of abnormal absorption at high latitudes are described and compared for low energy cosmic ray events geomagnetic storms and combined cosmic ray events and storms the energy spectra of the solar pr particles involved are discussed and summarized 8935 the ionosphere over halley bay the ionospheric phenomena observed at halley bay are briefly described and the influence of the weddell sea magnetic dip anomaly stressed some ionization is generated in the lower ionosphere by solar photoionization processes at solar zenith angles up to about the f layer variations appear to be dominated by movements of ionization which can also be seen near the maximum of the f layer ionization drift velocities in the e region reverse with season and are greater in winter than in summer other features of drift and absorption are generally consistent with those expected 8936 ionospheric drifts determined from radio star scintillation observations spaced receiver observations have been made at halley bay and ionospheric velocities deduced from the motion of the diffraction pattern over the ground both the time of midnight reversal and the drift speed correlate well with evans measurements of motions of auroral forms 8937 spiral patterns in geophysics the spiral patterns found in recent analyses of magnetic and ionospheric data are incompatible with stormer theory 8938 latitude distribution and seasonal variation of aurora over the british isles during and 8939 on the origin of radar echoes associated with auroral activity observations at kiruna sweden at indicate that the predominant echo mechanism is closely connected with ionized and often invisible auroral forms which are directed along the geomagnetic field 8940 systematic movements of aurorae at halley bay all sky photographs have been used to determine the movement of individual auroral features on the assumption of a fixed height of occurrence 8941 auroral results from halley bay during the international geophysical year 8942 auroral radio echoes at halley bay the echoes observed are shown to fit closely the case of specular reflection from columns of ionization aligned along the local magnetic field at a height of about km 8943 the effect of proton gyration in the outer atmosphere represented on the dispersion curve of whistler whistlers observed at kyoto geomagnetic latitude reach a height of km the dispersion of a very pure whistler at kyoto in was measured from to less than and compared with that calculated using the complete dispersion law it is concluded that the dispersion was influenced by the effect of proton gyration 8944 propagation of whistlers to polar latitudes an analysis of observation made in new zealand north america and antarctica of the dispersion characteristics of a whistler associated with a depression which occurred in the area of the tasman sea at on april reception to this whistler in the antarctic would imply a final stage of propagation under the ionosphere for more than km 8945 observations of earth ionosphere cavity resonances 8946 the stabilization of control systems with backlash using a high frequency on off loop an auxiliary loop is used to drive the motor across backlash in the gear whenever the motor and load tend to separate 8947 the effect of an additional nonlinearity on the performance of torque limited con rol systems subjected to random inputs the addition of a nonlinear error detector gives an improved response 8948 a calculation of switching functions as a means of minimizing error in an on off control system adaptive switching functions are discussed and the principles illustrated on a mathematical model of an ideal servomechanism 8949 extension of the dual input describing function technique to systems containing reactive nonlinearity an extension of the work of kochenburger and of west et al enabling the nonlinear coefficient to be associated with any term in the differential equation 8950 the stabilization of direct voltage supplies a functional diagram is proposed by studying the control and stabilization of a dc supply system under load and no load conditions 8951 designing solid state static power relays the performance and design of relay circuits using si controlled rectifiers is considered 8952 construction of a thermionic energy converter discussion of design data for a c vapour type of energy converter the construction and testing odevelopment of japanese digital computers parametron and transistor circuit techniques widely used in japanese computers are described and the general characteristics of types of computer are tabulated 8953 a vlf function generator an electromechanical device producing a readily variable function is described 8954 microminiaturizatio illustrated review of current achievements 8955 calculation of the parameters of a quadripole by means of signal flow graphs 8956 a modified synthesis procedure for two terminal pair networks a general theorem given previously of is extended for a particular case of a network with one pair of terminals open circuited 8957 design of optimum filters the design of low pass filters using easily computed rational functions instead of elliptic functions permits more accurate location of the poles of the transfer function when the number of poles exceeds four and computation is less laborious 8958 general principles of polyphase vacuum tube oscillator 8959 synchronization of frequency modulated free running oscillators investigated by servomechanism methods application of a servo system to the control of a free running oscillator a method is described for determining the frequency response of the closed loop from measurements of open loop characteristics quadripole correctors for improving the response will also widen the frequency range over which control may be exercised 8960 pass band and selective af amplification f of a hf oscillator the bandwidth of a hf oscillator has been investigated theoretically and experimentally by studying the behaviour of the oscillator as a selective af amplifier 8961 analysis of a semiconductor multivibrator with emitter capacitance an analysis of an emitter coupled transistor multivibrator showing the effect of emitter capacitance in increasing the thermal stability of the pulse duration parameters 8962 fast transistorized time to pulse height converter a converter of simple design is described having a timebase and giving a resolution of using conventional scintillation counters it was used to analyse particle beams by time of flight measurements 8963 a reversible dekatron circuit a description of the unit with discussion of its limitations 8964 regenerative fractional frequency generators a self starting regenerative frequency divider circuit is described which has the advantages of simplicity and of lock in stability over a i wide range of frequencies an approximate analysis is given which shows the dependence of performance on diode characteristics and transistor input impedance 8965 simple logarithmic dc amplifier a simple double triode amplifier is described it has an accuracy within for input voltages from to and is easily adjusted for differing valve characteristics 8966 the bootstrap amplifier an analysis of a rc coupled pentode amplifier with the anode decoupling capacitor returned to the cathode of a cathode follower the effects of the coupling and decoupling capacitors on the low frequency response characteristics are calculated 8967 analysis of half wave magnetic amplifier circuits with ac bias voltage detailed analysis with special reference to the elimination of the rectifier from the control circuit of rameys half wave magnetic amplifier 8968 a nonlinear effect in transistor amplifiers with feedback the nonlinear effect described in an earlier paper of is analysed it is attributed to to variations of carrier transit time with transistor collector voltage 8969 use of slow molecules in molecular generators methods of improving the absolute frequency stability of a beam type maser are considered based on the use of molecular beams with mean velocities much less than the thermal velocity at room temperature three techniques are described removal of high velocity molecules from the beam retardation of the molecules by an external field reduction of the temperature of the molecular beam 8970 systems applications of solid state masers progress in solid state maser technique is surveyed operating principles and circuit design are outlined 8971 the optimum line width for a reflection cavity maser extension of previous work of to show that the maximum gain bandwidth product is achieved 8972 electrically tunable travelling wave masers at l and s bands tuning ranges of and greater have been obtained by varying only the applied magnetic field and the pump frequency test data are given 8973 coupled cavity travelling wave parametric amplifiers analysis detailed information is given on operating characteristics of a travelling wave circuit consisting of a chain of inductivity coupled cavities loaded by diodes in the capacitive region calculations show that unilateral gains of over relatively wide bandwidths are attainable with diodes 8974 coupled cavity travelling wave parametric amplifiers part experiments gain bandwidth products of with a bandwidth have been obtained at s band frequencies using commercially available diodes noise temperatures of have been measured methods for achieving short circuit stability are investigated these n include the use of ferrite loaded coupling irises and of upper frequency pass bands 8975 gain of a travelling wave parametric amplifier using nonlinear lossy capacitors an analysis of a travelling wave parametric amplifier considering reverse biased diodes as lossy capacitors 8976 aspects on wide band parametric travelling wave amplifiers methods are described for calculating amplification bandwidth phase conditions and noise figure 8977 gain optimization in low frequency parametric up converters by multi diode operation a method is proposed for optimizing the gain of an up converter using more than one variable capacitance diode at the same point results of a first order analysis made with two diodes are given 8978 idler noise in parametric amplifiers 8979 esaki diode amplifiers at and stable gains of up to at and at have been obtained with the diode in a cylindrical reflection cavity which has been described earlier of january trambarulo 8980 criterion of uniqueness for the solutions of maxwells equations 8981 the dirac electron in rectilinear fields diracs equations for an electron in a rectilinear field are first reduced to a single equation of simple form suitable for the solution of problems an explicit solution is then obtained for an electron in a constant electric field 8982 variational treatment of warm electrons in nonpolar crystals deviations from ohms law in nonpolar crystals are treated by the variational method for the case of weak fields the second order term in the electrical conductivity is calculated 8983 effect of random inhomogeneities on electrical and galvanomagnetic measurements a theoretical treatment is given in which the scale of inhomogeneities is supposed small compared with the specimen size but large compared with the mean free path and debye length comparison with exactly soluble cases shows the derived formulae to e valid for sizable fluctuations 8984 the validity f the concept of specific surface resistance and its measurement extension of earlier work by lacoste of to show tht the criterion for surface conduction is independent of the electrode system configuration the influence of the configuration on accuracy of measurement is considered 8985 steady state distribution function in dilute electron gases the effects determining the distribution function of optically liberated carriers are investigated for a simple model semiconductor significant deviations from the boltzmann distribution are possible at temperatures below a few degrees kelvin 8986 on the possible influence of electron interaction on the reflectivity of metals continuation of the work by benthem and kronig on the influence of electron viscosity on the absorption factor of metals in the infrared region 8987 sustained localized pulsed micro wave discharge in air details are given of a small localized discharge obtained in low pressure air using a pulsed x band radar transmitter as the microwave source 8988 transmission of slow electrons through thin film 8989 investigation of a plasma column continuously fed and subjected to a magnetic field first order approximations for the diffusion velocities manifestation of a frontier zone 8990 free path formulae for the coefficient of diffusion d and velocity of drift of ions and electrons in gases 8991 ion resonance in a multicomponent plasma interactions between different types of ion produce additional resonances 8992 oscillations of an electron ion plasma investigation of the spectrum of longitudinal oscillations for the case of low temperature fermi distribution and high temperature maxwell distribution for low values o the wave vector the dispersion equation has two branches corresponding to optical and acoustic modes 8993 direct exchange in ferromagnets evaluation for all internuclear spacings of the direct exchange integral occurring in the heisenberg theory of ferromagnetism leads to the conclusion that direct exchange is not responsible for ferromagnetism in ferromagnetic metals 8994 collective excitations of electrons in degenerate bands part spin waves in stoners model of ferromagnetism spin waves in the collective electron model of ferromagnetism are derived 8995 anisotropic superexchange interaction and weak ferromagnetism a theory is developed by extending the anderson theory of super exchange to include spin orbit coupling 8996 determining the dielectric permittivity and magnetic permeability tensors of a medium an analytical note on the separation of gyroelectric and gyromagnetic effects 8997 transition radiation in a waveguide investigation of the radiation which arises in a waveguide by the passage of a charged particle through the boundary between two media at ultrarelativistic charge velocities the radiation is mainly in the forward direction and its magnitude is proportional to the particle energy formulae for the total energy of the radiation and its spectral distribution are derived 8998 some absorbent materials at uhf the characteristics of two types of absorbent material are described a plastic or rubber sheet impregnated with carbon powder applicable over a wide band of frequencies and a similar material thick impregnated with carbonyl iron or carbon power and backed with a thin metallic sheet applicable over a narrow band 8999 contribution to the study of diffraction of electromagnetic waves by spheres a thesis describing theoretical and experimental methods of obtaining the diffraction field of both a single sphere and a pair of spheres for a report of experimental apparatus see of 9000 diffraction of a plane electromagnetic wave by cylinders with anisotropic conductivity 9001 a study of surface roughness and its effect on the back scattering cross section of spheres experimental data obtained by measuring the back scattering cross section of a large rough sphere at three frequencies in the s x and k bands are presented even for a sphere whose depth of roughness is as large as the measured change in cross section is no more than this is in good agreement with the theoretical prediction 9002 line breadths in the ammonia spectrum measurements have been made of the inversion spectrum from the results a value of per mm at has been obtained 9003 line structure in paramagnetic resonance and direct measurement of the moments 9004 the influence of modulation on the recording of resonance phenomena curves based on the standard resonance curve of a simple harmonic oscillator are given as an aid to the construction of spectrographs and the analysis of recorded spectra 9005 nonlinear effects of crystalline anisotropy on ferrimagnetic resonance analysis shows that the magnetic resonance frequency depends quadratically upon the precession amplitude to lowest order this can cause a foldover of the resonance line 9006 cross relaxation in dilute paramagnetic systems 9007 the direction dependence of magnetostriction tensor methods are used to describe the lattice distortion caused by magnetostriction for similar calculations of the direction dependence of crystal energy see 9008 proceedings of the international congress on many particle problems the text is given of invited papers read at a conference held in utrecht june 9009 ion size effect and mechanism of electrolytic rectification previous theories of electrolytic rectification are shown to be inadequate extensive experimental work is presented which shows the importance of the size of the cation in solution and the existence of an extremely thin surface barrier of height about 9010 note on the transference of angular momentum within the galaxy through the agency of a magnetic field 9011 magnetic field of jupiter a review of theoretical and experimental evidence in support of the hypothesis of an ionosphere and magnetic field associated with jupiter 9012 the correlation of radio source scintillation in the southern and northern hemispheres observations of radio source scintillation made simultaneously at halley bay and jodrell bank show a significant correlation this is relevant to theories with auroral activity 9013 the magnetic storm time variation of radio star scintillations and auroral radio echoes the variations of scintillation rate and auroral echo incidence during periods following magnetic sudden commencements resemble the variation of magnetic k index 9014 a determination of the principal plane of the galaxy data from the leiden and sydney surveys of the milky way have been used to determine the position of the plane of the neutral hydrogen layer which is found to be exceedingly flat over the galaxy within kiloparsecs from the centre 9015 radio data relevant to the choice of a galactic coordinate system because of the large scale association found between sources of the radio continuum and the distribution of the cm hydrogen line radiation the coordinate system may be defined by the principal plane and by a centre situated in sagittarius a 9016 some statistics of solar radio bursts at sunspot maximum bursts at and are mainly of spectral type and occur more frequently than bursts at and which are of a greater intensity and of spectral type 9017 on the identification of extragalactic radio sources radio data from sydney and cambridge have been compared with a catalogue of galaxies in a limited region of the sky possible identifications of rf sources with galaxies have been made and with clusters of galaxies 9018 solar modulation of primary cosmic rays the observed solar modulation of cosmic rays may be explained assuming the existence of two solar magnetic fields one uniform and the other irregular and two solar streams one continuously ejected and the other produced by solar eruptions 9019 sou hern hemisphere meteor shower activity in july and august observations for are described and measurements of the radiant coordinates and echo rates for the aquarids and three other minor showers are summarized 9020 meteor height distributions and the fragmentation hypothesis a comparative study of fragmentation amongst bright and faint meteors 9021 volume density of radio echoes from meteor trails 9022 the importance of initial trail radius on the apparent height and number distributions of meteor echoes fewer echoes from faint meteors of magnitude are observed at than at this effect is attributed to an attenuation in echo amplitude due to the large initial radii of the ionized trails 9023 the determination of the incident flux of radio meteors simple formulae are derived which allow the incident flux of shower meteors to be deduced from the observed rate after allowing for the aerial characteristics and the geometry of reflection the limitations of the method are discussed 9024 the interaction of the terrestrial magnetic field with the solar corpuscular radiation the shape of the cavity between the earth and a neutral solar stream differs by only from a hemisphere of radius earth radii on the incident side but is elongated on the other side to a distance of the order of earth radii the cavity is idented at the polar latitudes where the current layer reverses 9025 the cause of magnetic storms and bays circulating currents set up around regions of proton and electron precipitation by the hall effect are suggested as the cause of magnetic bays and storms 9026 daytime enhancement of the amplitude of geomagnetic sudden impulses in the equatorial region igy data from equatorial stations provide some evidence that sudden impulses and sudden commencements are caused by similar mechanisms 9027 evidence of quasi perpendicular propagation of hydromagnetic waves caused by nuclear explosions over johnston island 9028 verification of earths pear shape gravitational harmonic errors in the predictions of the orbit of the transit ib satellite are accounted for by a third order gravitational harmonic previously evaluated by okeefe et al 9029 the relation of the satellite ionization phenomenon to the radiation belts during march and april when telemetry transmissions from explorer were monitored the strongest enhancements of wwv signals received at columbus ohio occurred at times of peak counting rate aboard the satellite many of these events were accompanied by a partial or complete fade out of the satellite signal see also of 9030 some characteristics of the signal received from the correlation between scintillation effects and the occurrence of spread f is noted and skip distance phenomena a observed in ordinary and extra ordinary wave propagation are discussed 9031 electromagnetic waves and satellites echoes from ionized trails of satellites at high frequency ionized trails from and were detected at using a pulsed transmitter and a receiver with bandwidth the results are discussed and the most favourable conditions for detecting echoes are examined 9032 on the lunar semidiurnal variation of the d and f layers the variations at freiburg genoa and leopoldville are compared with those obtained by other authors magnetic dip rather than geomagnetic latitude controls the variation in the f layer the amplitude of the variation is plotted against magnetic dip 9033 on some disturbances in the e region a discussion of e layer stratifications and complex phenomena observed on ionograms in relation to computed electron distributions the passage of transient cusps on curves if o found to be due to redistribution of e le layer ionization factors influencing the identification of e layer penetration frequencies are discussed 9034 investigation of the transparency of the ionospheric e layer report of an analysis of world wide observations of diurnal changes in e results are discussed and tabulated in the form of an index called the degree of occultation which is defined as the ratio where is the blanketing frequency for reflections from the f layer and the highest frequency at which reflections from the e layer are detected 9035 mechanism of ionization of the sporadic e layer observations made using a technique based on that introduced by naketa et al and have shown that the height of e varies in a systematic way during the lifetime of an e event if the intensity of ionization increases the layer height decreases 9036 horizontal drift in the ionosphere over delhi the drift was measured using spaced receiver techniques and both e and f layer reflections are analysed for the period april march velocity histograms of the ns and ew components and plots of the seasonal variations in velocity and drift directions are given 9037 on the observational results of at yamagawa measurements of and made between august and february showed the presence of the winter anomaly in absorption at night 9038 on the d electron and ion density distributions from the lower up to the uppermost pz part of the f region the thesis that the main ionizing radiations in the f region are the helium resonance lines at and the lyma continuum leads to the following results the calculated electron density distribution in the lower f region is in good agreement with experimental electron density profiles the observed and calculated relative abundances of the ions and are not in good agreement unless their charge exchange reactions are assumed to be a few orders of magnitude slower than expected on simple theory and if a scale height gradient of is assumed then the calculated and experimental electron densities are in agreement up to above the f region maximum 9039 on the f region of the ionosphere a continuation of earlier work of to include calculations of diurnal variations of production rate for march using the attachment coefficient model suggested by ratcliffe et al results are compared with those for january given in the earlier paper and are found to be consistent with bradburys hypothesis for the formation of th f layer 9040 world wide da ly var ations in the height of th maximum electron density in the ionospheric f layer the heights given by the method of shimazaki of which related and the height of a parabolic f layer have been compared with the more correct values derived from corresponding profiles the agreement between the two methods is quite good during the night in middle and low latitudes but during the day in these latitudes and for all hours at high latitudes shimazakis relation overestimates the height by about km 9041 investigation of the formation of the ionospheric f layer at leopoldville binza data for the period are analysed photo ionization and drift are insufficient to explain the variations of maximum electron density additional ionization due to corpuscles accelerated in a region near the earth is suggested 9042 bifurcation and other irregularities of the ionospheric f layer splitting is considered to occur when the excess of energy of each ionizing photon over the ionizing potential is transformed into heat on account of the quasi neutrality the rarefaction of the gas at the maximum of ionization can create a small secondary minimum of electron density which separates the f layer into f this secondary minimum of electron density appears just at the maximum of electron production 9043 effects of diffusion of electrons near the magnetic equator if it is assumed that ionization in the f layer is produced according to chapmans law then as the magnetic equator is approached the rate of increase in ionization wil exceed any decrease due to the effects of vertical diffusion described by schmerling of the hypothesis of vertical diffusion does not therefore account for the geomagnetic anomaly 9044 the geomorphology of spread f the occurrence of spread f is roughly symmetrical about the geomagnetic equator and is greatest in the equatorial and auroral regions it occurs mainly during the night and is greatest in winter in the auroral region and at equinox in the equatorial region 9045 the belt of equatorial spread f igy data are used to discuss the morphology of nocturnal spread f incidence in the equatorial belt and this is compared with the morphology of the post sunset increase of f layer virtual height between magnetic latitudes the incidence of spread f is high but decreases during periods of magnetic disturbance existing theories are inadequate to explain the observations 9046 muf factor and solar activity an analysis of ionospheric data for delhi and ahmedabad indicates that a linear relation exists between and the sunspot number for both places 9047 hydromagnetic waves in the ionosphere the results of numerical integration of the hydromagnetic wave equations in the ionosphere are presented earlier estimates of ionospheric heating by hydromagnetic waves are confirmed 9048 electron densities in the f region of the ionosphere from rocket measurements the recording and analysis of faraday rotation and range error measurements on radio waves from long range military and satellite launching rockets are described corrections for horizontal gradients and refraction are included the results from seven launchings show that the vertical electron density gradient is greatest near sunrise and lowest after sunset suggesting a time lag before diffusive equilibrium is reached 9049 the d layers and the absorption of radio waves the possibility of separating absorption at different levels in the lower ionosphere is discussed theoretically with experimental examples 9050 the sunrise in the ionosphere and its repercussions on long wave propagation the basic data are the records made at zurich of the variations in number and direction of arrival of atmospherics at a frequency of the sudden fall in number of received atmospherics near dawn is attributed to the sunrise at a height of at a point on the wave trajectory the height of the ozone layer is found to be km the transitory nose effect in recordings of atmospherics is attributed to the transition from d layer to e layer propagation 9051 physical parameters of the atmospheric escape layer the height of the atmospheric escape layer is approximately in the daytime dropping to at night the temperature of the layer is too low to cause the dissipation of helium from the atmosphere ad it is suggested that this process occurs during solar disturbances 9052 adaptation of the radiosonde for direct measurement of radio refractive index the sytem described is based on standard meteorological sensing devices and provides an accuracy sufficient for many radio propagation applications 9053 on the magnetic time dependence of the auroral zone currents the geomagnetic time for the evening passage of the geomagnetic component h through the zero disturbance level was measured at kiruna and college on days a time difference of min was found only part of which can be explained by means of higher spherical harmonic terms of the geomagnetic field 9054 a dynamo theory f the aurora and magnetic disturbance a model of the aurora is examined in which a slab of ionized air exists parallel to the geomagnetic field a wind of neutral molecules causes movement of the aurora and certain features of auroral and magnetic disturbances are explained 9055 radiation from protons of auroral energy in the vicinity of the earth cyclotron radiation of protons in the earths magnetic field could be one source of dawn chorus 9056 choice of a parameter characterizing radio whistlers the dispersion d is proposed as a character figure for whistler it is also proposed that as long whistlers have a dispersion which is dependent on frequency the frequency should be stated zero frequency is considered optimum for this purpose 9057 travelling wave amplification of whistlers theory of the travelling wave tube is applied to af waves in the ionosphere to explain the generation of whistlers 9058 auroral noise at hf observations made with fixed frequency back scatter equipment and riometers are discussed 9059 on the theory of amplitude distribution of impulsive random noise and its application to the atmospheric noise atmospheric noise is considered to be a superposition of sources of independent randomly occurring poisson noise wave packets theoretical amplitude distributions from both discrete and continuous spatial distributions of sources are compared with actual noise measurements with considerable agreement 9060 physics of the upper atmosphere 9061 instrumentation wide band magnetic tape recording the development of a recorder with a bandwidth from dc to is described 9062 the mechanical considerations of magnetic recording heads manufacturing problems associated with multitrack heads are discussed in relation to the effects of mechanical variations on head performance performance criteria are listed 9063 some engineering aspects of magnetic tape system design a system is described for the evaluation o random and transient effects in terms of specific measurements on waveforms generated by standard tapes rather than in terms of dimensional tolerances 9064 a fast start stop machine for handling magnetic tape the wide tape is handled at a speed of with start stop times of referred to of the final speed the tape loop length is controlled by phototransistors driving an error correcting servomechanism 9065 the development of a high performance tape handler magnetic tape wide is handled completely out of contact at by means of vacuum techniques start stop and reverse times are better than 9066 stabilized voltage supplies using transistors two completely transistorized circuits producing from a dc supply 9067 reverse characteristics with surface breakdown of silicon psn rectifiers the influence of surface recombination on the reverse and breakdown characteristics is investigated measurements were made on si rectifiers with weakly doped diffusion region which had been exposed to dry nitrogen and oxygen with or without ozone for different lengths of time with or without heat treatment for measurements in moist gases 9068 stabilization of a magnetic field by means of a galvanometer photocell assembly note on the application of a galvanometer amplifier system of for magnetic field stabilization 9069 computer generated displays a survey of methods and techniques in the presentation of computer outputs references 9070 magnetic film memory design a storage system for ten bit words has been operated successfully in the destructive mode with a minimum cycle time of 9071 high density digital magnetic recording techniques 9072 the simulation of neutral elements y electrical networks based on multi aperture magnetic cores the basic operations of multilevel storage gating controlling threshold level and summation are common to many simulating networks and can be attained by use of multi aperture magnetic cores 9073 new storage systems based on the magnetization of three dimensional elements three systems are described two are diode controlled circuits for switching magnetic storage devices and the third biax is a multi aperture ferrite element using the principle of flux interference see also 9074 nonstationary parametrons 9075 a computer subsystem using kilomegacycle subharmonic oscillators a phase locked oscillator is described which operates at and has a logical operation time 9076 frequency division by carrier storage 9077 computer memories a survey of the state of the art 9078 a survey of tunnel diode digital techniques 9079 calculated waveforms for tunnel diode locked pair the phase locked pair functions as a computer element in a similar manner to that of a phase locked harmonic oscillator and also requires a three phase power supply its main advantages are high gain and high transition speed 9080 the negative resistance concept in modern electronics a survey with particular reference to the operation of semiconductor diodes and microwave valves 9081 nonstationary parametrons to eliminate the necessity for the critical adjustment of amplitude and phase of the excitation current dc controlled and diode controlled parametrons were investigated a fast decay time was achieved with diode control resulting in a high speed of operation in logic circuits 9082 the cryosistor a new low temperature three terminal switch a reverse biased pn junction is used to control the ionization between two ohmic contacts its uses might be as a fast monostable or bistable switch and as a pulse amplifier 9083 observations of some theorems for linear passive networks an extension of cohns theorem for linear passive two poles see eg of is proposed facilitating the determination of energy relations in such networks 9084 theory of forced oscillations in electromagnetic cavities and the equivalent circuit of a cavity the em field inside an excited cavity coupled to a two way transmission line is calculated on the basis of a series expansion of arbitrary vector fields in cavity resonators in terms of orthogonal eigenfunctions the equivalent circuit derived consists of an infinite number of lumped elements approximation formulae for practical application are given 9085 the cylindrical te mode cavity including a semiconductor sample with tensorial electrical conductivity the impedance matrix and characteristic s matrix are derived for two configurations of the input guides one case is suitable for the measurement of hall mobility and for the other the proper conditions for use as an isolator are investigated 9086 iterative networks as coupling networks in oscillator circuits the conditions for self oscillation are established for valve and transistor oscillators the characteristics of iterative networks consisting of purely resistive and reactive elements are summarized and their application in valve and transistor oscillators is investigated formulae are given for operating parameters and are verified experimentally 9087 explicit formulae for the calculation of the characteristic function of filters with tchebycheff pass band behaviour 9088 a wide band voltage controlled oscillator continuously variable frequency control of an lc oscillator over the range is obtained by electronic switching of a number of fixed capacitors across the inductance the number of depending on a dc control signal voltage 9089 a transistor relaxation oscillator and its applications the modifications of the schmitt trigger circuit necessitated by the use of transistors are investigated practical circuits and operating characteristics are given 9090 frequency division by carrier storage a circuit using a junction diode with forward bias that produces output pulses at half the frequency of a input sinusoidal voltage is described possible computer applications r are noted 9091 amplification by means of nonlinear reactances the theory of parametric amplification is considered on the basis of the manley rowe power relations the properties of varactors and their use in parametric amplifiers are discussed some experimental results are given 9092 experimental demonstration of parametric amplification simple experiments are described to demonstrate the basic principles of pr parametric amplification using a variable capacitance circuit and by means of a mechanical system for setting up waves on a water surface 9093 noise figure and gain of parametric converters a correction is given for a term in a noise figure equation for a parametric frequency converter given in an earlier communication 9094 an electron beam parametric amplifier for the region 9095 power amplifiers based on electro optical effects a survey the gain bandwidth and noise factor of electro luminescent photoconductive transducers are considered taking into account the effects of feedback and matching suggested practical applications of single and cascade devices are discussed 9096 instability effects in a semiconductor amplifier with negative effective carrier mass critical comment on the proposal of kromer 9097 simple periodic behaviour of the ring modulator an analysis of ring modulator theory where the signal and carrier frequencies are equal or one is a multiple of the other curves are given for determining the performance of frequency dividers of the miller type 9098 theory of the complex refractive index a quantum mechanical formalism is developed for representing the complex refractive inded of a gas 9099 theory of impurity resistance in metals a many body technique is developed for the calculation f the dc resistivity of a fermi fluid in the presence of a few randomly distributed fixed impurities 9100 electron relaxation time in a high frequency electromagnetic field and the surface impedance of a metal an analysis of effects due to quantization of the em field and the electron orbits in a constant magnetic field 9101 the passage of electrons through a rectangular potential barrier with a small cylindrical inhomogeneity a treatment of the tunnel effect in electron emission by first order perturbation theory 9102 on certain special features of ohmic heating of an electron gas in a plasma an investigation of ohmic heating in a constant field taking account of inelastic collisions shows that the electron temperature may be in a steady state only for low values of electric field intensity see also of 9103 the origin of a backward wave in a nonmagnetized plasma cylinder bounded by air the conditions for the existence of such a wave are derived 9104 radiation of plasma oscillation radiation of em waves from a mercury discharge tube was picked up by a horn feeding a receiver tuned to a peak value of received signal was obtained for a discharge current corresponding to a plasma resonant at reflections from the plasma were also observed they reached a peak value at the same discharge current but did not fall with higher currents 9105 a note on effects of relatively strong fields on the propagation of em waves through a hypersonically produced plasma see of 9106 a note on the relation between the exact and simplified theories for em wave propagation in ionized gases comment on and correction to the paper by sisco and fiskin 9107 cyclotron absorption of electro magnetic waves in a plasma brief analysis of the absorption due to the thermal motion of electrons and ions 9108 plasma oscillations in a magnetic field a theoretical treatment of longitudinal electron oscillations 9109 stability of a plasma sheet in time periodic magnetic fields the behaviour of a thin sheet of electrons in a time varying square wave magnetic field is investigated and it is shown that the growth of an initial disturbance in the first half period is entirely annulled in the second both the displacements and velocities returning to their initial values 9110 the field of an electric current in general relativity a solution is given for a wire loop for which it is necessary to endow the wire with a gravitational mass which corresponds to the energy of the magnetic field created the gravitational effect of the current is not far below the present limit of experimental detection 9111 aoaipparatus for investigating polarization in the diffraction of centimetric electromagnetic waves a semi automatic rotating analyser for measurement of the polarization of scattered waves in free space is described see also of 9112 solution of a diffractive problem the problem of radiation from a semi infinite parallel plate waveguide terminated by an infinite plane flange double wedge is investigated in the k representation when the width of the double wedge is and 9113 theoretical and experimental study of back scattering cross section of an infinite ribbon the geometrical optics approximation is derived for the back scattering cross section per unit length of an infinite ribbon a comparison is made with the exact theory the approximate theory of sommerfeld the variation method and with experimental results obtained through the space separation method for the measurement of back scattering cross sections in a parallel plate region 9114 reflection of electromagnetic waves from a plasma moving in slow wave waveguides report of an experimental investigation carried out at using a a helix slow wave structure to reduce the phase velocity of the waves to the double doppler effect observed in reflection from a plasma piston increased the frequency by application of the effect for microwave amplification and frequency multiplication is indicated 9115 possible transmission of electromagnetic waves through a metal in a strong magnetic field analysis shows that an em wave propagating along a magnetic field can penetrate a metal plate perpendicular to the field if the larmor frequency is higher than the frequency of the wave and much higher than the collision frequency and if the larmor electron radius is smaller than the wave length in the metal 9116 microwave spectroscopy the basis of molecular modulation is discussed with special reference to the stark effect and maser amplification the various types of spectrometer and their applications are discussed 9117 crossover transitions finite rotation operators are used to simplify the calculation of second order crossover transitions for a spin system with trigonal symmetry the resonant frequency and transition probabilities for the crossover transition with negative d or with positive d are calculated 9118 the second moment of a paramagnetic absorption line taking account of the effect of fine and hyperfine structures formulae are derived for calculating the reduced second moment of a resonance line and the fine structure constants of nuclear and electron paramagnetic absorption 9119 corbino disk a comprehensive treatment of the behaviour of the electric current and magnetic field distribution patterns in a disk with concentric inner and u outer contacts and a magnetic field applied along its axis the effects discussed are large in materials with a high mobility such as bi ad the corbino disk appears to be useful as a rectifier and voltage regulator 9120 spin susceptibility of an electron gas the generalized random phase approximation is used to investigate the effects of electron electron interaction on the spin susceptibility of an electron gas 9121 electron levels in a one dimensional random lattice 9122 apparent steady component of the interplanetary magnetic field arguments based on the results of coleman et al of ad on the direction and sense of terrestrial storm fields show that the apparent steady component of the interplanetary field also known as quiet time field is probably directed from the north to the south of the ecliptic 9123 existence of net electric charges on stars comment on of ad authors reply 9124 cosmic noise absorption measurements at stanford california and pullman washington the absorption was measured at using a riometer after making allowances for the diurnal vz variations due to absorption in the d and f layers a residual diurnal variation remains which has not yet been explained 9125 the cross sed grating interferometer a new high resolution radio telescope 9126 malvern radio telescope 9127 a survey of radio stars at a frequency of this paper describes a survey of small diameter radiostars made with an interferometer at the positions and flux densities of radio stars all of which are confirmed by other surveys are given in the catalogue 9128 relation of jupiters radio emission at long wavelengths to solar activity observations at boulder during the period january june shows a strong positive correlation between jupiters emission in the range and solar continuum emission the time delay of one to two days indicates that fast solar particles at velocities of about may be involved in the planets atmosphere or magnetic field see also of february 9129 sol radio emission on centimetre waves and ionization of the e layer of the ionosphere the correlation coefficient relating solar rf noise flux on wavelengths between and to daily ad monthly e layer indices described by minnis and bazzard of and of has been calculated the coefficient lies in the range wavelengths between and cm b above cm it falls to 9130 radiation environment in space summary of information on radiations in space obtained by means o satellites and space probes 9131 relation between results of measurements of charged particles by means of traps on soviet cosmic rockets and measurements of the magnetic field on the american satellite explorer and the rocket pioneer v results of measurements carried out by different methods on the soviet rockets indicate the existence of a geomagnetic belt of charged particles from the centre of the earth 9132 moon reflection studies with bistatic radar at the reception at austin texas of moon echoes of transmissions from malvern england is reported discrete spike echoes persisted for about simultaneous observations at malvern and austin show no correlation between individual spikes this is interpreted in terms of an undulating lunar surface 9133 radio echo measurements of the orbits of faint sporadic meteors a survey has shown tht many such meteors move in orbits of very short period the moe eccentric orbits are near the plane of the ecliptic but some are circular and have inclinations near the significance of the results is discussed 9134 the calculation of meteor velocities from continuous wave radio diffraction effects from trails meteor velocities are calculated from the time interval between cw echo maxima or minima neglect of the initial phase relation between echo and ground wave introduces large errors an analytical method is described and preliminary results are given 9135 the structure and magnetic field of the solar corona radio observations in of the crab nebula made at using four interferometers are described anisotropic spreading of the source occurred as it passed near the sun radial filamentary irregularities of ionization extending out to solar radii are deduced 9136 possible magnetic effects with high altitude explosions of atomic bombs the effects of a dense diamagnetic plasma expanding in the earths magnetic field are discussed with reference to the periodic magnetic disturbances associated with the argus experiment 9137 an approximate method of estimating the size and shape of the stationary hollow carved out in a neu ral ionized stream of corpuscles impinging on the geomagnetic field a two dimensional case is considered in which the permanent field is due to a current acting perpendicular to the stream the breadth of the hollow at infinity is shown to be finite 9138 the latitudinal distribution of magnetic activity in canada measurements of the hu hourly ranges in the principal horizontal field component at canadian igy stations are described a narrow zone or area of enhanced magnetic activity exists at high latitudes with a maximum near alert the seasonal and diurnal variations of magnetic activity at different latitudes are also considered 9139 perturbations of the orbit of the echo balloon predictions of the influence of solar radiation pressure are confirmed by the changes in orbit of satellite during the first days after its launching 9140 perturbations of the orbit of the echo baloon predictions of the influence of solar radiation pressure are confirmed by the changes in orbit of satellite during the first days after its launching 9141 observed solar pressure perturbations of echo i a decrease in perigee height of day and an increase in the eccentricity of per day were observed during the first days after launching of 9142 a method for interpreting the doppler curves of artificial satellites a graphical analytical method for determining the point of inflexion and the maximum slope is explained in detail see 9143 irregular fading of satellite transmissions the distribution of the mean scintillation index with magnetic inclination derived from observations at slough of transmissions from is discussed in relation to comments by mawdsley of 9144 sudden amplitude variations of sputnik signals two distinct causes of drop outs in the signal received from are identified a change in transmitter characteristics and a localized absorbing or scattering region in the ionosphere 9145 field aligned ionospheric irregularities and the scintillation of satellite radio transmissions observations of radio transmissions from made at brisbane during july september have been analysed results indicate that the scintillation activity associated with propagation along the lines of the earths magnetic field is more pronounced than that associated with other directions of propagation the results are in agreement with those of rush and colin 9146 radar echoes obtained from earth satellites alpha and beta observations at stanford california using a radar with a steerable paraboloid are described echoes from and were seen on occasions the echoes usually lasted abu sec as the satellite crossed the aerial beam cyclic fading at occurred usually with constant polarization and attributable to satellite tumbling on one occasion passed within ki of an auroral disturbance detected on the radar large amplitude fluctuations were seen and the echo lasted longer than usual 9147 structure of the thermosphere the vertical distribution of density in the thermosphere as deduced from satellite observations is examined and it is shown tht the varying scale height gradient s is due to a decrease in the molecular weight of the atmospheric constituents the temperature of the night time isothermal atmosphere and the distribution of scale height in the sunlit atmosphere is related to the ultraviolet heating available during the day 9148 origin of the d region the d region may result from the ionization by lyman alpha radiation of molecules in an excited state the mechanism for the excitation of the molecules is discussed 9149 anisotropy in ionospheric diffraction and its effect on drift measurement a method of analysis is developed in which five statistical parameters and a few simple formulae are used and which takes into account te effects of random motion as well as anisotropy 9150 lunar tide in the f layer of the ionosphere near the geomagnetic equator lunar variations of at leopoldville during the period november october are analysed and compared with those for other low latitutde stations results suggest that stations having the same magnetic latitude rather than the same geomagnetic latitude experience similar variations of see also of 9151 insoc spread f and multiple scattering in the ionosphere the mechanism of spread f is examined statistically a model is derived based on the assumption of gallet turbulence in the underside of the f layer under night time conditions and is applied in detail t a typical example of article spread f 9152 ionospheric disturbances at the time of cosmic ray increases ionospheric and magnetic conditions at the time of a cosmic ray increase on january are analysed and compared with those at the time of an increase on december although the cosmic ray increases were in some respects analogous they were associated with quite different ionospheric conditions 9153 enhancement of ionization in the e layer due to solar flares during the international geophysical year the value of observed at slough at the hour preceding the commencement of each clare of importance and and at the two succeeding hours have been examined in relation to normal values results show that during the interval min after the commencement of a flare there is a mean increase in the intensity of e layer ionizing radiation which is at least for class flares and for class flares 9154 spread f and the latitude variation of occurrence of whistlers an explanation of the latitude variation of whistler activity based on propagation within field aligned ducts of is consistent with current ideas for interpreting spread f echoes 9155 on the generalization of the appleton hartree magneto ionic formulas 9156 the polar radio black out of the ionosphere of ionospheric data are used to study the polar cap absorption effects occurring in both hemispheres after the flare on july it is suggested that electrons first precipitated to the highest latitudes and then protons and helium ions to lower latitudes 9157 a theory of ionospheric currents associated with aurorae the current distributions induced by dynamo action in a sheet of partially ionized gas moving with uniform velocity across a perpendicular magnetic field are derived for the case where the gas contains an elliptical region of greater ionization density on the basis of the theory the average ionospheric current flowing along a long homogeneous arc is calculated and some results predicted by the theory are compared with observational evidence 9158 studies of auroral echoes part the results of radar observations at kjeller and tromso are discussed the velocity and direction of the drift of auroral ionization was measured by the technique used at n jodrell bank by byllough and kaiser of in which the time variation of echoes observed on aerials directed nw and ne is recorded an interferometer was used to measure fine structure and a vertically sliding aerial to measure the angle of elevation of the arriving echoes the observed drift and structure at kjeller was similar to that at jodrell bank but was more irregular at tromso 9159 radar echoes from the aurora at experimental results show tht the reflecting layer has a mean height of and a thickness of the results r are discussed in relation to reflection theory in general an auroral disturbance of sufficient intensity to be observed at will only occur after a very vigorous solar upheaval in association with extreme magnetic storms 9160 recent results in the investigation of the relation between lightning discharges and whistlers harmonic analysis shows that lightning discharges which produce whistlers have a pronounced energy peak near multiple whistlers r are caused by multiple discharges through the same lightning channel 9161 speed control of dc motors two designs of a continuously variable type of servo system are s described the first employs a phase lock feedback system and the second a simple velocity feedback system 9162 multitapped potentiometers as accurate linear transducers a method is given for calculating the su shunt resistance values required to compensate t for the load error which enables the potentiometer resistance the minimum input resistance and the load to be independently specified 9163 durable high resolution ferrite transducer heads employing bonding glass spacers the construction is described of various types of ferroxcube magnetic recording head which have high resistance to wear and improved signal noise ratio 9164 the development of the flexible disk magnetic recorder the optimum operating conditions for supporting a rotating flexible mylar disk with magnetic coating above a rigid back plate using a gas film are discussed 9165 high density digital magnetic recording techniques a comprehensive readback simulation computer program is described which will automatically simulate for any characteristic pulse all possible readback signal patterns and test them for specified reading logic as a function of bit density 9166 analysis of the dc characteristic of selenium rectifiers the method of analysis given permits the separation of the various physical phenomena in the rectification process an empirical equation for a limited section of the rectifier characteristic is derived the reduction of the slopof the logarithmic characteristic relative to the theoretical value is attributed to the effect of the contact of se with the n type intermediate layer of and 9167 constant current supply for very high resistance loads battery operated transistorized equipment using a photo resistor for current control in the range for any load resistance from zero to is described measured changes in current with various load conditions do not exceed 9168 the testing of metal tape magnetic cores for use in a code translator acceptance tests are described which simulate the actual conditions under which the cores will be used 9169 a multipurpose computer element a long tailed pair waveform reshaper is described which in conjunction with a number of logical gates can be used as a basic element in computer design 9170 microcircuit binary full adder uses unipolar transistors are used for both active and passive elements 9171 circuit considerations relating to micro electronics a discussion of the problems associated with microminiaturizatio especially power dissipation ad and its relation to circuit functions and packing density 9172 barkhausen noise in transformer cores the following are discussed isolation and measurement of the noise its relation to the slope of the hysteresis loop and the cycling rate an equivalent circuit which includes the noise source and the frequency spectrum of the noise when sinusoidally polarized 9173 margin considerations for an esaki diode resistor or gate worst case margin considerations imply that applications are restricted to storage systems flip flops shift registers and the like 9174 a helix type variable capacitor maximum to minimum capacitance ratios of or more are obtainable 9175 two terminal network functions through prescribed b points additions to the interpolation problem of pick and nevanlinna the synthesis of two terminal networks consisting of resistive inductive inductive and capacitive elements and having a given impedance function is considered 9176 quartz at type filter crystals for the frequency range design data are given for suppressing the unwanted modes to at least below the main mode see also of 9177 design of cavity resonators with maximum q factor summary of theory and design formulae for cylindrical cavity resonators with details of constructional features and coupling arrangements 9178 exact solution of a time varying capacitance problem a new method is developed giving a closed form solution for the harmonics generated by a sinusoidally varying capacitance in series with a fixed resistor and battery practical applications are discussed with reference to the condenser microphone and vibrating reed electrometer and a special loudspeaker improvement 9179 the quadratic invariances of a generalized network in systems where the matrix operator has eigenvalues which are unity or can be taken in reciprocal conjugate pairs the number of invariant quadratic forms is at least equal to the number of degrees of freedom 9180 the imaginary part of the characteristic impedance in the pass band of filter circuits the use of filter circuits with complex characteristic impedance in the pass band extends the number of possible bridge type filters filters with variable pass ab band can be realised 9181 a quick method for the design of butterworth filters a design procedure and worked example are given 9182 a variable bandwidth a band pass filter a method is described whereby several bandwidths may be ot obtained in an lc filter employing one set of inductors only the design of a typical filter with an actual plot of its attenuation characteristic is included 9183 a continuously variable band pass filter for the audio frequency range the design of a band pass filter whose bandwidth and lower cut off frequency are continuously variable is described the requisite crystal filters are derived from the band pass elements given by image parameter theory the equipment and some of its response curves are illustrated 9184 synthesis of n port active rc networks it is proved that n is the sufficient and in general minimum number of con rolled sources required to relize an arbitrary matrix of real rational functions as a transformerless active rc n port network 9185 the hamiltonian formalism of damping in a tuned circuit an lc circuit coupled to a transmission line is studied as an example of introducing damping into the quantum mechanical treatment of a harmonic oscillator the problem of coupling a spin system to the current in the inductance is also studied 9186 the stability of relaxation oscillations synchronized by pulses a finite difference equation is derived for the pulse synchronization of relaxation oscillators solutions are obtained by a graphical method and possibilities of simplification are considered the procedure is also applied to the case of frequency division calculated parameters are verified by measurements on a multivibrator circuit 9187 description of the change over process in multivibrators the dynamic processes occurring in multivibrators are described using a graphical method a bistable circuit is considered as example and a system of curves representing all possible internal processes is derived on the basis of differential equations for the characteristic time functions of this circuit the influence of the duration and amplitude of the triggering pulse on transition time is determined 9188 cdecoding circuits with semiconductor elements various types of circuit for binary decoding systems are given and requirements regarding the minimum number of semiconductor diodes and transistors to be used are evaluated and compared 9189 the problem of frequency synthesis review of the basic techniques employed for addition subtraction ad division in frequency synthesizers 9190 continuously variable glass delay line stress waves are optically monitored by using the birefringent properties of glass under stress 9191 designing grounded grid amplifiers with controlled gain a six stage low noise if amplifier with microminiature ceramic triodes is described 9192 review of nonlinear distortion in transistor stages including cross modulation the nonlinear transfer function is approximated by a taylor series expansion and from this equations are derived for various types of distortion in earthed emitter transistor circuits methods of compensating cross modulation are considered the results of cross modulation measurements are found to be similar to those obtained by akgun and strutt of 9193 selective rc amplifier using transistors investigation of the use of phase shift networks in transistor circuits the dual of the wien bridge arm is used to form an oscillator and a selective amplifier which has constant gain while the selectivity and tuning are continuously variable 9194 equation for the performance of a nonlinear transistor amplifier a first order differential equation is derived to describe the performance of a nonlinear amplifier discussed earlier by gumowski of 9195 investigation of the shift in frequency and of the amplitude of oscillations of z a maser type self oscillator with liquid flow an experimental investigation of the effect of detuning a maser oscillator of the type described earlier of and of the influence of the rate of flow on the resonance line width the range of oscillation extends from to 9196 cross relaxation phenomena in solid state masers with the direction of the applied magnetic field close to the axis of a ruby maser amplification for different crystal orientations was confined to two narrow frequency bands within the rang used possible mechanisms concerned are spin spin energy exchanges involving four ions and seven ions 9197 three terminal variable capacitance semiconductor device an analysis of the operation of the device which is based on the change in junction transition capacitance associated with the change in collector voltage gradient in an avalanche controlled semiconductor amplifier 9198 a variable diode parametric standing wave amplifier details are given of experimental work on the type of amplifier discussed by landauer 9199 using voltage variable capacitors in modulator design circuits and design equations are given for phase and frequency modulators and for ssb amplitude modulators 9200 pseudo rectification and detection by simple e bilateral nonlinear resistors an analysis of ac dc converting circuits using symmetrical nonlinear resistors the operation of which may be largely independent of temperature two applications are described for developing the hv focusing potential bias for a picture tube and for improving the detection threshold of a photoelectric sensing device 9201 gausss principle of least constraint applied to electrical networks gauss principle of mechanics when adapted to electrical networks leads to kirchhoffs laws 9202 swept langmuir probe system for intense gas discharges apparatus including a low impedance voltage sweep generator and a logarithmic amplifier is described for measurement of electron temperatures up to and ion densities up to 9203 exploration of oscillating beam plasma fields with a transverse electron beam the results appear to be compatible with considerable randomization and possible break up of the main beam by the oscillations 9204 electrodynamics of the image force the processes of ion emission ad and absorption at semiconductor surfaces are analysed see of february 9205 electron density fluctuations in a plasma the spatial fourier transform of the electron distribution is in a plasma is obtained together with is time variation using assumptions consistent with an ionospheric application 9206 space charge instabilities in synthesized plasmas potential transitions dependent on boundary space charge conditions are shown to be possible by a theoretical analysis of an idealized model such transitions are observed experimentally the voltage jumps are in good agreement with the theory 9207 method for the determination of the electron density of a plasma by group velocity 9208 method of measuring simultaneously the confining magnetic field and the electron density of a plasma extension of earlier work 9209 microwave measurements of the radiation temperature of plasmas measurements are described of radiation temperature of positive columns of glow discharges in helium neon and hydrogen the microwave noise radiation was detected at the results are compared with calculations and with langmuir probe measurements of the electron temperature 9210 nonlinear phenomena in a plasma located in an alternating electro magnetic field a detailed treatment of elementary and kinetic theories of a nonrelativistic nondegenerate plasma in a uniform electric field with particular reference to the distribution function of electron collisions the el effective electron temperature and total electric current density results are applied to determine the nonlinear effects occurring in the in the propagation of radio waves in the ionosphere including self interaction cross modulation and the interaction of unmodulated waves 9211 oscillations and diffusion in weakly ionized plasmas the diffusion of weakly ionized plasma particles is observed in a direction perpendicular to the magnetic field 9212 magnetic moment and magnetic charge the definition of magnetic dipole moment and magnetic charge in relation to the theory of permanent magnets is discussed 9213 some properties of concentrated and dilute heisenberg magnets with general spin the constant coupling approximation is used to obtain the thermodynamic properties of a heisenberg ferromagnet above the transition temperature and the dependendence of these properties on magnetic concentration in an alloy is c considered z antiferromagnets are also discussed 9214 the behaviour of magnetic systems with dilution generalization of the bethe peierls weiss method to the case of alloys and application to the dilution of classical heisenberg ferromagnets with nearest neighbour interaction only 9215 microwave modulation of light in paramagnetic crystals the considerations of dehmelt and others about the modulation of light by rf signals in atomic vapours are extended t paramagnetic solids experimental design criteria are discussed and some possible applications reviewed 9216 anisotropic magnetization discussion of the magnitude and temperature dependence of anisotropic magnetization with application to different classes of materials 9217 electromagnetic energy density in dispersive media general expressions for energy densities and losses are derived 9218 electromagnetic reflection from sound waves 9219 inhomogeneous waves in the diffraction field near loss free dielectric circular cylinders measurements were made at of the diffraction field near solid and hollow dielectric cylinders of equal external diameter placed in a parallel plate transmission line results are compared with those obtained for a solid metal cylinder of equal diameter and with the field distribution given by a graphical method an explanation is given of the inhomogeneous waves which contribute to the measured diffraction field 9220 diffraction by an irregular screen of limited extent information that may be derived about the screen by measurements of the diffraction pattern at different distances is considered close to the screen the pattern gives information about the small scale structure at greater distances it is related to the overall extent of the screen measurements of the angular diameter of stars ionospheric irregularities and meteor trails are discussed 9221 diffraction by finite irregular objects the problem considered in above is treated by a different method its application to lunar radio echoes is discussed 9222 nonresonance absorption of electromagnetic waves in a magneto active plasma analysis of the absorption of ordinary extraordinary and plasma waves outside the gyromagnetic resonance regions taking account of collisions and the specific absorption mechanism 9223 growth of electromagnetic waves in interpenetrating infinite moving media phenomenological treatment of the propagation of plane monochromatic waves in mutually interpenetrating media equations are derived for the refractive index and are applied to the problem of stability build up and damping factors are determined for the case of a plasma moving through a dispersionless dielectric 9224 influence of frequency and structure on the complex refractive index of metals and thin metallic films 9225 quantum theory of spatial dispersion of electric and magnetic susceptibilities electromagnetic effects in a homogeneous medium can be described in terms of a conductivity dependent on frequency and wave vector and a susceptibility dependent only on the wave vector a universal relation between conductivity and susceptibility is derived 9226 the influence of coherent magnetic dipole radiation field on magnetic resonance corrections to the relaxation time and resonance frequency shift due to the effect of the radiation field are computed 9227 beam type masers for radio frequency spectroscopy the behaviour of the beam type maser is considered theoretically with particular regard to sensitivity and line width experimental results for a formaldehyde transition are given for comparison 9228 general spin wave dispersion relations the derivation takes into account the effects of conductivity exchange and propagation 9229 calculation of the widths of ferrimagnetic absorption lines and of relaxation times in the case o spin waves of non negligible amplitude 9230 pulsed field measurements of large zero field splittings 9231 the hamiltonian formalism of damping in a tuned circuit 9232 proposed fibre cavities for optical masers the practical possibilities of employing fibres as dielectric waveguides at optical infrared wavelengths ar discussed 9233 electron effective mass in solids a generalization of bardeens formula a formula is derived for the effective mass of an electron in a crystal which replaces the sum over excited states in the usual sum rule by an integral over the surface of the unit cell the integrand of the surface integral involves the wave functions at the symmetry point or band extremum ad a second solution of schroedingers equation at the same energy but satisfying inhomogeneous boundary conditions on th cell surface 9234 an all electric univers outline of theory ascribing the evolution of the universe to electrical discharge processes an interpretation is given of observed cosmic phenomena 9235 the theory of force free magnetic fields the general features of force free magnetic fields are established and several models are discussed in relation to special coordinate systems see also 9236 a curious feature of the radio sky an examination of existing theories regarding the spur of intense radiation which appears to emerge from the galactic plane at about and to run upwards towards the north galactic pole radio observations may be interpreted more reasonably in terms of an irregularity in the local spiral structure or a remnant of a supernova 9237 observations of cosmic radio noise at in hawaii cosmic radio noise measurements at hawaii on a frequency of are described on numerous occasions considerable flux continued to arrive when thef region critical frequency exceeded this effect is possibly due t cosmic radio radiation being trapped and propagated under the ionosphere attenuation measurements suggest that an ionospheric window effect exists 9238 secular variation f the flux density of the radio source cassiopeia a comparative measurements at on the rf sources in cassiopeia a and cygnus a indicate that the flux density of cassiopeia a is decreasing at a rate of per annum 9239 statistical analysis of radio star scintillation radio star scintillation data are analysed by statistical techniques t find the auto correlation functions and power density spectra of the fluctuations in amplitude and phase interpretation is given in terms of a drifting phase changing screen as postulated by booker ratcliffe shinn of it is shown how the drift velocity of the irregularities in ionospheric electron density that lead to the scintillations as well as the mean square amplitude and phase of the fluctuations may be obtained from these records 9240 preliminary report on positional fluctuations of solar radio sources on mc an analysis indicates that the magnitude of the positional fluctuations is less when the solar rf source is closely connected with a magnetic field in the active region no increase in the magnitude of positional fluctuations was found on as the source moved towards the solar limb 9241 on the features f storm bursts in the range the characteristics of short pips which occur during noise storms are discussed for brief reports of this work see and of 9242 solar noise burst of november a burst of rf noise of high intensity is associated with a flare from a sunspot area which had just disappeared behind the suns west limb 9243 mirror and azimuthal drift frequencies for geomagnetically trapped particles the charged particles trapped in the geomagnetic field the frequencies of the mirror oscillations and the azimuthal drift are defined as appropriate averages over the helical motion around the field lines and the mirror motion between reflection points in the two magnetic hemispheres these integrals for and are evaluated numerically results are tabulated illustrated and represented by approximate analytical expressions 9244 investigation of cosmic rays and terrestrial corpuscular radiation by means of rocket and satellite flights detailed report of observations showing that the earth is surrounded by two separate zones of high intensity radiation the outer zone is composed of electrons ad in the equatorial plane extends from to km from the centre of the earth it comprises two main energy groups of the order of and the inner zone extends from to about km above the earth and is composed of protons with energies of see also and 9245 the cosmic ray flare on november and solar activity during the period november short report of optical radio astronomical cosmic ray and earth current observations made at nera netherlands paramaribo and hollandia 9246 interplanetary magnetic field and the auroral zones the current system is explained qualitatively using hoyles suggestion that auroral particles are accelerated at the neutral points between the geomagnetic and interplanetary fields 9247 pulsations of the earths electromagnetic field with periods of to seconds and their connection with phenomena in the high atmosphere pulsations are closely correlated with aurora and the various phases of magnetic storms the time of onset of a storm sudden commencement determined from pulsation data appears to be the same within a few seconds over the whole world 9248 world wide characteristics of geomagnetic micropulsations the characteristics of associated with negative or positive bays in the auroral zone are examined and a distinction is drawn between short period and those of longer periods the long period continuous pulsations which appear simultaneously with in polar regions are also discussed equivalent overhead current systems are derived for particular cases of each type 9249 a theory of polar geomagnetic storms the third of a series of papers which outline a hydromagnetic theory of storms see and of the three phases of the variations are accounted for by hall currents set up around space charge accumulations in the lower ionosphere these accumulations result from the deformation of lines of force due to interaction with the solar wind near and hr local time 9250 the application of ray tracing methods to radio signals from satellites 9251 project oscar general information is given about a g proposed orbital satellite carrying amateur radio 9252 telemetry signals from sputnik the equipment transcribes from magnetic tape to mm film displaying the coded pulse signals in a raster form which clearly shows pattern changes the telemetry coding system is given and two transits are analysed 9253 scale times and scale lengths of variables with geomagnetic and ionospheric illustrations the conception of the atmospheric scale height is generalized to apply to any scalar or vector function of time and or position examples are given relating to magnetic fields and the ionosphere 9254 a maximum of temperature in the middle ionosphere a method is outlined for determining variations in scale height h and electron density with height from profiles and from calculations of the electron loss results obtained from observations at puerto rico show that h has a maximum value at a height of about km with considerable daily and yearly variations 9255 a new method for the calculation of profiles from ionospheric curves the basic integral for virtual height has bee rearranged so that the integrand is a function of phase refractive index instead of group refractive index this technique avoids an infinity in the integrand at the reflection condition 9256 the effective recombination coefficient of an ionosphere containing a mixture of ions the effective recombination coefficient in the e layer can be estimated from the fall in electron density during the night from the changes during solar eclipses from the time lag in the diurnal peak density these coefficients can be expressed as functions of the coefficients for each of several different ions present and are shown to be different from each other it is suggested that and are the ions responsible during the day and that no ions predominate at night 9257 the formation of the sporadic e layer in the temperature zones a hypothesis for e formation based on the observation that e occurrence is correlated with the horizontal intensity of the earths field see of if the horizontal wind varies vertically the horizontal field will produce vertical motion of electrons ad ions an accumulation of electrons will occur at the height for which the vertical velocity passes through zero the theory also accounts for the persistence of e 9258 seasonal variations of mean electron density at heights between and electron density profiles are given for summer and winter which are based on observations of faraday fading of signals from satellite 9259 a note on the cause of sudden ionization anomalies in regions remote from high altitude nuclear bursts the sudden changes in vlf propagation characteristics associated with the nuclear explosions over johnston island are attributed to bomb induced ionization in the ionospheric d layer it is suggested tht this ionization is caused by particles resulting from the decay of fission neutrons 9260 geomagnetic disturbance effects in equatorial e a correlation between the disappearance of equatorial e observed at kodaikanal india and magnetic storm disturbances is reported a lowered e critical frequency occurs with a decrease in horizontal magnetic force 9261 the total electron content of the ionosphere during te magnetic disturbance of november measurements of the total electron content of the ionosphere have been made with the radio telescope at jodrell bank by observing the differential faraday fading of lunar radio echoes results show that the reduction in maximum electron density was accompanied by a proportional reduction in 9262 ionospheric absorption at times of auroral and magnetic pulsations variations in auroral absorption during march and april were closely related o to magnetic field micropulsations and short period intensity changes at the amplitudes of the magnetic micropulsations were diminished during periods of polar cap type absorption 9263 a no e on polar blackouts the twilight effects in polar cap blackouts are explained in terms of the c detachment of electrons from negative oxygen ions in the region of and higher by visible light h which has been attenuated in the atmosphere 9264 ionosphere review declining sunspot activity forced signal frequencies down 9265 an estimate of electron densities in the exosphere by means of nose whistlers by examining successive members of families of nose whistler for march it was possible to choose between three mos of electron density distribution for the exosphere the distribution with the best fit was where n is electron density r is the distance from the earths centre and k is a constant this fact suggests that the density at earth radii is of the order of electrons cm 9266 a study of auroral coruscations coruscations represent of the total light in the region and have a period of sec they are closely related to pulsations and ionospheric absorption of cosmic radio noise the electron density profile associated with the aurora was found to have a maximum in the e region of electrons cm 9267 spaced observations of the low frequency radiation from the earths upper atmosphere observations of radio noise with a network of four stations extending across southern australia are described it is shown tht there is often good correlation of the amplitude variations over a distance of and tht the observed amplitude differences may be explained by assuming tht the radiation propagates in the earth ionosphere waveguide from geographically large sources some discrete sources were observed 9268 sferics from intracloud lightning strokes the experimental observation tht many elf atmospherics are of negative polarity indicates that intracloud lightning strokes radiate significant energy at very low and extra low frequencies see alsf 9269 the magnetic flash of the nuclear test of february at reggane an em signal originating in the explosion at reggane has been recorded with a field strength of at a distance 9270 experiments on magnetic tape read out with an electron beam the feasibility of the method is demonstrated experimentally theoretically a video signal with a bandwidth of could be reproduced with a signal electron shot noise ratio of from a recorded area density of cycles mil 9271 telemetry signals from sputnik 9272 precision variable frequency power supply a ballast tube in thermal regulating bridge controls the amplitude of the output and an adjustable filter controls the frequency from to 9273 unconventional methods of generating electrical power a review of methods for the direct generation of electricity from other forms of energy including methods based on electrochemical and photoelectric conversion solid state devices and high velocity ionized gas a comparative table of the principal devices is included 9274 considerations on the solar cell the absorption curve of the material and solar spectrum effects are contained in a single function readily obtained by numerical integration 9275 stabilization of a magnetic field by a nuclear magnetic resonance maser the system briefly described will give an absolute long term stability within part in 9276 overload protection for transistor voltage regulators various circuit modifications are described for protection against overload 9277 patterns of thin films make fast nondestructive memories the kerr magneto optic method is used to show that irreversible domains can be formed in thin magnetic films 9278 the problem of coupling in a switching circuit system circuit consisting of thin magnetic films problems relating to the design of logic switching circuits formed by magnetic film elements are reviewed 9279 the impedance value of carbon film resistors as a function of frequency and dc resistance an arrangement is described for impedance measurements in which the dimensions of the mounting are standardized in relation to resistor dimensions so that comparisons are possible between results obtained for resistors of different size curves are given of maximum usable frequency as a function of dc resistance and of skin effect as a function of frequency and surface resistance 9280 methods o analysis of circuit transient performance a survey of some numerical methods for studying the performance parameters associated with transient behaviour of switching circuits 9281 properties and characteristics of tantalum capacitors with solid electrolyte 9282 nonlinear thermal fluctuations in a diode as an example of nonlinear noise the fluctuations in a circuit consisting of a diode and a capacitor are studied and th complete fluctuation spectrum is calculated 9283 time delay and frequency response of resonant cavities the frequency response and time delay characteristics of resonant cavities are discussed it is found that a signal travelling through a resonant cavity undergoes a time delay dependent on both the cavity q and also the difference between the signa and resonant frequencies the time delay for a frequency modulated wave is calculated and checked experimentally 9284 application of distortion functions to instananeous nonlinear circuits mathematica treatment of nonlinear nonreactive networks using the functions derived in of 9285 the propagation coefficient of a general linear quadripole current and voltage relations in a quadripole joining two transmission lines are calculated using methods of image parameter theory 9286 determination of the characteristic impedance of any quadripole at microwave frequencies measurements made on the quadripole under certain load conditions are used in determining the characteristic impedance by a graphical method 9287 the modification of wide band noise phenomena by linear transmission systems for simple types of filters the distortion of the power spectrum and autocorrelation function is investigated with wide band noise as input relations between parameters of classical and of statistical system theory are derived 9288 antimetric ladder filters all parameters of a quadripole antimetric ladder filter are shown to depend on four polynomial functions of being the complex angular frequency between which a relation exists the theory is applied to antimetric band rejection filters and to high and low pass filters and tables are given facilitating calculations 9289 extension of the possibilities of filter circuit construction by means of regions of imaginary characteristic impedance in the pass bad and regions of real characteristic impedance in the stop band the choice of filters with favourable transient characteristics the design of networks with the desired characteristics for pulse shaping circuits is based on an analogue computer method of examples are given of filters with idel idealized response or with transfer function approximated by polynomials 9290 audio frequency comb filter details r are given of the design of a mechanical system consisting o a stretched metallic string for suppressing hum and associated harmonics in the output of an af amplifier experimental results are noted 9291 the scattering matrix of generally interconnected multipoles the scattering matrix of the network is formed by the simple manipulation of matrices based on the scattering matrix of the individual multipoles 9292 research on submillimetre wave generation and techniques experiments and experimental equipment are described for investigations on sub mm wave generation including a tornadotron in which em radiation is produced by the action f of pulsed magnetic fields of the order of on a trapped electron cloud aspects of instrumentation suitable for these frequencies are briefly discussed 9293 frequency modulation o a pound stabilized oscillator a method is outlined for applying frequency modulation ot an improved pound stabilized oscillator of herve the frequency deviation is limited to about 9294 impulse governed oscillator techniques part theoretical aspects of igo techniques are given part 9295 microwave generators for the ien caesium standard two microwave generators are described which are used in the atomic frequency standard of the istituto elettrotecnico nazionale in turin for cs resonance excitation by molecular beam technique measurements of phase drift and frequency stability are also considered 9296 plate voltage control of phantastron frequency two pentodes each forming a phantastron circuit are interconnected so that both mark and space of their combined output waveforms are controlled by linear rather than exponential sweeps circuit jitter is less than at pulses sec repetition rate 9297 phantastron circuits using transistors arrangements of three transistors to simulate the screen anode current partition of a pentode enable transistron type circuits to be designed 9298 the eccles jordan circuit with transistors for high speed counters a static analysis of a transistor flip flop circuit is given and the counting frequency limits for high speed counters consisting of balanced flip flop elements are discussed circuits operating at frequencies in excess of are described 9299 one tunnel diode flip flop a note on the operation of a simple bistable device 9300 designing tunnel diode oscillators analysis of relaxation oscillators and associated circuits for sine wave and square wave generation 9301 mathematical analysis of pulse networks linear systems are analysed which comprise an element capable of converting a continuous input function into pulses of any desired shape a pulse network equation is derived which is applicable to closed loop control systems 9302 the generation of very short needle shaped pulses the design of pulse generators and pulse shaping networks is discussed details are given of a double differentiating network for the generation of pulses of amplitude further improvements by means of tunnel diodes appear possible 9303 low level linear microsecond gate a six diode gate linear over the range is described 9304 a solenoid delay line with constant delay description of a compact delay line which consists of a solenoid wound on a ceramic tube of high dielectric constant with a metal core delay can be made independent of frequency with an appropriate tube core diameter ratio 9305 the effect of an intermediate layer on the frequency characteristics of ultrasonic delay lines general expressions are derived for the line conversion factor taking account of an intermediate layer between the transducer and the line the effect of this layer on the frequency characteristics and transmission band is considered and the relevant characteristics of different transducer and layer materials are tabulated 9306 amplification modern trends techniques and problems 9307 the behaviour of a nonlinear transistor amplifier in the region of its stability limit an extension of earlier work the limit of stability of the amplifier is established from the form of the solution of a first order differential equation describing the amplifier 9308 transistor amplifiers with feedback analysis of the properties of transistor amplifiers using the parameters feedback circuits with special characteristics are reviewed over references 9309 semiconductor amplifiers and generators with carriers having negative effective mass it is not possible to produce states with negative losses in a semiconductor by means of a constant electric field it is necessary to have a state with negative losses in a semiconductor by means of a constant electric field it is necessary to have a state with negative temperature as achieved in molecular generators or using pulsed excitation by a electric field 9310 cross relaxation masers the ways in which ruby spinel rutile and emerald can amplify at frequencies small compared with their zero field splitting frequencies are surveyed cross relaxation is shown to give a two fold improvement in maser performance analytic expressions for the energies are given 9311 sewsaw maser operation cross relaxation between adjacent intervals may be used to secure an advantage in maser operation comparable to that obtained by push pull pumping equations for the rate of change of populations in a scheme of four levels when ac is pumped and cross relaxation takes place bt between have been formulated and the steady state condition corresponding to various assumptions regarding lattice relaxation times is discussed in an experimental investigation of maser operation based on this scheme and using ruby as the active material an inversion of was obtained at a signal frequency of when pumping at 9312 travelling wave parametric amplifier analysis using difference equations a second order difference equation is derived for both periodically and uniformly distributed parametric amplifiers gain and voltage output are calculated the results are specifically applied to an lc distributed amplifier 9313 effect of upper sidebands in travelling wave parametric amplifiers the effect of higher sidebands on paramagnetic amplification is investigated for circuits of limited bandwidth and infinite bandwidth 9314 theoretical considerations regarding the application of parametric amplifiers to radio telescopes the improvement of resolving power obtained by using one parametric amplifier immediately preceding the aerial and another as preamplifier stage of the receiver is discussed 9315 parametric amplifier for space probe tracking description of the parametric amplifier used with th jodrell bank radio telescope for reception of the pioneer v space probe signals from distances of over miles a description of a parametric amplifier tester using transistors is included 9316 parametric circuits at low frequencies using ferrites and thin magnetic films the design of parametric circuits incorporating ferrite cores and films with nonlinear characteristics is discussed films appear to be more suitable for operation at higher frequencies an advantage of the use of ferrite and magnetic film devices is their resistance to nuclear radiation 9317 the reactance tube as a parametric frequency divider and amplifier derivation of the equivalent circuit of a parametric amplifier in which a reactance valve functions as a time varying inductance i if the signal source is removed the circuit will operate as a frequency divider where the output is a subharmonic of the pump frequency 9318 energy balance in a parametric electron beam amplifier 9319 coupled mode theory of electron beam parametric amplification 9320 designing tunnel diode rf amplifiers a strip line filter and tunnel diode are combined to give low noise amplification at uhf in a small module 9321 time averaged effects on charged particles in ac fields the basic theory is developed and applied to plasmas including some cases with a dc magnetic field a bibliography and a critique of theory and experiments are included 9322 transient response of a thermo couple circuit under steady currents 9323 experimental study of anomalous electron stream behaviour experimental measurements on the characteristics of the sole current in a rectilinear crossed fil field beam are reported the sole current may be assigned a kinetic temperature of the order of corresponding to energy in excess of that corresponding to motion in static fields the energy exchange leading to this excess energy exchange leading to this excess energy is believed to be associated with multiple loop trajectories in the low potential region near the cathode 9324 noise generated in the ion sheath of a probe the frequency dependence of the saturated diode current is examined theoretically and results obtained are compared with measured values 9325 the general theory of the motions of ions and electrons in gases the chief formulae for the drift velocities and diffusion coefficients of ions and electrons in gases are derived in general form by the application of dynamical principles 9326 an error in the thermal conductivity for a fully ionized gas a discrepancy between formulae of marshall and of rosenbluth and kaufmann of is due to an error in the last collision integral of marshall 9327 the investigation of high frequency plasmas by means of a dc probe 9328 instability of longitudinal oscillations of an electron ion plasma in an isotropic plasma the oscillations are always damped in an anisotropic medium ion motion may lead to instability 9329 interaction of an electron beam with plasma an experimental investigation of modulated and unmodulated beams of high energy electrons with a high frequency discharge plasma is reported when an unmodulated beam moves through the plasma oscillations are produced in the beam at frequencies close to the plasma frequency 9330 interaction of an electron beam with a fully ionized plasma an electron beam modulated at microwave frequency passes through a thermal plasma critical frequency cyclotron frequency gain in beam modulation amplitude is measured theory is outlined which predicts gain for with a maximum at preliminary experiments agree with theoretical predictions a measured gain at is reported 9331 magnetic polarizability of a short right circular conducting cylinder a comprehensive mathematical analysis using a method given earlier of february 9332 production of magnetic fields exceeding kilogauss by a superconducting solenoid experiments with in wire form are described critical field data are given 9333 cherenkov radiation of a particle possessing a charge and an intrinsic magnetic moment analysis by quantum electrodynamic methods of the effect of the spin on the intensity and polarization of the radiation produced in a ferrite by a charged particle with an intrinsic magnetic moment 9334 energy momentum tensor for plane waves a general form is established for the energy gating in a homogeneous medium the field equations of which are derivable from a quadratic lagrangian function 9335 limit of applicability of the method of smooth perturbations i the problem of wave propagation through a medium with inhomogeneities mean square values of the phase and amplitude fluctuations and of the amplitude correlation function are discussed conditions are determined under which the effect of the layer with inhomogeneities on the traversing radiation can be replaced by the perturbation action of an equivalent phase screen 9336 diffraction of a scalar wave by a slit and by a circular aperture in a screen of arbitrary thickness an expression is derived for the transmission coefficient and its variation as a function of screen thickness and aperture size is plotted 9337 an electromagnetic diffraction problem involving unidirectionally conducting surfaces the exact value of the em field scattered by a undirectionally conducting surface under plane wave excitation is obtained the surface which is an entire plane is the junction of two unidirectionally conducting half planes whose conductivity directions are inclined at an arbitrary angle to each other and to the boundary line 9338 on the theory of diffraction by a composite cylinder general formulae are developed for the diffraction field around a perfectly conducting cylinder with a dielectric sleeve these formulae represent the field due to a unit electric line source parallel to the cylinder limiting cases are examined 9339 gyro resonance absorption of electromagnetic waves in a plasma an earlier analysis is extended to frequencies near the gyro frequency and multiples of this taking account of the thermal motion of electrons 9340 microwave analogue to the scattering of light by nonspherical particles total scattering cross sections and angular distributions have been measured some approximate theoretical methods appear to be useful the results are referred to the effects of interstellar matter on starlight 9341 paramagnetic resonance spectroscopy at zero magnetic field two spectrometers covering the range are described 9342 frequency stabilization scheme for the pound watkins rf spectrometer a scheme is described for locking the frequency of a marginal oscillator rf spectrometer to that of an external standard this makes it convenient to use such a spectrometer for high resolution nmr work 9343 comparison of the sensitivities of the beam maser and cavity absorption spectrometers a formula is derived for the signal noise ratio of the beam maser considering it as a special case of cavity spectrometer the sensitivity of the maser rr relative to the spectrometer varies inversely with the frequency 9344 high level oscillator for nuclear resonance a modification of the cathode coupled circuit see og of which functions at rf levels in the range 9345 theory of laser oscillation in fabry perot resonators an approximate condition for oscillation is derived 9346 stimulated optical emission from exchange coupled ions in 9347 simultaneous optical maser action in two ruby satellite lines maser oscillations have been obtained simultaneously at wavelengths of and is concentrated ruby 9348 population inversion and continuous optical maser oscillation in a gas ds discharge containing a he ne mixture experimental data on the physical properties of the system are discussed 9349 radio wave absorption of several gases in the to frequency range an extension of earlier work of to the gases and they were contained within a diameter tube up to long and a wide pressure range was used 9350 precise measurement of the microwave absorption frequencies of the oxygen molecule and the velocity of light ten microwave absorption frequencies of the oxygen molecule in the region have been measured with an accuracy of about the result is interpreted by successfully refining the existing theory comparing the resultant value of the rotational constant b with the value obtained in ultraviolet spectra the velocity of light is calculated to be km 9351 a catalogue of radio sources between declinations this list of sources supplements a previous catalogue for declinations between and of angular sizes of the strongest sources are given several of these being less than arc in size 9352 a receiver for radio astronomy and some observational results description of a superheterodyne receiver in which the hf amplifier contains two disk seal triode valves in cascode the effective cathode resistance of the second valve being made very high by a simple neutralization circuit a noise factor of has been obtained at radio astronomy observations are described which have been made with this receiver and the parabolic reflector at swingeloo an isophot chart of the sky drawn from these observations is reproduced 9353 an interferometer for the measurement of radio source sizes the cross type radio telescope at sydney o has been modified to study sources in the range arc the instrument and its operation are described 9354 direction finding on diffuse sources of electromagnetic radiation by combining the characteristics of an adcock type and rotating loop type of direction finder the position and size of an extended source can be determined 9355 an attempt to detect linear polarization in the galactic background radiation at observations of a strip of sky about declination set an upper limit of to the degree of linear polarization for bandwidths of 9356 recent developments in solar radio astronomy 9357 the radio brightness of the quiet sun at cm wavelength near sunspot maximum th quiet sun temperature measured using pencil beam and fan beam techniques is approximately this value is twice that for the same wavelength at sunspot minimum 9358 investigation of the relative positions of solar radio storm sources and of associated optical centres of activity a comparison has been made between the mean positions of radio storm centres observed sunspots results show a systematic difference between the apparent and true positions of the former and for more intense storm centres a directivity effect with latitude 9359 solar radio emissions and geophysical disturbances during july 9360 cosmological significance of angular measurements of distant radio sources 9361 solar proposed cosmic rays near the north and south poles results of ground observations during the storms of and november are presented 9362 x rays from van allen belt electrons it ought to be possible to detect the x ray flux at peak intensity above the cosmic radiation background at baloon altitudes 9363 electrons in the primary cosmic radiation extraterrestrial electrons with energies in the range and greater have been observed on three baloons flights 9364 charged particles in the inner van allen radiation belt results are given for the flight through the inner van allen belt of emulsion stacks carried in an atlas rocket the measured proton energy spectrum was in accord with a cosmic ray albedo source down to however below the spectrum exhibits structure with a maximum at and a minimum at penetration of solar protons into the belt over a period of days can explain the effect 9365 hydromagnetic waves and the trapped radiation a theoretical discussion and comments on the results of the argus experiment 9366 an estimate of the peak sunspot number in detailed analysis of the statistical properties of the twenty peaks in the sunspot cycle since results of which were given earlier of 9367 unusual solar disturbance no solar flare could be observed at the time of a radio disturbance of importance at on june the flare became observable after a delay of this and other anomalies are discussed in relation to two assumptions concerning the flare that it occurred on the far side of the sun that it originated at a lower level in the suns z atmosphere than the source of rf emissions 9368 geomagnetic micropulsations simultaneous observations latitudes and sho ed no change in period with latitude but a monotonic increase in amplitude for periods between and sec the interpretation of these results is discussed 9369 the simultaneity of geomagnetic sudden impulses analysis of several events during the igy shows that sudden impulses are propagated from high latitudes to low latitudes in times of about min 9370 the theory of artificial satellites in terms of the orbital true longitude previous theory of has been developed in terms of orbital true longitude and leads to faster convergence for large eccentricities and to a smaller number of terms in the series representing the perturbations 9371 on the large scale regions of irregularities producing scintillation of signals transmitted from earth satellites evidence is presented which indicates that absence of scintillation is not due primarily to high aspect sensitivity of scattering from field aligned irregularities 9372 ionospheric scattering of satellite trn transmissions reports of observations of night time scintillations of satellite transmissions are briefly analysed in relation to the position of the observing station and the direction of passage of the satellite results demonstrate the ability of field aligned irregularities to scatter radio waves in a manner highly sensitive to aspect see also of april 9373 observed field strength in te neighbourhood of the skip distance examples of ray focusing due to the satellite crossing the skip distance boundary are given the skip distance agrees well with h values derived from ionograms 9374 ion neutral reactions a list is given of reactions which may control the chemical composition of positive ions in the ionosphere under certain assumptions about reaction rate coefficients nitrogen is substantially dissociated in the f region to the theoretical conclusions of other investigators 9375 a preliminary mode for the variations of upper air densities a model is proposed covering variations of density with a period greater than one day the highest parts of the ionosphere the text is given of the symons memorial reviewing current theories concerning the formation and structure of the ionosphere above 9376 incoherent scattering by free electrons as a techniqe for studying the ionosphere and exosphere some observations and theoretical considerations observations confirm the existence of the incoherent scatter at predicted levels bu indicate less doppler broadening than expected for which an explanation is offered 9377 a possibility for determining the existence of a permanent form of magnetic field aligned ionization irregularities incoherent scatter from a direction perpendicular to the earths magnetic field is discussed 9378 internal atmospheric gravity waves at ionospheric heights irregularities and irregular motions observed in the upper atmosphere are interpreted in terms of a spectrum of waves propagated upwards and modified to produce different dominant modes at different heights 9379 vertical characteristics of travelling ionospheric disturbances a comparison between the occurrence of disturbances on fixed frequency records and profiles for the same period reveals that there appears to be an upper limiting height for the occurrence of disturbances on fixed frequency and the direction of travel of disturbances is related to season only and seems unrelated to height in the ionosphere 9380 the analysis of night time records a correction of electron density profiles for errors due to underlying ionization by the use of the extraordinary ray 9381 theoretical world curves of maximum f ionization part a time dependent solution of the continuity equation including vertical diffusion of ionization is used to obtain a theoretical variation of maximum f layer electron density with latitude and local time some similarity to experimental data is found but the equatorial trough does not occur in the theoretical solution see also of 9382 on the influence of horizontal motion of the neutral air on the diffusion equation of the f regin the equations of motion of a plasma in applied fields are discussed with reference to the f region the plasma sets the neutral air into motion horizontally within about but is not free to move vertically the consequences of this result on a world wide scale are discussed 9383 movements of the f layer of the ionosphere during geomagnetic bay disturbances the vertical movement of the f layer during and after geomagnetic disturbances i evaluated from ionospheric soundings made at lindau germany the movement is treated theoretically on the basis of the plasma theory developed by lucas and schluter of and to account for the rise of the layer use is made of martyns theory allowing for the influence of the neutral gas by comparing calculated and measured data estimates of conductivity and neutral gas density in the ionosphere can be made 9384 the occurrence of the spread f and the geomagnetic field spread f is more probable in days after a sudden commencement at high latitudes and less probable at low latitudes especially at the equinoctial seasons there is a strong correlation between the magnitude of the geomagnetic field and the occurrence of spread f at low latitudes a turbulence mechanism is suggested to explain this 9385 measurement of positive ion density in the ionosphere by sounding rocket preliminary results are given of measurements made over the akita rocket range japan in september two rockets were launched one during the daytime and one at night each equipped with a spherical langmuir probe ascent and descent records for each flight show close agreement and values of l electron density scaled from records agree fairly well with those obtained from rocket measurements 9386 vertical incident doppler inoogram an improved apparatus has been constructed for the measurement of doppler shifts produced by vertical movements of the ionosphere 9387 contribution to an investigation of ionospheric absorption on a fixed frequency a thesis concerning theoretical and experimental aspects of ionospheric absorption mes measurements by vertical incidence sounding measurements made on a frequency of during the period september march are analysed 9388 determination of ionospheric absorption from recordings of field strength and cosmic noise brief descriptions are given of a method of determining the ionospheric absorption index from oblique incidence recordings and of the riometer method using extraterrestrial noise sources 9389 statistical study in the occurrence of polar blackouts the distributions of radio blackouts in both hemispheres are examined using data at stations in the north and stations in the south the changes of blackout occurrence and times of maximum occurrence frequency with pso position are studied 9390 a theoretical model of electron density distribution along a geomagnetic line of force in the exosphere a model of electron density in the exosphere is set up by supposing electrons to diffuse along tubes of force electron densities in ionosphere and exosphere are related by steady state solutions the particle source is in the ionosphere under normal conditions but during a magnetic storm particles are injected into a tube of force at its furthest point from earth the role of collisions is discussed 9391 a note on the disposition of daytime auroral ionization in space radio aurorae are classified into two groups according to latitude spread the properties are compared and their relation to diffuse and discrete aurorae is discussed 9392 the slant e echo a high frequency auroral echo the slant e d echo is associated with vhf auroral echoes it is formed by scattering from randomly distributed field aligned irregularities and is enhanced by least time focusing and aspect focusing 9393 temporal variations of auroral radio echo activity in subauroral latitudes the diurnal day seasonal and year variations in the occurrence f of radio aurorae are investigated and also the time delay between class flares and the appearance l of aurorae is measured the bimodal diurnal distribution may be a consequence of the specular reflection properties of the auroral echoes 9394 auroral radio echoes and magnetic disturbances the occurrence of radio echoes from aurora is strongly correlated with local k index the position and motion of individual echo regions correspond closely with the current systems causing magnetic disturbances 9395 space research contains the text mainly in english of the scientific papers presented at the first international space science symposium nice 9396 an atlas of oblique incidence ionograms the atlas is published as nbs technical note no and contains routine records for the paths washington st louis washington boulder a discussion of equipment is given and seasonal variation layer formation and disappearance spread echo extension and other phenomena are illustrated 9397 a kilowatt microsecond vacuum tube pulser a full description is given of a circuit designed for operation of gas discharge tubes in plasma research 9398 distribution of losses and the efficiency of different processes in photoelectric solar energy converters an attempt at a quantitative analysis of essential processes 9399 theory of electrochemical diodes a theoretical analysis is given of the behaviour of an electrochemical diode based on the equation of diffusion of ions the non ohmic characteristic the shunting effect observed with a rapidly changing voltage and the rectifying action are determined 9400 a versatile forcing function generator an electronic generator for use with analogue computers which produces sine square triangular ramp step or impulse functions over the range to an accuracy within 9401 a successful version of the beevers macewan fourier synthesizer using dekatron counters a fourier synthesizer is described which allows a possible harmonics to be specified with amplitudes ranging from units both positive and negative harmonic components are acceptable see also of 9402 a dielectric drum storage system the basic theory of a dynamic electrostatic storage system is given experimental results with a ceramic drum are given packing densities of were obtained wit signal ratios of 9403 designing thin magnetic film memories for high speed computers a storage system has been built which will store words each of bits and which has a cycle time of 9404 current operated diode logic gates the basic logic circuits are described and practical examples are given 9405 an analogue computer for aerial radiation patterns 9406 stable oscillation conditions for the magnetic film parametron a mathematical analysis of a parametron is given this parametron uses a single domain magnetic film as the core of a nonlinear nductor absorbing energy from an alternating pump field and delivering energy to a signal winding graphical means of determining stability conditions amplitudes and phases of the oscillating variables and the range of operating frequencies are discussed 9407 microwave bistable circuits using varactor diodes using a carrier frequency switching speed between states was less than threshold logic circuit with power gain is illustrated 9408 symmetrical transistors as ac or dc switches and their applications in modulator and demodulator circuits 9409 an investigation of columbium as an electrolytic capacitor metal the characteristics of capacitors prepared from are very similar to those of ta except that the working voltages are about one third and the dc leakage currents about double that of similar ta capacitors 9410 extension of a theorem for normal passive electrical two poles in the steady state the theorem of which gives the terminal resistance of a two pole network as a function of the resistances of its elements is extended to allow for n degrees of freedom of the network satisfying the reciprocity condition 9411 the representation of coupling free branched circuits on an analogue computer a method is given for simulating branched circuits on an analogue computer so that each circuit component can be varied independently to determine its effect on circuit characteristics 9412 realization of second order two pole functions with transformerless canonical circuits by means of program controlled computers 9413 the size effect of ferrite spheres the integral equation technique is used to derive an approximate formula for the apparent susceptibility of a small ferrite sphere within a microwave cavity using a variational principle a first order estimate is obtained for the effect of a plane wall and the effect of the size of the sphere 9414 calculation of the transfer function from the magnitude of the transmission factor generalization ad modification of kupfmullers system theory to eliminate certain contradictions with practical systems 9415 the matrix of a recurrent network of equal quadripoles representation of any power of a matrix an explicit expression is derived for the n power of a matrix representing n equal four terminal networks in cascade 9416 synthesis of electrical filters from operating parameters by means of zolatarev fractions design formulae are given in which special functions are avoided by using mathematical tables of glowatzki see of and which involve less calculation than is required using the grossman formulae of 9417 electrical wave filter with prescribed operating characteristics calculations are simplified by the application of image parameter theory to filter design which may outweigh the advantages of economy in circuit components resulting from the use of insertion loss methods exact relations are derived between the quadripole and insertion loss characteristics of reactance quadripoles and examples are given 9418 gaussian response filter design exact data are given for the design of both low and band pass filters having characteristics which are nth order approximations to the perfect gaussian amplitude response n being the number of elements in the complete filter 9419 general low pass and high pass antimetric filters inserted between equal resistances 9420 filter circuits for extremely low frequencies without the use of inductances description of filter design procedure using double t rc networks passive and active filter circuits are given 9421 electromechanical quadripoles as coupling filters the equivalent circuits of mechanical resonators and electromechanical transducers are derived and the design of band pass filters consisting of input and output electromechanical transducers coupled by a mechanical transmission line is described 9422 ceramic if transformers discusses the principles of design of the radial mode resonator as used in if circuits 9423 design data for band pass ladder filters employing ceramic resonators graphical and tabulated design data based on image parameter theory are given for filter comprising piezoelectric disks resonating in a radial mode with or without capacitors the ranges of centre frequency bandwidth and image impd impedance achievable are discussed 9424 an analysis of the magnetic second subharmonic oscillator the analysis refers to a parametric oscillator with two ferromagnetic cores the steady state operation with both current and voltage pump drives is studied to determine the values of the circuit parameters which will give subharmonic oscillations the experimental waveforms are close to those predicted 9425 oscillator circuits with variable parameters pheolinear oscillators approximation formulae are given for determining pull in range and gain of parametric oscillators sinusoidal variation of capacitance and ao of attenuation are the cases particularly considered 9426 an airborne frequency generating unit for the hf communication band the unit gives an output frequency with channel spacing of in the band a variable oscillator is phase locked to a frequency derived from a standard 9427 piezoelectric excitation of quartz oscillators operating in the thickness mode by means of a parallel field the parallel field excitation of at and bt cut crystals is considered and its advantages are discussed equivalent circuits are given of two experimental oscillators for and using cut quartz crystal resonators 9428 frequency control and frequency fluctuations of the astable multivibrator a modified multivibrator circuit is given which permits frequency variation over the range by means of grid bias control the causes of fluctuations of pulse repetition frequency are investigated and design formulae are derived for minimizing these effects 9429 high frequency transistor polyphase oscillator conditions for oscillation of a polyphase transistor oscillator are developed from its valve equivalent of march experimental results show the relative performances of single polyphase and push pull transistor oscillators and demonstrate the superiority of the polyphase oscillator when a high power output is required at high frequencies 9430 waveguide harmonic generators the generator suggested by hedderley of is regarded as a multiphase rectifier circuit 9431 the synthesis of high purity oscillations suitable for single sideband receivers a phase locked oc oscillator has its output mixed with part of a spectrum to form an if in the region an interpolating signal with unwanted components down is used to lock the loop frequencies at intervals between and are derived 9432 harmonic generators for the band description of two signal generators covering the ranges and they incorporate a klystron oscillator and si diode frequency multipliers of 9433 increase of the gain of a wide band distributed amplifier by compensation of its zeros and by arrangement of the residual poles in a tchebycheff ellipse a set of equations is obtained for a two valve distributed amplifier and its component values and characteristics are calculated for a limiting frequency of general formulae for distributed amplifiers with any number of valves are derived theoretical results are verified with the aid of an experimental two valve circuit the tchebycheff type of amplifier is shown to have a gain greater by a factor of than the conventional distributed amplifier 9434 bandpass transistor amplifiers a determinant method is given for the analysis of amplitude and phase responses of tuned amplifiers having complex internal feedback circuits 9435 a wide band single diode parametric amplifier using filter techniques an arrangement is described using parallel tuned circuits at appropriate points along the signal line to give bandwidths up to at a centre frequency of 9436 a nondegenerate s band parametric amplifier with wide bandwidth band pass filters in the input ad and idler circuits are used to give a bandwidth of at a centre frequency of operation in four different modes is possible 9437 a nearly optimum wide band degenerate parametric amplifier a double resonator single diode design with bandwidth of 9438 interpretation of the transmission line parameters with a negative conductance load and application to negative conductance amplifiers 9439 behaviour of thermal noise and beam noise in a quadrupole amplifier 9440 a broad band tunnel diode amplifier a first order theory for an amplifier using tunnel diodes is presented the series resistance and inductance of the diodes is neglected except where stability is concerned the amplifier could be built using strip or coaxial lines 9441 elimination of even order modulation in rectifier modulators the time varying resistance function of the modulator is considered not to be a square wave but to contain even order carrier harmonics 9442 the relative magnitudes of modulation products in rectifier modulators and some effects of feedback the various modulation products occurring in series shunt and ring modulators are evaluated for square wave switching of the rectifiers assuming that the terminations are resistive the information is used in the design of feedback modulators 9443 the round travis discriminator a reexamination of johnstones analysis of the round travis amplitude discriminator of shows that the conditions indicated are not those giving minimum distortion a correction is proposed 9444 thermal noise in dissipative media to account for the spontaneous thermal fluctuations in a general dissipative medium a current source term is introduced into maxwells equations the results are applicable to nonuniform media and to media at nonuniform temperatures 9445 theory of electron phonon interactions the theory of the interaction of electrons and acoustic phonons in nonpolar crystals has been formulated in terms of a new set of basis states whose wave functions are essentially bloch functions that deform with the lattice the major part of the interaction may then be calculated in terms of ten be calculated in terms of the strain tensor rather than the displacement of the lattice a result of the theory is a generalization of the deformation potential theorem 9446 a gas discharge free in space glowing at the focus a of a radar paraboloid an electrodeless gas discharge in a low pressure vessel was achieved using an arrangement of two paraboloidal mirrors and coherent em radiation at cm 9447 on the relation between zener breakdown and residual resistance in crystals the theory of zener breakdown in crystals is extended to the case of very strong electric fields 9448 energy dissipation and secondary electron emission in solids experiments show a proportionality between secondary electron yield and energy dissipation by incident electrons 9449 contribution of back scattered electrons to secondary electron formation the contribution observed was large even in materials of low it was in for electrons 9450 pulse conduction in decaying plasma apparatus has been constructed in which plasma ionized by ry rf excitation is subjected to repeated submicrosecond c voltage pulses immediately after excitation is removed the current is measured 9451 generation ad measurement of highly ionized quiescent plasmas in steady state a simple generation technique is described experimental results validate double ambipolar diffusion in homogeneous dc magnetic fields and give a recombination coefficient of plasmas below 9452 drift velocities of slow electrons in helium neon argon hydrogen and nitrogen 9453 electromagnetic interaction of a beam of charged particles with plasma the theory of growing plasma waves is generalized to include waves propagated in directions other than the beam direction 9454 a method for measuring high electron densities in plasmas it is proposed that the standing wave pattern produced by plane microwaves at the plasma boundary be measured to give the complex reflection coefficient which is related to the electron density and collision frequency 9455 diffusion of plasma across a magnetic field 9456 the influence of the langmuir stratum between plasma and container wall on wave propagation in a plasma cable 9457 field external to open structure magnetic devices represented by ellipsoid or spheroid mathematical expressions for the fields are given and curves are plotted with dimensional ratio as parameter 9458 the electromagnetic fields of a dipole in the presence of a thin plasma sheet under the assumption that the thickness of the slab is small expressions for the resultant fields are obtained see also 9459 impedance boundary conditions for imperfectly conducting surfaces it is shown how the exact em boundary conditions at the surface of a material of large refractive index can be approximated to yield the usual impedance or leontovich boundary conditions 9460 propagation of electromagnetic surface wave along wedge surfaces the conditions under which surface waves can be excited by a plane em wave incident on a wedge are determined 9461 impedance boundary conditions for statistically scalar diffraction by a prolate spheroid at low frequencies 9462 scattering by a narrow unidirectionally conducting infinite strip expressions for the far zone fields and the first two terms in the series for the total scattering cross section are obtained 9463 back scattering from a conducting cylinder with a surrounding shell 9464 scattering by a grating parts anomalies occur in the angular spectrum of plane waves scattered by a grating when any of the waves propagate tangentially along the surface this behaviour is analysed theoretically for a wave function vanishing on the grating elements and for the derivative of the wave function vanishing 9465 nonlinear interaction of an electromagnetic wave with a plasma layer in the presence of a static magnetic field part theory of harmonic generation theory of propagation through an anisotropic ionized layer as a function of incident field strength and layer thickness is presented 9466 penetration of microwaves into the rarer medium in total reflection using right angle prisms separated by a narrow air gap transmission and reflection coefficients of paraffin sulphur and have bee measured at as a function of the gap width 9467 refraction and diffraction of pulses a solution for reflection and refraction of a plane pulse at a plane surface is obtained by fourier synthesis using a method which is also valid when total reflection occurs 9468 a spectrometer for paramagnetic electron resonance with different methods of detection the equipment described can be used for the klystron frea spectrometer for paramagnetic electron resonance with different methods of detection the equipment described can be used for the klystron frequency modulation and magnetic sweep methods of measurement 9469 theory of ferro and antiferromagnetic resonance absorption 9470 longitudinal ferrimagnetic resonance susceptibility components are calculated for a triangular ferrimagnetic system when the oscillating field is parallel to both the constant field and the net magnetization 9471 the relation of transition parameters for linear processes to measurable parameters in ferrimagnetic resonance calculated expressions include the effect of the reaction of spin waves back on to the uniform precession the consequences of its neglect in previous calculations by others are discussed 9472 confocal multimode resonator for millimetre through optical wavelength masers the mode patterns and diffraction losses are obtained for a resonator formed by two concave spherical reflectors these are shown to be a minimum hen the reflector spacing equals the common radius of curvature of the reflectors the optical alignment is not extremely critical 9473 resonant modes in a maser interferometer a theoretical investigation is made of the diffraction of em waves in fabry perot interferometers when used as resonators in optical masers curves for field distribution and diffraction loss are given for different mirror geometries and different modes 9474 collective excitation of electrons in degenerate bands part collective excitations in a metallic band 9475 the radio telescope for metres wavelength at the mullard observatory the pencil beam system described is based on the principle of aperture synthesis and has a resolution of a survey of the sky between and declination to is given 9476 the radio spectrum of the andromeda nebula new observations have been made and results are compared with those made at jodrell bank at by large et al of and show that all parts of the nebula have a similar spectrum 9477 asymmetry in the recovery from a very deep forbush type decrease in cosmic ray intensity analyses the intensity time curve for cosmic rays recorded at locations all over the world recovery occurred at each station at the same effective local time corresponding to arrival from directions making and with the sun earth line 9478 cosmic ray flare of november a solar flare was observed visually at a height at least above the chromosphere during a period of increased cosmic ray neutron flux and a burst in solar noise flux of may 9479 the drift velocity of charged particles in the magnetic dipole field a more accurate expression for the drift velocity of particles in the vicinity of the equator is derived by allowing for a second centrifugal force term in the original equation 9480 equation of a charged particle shell in a perturbed dipole field the equation obtained agrees with the shell measured by satellite following the nuclear explosion of september 9481 effect of hydromagnetic waves in a dipole field on the longitudinal invariant hydromagnetic waves of period sec and amplitude at earth radii may cause a systematic lowering of mirror points with subsequent loss of particles in atmospheric collisions two models for electron density variation along a field line are investigated particle acceleration by the fermi process is dominated by particle loss at mirror points and it is suggested that only high frequency waves will give effective acceleration 9482 preliminary report on cosmic ray intensity during magnetic storms in july observations at three stations show that there was no appreciable change in the primary variation spectrum for three successive forbush decreases this may be interpreted as an indication of a linear superposition of cosmic ray modulation effects during the july disturbances for an analysis of cosmic ray intensity recorded at mina aguilar during this period as a function of time 9483 cosmic ray intensity variations during the magnetic storm in may the primary variation spectrum has been estimated in a similar manner to that used for the july storms above results for both storm periods have been compared showing a number of common features 9484 some properties of radio waves reflected from the moon and their relation to the lunar surface the properties of the echoes are described in terms of the correlation of the complex amplitudes of two sine waves at frequencies separated by reflected from the surface the correlation technique can be extended to two dimensional mapping of a rotating rough body a statistical model of the lunar sunface roughness is derived in which rms slopes of to are assumed 9485 a method of evaluating the intensity of radio signals reflected from the surface of the moon propagation losses can be determined by supposing that the reflected wave is formed within the limits of the first fresnel half zone and taking account of the curvature of the reflecting surface the method provides a more accurate picture of the reflection phenomena 9486 some evidence of hydromagnetic waves in the earths magnetic field combining changes in the h and d components of field indicate that the horizontal magnetic vector is elliptically polarized this may be due to a hydromagnetic wave travelling obliquely to the earths magnetic field 9487 low latitude and high latitude geomagnetic agitation detailed study is made of geomagnetic agitation above the three daily maxima of have spiral loci agitation is an order of magnitude lower at middle latitudes increasing again towards the equator ionospheric current systems with auroral electrojets are examined in the above context the occurrence frequency of sudden commencements at one station exhibits a diurnal variation a recent theoretical explanation of this is examined 9488 on the seasonal variation in lunar and solar geomagnetic tides in the geomagnetic equatorial region 9489 influence of sunspots on geomagnetic disturbance the hypothesis that the ejection of solar corpuscles is influenced by interactions of active region magnetic fields is tested empirically the results do not support the hypothesis 9490 dipole field type magnetic disturbances and auroral activities the magnetic perturbation produced at the ground by the current system associated with an electric dipole at is calculated magneto grams obtained during an auroral display are analysed to deduce the position ad motion of the equivalent dipoles these correspond closely to prominent visual auroral forms 9491 minimum range to artificial earth satellites a complete expression for calculating from doppler measurements the minimum passing range between satellite and observer is derived and its application under various orbital conditions id discussed 9492 loss of mass in echo satellite correction to of april and comparison of predictions with observed orbital data 9493 spin rate of the satellite echo as determined bya tracking radar radar observation of echo indicate that between passes and the spin rate increased from to rev min between these two observations the satellite first started passing into the earths shadow which possibly resulted in changes in internal pressure and subsequent deformation of the baloon 9494 new satellite tracking station in great britain 9495 magnesium and calcium ions in the upper atmosphere of the earth the presence of mg and ca ions was recorded by a rocket borne mass spectrometer launched from a moderate latitude peaks in the mg ion concentration reaching were observed at heights of and 9496 daytime and night time atmospheric properties derived from rocket and satellite observations a summary of the values of atmospheric density obtained during the interval from rockets and satellites is presented and is fitted into a model atmosphere obtained by integrating the hydrostatic equation a general decrease since in atmospheric density at all z altitudes is confirmed 9497 rocket electron density measurements at fort churchill canada a discussion of the results of a rocket flight during quiet ionospheric conditions using the two frequency phase comparison technique of seddon of 9498 longitudinal and latitudinal effect of the ionosphere estimated by observation on board the soya values of at hourly intervals are plotted against geomagnetic latitude for the range covered by the voyages from japan to antarctica in december and january in 9499 ionization of e layer by x rays the total amount of solar x ray energy absorbed within the e layer is calculated from available rocket and absorption measurements only x rays in the wave length region are absorbed the amount of energy involved being estimated at 9500 some observations of the occurrence and movement of sporadic e ionization an analysis of simultaneous observations of clouds in europe by ionosondes at various locations by a rotating aerial back scatter sounder at slough england and by an oblique propagation experiment at over the mean cloud diameter was about about twice as many clouds occurred to the south of slough as to the north with an average duration of hu hours of clouds one third drifted predominantly to the south west at a mean speed of the movement of the clouds did not correlate with wind velocities 9501 the f layer at sunrise observations at cambridge and slough show that at fixed heights in the f region just after layer sunrise the electron density increases faster in winter than in summer and faster at sunspot maximum than at sunspot minimum it is postulated that seasonal changes of atmospheric composition alter the rates of electron production and loss thereby causing both the noon and sunrise seasonal f layer anomalies 9502 diffusion of ionization in the sunrise f layer some idealized calculations support the assumption made in above that the rate of increase of f region electron density just after sunrise depends primarily on the rate of production of ionization at this time the loss diffusion and transport of ionization are of secondary importance 9503 travelling disturbances in the f region over waltair a description is given of the general diurnal and seasonal characteristics of travelling disturbances as observed on and records extending over two years 9504 simultaneous observations of pulsations in the geomagnetic field and in ionospheric absorption on and september at regular pulsations were recorded simultaneously on a riometer operating on a frequency of and a magnetometer measuring the h component of the geomagnetic field for many cycles the pulsations remain in phase but on occasions they are in antiphase the period of the geomagnetic pulsations suggests that they are due to toroidal hydromagnetic oscillations of the outer atmosphere possible connections with ionospheric absorption are briefly considered 9505 analysis of the variation of e and index of solar activity it is assumed that for both the diurnal and annual changes in the critical frequency is proportional to cos the values of are extrapolated to for several stations and an empirical relation between the values for and the sunspot number is derived 9506 vertical drift in the e layer of the ionosphere during geomagnetic disturbances the velocity is estimated of the vertical drift due to geomagnetic disturbances the possible rise of the e layer is shown to be a few hundred metres only which cannot be measured by ionospheric recorders for an investigation of f layer movements see of june 9507 active high frequency spectrometers for ionospheric sounding part direct recording of ionospheric characteristics on the basis of the method noted earlier of equipment has been designed which provides direct records of and as a function of time sample records are reproduced and applications of the method are discussed a method of distinguishing height ranges in f layer records using colour film is noted 9508 analysis of random fading records 9509 measurement of the ionospheric absorption during the igy at kokubunji the diurnal variation in absorption shows an asymmetry about noon which is attributed to the changes in vertical drift motion in the d layer associated with the current system the marked winter anomaly effect cannot be explained by a change in the electron density distribution in the normal d layer 9510 ionospheric motions observed with high frequency back scatter sounders techniques for determining the characteristics of movements of irregularities in the f region by the use of back scatter records are described the results of an analysis of back scatter data obtained during december at sterling virginia at a frequency of about are presented and found to be in good agreement with those of other investigators of ionospheric motions 9511 effect of the magnetic field in ionospheric back scatter back scatter spectral lines may be used to calculate magnetic field ion mass and plasma temperature see also 9512 high frequency radio wave blackouts at medium and high latitudes during a solar cycle 9513 theory of auroral morphology the theory is based on the production of instabilities in electron sheets it predicts observed features relating to the duration of homogeneous arcs and the transition from glow to homogeneous arcs to ray arcs and draperies other observations explained are certain phenomena in flaming aurorae and the lowering of mirror points in certain conditions 9514 reply to some comments by malville concerning the midnight auroral maximum the preponderance of aurora near magnetic midnight is discussed 9515 the relationship between unique geomagnetic and auroral events at eleven canadian stations a high correlation is found between the geomagnetic latitudes of the southern extends of aurorae and the most southerly current lines a southward drift occurs simultaneously in an aurora and the accompanying ionospheric currents 9516 relationship between red auroral arcs and ionospheric recombination an aurora arc observed photometrically to be north of boulder colorado has been identified with oblique echoes on ionograms taken near boulder 9517 generation of very low frequency noise in the exosphere by the cerenkov effect the cerenkov effect produced by relatively slow moving particles of solar origin is considered as a possible mechanism for the generation and propagation of vlf noise the theory is briefly discussed in relation to a travelling wave tube model proposed by gallet of to explain similar vlf emissions 9518 energy fluxes from the cyclotron radiation model of vlf radio emission comment on a paper by santirocco of 9519 classification of the waveforms of atmospherics a review with references 9520 the determination of the distance of atmospherics from their waveform diagrams facilitating the determination of the distance of atmospherics are given their use is discussed with reference to the results of measurements a reflection height of was assumed for daytime conditions and for night time propagation 9521 guidance of radio whistlers by the earths magnetic field in an anisotropic medium there is for each frequency an emission angle of such a value that the ray propagates strictly along the line of magnetic force with a velocity which is independent of frequency 9522 remarks on the annual and diurnal variations of the occurrence of whistlers the annual variation of whistler density observed at kuhlungsborn appears to be correlated with the thunderstorm activity of south africa and not with that of the conjugate point which is at a higher geomagnetic latitude nocturnal variations of whistler density show phase differences between summer and winter which are attributed to absorption in the lower ionosphere 9523 the hydrogen ion effect in whistler dispersion careful analysis of four low altitude whistlers shows deviations at low frequencies from the law const this observation is explained in terms of a simple atmospheric model in which the gas above about is mainly hydrogen 9524 initial results of a new technique for investigating sferic activity the system was developed for the automatic measurement of the complex spectral characteristics and for the au omatic high speed processing of statistical data typical results are presented and discussed 9525 the change of state crystal oven the action of the oven depends upon the constancy of the melting point of crystalline material and the thermal ballasting due to the latent heat of fusion an oven of this type can restrict the frequency shift to parts in for a temperature change of 9526 precise frequency control for a rotary converter the royal research ship discovery has been provided with a power supply whose frequency is precise to approximately part in by locking the phase of a small rotary convertor to that of a reference signal derived from a quartz crystal oscillator 9527 detailed balance limit of efficiency of pn junction solar cells a theoretical upper limit for efficiency is deduced assuming that recombination is entirely radiative maximum efficiences of are found 9528 characteristics of a high solar conversion efficiency gallium arsenide pn junction spectral emissivity and response data are given for photocells which have an open circuit voltage of about and short circuit current density cm 9529 the choice and design of dc convertors the design of single and two transformer converters using transistors is discussed and their performances are compared design steps are indicated and two practical examples are given 9530 power semiconductor ratings under transient and intermittent load methods of calculating maximum allowable dissipation are discussed with examples 9531 transient thermal impedance of semiconductor devices 9532 a new dc level control for adaptive systems a novel electronic circuit is described and analysed which maintains the potential drop across a load constant to within a fraction of while permitting the dc level of the load to be varied through a wide range the circuit requires only standard tolerance electronic components and high precision is obtained by an error compensation technique 9533 accuracy and limitations of the resistor network used for solving laplaces and poissons equations the accuracy of a resistor network is higher than that of the best comparable electrolyte tank improved methods of simulating boundary conditions are described 9534 storing decimal digits with one clock pulse a method based on the magnetization time of ferrite cores 9535 transistorized electronic analogue multiplier a four quadrant circuit using the exponential characteristics of the input of grounded base junction transistors is described the performance compares favourably with that of other types 9536 solving design problems in all magnetic logic a survey of general problems and methods of design of magnetic logic circuits excluding parametron and ferroresonant circuits 9537 discrete analogue computer compensation of sampled data control systems a description of operational m amplifiers and si diode switches for performing the basic functions of sampling holding and time delay performance is analysed and an arrangement for avoiding saturation in a feedback system is also described 9538 tin oxide resistors the characteristics of thin oxide films are discussed and techniques of manufacture and performance figures of tin oxide resistors for various applications are given 9539 rf switching circuits and hybrid ring circuits used in radio astronomy low loss i diode and other switching systems used in comparing small rf noise powers are described 9540 designing avalanche switching circuits 9541 the equivalent wave source the application of wave parameters to two terminal sources is discussed an equivalent wave source is derived which corresponds to the conventional equivalent voltage or current source 9542 the law of small variations in characteristics and its application to nonlinear and linear networks current changes resulting from small variations in characteristics in nonlinear dc networks can be calculated approximately by reference to an equivalent circuit examples of linear networks considered are a wheatstone bridge circuit and reactance two poles 9543 the realizability conditions for the impedance functions of electrical two pole networks allowing for losses in coils and capacitors 9544 some energy relations for rc networks certain relations are established and associated with the compact rc network whose open circuit impedance parameters have residues that possess the same ratio at corresponding poles 9545 non ideal gyrators the analogy between non ideal gyrators and non ideal transformers is established equations are derived for the perfect gyrator and the gyrator with leakage matching and directional characteristics are discussed 9546 the effect of tolerances in the elements of image parameters filters 9547 the insertion characteristics of cascaded circuits a method of dealing with series connected filter circuits in particular those consisting of electromechanical elements is considered a single quaripole is derived to represent cac cascade connected equal and symmetrical quadripoles and different types of end section are added to this equivalent quadripole the impedance matrix of the equivalent network is determined the application of the principle to a combination of unequal quadripoles is outlined 9548 piezoelectric ceramic transformers and filters a description of some of the types of transformers and filters which are produced from the lead zirconate lead titanate series 9549 magnetostrictive transducers as selective quadripoles the relations between electrical and mechanical quantities in magnetostrictive energy transducers are given and equivalent circuits derived design formulae are obtained using image parameter theory 9550 some comments on narrow band pass filters 9551 the measurement of the characteristic values of electromechanical coupling filters 9552 quadripole networks for phase correction in low pass and band pass amplifiers the design of delay equalizers for television transmission systems is described 9553 bodes variable equalizer design procedure for ar an equalizer in which the insertion loss characteristic can be varied by the variation of one network element a thermistor is developed from basic theory 9554 coupling of multipoles represented as a wave transmission problem the method of solving multiple coupling problems by means of a scattering matrix is described 9555 network synthesis with negative resistors the theory is presented of the incorporation of the negative resistor as a basic circuit element in problems of linear network analysis and synthesis nine circuit theorems are given 9556 note on coherence vs narrow bandedness in regenerative oscillators masers lasers etc 9557 a method for generating signals of arbitrary yet frequency independent phase differences two balanced peak detectors are used the phase difference remains constant over a range 9558 improvement of the frequency stability of a high frequency oscillator frequency modulated by means of a condenser microphone a frequency stabilizing system is described in which the condenser microphone serves simultaneously for frequency modulation and as an es control element the system finds application in miniature vhf transmitters and eliminates the need for crystal control 9559 high frequency oscillator stabilization by pulse counting techniques a system is described for frequency stabilization to within parts in the range using an lc tuned oscillator locked to a standard frequency a description of the trochotron divider used in the circuit is given 9560 quality measurements on oscillator crystals by the decay method equipment is described for measuring the time constant of the decay of free oscillations of quartz oscillators the method is suitable for measuring the q factor of crystals of high resonance frequency 9561 and nanosecond carrier pulses produced by harmonic generation pulses are generated directly from the harmonics present in the sharp step at the end of the recovery transient of a selected type diode which is mounted across a waveguide used as a high pass filter 9562 a simple method of generating nanosecond pulses at x band the technique is based on the pulse response of a travelling wave tube 9563 magnetic gate circuits controlled by high frequency signals principles of operation of three and four core gating circuits based on the nonlinear properties of parametron type cores are described experimental characteristics and applications are noted 9564 high efficiency variable reactance frequency multiplier a conversion efficiency of was obtained using variable capacitance diodes with input frequency of and output frequency mc 9565 stabilized delay circuit provides high accuracy a transistorized circuit is given providing delays up to with a high degree of accuracy and stability 9566 electrically variable time delay using cascaded drift transistors eight cascaded transistors provide a variation of delay of with a minimum cut off frequency of 9567 parametric up converter tunable over an frequency band by using an adjustable x band pump frequency a gain of is obtained with signal frequencies ranging from to mcs 9568 two simple estimates for overshoot and group delay approximations relating to the transient response of cascade connected quadripoles 9569 low noise amplifiers for centimetre and shorter wavelengths a summary of the techniques used to make low noise amplifiers the devices covered are travelling wave tubes parametric amplifiers tunnel diodes masers photon counters and photosensitive detectors 9570 calculations of distortion and interference effects in transistor amplifier stages on the basis of the equivalent circuit diagram low frequency conditions and input signals up to maximum permissible amplitude are considered and the calculations are applied to two stage circuits the extension of the theory to high frequency conditions is indicated 9571 improving gain control of transistor amplifiers better temperature stability and z lower noise figure are obtained by using separate agc loops for each stage 9572 proposal for a pulsed ferromagnetic microwave generator spin precision is induced by rotating the applied field from a metastable to a stable magnetizing direction 9573 stimulated emission from gas maser observed at is considered as an alternative to for a gas maser the relative position and strength of the absorption lines are shown and the construction of the proposed maser is described 9574 beam maser for millimetres uses hydrogen cyanide a practical description of the development and construction of a maser operating at which may be useful as a power source amplifier or as a frequency standard 9575 an operational ruby maser for observations at centimetres with a foot radio telescope details are given of a preamplifier weight for mounting at the focus of a reflector an automatic gain stabilization system is incorporated total input noise temperature of the radiometer is with gain stabilization and without 9576 a variable dual reactance travelling wave parametric amplifier g two transmission lines are coupled together by inductance and capacitance which vary at a pump frequency 9577 k band ferrite amplifier a parametric amplifier using a sphere of garnet and giving gain at 9578 parametric amplification by charge storage both parametric amplification and subharmonic oscillation can be obtained through charge storage effects suing the circuit described 9579 c band nondegenerate parametric amplifier with a bandwidth the amplifier uses two si pill varactor diodes in a balanced circuit and has a gain of db 9580 parametric excited resonator using junction transistor oscillations in the collector circuit are phase locked by a signal applied to the reverse biased emitter 9581 a matched amplifier using two cascaded esaki diodes a circuit consisting of a quarter wave transmission line whose ends are terminated by negative conductances is discussed and its characteristics calculated a amplifier using two esaki diodes has been found to have a gain of with a noise figure of 9582 general relativity for the experimentalist 9583 direct determination of boltzmanns constant from resistance noise the value of obtained frl from thermal noise measurements in the frequency range is joules degree to an accuracy within 9584 friedel sum rule for a system of interacting electrons 9585 theory of the magnetoresistance effect magneto resistance effects in metals are studied on the basis of a single quantum theory of electron transport in a magnetic field 9586 response of a thermocouple circuit to non steady currents a general expressions for the transient response is derived and applied to several special forms of time dependent current 9587 note on the mechanism of the multipactor effect by modifying the theory of m krebs to take into account the velocity distribution of secondary electrons and the phase defocusing effect excellent agreement is obtained with the experimental results of hatch and williams of 9588 determining electron density and distribution in plasmas a microwave interferometer technique is used for measurements on low temperature magnetically contained plasmas 9589 transport coefficients of plasmas in a magnetic field the electrical and thermal conductivities and the coefficient of thermal diffusion are calculated 9590 proposed diagnostic method for cylindrical plasmas expressions are derived for two methods whereby the electron density variation across a plasma column can be obtained more easily than hitherto from an observed diffraction pattern 9591 microwave attenuation by cyclotron resonance in a slightly ionized gas the boltzmann equation is solved for the distribution function of electrons in a static magnetic field b and a hf electric field the tensor dielectric constant and propagation constant k are hence obtained the attenuation spectrum is discussed for the two cases of parallel and perpendicular to b 9592 spectrum of the electron synchrotron resonance in a plasma experimental verification of a theoretical formula for cyclotron resonance frequency 9593 heating of an ionized gas sheath by microwaves formulae are derived from which the temperature of a plasma sheath can be found as a function of time when it is heated by high energy microwave radiation 9594 backward wave microwave oscillations in a system composed of an electron beam and a hydrogen gas plasma a travelling wave interaction structure is used to investigate the properties of a low density plasma microwave oscillations near the electron cyclotron frequency are observed as the result of growing waves in a beam plasma interaction electron ction electron densities determined by observing the correlation between the measured frequencies of oscillation and the theoretical predictions of trivelpiece and gould of are verified by observation of the shift in the resonance frequency of a microwave cavity containing the plasma 9595 the influence of the cross sectional distribution of electron density of a longitudinally magnetized plasma in a metal waveguide on the propagation of em waves 9596 the magnetization and field of rod shaped objects the magnetization process is analysed and general formulae are given for the demagnetizing field an electron optical method of for determining the magnetic distribution in and around the rod is discussed 9597 determination of the energy of a plane magnetic field by representation f the latter in an electric current field 9598 equipment for generating strong magnetic fields f short period constancy a suitably terminated low pass filter network is used to produce flat topped current pulses for generating strong magnetic fields which are constant for periods of the order of 9599 a dipole absorber for centimetric electromagnetic waves with reduced reflection at oblique incidence the addition to a resonance absorber of arrays of dipoles parallel and perpendicular to the absorber surface minimizes reflection at oblique incidence experimental results and theory are given 9600 multiple scattering by a random stack of dielectric slabs when the number of slabs is large the neumann series for the mean square transmission and reflection coefficients converges much more rapidly than would be inferred from the smallness of the perturbation of the incident field by the scattering medium 9601 detection of double resonance by frequency change application to hg feb 9602 the three level gas maser as a microwave spectrometer a method of microwave spectroscopy using three level maser action is described and results of experiments on hdco are discussed in relation to theory 9603 distribution of fields from randomly placed dipoles free precession signal decay as result of magnetic grains 9604 ferromagnetic relaxation caused by interaction with thermally excited magnons 9605 note on the back reaction term in ferromagnetic relaxation equations a clarification is given of the status of the last term of the equation proposed to a paper on the analysis of ferromagnetic resonance line width in ferrites of and 9606 on the theory of spin lattice relaxation in paramagnetic salts 9607 spatial coherence in the output of an optical maser 9608 optically efficient ruby laser pump 9609 note on the magnetic structure of the galaxy a resessment of earlier theory see of march 9610 a comparison of three surveys of radio stars a recent survey of radio stars is compared with results of earlier measurements by mills et al and edge et al 9611 first results of radio star observations using the method of aperture synthesis four surveys centred on declinations of and have been made at a wavelength of with a large interferometric radio telescope based on the technique of aperture synthesis of ryle and hewish details of the observational method calibration data reduction and analysis of the computed results are given 9612 observations of some radio sources on cm a report of observations of discrete rf sources taurus a orion cygnus a and cassiopeia a made during june with a radio telescope 9613 rf switching circuits and hybrid ring circuits used in radio astronomy 9614 an operational ruby maser for observations at centimetres with a foot radio telescope 9615 on the relativistic electrons in the solar atmosphere the ejection of relativistic electrons in association with flares is discussed and the loss of energy of these electrons through synchrotron radiation is related to type rf bursts 9616 the surface brightness of radio sources at galactic latitudes greater than 9617 the relation between the optical and radio magnitudes of galaxies a statistical relation is found from observations of sources 9618 a radio wave mechanism to account for the known distribution of van allen belts about the earth a mechanism based on a conducting spherical earth illuminated by em and corpuscular radiation from the sun is given to account for the positions of the van allen belts interference between back scattered and incident radiation exhibits resonance peaks in a standing wave pattern in which peaks solar particles are trapped 9619 motion of low energy solar cosmic ray particles in the earths magnetic field 9620 cosmic noise measurements from at noise field strengths are given as measured in the satellite for positions in both hemispheres 9621 a new determination of the solar parallax by means of radar echoes from venus the value of arc obtained for the solar parallax is compared with values obtained by other workers 9622 the time variations of solar cosmic rays during july at minneapolis baloon observations with ion chambers geiger counters and scintillation counters of solar cosmic rays accompanying three large solar flare are reported correlation with magnetic data is given and proton energy spectra are calculated 9623 the high energy cosmic ray flare of may high altitude ionization and counter measurements measurements of cosmic rays from a solar flare are reported various types of counters were used in a balloon the rate at which the particle flux decreased with time is compared with neutron flux measurements at the ground 9624 the high energy cosmic ray flare of may part emulsion measurements nuclear emulsions recovered from a balloon give the energy spectrum of the cosmic rays excess flux was observed of protons in the range above 9625 experimental analysis of magnetic and telluric effects of the argus experiment recorded at french stations recordings made at six stations have been analysed results are produced in tubular form and photographic reproductions of typical records are given 9626 the steady state of the chapman ferraro problem in two dimensions the form of the cavity in the plane of the dipole and uniform solar stream is derived using the method of complex potentials large scale electron bombardment of the atmosphere at the sudden commencement of a geomagnetic storm x ray bursts coincident in time with two sudden commencement peaks in magnetic records were observed with balloon borne geiger counters ionospheric absorption data are given an estimate is made of the electron flux required to account for the x ray intensities and their origin is discussed 9627 solar stream distortion of the geomagnetic field and polar electrojets the geomagnetic field distortion may introduce longitudinal field gradients which will lead to electrojet current systems of the form observed 9628 radiation from a current filament above a homogeneous earth with application to micropulsations near field considerations are used to steady the radiations at micropulsation frequencies from an ionospheric current 9629 the diurnal variation of k indices of geomagnetic activity on quiet days in local tim and universal time components are derived from the k numbers from six observatories in moderately low latitudes 9630 measurement of the temperature in the upper atmosphere to in a rocket experiment spectroscopic observation of sunlight reasonantly scattered from a sodium cloud formed by ejection of sodium from a rocket gave atmospheric temperatures between and 9631 the motion of the third soviet cosmic rocket an investigation of the motion of lunik from october to march results are summarized in tabular form 9632 satellite orbits about a planet with rotational symmetry an approximate closed form solution of high accuracy and without restriction on the inclination angle or eccentricity is obtained for the equations of motion of an earth satellite 9633 satellite orbit perturbations in vector form 9634 the doppler effect and inertial systems the minimum range equation for the general case of curved orbits of satellite and observer is compared with the equation valid for inertial systems 9635 instrumentation for the first anglo american scout satellite the satellite is primarily designed for studies of the ionosphere the techniques for measurement of electron density and temperature ion mass solar x rays and lyman flux are described 9636 earth satellites and geodesy examination of possible methods for determining geocentric coordinates of points on the earths surface from observations of the moon and artificial earth satellites the determination of the difference between ephemeris and universal time is considered 9637 determination of position on the earth from a single visual observation of an artificial satellite if a reliable orbit is available and an observation of the satellite against a background of of stars can be made to an accuracy within and timed to the position of the observer can be determined with sufficient accuracy for navigation purposes a single visual observation of echo provides the reference in a worked example 9638 ground equipment for radio observations of artificial satellites 9639 design and results of first tests on a camera with a moving film for the photography of faint artificial satellites 9640 air density variations in the mesosphere and the winter anomaly in ionospheric absorption the air density variations observed in winter by jones et al may indicate air movements which could cause an enhancement of the no content and give rise t in turn to increased ionization and radio wave absorption 9641 ionization loss rates below km a discussion of the loss processes in the d region with a review of data on the rate coefficients involved theoretical height distributions of electrons and of positive and negative ions are given 9642 world maps of f layer critical frequencies for the solstice and equinox months of and hourly world maps of are analysed as a function of solar activity results show asymmetrical distribution over the two hemispheres discontinuous diurnal movement of world maximum ionization and the existence of four poles in the distribution of the mean diurnal rate of increase of ionization due to solar activity two of these poles corresponding to the magnetic poles and the other two being located in the equatorial belt where the geomagnetic equator is further from the geographic equator it is concluded that these phenomena cannot be explained by existing theories and that the possibility of corpuscular discharge from a van allen belt should be investigated particularly in relation to equatorial regions 9643 on the nature of equatorial spread f transequatorial propagation on via scattering from the f region above huancayo was closely associated with equatorial type but not temperate type spread f on huancayo ionograms ie range spreading not frequency spreading the irregularities take the form of thin sheets near the bottom of the f layer they are elongated in the direction of the earths field being or more in length and of the order of in at least one dimension transverse to the field it is suggested that equatorial spread f can occur only when the contours of mean electron density are parallel to the lines of force of the earths field 9644 critical remarks on the calculation of true heights the conditions are given and discussed which permit an unambiguous solution of the integral equation of ionospheric virtual height practical procedures and possible sources of error are indicated with some proposals for improved methods of evaluation 9645 the anomalous ionospheric absorption on winter days the mean diurnal variation is evaluated from ionospheric absorption measurements made at geenoa during abnormally high absorption observed in january and february is discussed with reference to data obtained at other stations the geographical distribution of the phenomenon and the influence of meteors are considered 9646 the ionosphere at the garchy station at the time of the eclipse of october ionization density for true heights ranging from to is plotted as a function of time for the pr period results are briefly discussed 9647 some results of direct probing in the ionosphere results of electron density measurements at two frequencies using two different rf impedance probe techniques are given 9648 ionospheric electron content and its variations deduced from satellite o observations faraday fading observations of signals from satellite on and have bee analysed to show diurnal and seasonal variations of electron content from september to december in twelve instances a decrease in content was observed following a magnetic storm 9649 a local reduction of f region ionization due to missile transit an explanation of an unusual c echo received on local ionospheric sounders following the firing of vanguard is given in terms of a reduction in the ionization density at the f layer maximum the interpretation is extended to explain spread f and radio star scintillation 9650 active high frequency spectrometers for ionospheric sounding part selection of the echo signals from the noise background the prior knowledge of echo properties such as periodicity signal shape rf phase and direction of arrival may be used to improve ionospheric recording methods 9651 the relationship of low height ionosonde echoes to auroral zone absorption ad vhf d scatter weak diffuse echoes are shown at heights between and in the frequency range the diurnal seasonal and height characteristics of the layer indicate that it is related to auroral zone absorption and is responsible for vhf forward scatter 9652 man made heating and ionization of the upper atmosphere absorption of radio signals by cyclotron resonance is shown to be possible within a very narrow layer of the atmosphere km thick just below for a plane polarized signal only of the power can be absorbed better results are obtained with a circularly polarized radio wave the absorbable power is limited by the effects obtained so that an electron density of and an electron temperature of cannot be exceeded the reason for this is the weakness of the a earths magnetic field 9653 new principle of measurement of ionospheric absorption the mean coefficient o absorption in the region of the ionosphere eb below an artificial satellite may be calculated from measurements of the signal strength of the satellite transmission received on an omnidirectional aerial 9654 the arctic ionosphere and solar activity ionospheric conditions at several arctic stations have been correlated with solar activity using monthly median critical frequencies for the e f and f layers and the month mean zurich sunspot numbers 9655 a neutral line discharge theory of the aurora polaris 9656 southernmost extent of aurorae according to german observations on land and sea during the international geophysical year results of observations are interpreted with rf reference to data from us satellite measurements 9657 a note on auroral echoes detected at stanford following the solar event of november the time of transit of the auroral particles determined from radar observations was min a change in range of echoes corresponding to a velocity of was also observed 9658 on the origin of vlf noise in earths exosphere the primary cause of vlf noise in the exosphere is cerenkov radiation due to high speed protons the natural thermal noise and proton cyclotron radiation effects are considered to be secondary noise sources 9659 graphical methods for the determination of the distance of atmospherics from their waveform extension of the graphical method outlined in of july delay time diagrams are given for reflection heights of and comparisons are made with tabulated meteorological data 9660 determination of the direction of arrival and the polarization of whistling atmospherics measurements have ben made at using two pairs of identical aerials located at the ends of perpendicular base lines received signals were passed to a central measuring station via microwave links results show that the direction of arrival of the signal makes an angle of between and with the magnetic field polarization is consistent with the direction of arrival observed and leads to electron densities about ten times smaller than those given by storey of 9661 whistlers excited by sound waves sound waves generated by a nuclear explosion could excite transverse waves in the ionosphere capable of propagation in whistler modes 9662 power supply for the tiros meteorological satellite 9663 low impedance thermoelectric device powers tunnel diodes the power supply described consists of of several couples in series heated by ac or dcdriven resistance elements and having an output impedance of results obtained with tunnel diode microwave oscillators are briefly discussed 9664 the effect of series resistance on photovoltaic solar energy conversion the series resistance in a photovoltaic cell is divided into two components contact and sheet resistance each of the components is examined theoretically and experimentally and qualitative agreement between theory and experiment is shown it is concluded that contact resistance reduces the conversion efficiency more than sheet resistance 9665 considerations of photoemissive energy converters the efficiency of a o solar energy converter consisting of a emitter and an ag collector is calculated taking into account the initial velocities of the photoelectrons but ignoring space charge efficiencies between and are obtained for output voltages between and the efficiency increases as the percentage of blue and ultraviolet radiation in the source is increased to minimize space charge effects the emitter collector spacing must be of the order of or less 9666 optimum capacitor charging efficiency for space systems several theorems for the perfect time shaped source voltages which optimize the efficiency of energy transfer from source to load are derived the practical application of the theorems is discussed 9667 lectures on electronic computing english summaries are given of the following papers the history of the electronic computing machine ptera purpose and possibilities the functioning of the electronic computing machine ptera programming for the electronic computing machine ptera discussion of programme for the electronic computing machine tera the complete papers are published in bedrijf 9668 elimination of waiting time in automatic computers with delay type stores a critical survey is made of methods which have been tried for eliminating waiting time and a description is given of a process developed for determining the amount of waiting time eliminated the optimum programming method adopted with the ace pilot model is found to be a combination of several methods it appears that reduction of waiting time generally has to be paid for in extra complication of programming or design some exceptions to this rule are indicated 9669 applications of electronic computers to clerical work an examination is made of different types of clerical work and the circumstances in which an electronic computer can be used with advantage experience obtained with leo the lyons equipment is discussed 9670 numerical methods in digital real time simulation 9671 a simple microwave correlator the correlator described uses the ring modulator circuit as a rapid response multiplier it accepts signals on coaxial cables and has a wide frequency range two types those with positive and those with negative output pulse applications in the following computer circuits are described single ended electrical delay line store shift register circuits performing logical operations 9672 a versatile transistor circuit the design is described of point contact transistor switching circuits such that direct currents of the order of several tens of milliamperes can be handled with a voltage drop of only one or two volts applications of these circuits in a symmetrical push pull magnetic writing circuit and a shift register are considered 9673 the mechanical particle an analog computing machine an arrangement is described in which a mechanism guided by remote control moves over a contour map to simulate the motion of a charged particle in a two dimensional magnetic field 9674 a method ensuring channel width stability and equality in a pulse amplitude analyser apparatus based on wilkinsons work has the following characteristics channel width variable between channel stability within for a period of operation possible channels or more according to the type of recorder available 9675 a flexible single channel pulse amplitude analyser the instrument described is designed for measuring the amplitude of voltage pulses of duration by pre setting two voltage limits it can also be used as a simple discriminator the complete circuit diagram is given including details of component values valve types etc 9676 computation methods for transistors and transistor circuits treated as active quadripoles upper and lower limits for frequency of operation are found using experimentally determined values for the equivalent network impedances stability is discussed 9677 raising the cut off frequency of transistors the cut off frequency of transistor operation is raised by neutralizing the collector capacitance by means of inductance connected between collector and emitter calculations of the bandwidth between the points on both sides of the resonant frequency are made for grounded base grounded emitter and grounded collector arrangements 9678 noise in resistors account of an extended investigation of the noise produced by resistors carrying a c exciting voltages were used having magnitudes between and times the noise voltage over a narrow frequency band the filtering techniques for separating these two voltages are discussed measurements on various types of resistor were made at with excitation frequencies ranging from to and various excitation levels the noise varies as an inverse power of frequency up to a feq megacycles per second beyond which it is independent of frequency the noise in volts per cycle bandwidth depends on a power of the applied voltage which ranges from some composition type resistors exhibit an increase in noise output after passing for long periods 9679 component design trends precision potentiometers use new materials use of resistance elements made from deposited metal films conductive plastics or lossy liquid dielectrics given infinite resolution other new design and construction tech niques give increased life and reliability 9680 dimensioning solenoids for transmitter circuits simple formulae and a graph based on medhursts expression for of are assembled and their use illustrated in four worked examples 9681 the effect of certain contaminants on the capacitance and losses of pyralene impregnated paper capacitors undesirable effects can be eliminated by avoiding the use of resin flux in the soldering process 9682 conversion of a brune cycle with an ideal transformer into a cycle without an ideal transformer an alternative proof to that of bott and duffin is given for the existence of a network configuration without an ideal transformer corresponding to any positive real function 9683 on electrical network determinants four theorems dealing with the relation between the loop determinant and the node determinant of a network are presented with examples of their application 9684 analysis of transmission line directional couplers five different types of transmission line systems are analysed and are shown to possess directional properties at the lower radio frequencies the conditions of mismatch on either transmission line or on both transmission lines have been taken into account as well as lengths of coupling greater than a fractional wavelength a new and more general scatter matrix for directional couplers which includes the condition of mismatch is developed in addition lumped circuit directional couplers have been developed as a consequence of the general transmission line theory 9685 the relations between circuit bandwidth and time constant a correct method for specifying bandwidth involves fixing a priori limits for a response curve and considering the relation between amplitude and phase distortion in order to determine the limits applicable under transient conditions 9686 weighting functions for time varying feedback systems technique is presented for analysing the response of a linear time varying system to a step function input using an analogue computer the method involves synthesis of the adjoint system 9687 measurement and calculation of carrier frequency transients a carrier modulated by rectangular pulses is passed through a transmission system and the output is observed oscillographically the timebase being synchronized by the pulses the oscillogram thus displays the envelope of outputs for different carrier phases at initiation of the pulses it is shown mathematically that this envelope corresponds with the result obtained ae theory is outlined and a survey is made of known applications such as attenuators modulators gyrators etc advantages and disadvantages of devices based on this effect are compared with those of devices based on the faraday effect deeper understanding of the physical processes involved is necessary for further practical development 9688 molecular microwave oscillator and new hyperfine structure in the microwave spectrum of 9689 resonance absorber for electromagnetic waves an absorber for centimetre wavelengths consists of resonators regularly distributed over a metal plate the resonators are cavities containing a few milligrammes of fe powder and absorb energy by interaction with the magnetic component of the e m field the impedance of the absorber depends on the losses of the individual resonators and on their concentration a system theoretically giving total absorption at is obtained by making the impedance the characteristic impedance of free space 9690 new null transmission networks three frequency selective networks are discussed a balanced lattice a variable a mutual inductance type gives the largest off null outputs but is not easily adjustable over a range of frequencies an application of type for transformer testing is described 9691 the parallel t resistance capacitance network correction to paper abstracted in 9692 the transfer function of networks without mutual reactance extension of analysis presented previously the theory is applicable generally to two terminal pair networks synthesis procedure is illustrated by examples 9693 an electrodynamic perturbation theorem with application to nonreciprocal systems a modification of the reciprocity theorem is used to evaluate the antisymmetric part of the admittance matrix of an electrodynamic system in terms of the fields produced by the applied voltages the effect of system perturbations on the admittance matrix is determined the method is applicable to and microwave gyrators as well as to reciprocal systems but gives solutions only to a first order of approximation 9694 the voltage ratio and output impedance of a ladder network composed of similar elements simple expressions are derived using thevenins theorem 9695 the complete specification of a network by a single parameter if the transfer function of a linear passive network is defined as the output response divided by the input driving force it can be written in iether polar of cartesian form where is the amplitude response is the phase characteristic is the in phase component and is the quadrature component the transient response to a unit step function can be determined within a constant from either alone and are all related and any one can be used to compute the other two the derivation of these relations is valid for networks with either distributed or lumped constants including transducers and the question of minimum phase does not arise a graphic method is described for computing from either and universal curves are included equipment is described which sweeps or a polar plot of and directly an intensity frequency marker circuit is included which produces multiple harmonically related dots on the sweep response it is also possible to sweep the departure from phase linearity by a heterodyne process the sweep can be used on low pass or band pass systems 9696 a new transducer diagram a diagram is presented in which a loss free quadripole is completely represented by two straight lines and a point the method is based on projective geometry and gives a visual as well as a numerical presentation of the impedance transformation effected by the network 9697 the correspondence between ladder filters connected between a resistance and zero or infinite impedance and ladder filters connected between two resistances the response curve of a quadripole defined in terms of image parameters and inserted between two finite resistances is determined by separating the actual insertion loss into components the analysis is developed for the case of one of the resistances becoming infinite or zero alternative analysis is given for the quadripole defined in terms of its component impedances relations are derived for transforming a ladder filter connected between two resistances to a network giving the same attenuation frequency characteristic when the source impedance is infinite or zero 9698 antimetrical lattice filters detailed treatment by image parameter theory illustrates the complete correspondence between this class of filter and the conventional symmetrical type practical examples are given and design formulae for low pass high pass and band pass networks are tabulated 9699 delay line equalizer experimental equipment designed for low definition television can be used either in conjunction with test signals or on lines in service manual adjustments are made according to the position of the pulse on the oscillograph screen a total delay of is provided in steps of and the cut off frequency 9700 some properties of linear networks with three pairs of terminals and their applications in realizing negative impedances and negative feedback amplifiers analysis of six terminal networks based on a generalization of thevenins theorem gives a general method of circuit synthesis in which the prescribed impedances may have a positive or negative real part which is independent of the gain and internal impedance of the active element a method of amplifier design on this principle is illustrated in which input and output impedances are independent of the terminations at the opposite ends 9701 theory of pulling in by a small amplitude external force a method is developed for calculating the effect of small periodic external forces on an oscillating system the method is illustrated by considering the effect of a small sinusoidal voltage of frequency on a valve oscillator with a natural frequency the difference between the frequencies being small 9702 nonlinear study of frequency modulated oscillator analysis is presented to show how the nonlinear damping of the valve limits the growth of oscillations in the case of parametric excitation thus permitting the establishment of a stationary oscillation 9703 generalized equations for rc phase shift oscillators correction to paper abstracted in 9704 the design of a simple modulator of moderate cost a low power pulse generator for laboratory work designed to deliver or pulses at varying repetition frequencies when the load impedance may vary between and is described since the power required is low a type thyratron with a delay line in the anode circuit is used to drive the double tetrode modulator stage 9705 a low frequency pulse generator with independent control of pulse shape and pulse frequency a modified multivibrator circuit is described in which the pulse repetition frequency is controlled by a variable resistance in the control grid circuit of a heptode and the pulse duration by the voltage on a second control grid the screen voltage being stabilized the circuit shown can be used with the photoformer described by sunstein to generate pulses of any shape with repetition frequency variable between and pulses and pulse duration 9706 multiloop feedback amplifiers a stability criterion is derived which involves only one nyquist plot rational negative feedback and equalizer circuits or servomechanisms with prescribed characteristics the basic feedback amplifier circuit is examined with the object of determining the design of the transformation and feedback networks so as to obtain a given overall frequency response for a given response of the amplifier alone servomechanisms and equalizers are treated as particular cases 9707 wide band amplifiers for bandwidths up to an account is given of amplifiers of the type using low pass filters as interstage couplings these are superior to distributed amplifiers up to a certain frequency the value of which is about when valves are used and with valves a practical limit for the number of reactances in the coupling circuit is about five further increase would call for too narrow tolerances on the components and would greatly increase alignment difficulties theoretical computations of the coupling circuit could not be made accurately because of frequency variation of the components a high accuracy frequency sweep generator is essential for the experimental investigations 9708 the transfer function as a tool in the analysis of a resistance capacitance coupled voltage amplifier 9709 fifty watt amplifier for high quality audio 9710 a hyperbolic detector the detector considered comprises a double triode the grids of which are in parallel the anodes in push pull and the cathodes biased separately the detection characteristic will be hyperbolic if a rectangular or trapezoidal characteristic is obtained on plotting the difference between the anode currents against the grid voltage the effect of varying the modulation voltage is considered 9711 space modulation of amplitude limited oscillations simple theoretical considerations show that demodulation can be achieved by using a detector with rectangular characteristic the amplitude modulated amplitude limited signal is converted by this detector into rectangular pulses whose width is determined by the rate of variation of the input signal voltage the amplitude modulation can then be detected by using a second detector having similar characteristics 9712 wide band limiter circuits for frequency modulation a systematic analysis with special reference to multiplex requirements the general characteristics of a limiter are defined and two types considered in detail a grid limiter and a crystal diode limiter circuit arrangements giving best results for large bandwidths are discussed 9713 magnetic amplifier circuits recommended to all designers and users of magnetic amplifiers 9714 the decilog a unit for logarithmic measurement difficulties resulting from an extended use of the term decibel are discussed suggested new logarithmic units of ratio are reviewed it is proposed to supplement the decibel by introducing the decilog whose value is such that the number of decilogs is equal to times the logarithm to the base of the ratio 9715 lowest eigenvalues of nearly circular regions analysis relevant to waveguides and vibrating membranes is presented the principal eigenvalue of the nearly circular element is found by a method involving the circle of equal area the usefulness of the method is illustrated by comparing approximate values thus found for a rectangle with the exact values 9716 electrodynamics problems of non ideally conducting bodies having angularities 9717 thermomagnetic properties of thin metallic films theory presented by is extended to cover cases involving temperature gradients 9718 electrons in lattice fields a study of the motion of a free electron in the conduction band of an ionic crystal taking account of the lattice vibrations 9719 ignition of electric discharge in gases by audio frequency current in tubes with external and internal electrodes an experimental investigation is reported of the dependence of ignition and discharge conditions on the frequency of the applied voltage up to tubes filled with or at a pressure with either plane or external annular electrodes were used results are presented graphically 9720 interpretation of electron emission from metals and nonmetals after mechanical working or irradiation conflicting theories of can br reconciled by assuming that the emitted electrons come from high energy levels so that only small amounts of energy are needed to enable tham to escape 9721 temperature and field emission of electrons from metals calculations are made of emission current density and energy distribution for surface electric field strengths between and temperatures up to and various values of work function the evaluation is made by numerical integration of the known expression for the emission based on the free electron theory of metals and the wave mechanical barrier transmission coefficient of results are presented graphically and are consistent with the field emission equation for low temperatures and with the richardson thermionic emission formula for low fields the work is relevant to previously reported investigations of the vacuum arc 9722 backscattering of kilovolt electrons from solids the total number and energy distribution of backscattered electrons with incident electrons of energy have been measured for and using retarding potential technique the dependence on the energy of the incident electrons is characteristically different for elements of atomic number above and below the ratio fo the mean energy of the backscattered electrons to that of the incident electrons is about for and increases only slightly with atomic number the results are interpreted as indicating the inelastic processes are predominant in the scattering of medium energy electrons 9723 velocity of electron pulses the transit time of a brief pulse of electrons of known energy across a measured distance was determined by an arrangement involving two deflection gates opened sequentially for very brief intervals by a single surge travelling in a cable an electron multiplier was used as collector about of the electrons arrived within of the mean transit time the most probable transit time could be ascertained within the apparatus can be used as a velocity spectrograph and as a chronograph for measuring the time of rise of very steep surges 9724 theory of secondary electron cascade in metals a study is made of the diffusion energy loss and multiplication of secondary electrons prior to emission energy distributions consistent with experimental results are derived also values for the uield and the dependence of yield on work function 9725 effect of vapours of halogen compounds on the emission of positive ions from platinum 9726 angular distribution of secondary ions on bombardment of a tantalum plate by ions of alkali metals an experimental investigation is reported of the dependence of the energy and intensity distribution of secondary and ions on the angle of incidence of the primary ions results are presenred graphically 9727 low frequency plasma oscillations theoretical consideration of plasma comprising both electrons and ions with maxwellian velocity distributions shows that in the absence of an external field the low frequency plasma oscillations decay in the presence of an applied electric field undamped oscillations are possible 9728 excitation of plasma oscillations excitation of and plasma oscillations bu a beam of charged particles is considered theoretically taking account of the thermal scatter of the particle velocities results show that undamped and oscillations are possible in plasma with an applied electric field 9729 the attenuation of alfven waves when the collision frequency in an ionized gas is smaller than the wave frequency it is not permissible to treat the gas as a continuous fluid the equations for alfven waves are obtained by working with distribution functions the results illustrate the behavior of a gas when the collision frequency is low and may have applications in the interstellar gas or in the earths outer atmosphere 9730 a short modern review of fundamental electro magnetic theory the method of presenting concepts taking the inverse square law of force between magnetic poles or electric charges as starting point is recommended as stressing the symmetry of magnetic and electrical relations faradays laws of induction are discussed and maxwells equations are presented in terms of electric and magnetic flux density 9731 dimensional relations in magnetohydro dynamics an analysis is made of dimensional relations characteristic of phenomena in fluids in the absence of instabilities conditions favourable for accelerating particles to the higher cosmic ray energies can exist only when the linear dimensions fo the fluid are very large 9732 diffraction of electromagnetic waves by an aperture in a large screen 9733 molecular microwave oscillator and new hyper fine structure in the microwave spectrum of an experimental arrangement which can be used as a high resolution microwave spectrometer a microwave amplifier or a stable oscillator consists of a focused beam of molecules directed into a high oscillating cavity within which the molecules give up energy an emission line is seen when the excitation frequency of the cavity is varied through the molecular transition frequency 9734 radio observations of ionized hydrogen nebulae and other discrete sources at a wavelength of report of a second survey made during for first survey see preliminary results of both surveys are tabulated 9735 identification of extended radio source near gemini with residual nebula of nova flare up of the source reported by is identified it is predicted that on the each year the centres of the sun and this source will be only apart and hence an eclipse will occur this source which subtends an angle about equal to that of the sun affords the possibility of transillumination type observations f the solar corona a similar source in the crab nebula does not approach so closely to the sun but is smaller and has a higher radio flux 9736 a new type of interferometer for use in radio astronomy a new type of interferometer for measuring the diameter of discrete radio sources is described and its mathematical theory is given the principle of the instrument is based upon the correlation between the rectified outputs of two independent receivers at each end of a baseline and it is shown that the cross correlation coefficient between these outputs is proportional to the square of the amplitude of the fourier transform of the intensity distribution across the source the analysis shows that it should be possible to operate the new instrument with extremely long baselines and that it should be almost unaffected by ionospheric irregularities 9737 radio emission from the andromeda nebula observations have been made at a wavelength of with interferometers of different resolving powers to determine the distribution of radio brightness accross the nebula the results suggest the existence of a hitherto unexpected population of radio sources a similar population in our own galaxy might also account for a large part of the so called isotropic component of cosmic radio emission 9738 dependence of integrated duration of meteor echoes on wavelength and sensitivity 9739 the two helix method of polarization measurement of meteoric radio echoes an arrangement for investigating the polarization of radio echoes from meteors uses two helical receiving aerials wound in opposite senses in conjunction with a helical transmitting aerial the received signals are combined and displayed on a operating wavelength is and power output is the method is applicable to sporadic meteors results are in good agreement with theoretical values and with measurements made on shower meteors by 9740 the solar eclipse of brief report of observations made at about miles of including measurements of changes in the ionosphere of radio noise in the range and of geomagnetic field variations 9741 short period fluctuations of the earths electromagnetic field trains of fluctuations of amplitude up to and a mean period of oscillations in a train of were recorded simultaneously at four stations in central asia on several hundred occasions in the largest number of trains was recorded between and universal time when the sun is near the zenith of the north magnetic pole the fluctuations could be due to a focusing of solar corpuscular emission by the earths magnetic field 9742 index of refraction above feet calculations are made on the basis of refractive index measurements reported by in conjunction with relevant meteorological data to an accuracy within only the density of the air has any significant effect in relation to refractive index variations at and only at altitudes up to variations due to water vapour content and electrons in the ionosphere are negligible thus for practical purposes a standard refractive index can be based on a standard density distribution 9743 origin of nitrous oxide in the atmosphere an explanation of the presence of nitrous oxide based on a photochemical equilibrium is advanced the upper atmosphere brief report of a symposium held at at which a survey of the existing state of knowledge about the ionosphere was given by appleton meteor trail echo and radio star scintillation studies were also discussed 9744 ozone layer and air movements in the stratosphere 9745 on new investigations of the ozone layer and its variations various method of investigation are discussed including use of lunar eclipses 9746 recombination in the lower ionosphere observations of phase height polarization and absorption at are analysed to estimate the distribution of recombination coefficient over the altitude range theories of recombination are examined on the basis of this distribution recombination during the day and during sudden ionospheric disturbances is considered night time recombination is not dealt with the experimental results are consistent with negative ion theory for altitudes up to about above the predominant process must be dissociative recombination with an effective coefficient of about there is no evidence of an increase of recombination coefficient during disturbances 9747 measurements in the layer with the nacy viking rocket results of measurements made bq are examined a rapid increase in electron density from altitude to near is indicated followed by a very slow increase from electrons at to electron at seddons method of measurement is capable of giving accurate results provided suitable operating frequencies are chosen 9748 on the interpretation of the apparent ionization distribution in the ionosphere methods of deducing the highest and lowest ionization distributions which are consistent with a given pattern are indicated and the sources of error when using rapid methods of analysis are briefly discussed some examples are given 9749 electron distribution in the ionosphere a note of methods of analysing curves to determine electron density distribution and a procedure for taking account of the geomagnetic field simpler than that described by 9750 charge densities in the ionosphere from radio doppler data a method is described whereby the directly observable radial velocities of a missile relative to a ground receiver both in a radio doppler electronic system of tracking may be compared to radial velocities determined by vacuum trajectory formulae and the differences converted to ionization densities at the levels through which the rocket is passing this method was used to compute ion densities for several missiles fired at the white sands proving ground new mexico results gave density maximums of 9751 ionospheric wind systems and electron concentrations of the layer theory based on viscous stresses in the ionosphere leads to a simple meridional circulation which explains observed longitudinal differences in the electron concentration 9752 the solar control of the and layers at high latitudes 9753 experiments on interaction of radio waves in the ionosphere 9754 a comparison of the rates of change of current in the step and return processes of lightning flashes 9755 a statistical analysis of low latitude aurorae 9756 time sequences and spatial relations in auroral activity during magnetic bays at college alaska 9757 radio reflections from aurorae analysis of auroral echoes observed at jodrell bank indicates echoes are due to direct nonspecular reflection from an auroral arc extending more than along a parallel of geomagnetic latitude reflection occurs in a region of limited vertical extent at a height of about observed movements of intense reflecting centres represent the motion of an ionizing agent rather than a mass movement of ionized gas 9758 theory of the aurora based on magnetic self focusing of solar ion streams 9759 thunderstorm electricity a collection of papers dealing with various aspects of the subject most of them revised versions of papers presented at the conference held in chicago in 9760 the least squares criterion applied to linear servos 9761 transient performance of servomechanisms digest of paper published in a criterion of transient performance developed previously and based on the time integral of absolute value of error is applied to second and third order linear servomechanisms with derivate or integral type error correction and different types of input 9762 the terminology of servo systems definitions of fundamental concepts are given which are to be submitted by the french committee in the revision of the international electrotechnical vocabulary 9763 regulated supply has high efficiency description of unit using magnetic amplifiers for regulation in response to slow variations of line voltage or load and electronic clamping circuits for regulation in response to rapid variations 9764 direct current stabilizers for electromagnets general principles of operation and factors affecting stability are reviewed 9765 a new german differential analyser for differential equations a mechanical instrument built for the institute of applied mathematics university of bonn and comprising eight integrators 9766 a curve analyzer and general purpose graphical computer the analogue computer described comprises five photoelectric curve followers two integrators nine adding amplifiers and a pen recorder the independent variable is represented by a low alternating voltage increasing linearly with time the from of the equation is determined by the connections between the units and the values of constants are set by potentiometers 9767 harmonic cancellation from computing voltage source in servo analogue computers analysis showing how harmonics of the carrier can be cancelled out in the summing network of the servo amplifier by injecting appropriate harmonic signals into the quadrature rejection circuit the analysis is valid for very small phase shift the system is advantageous when harmonics cannot be sufficiently attenuated by filters 9768 some comparisons between analogue and digital computers the uses of analogue and digital computers in industry are discussed and a large scale machine of each class is described briefly 9769 electronic computers and industrial mathematics the mode of operation of a high speed digital computer is described in functional terms programming procedure is illustrated in relation to typical applications 9770 the application of electronic digital calculating methods to punched card machines principles of operation and design of the electronic multiplying punch are discussed an outline is given of the calculating process used for sterling and fof decimal systems 9771 welded joints on diodes reduce computer bulk diode mounting methods are discussed teking up the least possible space while affording adequate accessibility by using spot welding the diode leads can be shortened to an elongated matrix and a honeycomb arrangement accommodating up to diodes are among the alternatives described 9772 making use of curved characteristics for the higher types of calculation in electronic computers where errors up to a few per cent are permissible deliberate use can be made of the curvature of valve characteristics in analogue computers circuits for multiplying dividing squaring and obtaining square roots are discussed 9773 the design of an electrodynamic multiplier development of a design described earlier for use in a differential analyser 9774 the suppression of switching transients by a shunt circuit a detailed analysis is presented of the phenomena occurring when apparatus including shunt capacitance is suddenly switched across a low impedance source of power through a short transmission line conditions for the transient voltage in the shunt damping circuit to be nonoscillatory are deduced it is proved that the current through the switch can be made unidirectional numerical illustrations are given 9775 fast single channel pulse amplitude analyser designed for use with proportional of scintillation counters the equipment has a channel edge position stable to within under operation for periods up to hours 9776 description of a recording instrument the recorder was designed for operation with the pulse analyser described by guillon it has channels each comprising a decade counter and register one unit is recorded in the channel for every train of pulses details are given of circuits and operation 9777 migration of material in silver and platinum contacts an experimental investigation of deformation caused exclusively by the passage of current 9778 component design trends iron core transformers run smaller and hotter a survey of the developments in core materials coatings and insulating materials and of new construction methods which have in combination made possible a reduction of size of iron core components over a period of about ten years while permitting operation at much higher temperatures 9779 surface barrier transistor measurements and applications circuits for determining the transistor characteristics are described and examples of applications taking advantage of the high frequency cut off of the surface barrier transistor are given these include a two stage video amplifier for with measured power gain of at a crystal controlled oscillator delivering conversion gain from and a non saturating flip flop circuit with rise time and fall time 9780 new resistor voltage coefficient tester the variation of resistance with applied voltage is determined from measurements of the third harmonic generated by the resistor on application of a sinusoidal voltage the basic circuit is described and some experimental results are given the measurements of resistor noise at is also briefly described 9781 the design of a radio frequency coaxial resistor discussion on 9782 on the use of commercial wire wound resistors in high level video amplifiers by compensating the inherent inductance by means of a parallel network commercial wire wound resistors can be adapted for use in high power video amplifiers practical arrangements are illustrated and results of measurements are compared with calculated values 9783 measurements on current noise in carbon resistors and in thermistors measurements are reported on carbon and similar resistors in the frequency range from and on negative temperature coefficient thermistors between and in carbon resistors the current and inversely proportional to the square of the current and inversely proportional to approximately the first power of frequency in thermistors the noise level is lower and the spectrum shows deviations from the trlation this is in agreement with measurements by brophy 9784 calculation of iron cored inductances for direct current a method described by kammerloher is usitors are reviewed and design principles are prorresponding to the optimum gap length for lamin tions of given shape and size variation of the maximum with number of ampere turns is investigated examples are worked out 9785 a fixed gas dielectric capacitor of high stability factors contributing to instability of capaced the position of the maximum is determined composed for parallel plate types suitable for use under laboratory conditions a capacitor embodying these principles is described the performance figures indicate that a considerable gain in stability can be achieved without serious complication in design 9786 better audio specs needed the significance is explained of technical terms commonly used in catalogue descriptions of amplifiers loudspeakers and output transformers and a list is fiven of additional information required for a full technical description of components and apparatus 9787 microstrip kit note of a commercially available set of microstrip components permitting rapid construction of circuits for operation in the frequency range 9788 a mathematical technique for the analysis of linear systems the technique of the transformation developed for investigating sampled data systems is applied to the numerical solution of continuous linear systems a model of the linear system is devised in which sampling is introduced at some convenient point a polygonal approximation to the sampled function is reconstructed by means of a holding operator and the output of the system is computed as a train of pulses 9789 properties of some wide bank phase splitting networks errors in the design equations presented by luck are indicated and alternative methods of deriving the design parameters are mentioned the return difference matrix in linear networks 9790 the solution of a certain differential equation a method of obtaining approximate solutions to a class of nonlinear network problems is discussed the method wal developed in relation to the problem of a capacitor in series with a nonlinear resistor of the type and its application is illustrated by reference to this problem the resistor characteristic being assumed cubic and the applied voltage simple harmonic an exact steady state solution for this network is unobtainable but an approximate solution is obtained by choosing the constants in the formula for the voltage across the resistor such that the applied voltage has no third harmonic component 9791 matrix analysis of linear time varying circuits on cavity resonators with nonhomogeneous media perturbation theory is used to find the frequencies of oscillation and factors of a cavity containing a medium for which the permittivity and the permeability are arbitrary functions of position the theory is applied to cylindrical cavity containing a disc of dielectric which dies not extend over the complete cross section of the cavity 9792 quantum effects in the interaction between electrons and high frequency fields the problem of determining at what frequency quantum mechanical effects become apparent is approached by analysing the velocities of electrons after passage through a cavity resonator from the formulae derived a calculation is made of the ratio of minimum possible mean square deviation of velocity to velocity increment due to the field assuming the volume of the cavity to be of the same order as and the initial electron velocity to be of the order of 9793 synthesis of ladder networks to give butterworth or chebyshev response in the pass band general formulae are derived for the design of low pass ladder networks 9794 synthesis of constant time delay ladder networks using bessel polynomials a low pass minimum phase transfer function is constructed which produces a ma imally flat time delay frequency characteristic and a nearly gaussian impulse response evaluation of delay and loss characteristics is simplified since the transfer function can b expressed in terms of tabulated function synthesis of the corresponding ladder network using low elements is described characteristics of a class of related non minimum phase transfer functions are also discussed 9795 gain bandwidth limitations on equalizers and matching networks comprehensive theory is presented and new results are given for the optimum voltage transfer to an arbitrary load 9796 synthesis of transfer functions by active networks a criterion is presented for determining whether a prescribed transfer function can be synthesized by this means the arbitrary function can be treated by breaking it down into quadratic elements alternative methods involving inversion of the transfer function of a ladder network realization are also discussed 9797 power gain in feedback amplifier a search is made for a network figure of merit shich remains invariant for different connection conditions a quantity is found satisfying this requirement and identified as the available power gain when coupling is chosen to make the device unilateral the quantity may be useful for classifying active networks its value is unity for a gyrator the method directs interest to power gain and signal flow considerations rather than to voltage gain and the network interpretation of an impedance matrix 9798 determination of energy and phase characteristics of electrical filters the leontovich theorem which states that in nondissipative media the velocity is applied to the case of a filter considered as an equivalent waveguide system the velocity of propagation of energy can be calculated when the dispersion is known 9799 tunable audio filters electromechanical filters of clamped resonant reed type are described the factor can be varied from over the frequency range 9800 vibration filters the application of vibration galvanometers as narrow band electrical filters is considered theoretically experimental results for frequencies of are tabulated and presented graphically the corresponding band widths varied between 9801 inhomogeneous transmission lines as filters mathematical treatment of the filtering action of a transmission line with periodic structure design is based on an approximate integral formula expressing reflection coefficient as a function of characteristic impedance its application in a simple case shows that the centre frequency is determined by the length of a section and the width of the stop band is dependent only on the total length the number of sections the formula gives results in good agreement with e periment for a single section filter with ratio improved matrix and determinant methods for solving networks it is shown that a linear electrical network which may include valves and transformers can br represented topologically by a network composed entirely of elements of a single type comprises four nodes and two directed branches it is also shown that a linear electrical network can be represented algebraically by a matrix termed an h matrix if the elements of the network are shown in the network diagram in the form of elements of the above type the h matrix can be written down directly from the network diagram 9802 effect of electrical fluctuations on valve oscillator the oscillation frequency is considered theoretically and a method of calculating the effect is developed based on the einstein fokker equation 9803 frequency control of short wave oscillators by means of an electrodeless gas discharge continuation of investigations reported previously with lower oscillator power higher gas pressure and looser feed back coupling a characteristic of quite different type is obtained giving a rapid decrease of frequeecy with increase of anode voltage over a narrow range 9804 possibility oy obtaining very short continuous waves using a reylex klystron supplying energy at high order harmonics oy the fundamental oscillation a yormula is given yor determining the wavelengths oy the natural resonances oy the klystron cavity the dependence oy these wavelengths on the grid separation is shown graphically together with curves giving the values corresponding to exact harmonics oy the fundamental the two families oy curves intersect at an infinite number oy points at each oy which the cavity is capable oy oscillating at both fundamental and harmonic frequency using a klystron with a beam voltage oy about and current and reylector voltage oy about and current and reylector voltage wavelengths down to harmonic have been generated with a power oy some tens oy microwatts 9805 method for elimination of effect of stray capacitances in the production and amplification of step voltages discussion is presented of the charge and discharge mechanism of a multivibrator circuit to obtain a steep leading pulse flank a rapid discharge of the negative charge accumulated at one of the anodes is necessary this is achieved by using the anode dynode path of an auxiliary secondary emission valve pulses of amplitude up to with flanks of slope about sec were obtained application of the principle in frequency dividers is also described 9806 general properties of electromagnetic amplifiers the relations between gain bandwidth or time constant and power rating are discussed results to be expected from use of feedback are e amined the amplifiers considered include thermionic valve magnetic and rotating machine types devices for improving the shape of the pass band normally involve delay distributed amplifiers permit improvement of the gain bandwidth parameter but not of the gain time constant ratio 9807 starved amplifiers advantages of the starved amplifier valve operated with very low anode and screen voltages for high gain amplification are indicated relevant valve data must be determined by the designer typical curves for miniature pentodes are presented and discussed 9808 design of video couplings a method is presented for designing low rise time video amplifier coupling networks with three of four independent elements by the proper location of complex zeros and poles of the network function the relations between rise time overshoot and delay are determined graphs are presented for determining the type of response of a circuit with given type of response 9809 zero stabilisation of directly coupled amplifiers details are given of circuits in which stability of a direct coupled amplifier is achieved by use of a second amplifier in s feedback arrangement the auxiliary amplifier is highly stable but has a low cut off frequency hence low frequency signals are pre amplified giving enhanced signal noise ratio at these frequencies for high frequency signals the auxiliary amplifier is by passed 9810 an even harmonic magnetic amplifier the circuit is an adaptation of the inverter described by frost smith a typical figure for the power gain and for the output the zero drift is less than the shift produced by an input power of the input impedance ranges up to about making it suitable for use iwth many types of transducer but the poor response time restricts application to cases where the input varies slowly multistage amplifiers of this type are useful for control and measurement purposes 9811 fast response magnetic amplifiers expressions are given for the number of control turns and the gain of magnetic amplifiers of the type described by ramey in which load and control circuits operate on the magnetic state of the core on a time sharing basis 9812 effect of circular field on form of longitudinal magnetization curve the variation was investigated experimentally of the magnetization of an iron tube placed in a coaxial magnetic field combined with a circular field produced by a current flowing in a conductor placed along the axis of the tube the results which are presented graphically are of interest in the construction of transformers for amplification of weak currents 9813 feedback simplifies transistor amplifiers voltage amplification in transistor stages os obtained using a degenerative feedback path shunting the output and in series with the input use of interstage transformers or grounded collector stages is avoided 9814 a transistor remote amplifier a portable pre amplifier using point contact transistors is described precautions necessary to avoid damage to the transistors during construction of the equipment and during use are indicated 9815 ferroelectrics and the dielectric amplifier galvanomagnetic low frequency amplifier a simple arrangement is described based on the high magnetoresistance at low temperature the device is much less noisy than an ordinary valve or transistor 9816 magnetic demodulation with sinusoidal variation of the induction flux with magnetic demodulation using sinusoidal current in the demodulating reactor the flux is distorted by arranging instead for the flux to be sinusoidal the power can be increased analysis is given based on analogy with diode theory the flux being treated as the equivalent of the voltage across the diode essential differences between magnetic and diode demodulators are discussed 9817 statistical concepts in theoretical physics a plea for the teaching of classicas physics on an empirical basis on statistical lines to make easier the transition to quantum physics 9818 proposal for a new aether drift experiment further elucidation of the proposal made previously 9819 the maximum of the planck energy spectrum in the formula generally used for locating the maximum in the energy spectrum of a black body the spectral distribution is based on the amount of energy lying between two closely spaced wavelengths if the distribution is considered on a frequency basis instead of a wavelength basis a very diferent value is obtained for the position of the maximum for a body at roughly the temperature of the sun the maximum then falls which is outside the visible region re examination of plancks formula leads to a wien type law yielding a natural maximum fot the spectrum the location of this maximum does not alter on changing from a wavelength to a frequency basis 9820 apparatus for microwave spectroscopy the design of a spectrograph using stark modulation and a crystal or bolometer detector is discussed and a detailed description is given of a particular equipment 9821 diffraction of waves by a wedge greens functions of the wave equation for a wedge are given in the form of an integral representation for the two dimensional case and are evaluated by the residue theorem the half plane is considered as the limiting case of a wedge with angle the analysis is extended to the three dimensional case 9822 a uniqueness theorem and a new solution for sommerfields and other diffraction problems 9823 on the scalar diffraction by a circular aperture in an infinite plane screen application of variational principles reduces the problem of finding the aperture distribution to the solution of an infinite system of linear equations an investigation is made of a particular system of equations based on a convenient expansion of the aperture distribution given by bouwkamp 9824 general approximation method for solving diffraction problems a system of integro differential equations is established for the boundary values a known variational principle is used fo calculating certain functionals involved 9825 motion of charged particles in a homogeneous magnetic field with superposed magnetic field of linear current and electric field of cylindrical capacitor the problem considered theoretically by kelman and rodnikova is extended to include the effect of a magnetic field parallel to the axia of the cylinder calculated results for several particular cases are presented graphically 9826 conductivity in copper at wavelengths measurements indicate that reduction of conductivity below the value is caused not only by surface roughness but also by the presence of surface layers having conductivity lower than that of the bulk material and by stress in the bulk material these effects can be overcome by etching and annealing or by covering the surface layers by a process involving oxidation and reduction 9827 limits of practical application of pisarenkos formula pisarenkos formula expresses thermoelectric power in terms of charge carrier concentration and effective mass and of absolute temperature a constant factor is included to take account of scattering of the charge carriers in the crystal lattice calculations show that the errors are small up to carrier concentrations of about atomic lattice and ionic lattice crystals the errors are discussed and compared with those of other formulae results are tabulated 9828 the motion of electricity preliminary experiments are described on the mechanical transportation of electric charge by blowing streams of ionized air or by causing such streams to flow in tubes under a pressure difference tubes are used as detectors with loudspeaker indicators currents up to have been produced 9829 energy distribution function of electrons in pure helium 9830 microwave determination fo the probability of collision of electrons in helium 9831 sone effects in inductively coupled electrodeless high frequency gas discharges with super posed magnetic field the effects noted by lindberg were further investigated the resonance effect appears to be due to electrons moving initially in circular orbits coaxial with the tube wall rapidly acquiring energy in the alternating field an application fo the effect in a ion source is briefly described for another application 9832 extension of the spin wave theory of ferromagnetism to higher temperatures 9833 possibility of considering potentials and fields as quantities having density new type of quadrivector 9834 on multipole expansions in the theory of electromagnetic radiation a new method is developed for expanding the electromagnetic field of radiating charges and currents in multipole components outside a sphere enclosing all sources the field is represented in terms of debye potentials which are shown to be closely related to the radial components of the electric and magnetic vectors attention is drawn to remarkably simple source representations of these radial components a discussion of vector potential versus debye potential representation of multipole fields is included only familiarity with ordinary vector calculus is required 9835 the radiation greens functions analysis for the radiation field of a group of charges is derived using functions similar to the greens function of potential theory but applied to the time variables problems of radiation theory the method presents a model of interaction between a quantum of movement of a unit point charge and the corresponding excitation of a set of eigen fields it is illustrated by treating the case of a point charge rotating in a cylindrical cavity 9836 propagation of electromagnetic waves in a gyrotropic medium correction to paper abstracted direct comparison of hall effect and corbino effect by using a cylindrical sample immersed in a a radial magnetic field a transverse current is produced when an alternating voltage is applied between the ends of the cylinder this transverse current gives rise to an induced voltage in a coaxial coil both the corbino and the hall effects can be measured with this arrangement thus providing two independent means of determining the hall constant the discrepancy between the two results is 9837 the distribution of temperature along a thin rod electrically heated in vacuo the theoretical solution presented in part is considered in the light of formulae discussed by stead relating the temperature distribution in a finite rod to that in an infinitely long rod heated by the same current a useful expression is found for the temperature at the centre of a finite long rod as a function of its length detailed experimental verification of the main theoretical results is reported empirical formulae proposed by worthing are shown to follow from the theory developed the physics of experimental method sections are included on relevant mathematics mechanical construction and materials vacuum technique electrical measurements and electronics optics and photography natural limits of measurements and techniques of nuclear physics 9838 a comparison of the intensity distribution of radio frequency radiation with a model of the galactic system a comparison is made between the radiation to be expected from objects distributed like the common stars and the observed radiation satisfactory agreement with bolton and westfolds observations is obtained for the regions where the radiation is considerable near the galactic poles and in the hemisphere opposite the centre the observed temperatures are about in excess of the calculated values this excess is possibly due to a background of distant extragalactic nebulae 9839 methods and results of radio astronomy a survey sith over references 9840 radio observations of meteors a summarized general account with literature references of the most significant results obtained during the seven years up to the end 9841 present phase of solar cycle observations of the intensity of the coronal green line suggest that the minimum of solar activity is flatter and lower than that of a first indication of the rise of the new cycle was observed at the beginning of august the next maximum is expected to occur between summer and the end of and to be rather low 9842 the prediction of geomagnetic disturbances shapleys method for predicting geomagnetic indices is modified to take account of the variation of the periodicity of the disturbance about the day average and the maxima observed in the values of the indices in march and september 9843 rocket exploration of the upper atmosphere the text is given of papers read at a conference at oxford in august sections cover rocket techniques atmospheric phenomena and composition of the high atmosphere section deals with the ionosphere in particular and includes papers on wave propagation measurements made using rockets reported earlier a specially designed aerial used on dry rocky soil for short range sky wave measurements at an analysis of a method of determining charge densities from rocket tracking data and a suggested programme of rocket borne magnetometer measurements section sovers laboratory studies including an experiment on cross modulation 9844 study of layer splitting in the ionosphere an equation is derived expressing the conditions for one or more maxima to occur in the height distributions of temperature and recombination coefficient a numerical treatment is given for splitting with uniform temperature distribution would imply a highly improbable value for the recombination coefficient on the other hand the presence of a warm layer within the layer would lead to results consistent with the observations 9845 absorption of short waves in the ionosphere expressions are derived analytically for the value of the decrement for values of the frequency above and below critical assuming that collisions of electrons with ions are much more numerous than with neutral molecules 9846 high latitude ionospheric observations using extraterrestrial radio waves a preliminary account is given of observations made at college alaska over a two month period in the spring of the effect of the ionosphere on the reception of cosmic radiation at strong absorption of the diffuse background is most common at midday and least common during late evening it is correlated with no echo conditions and with variations of the geomagnetic field observations on localized radio sources indicate that scintillations are commoner in alaska than in england scintillations were observed whenever marked absorption occurred during transit of the localized source through the aerial beam this indicates that the lateral distribution of ionization during periods of absorption is nonuniform study of the scintillations shoud provide information about irregularities in the ionosphere 9847 the propagation of long electric waves round the earth in relation to transmission interference and lightning atmospherics 9848 an analysis of electric field after lightning discharges the thundercloud is represented by a vertical dipole and the in it is represented by a constant current generator the electric field comprises components due to the charge on each pole which depends on the conductivity of the air space charge related to the charge on the poles and free decaying space charge released after a lightning discharge dissimilarity between the field recovery curves for near discharges and distant discharges are explained by thid theory stant discharges are explained by this theory 9849 theoretical calculations of field of low frequency electromagnetic waves above earths surface 9850 analysis of systems involving difference differential equations a method alternative to that presented by chu for analysis of control systems 9851 compensation networks for carrier frequency servomechanisms methods are described for determining the transfer function and for the synthesis of gain and phase correction networks particularly symmetrical bridged t and parallel t networks 9852 power supply for automatically controlled transmitters descriptions are given of the normal arrangements for taking power from the public supply and of emergency arrangements using batteries or diesel generators 9853 selenium rectifier instantaneous characteristics current voltage characteristics obtained by applying a rectified sinusoidal voltage to a cell in the reverse direction have been recorded a current in the forward direction flows during a large part of the cycle a convenient equivalent circuit to explain this result comprises nonlinear capacitance and nonlinear resistance in parallel both resistance and capacitance decrease with increasing reverse voltage and are relatively independent of the frequency of the supply voltage over a wide range 9854 signal operated switching description of a fault warning system operated by cessation of an audio signal and used as a programme failure alarm the circuit is based on a thyratron valve 9855 dyseac the new n b s electronic computer 9856 the effect of interpretive techniques on functional design of computers analysis of the programmes for a number of computations performed by the computer indicates the feasibility of designing an adaptable and reliable computer having only a relatively small amount of rapid access erasable store and a larger amount of rapid access non erasable store in which would be held all interpretation routines function block ets the operator would require no knowledge of the actual machine code but wou d place his hyper programmes and data into a slow speed backing store 9857 programme design for the computer adaptation of routines for elaborate arithmetical operations discussion of the extension of the library routine system to deal with floating point multiple precision and complex arithmetic and certain combinations of these the interpretive method of programme organization is used 9858 some transistor circuits the characteristics of junction transistors are discussed at frequencies of the equivalent circuit is already as complicated as that of a thermionic valve at frequencies a hundred times higher particular circuits examined include one for a medium wave broadcast receiver in which the selectivity is automatically increased as the signal strength decreases it is pointed out that for a peak output power of the consumption is nonlinear distortion in transistors is compared with the corresponding effect in thermionic valves the upper frequency limit set by cut off of current amplification is considered in relation to trigger circuits a circuit including a and an transistor is shown which has properties resembling those of a gas filled valve with adjustable ignition voltage short ignition time very low discharge voltage drop and discharge noise 9859 dielectric potentiometers a voltage divider is described comprising a movable electrode and a system of fixed electrodes all immersed in a lossy liquid dielectric so that the paths between the electrodes are both resistive and capacitive the arrangement is suitable for wide band operation since the product of the equivalent parallel resistance and capacitance is a constant depending only on the nature of the dielectric various practical embodiments are described desirable characteristics for the dielectric are indicated 9860 current noise in carbon film resistors an experimental investigation at audio frequencies is reported the results are consistent with an empirical formula according to which the current noise voltage varies approximately directly with current in a few specimens the noise was found to depend on the direction of current 9861 the resistivity of composition resistors at radio frequencies continuation of the previous discussion of the mechanism causing the drop of resistance of composition resistors at experimentally obtained resistance frequency curves are presented for resistors comprising a cylindrical column of an aqueous solution of sodium chloride a cylindrical column of an aqueous solution of copper sulphate and a cylindrical column of carbon resin composition the resistance of type is practically constant at frequencies up to while that of types and drops considerably the drop in the resistance of the composition resistor is ascribed partly to the resistivity factor and partly to the external capacitance factor it is suggested that a frequency independent resistor could be obtained by mixing carbon with a material of high dielectric constant 9862 component design trends high frequency coils use new core materials points discussed include use of ferrite cores for coils operating at frequencies up to about use of glass and other low loss materials for formers and use of toroidal constructions 9863 the capacity and field of a split cylindrical condenser using the method of inversion the complex potential of a split cylindrical condenser is obtained by inversion of a known simpler case expressions are obrained for the value of the electrostatic field at points on the axes of symmetry the surface density of charge on a conductor and the capacity of the condenser the expressions obtained by adams using another method are deduced as one of three special cases for which tables and graphs are provided the results should prove of value in the design of electrode systems for various purposes 9864 miniature lacquer film capacitors a manufacturing process is described in which a thin film is cast on a supporting base and is metallized and slit while still supported after which it is stripped and wound into capacitor units metallized films thick have been produced the resulting capacitors are about a seventh the size of the smallest metallized paper types the support may be left in if the f lm is extremely fragile or if the capacitor is to operate at voltages below about a formula is derived for the effective series resistance 9865 thickness shear and flexural vibrations of a circular disk antisymmetrical modes of vibration in a quartz disk are investigated by considering the simpler corresponding case of an isotropic disk differences between the frequency spectrum in this case and in that of the rectangular plate are due to the presence of thickness twist modes in addition to the thickness shear and flexural modes 9866 theory of coupled endovibrators a system of two cavity resonators coupled by means of a narrow slot in their common wall is considered theoretically two classes of oscillations are considered those whose frequencies are determined primarily by the length of the slot and are nearly independent of the shape of the resonators those whose frequencies are near the frequencies of the oscillations in the resonators when not coupled 9867 the wien bridge as a phase shifter several circuits are presented illustrating the use of the wien bridge to provide phase shift with small amplitude change 9868 networks attenuation and input impedance useful formulae are presented 9869 four terminal networks ith transfer function having zeros with small real part analysis of low pass filter networks based on insertion loss principles to investigate the effect of critical zeros in the transfer function plot on the reactance to be developed the accuracy required in the calculation and the component values 9870 some aspects of mixer crystal performance correction to paper abstracted in please note change of number 9871 criteria for the amplitude stability of a power oscillator stability criteria for a tuned anode oscillator are established in the form of two inequalities derived from differential equations expressing the voltage variations of the grid and anode and involving the ratio of feed back power to anode power the ratio of the time constant of the grid leak and capacitor combination to the time constant of the tank circuit and functions of the angles of current flow for grid and anode experimental verification of the results using a triode is reported 9872 investigation of the dependence of natural frequency of oscillation on spectral composition a particular case of the theory of nonlinear electric oscillations is considered writing the solution of the equation as the sum of is the amplitude of the harmonic given by the fourier series the ratio using this relation the dependence of on the amplitudes of the spectrum can be calculated the measured and calculated frequency characteristics of relaxation oscillators agreed well the results are presented graphically see also van der for general introduction 9873 crystal frequency multipliers for centimetre and millimetre waves circuits are described for generating harmonics at frequencies using crystals the generator is coupled by a cross bar transition to the crystal which can be shifted axially for purposes of impedance matching higher frequencies can be achieved by use of crystals in a similar arrangement 9874 on the faithful reproduction of the flat top of a pulse in a high fidelity pulse amplifier an experimental verification is reported of analysis presented previously it was demonstrated that the anode current may sag appreciably if the time constants of the cathode and screen grid circuits are not properly chosen 9875 resonance circuits comprising or elements and some applications the frequency characteristics of the wien bridge and of an analogous inductance bridge are investigated theoretically pseudo resonance phenomena occurring in the neighbourhood of bridge balance are discussed true resonance is obtained when the bridge is associated with a feedback circuit to act as an oscillator the tuned amplifier and the and oscillators are described 9876 magnetic amplifiers a general survey of types and applications 9877 three phase high speed magnetic amplifiers the principle of the half wave magnetic amplifier is extended to three phase circuits various arrangements are described applications in the field of high power control systems are discussed 9878 the transistor as a amplifier for use in microwave measurements a junction type transistor with emitter earthed may have a current amplification as high as with low input impedance and high output impedance such an arrangement is seful for amplifying the current from a rectifier before application to a meter and enables the usual galvanometer to be replaced by a robust microammeter 9879 analyses of basic dielectric amplifier circuits analysis is based on a simplified charge voltage characteristic neglecting hysteresis both parallel and series connected arrangements are studied the steady state response can be found with succesive approximations transient response is also discussed 9880 photoelectric emission in the extreme ultra violet results of experimental studies on photoelectric emission from various metals for quantum energies up to cannot even qualitatively be ac ounted for by the common free electron surface effect representation a new theoretical model capable of explaining the observations at high photon energies is presented 9881 the influence of the cathode material on measured breakdown strengths of solid and liquid dielectrics 9882 kinetic equation for electrons in metals in strong fields 9883 on deviations from ohms law in metals it is shown on the basis of the kinetic equations of electrons in metals in strong fields that the deviations observed are due primarily to the delayed transmission of energy at the collision of electrons with the lattice at sufficiently low temperatures the resistance should pass through a minimum at a given current 9884 ettec n the dependence of the decay times of space charges by the static characteristic in intermittent discharges the validity of the hypothesis previously formulated has been investigated experimentally measured decay times depend on the external circuit associated with the discharge tube but the existence of an inherent decay time dependent only on the static characteristic of the tube is indicated an empirical method is developed for calculating decay times 9885 space charge formation and the townsend mechanism of spark breakdown in gases 9886 measurement of the current during the formative time lag of sparks in uniform fields in air measurements were made of the current in a parallel plane gap during the period between application of a voltage and occurrence of breakdown the current increased from a few microseconds after application of the voltage to just before breakdown for time lags between and the results are in agreement with previously developed theory except for an observed delay in the initial current rise a possible explanation of this is discussed 9887 determination of the electronic temperature in gas discharges measurements made in an electrodeless discharge over a pressure range and an electron concentration range of ratio to indicate that the electronic temperature remains practically constant its value being to within in dry air 9888 auger ejection of electrons from tungsten by noble gas ions report of an experimental investigation using atomically clean tungsten and ions with various charges the results indicate a value of about for the energy of the fermi level above the ground state in the conduction band in tungsten 9889 theory of auger ejection of electrons from metals by ions 9890 thermionic emission from copper at the melting point a ex e imental determination is reported of the constants and in the richardson dushman equation where is the electron charge and is the effective or isothermal work function for solid at the melting point the values of and were respectively for liquid respectively the discontinuity at the melting point is discussed 9891 recent developments in magnetism a survey with reference to publications dealing with various aspects of the subject 9892 magnetic flux produced by a dipole located inside a ferromagnetic circular wire an approximate formula is derived for the magnetic flux through a coaxial plane circular area normal to the wire due to magnetic dipole element inside the wire the radii of the circular area and the wire are assumed to be small compared with the axial distance between the circular area and the dipole element for experimental confirmation of the formula 9893 experimental investigation of change of magnetic flux in a wire when one domain is remagnetized the problem which is of importance in magnetic recording was investigated theoretically by rytov the calculated and experimental results are in good agreement 9894 theory of strong electromagnetic waves in massive iron maxwells equations are solved for propagation in material having a rectangular hysteresis curve formulae are derived for depth of penetration wave impedance and power input the results are compared with those of rosenberg 9895 reflection from a wire grid parallel to a conducting plane the parallel wire grid backed by a conducting plane can be represented by an impedance shunted across a transmission line as in the case of a single wire the value of this impedance depends on the angle of incidence the spacing of the grid wires and the distance between grid and backing plane conditions are derived for the reflection coefficient to become zero 9896 diffraction of electromagnetic waves by an aperture in a plane screen 9897 the diffraction of waves by an irregular refracting medium a method is described of calculating the diffraction effects produced by a thick stratum of an irregular refracting medium it consists of evaluating the statistics of the phase irregularities in the wave front after traversing the medium and treating these irregularities s having been produced by a thin phase changing screen for a particular statistical model of the irregularities in the medium the result is shown to be identical with that obtained using a different method 9898 a further note on dual integral equations and an application to the diffraction of electromagnetic waves a solution obtained previously is extended to cover cases in which the order of the bessel function kernel is not zero as an example the solution is applied to a problem in the diffraction of waves by a plane slit discussion of the problem is criticized results obtained are in agreement with those of muller 9899 hall effect in positive column report of measurements of hall voltage in the positive column of gas discharge tubes as a function of magnetic field tube current distance between probes and gas pressure 9900 theory of hall effect in ferromagnetics assuming phonon interaction the hall voltage is given by the equation where are constants are the resistances of the specimen at absolute zero and at temperature respectively is the intensity of magnetization at saturation and is the current density comparison with experimental results obtained from measurements on a bar shaped specimen shows close agreement 9901 hall effect in ferromagnetics anomalous effects are explained in terms of the spin orbit interaction of polarized conduction electrons 9902 wave functions for impurity levels a general method of solving difference equations arising in impurity calculations is developed 9903 propagation of electromagnetic waves radio location and radio astronomy a brief survey of recent progress particularly since 9904 detection of discrete radio sources at wavelength details are tabulated of sources observed at the naval research laboratory the equipment used is briefly described 9905 nature of discrete sources of cosmic radiation energy considerations of the colliding gas coronas n show that a considerable proportion of the kinetic energy of the colliding masses is transferred to a relatively small number of relativistic particles and hence into radiation the cut off frequency is estimated to be about assuming the particles to be electrons 9906 observations of cosmic noise at from observations made at a frequency of with an aerial of beam width between half power points and directed to a curve of equivalent aerial temperature as a function of sidereal time is derived the temperatures observed were of the order the curve is compared with curves derived for similar conditions by calculation from the results of observations at it is found that the equivalent temperatures increase rapidly with decreasing frequency but the ratio of maximum to minimum temperature decreases with frequency it is shown that atmospheric noise levels observed by the standard techniques sometimes contain a large contribution from cosmic noise at this frequency 9907 harmonics in the spectra of solar radio disturbances investigations over the frequency range indicate that spectral features of solar noise bursts are commonly duplicated at of below the frequency of the second harmonic the results are consistent with the hypothesis that the fundamental frequency corresponds to the natural plasma frequency of the corona in the vicinity of the source by applying this result to a standard model of the corona information is deduced regarding the position velocity and size of the sources velocities were found for two long duration outbursts and velocities as great as for short lived type bursts the generation of bursts may be associated with longitudinal plasma oscillations excited by fast streams of charged particles 9908 the emission polar diagram of the radio frequency radiation from sunspots the variation in received sunspot radiation with solar rotation was determined from a statistical analysis of observations made over a number of years half power widths of the radiation pattern of an average sunspot derived from this analysis are for frequencies respectively results indicate that the lifetime of the radiation sources is shorter for the lower frequencies the lifetime is comparable with that of a visible spot 9909 abnormal amplitude of seasonal effects in the ionosphere at the equator and structure of the upper atmosphere d layer absorption maximum ionization and structure of the layer have been studied seasonal variations observed in equatorial regions are much greater than expected from the geometrical variation of the suns position known theories assume simple variation of ionosphere parameters with cos the deviations observed are interpreted as indicating seasonal variations of the structure of the upper atmosphere particularly as regards temperature and its gradient molecular dissociation and movements of air masses at an equatorial station at the solstices not only is the solar radiation incident at an angle but the structure of the upper atmosphere is that appropriate ot a latitude of about 9910 motion of a single cloud in the ionosphere the system comprising cloud and ionosphere is treated as analogous to the system formed by a horizontal wire aerial and the ground the radiation pattern consists of minor lobes arranged symmetrically with respect to a central major lobe as this pattern moves with the cloud periodic fading of transmitted pulses is observed at the receiver periodic fading preceded and followed by a steady signal can thus with appropriate reservations be interpreted as due to a single cloud an example is discussed in which maxima were observed the wavelength being the horizontal length of the cloud is estimated to be about 9911 a monochromatically ionized layer in a non uniformly recombinant atmosphere with applications to the d and e ionospheric regions the recombinance fo the atmosphere is assumed to be given by a term independent of height together with a term which varies exponentially with height a recombinance datum level is defined as that at which the two terms are equal and heights are measured from this level in scale height units the level of the absorption peak being when the suns zenith distance is or when the level of the electron peak and the height distribution of the electron density are considered for different values of and of particularly when the electron peak is always above the absorption peak and for it is always above the recombinance datum level the electron peak for when the absorption peak is below the recombinance datum level is about half way between the two the decrease of on the underside of the electron layer can be much less steep than for a chapman layer if the absorption peak is below the recombinance datum level the results for the model atmospheres considered are tentatively discussed with reference to the and ionospheric regions but their potential value may be realized only when better data for the region become available 9912 focusing phenomena due to undulations of the ionosphere and determination of collision number 9913 electron density in the e layer during auroral displays deduced from measurements of absolute brightness the auroral luminosity values of electron density calculated from the photon emission for different auroral forms range from electrons below 9914 the association of pulsating and flaming auroras with complete ionospheric absorption at macquarie island simultaneous records show that pulsating or flaming aurorae are frequently accompanied complete absorption of waves incident vertically on the ionosphere but the nocturnal variations of frequency of occurrence of the two phenomena are markedly different in form 9915 equipment for accurate measurement of height of ionosphere layers use of timebase corresponding to a height range enables measurements to be made accurate to within the timebase triggering is controlled by means of a phase shifter calibrated in height so that any desired height range can be selected for close examination because of the pulse widening involved a differentiator stage with wideband amplifier is interposed between receiver output and indicator measurement procedure is described 9916 ionospheric height measurement by the method of delayed coincidence an outline description with block diagram is given of equipment in use at an indian station for regular observation of lunar tides in the upper atmosphere the apparatus can be readily adapted for automatic recording of curves the method is basically as described previously but the technique has been improved giving an accuracy within good results are obtained even in the presence of heavy atmospherics 9917 periodic fading of medium wave radio signals slow fading was found to correspond to interference between paths and between paths rapid fading to interference between paths the values of the vertical drift velocity of the layer calculated on the basis of observations of the three types of interference at an indian station for the period between and hours were and respectively ground wave fading indicates a drift velocity decreases during the morning depth of fading also decreases due to increasing d layer absorption 9918 variations of intensity of the aurora at macquarie island 9919 excitation processes in the aurora and airglow absolute intensities relative ultraviolet intensities and electron densities in high latitude aurorae excitation of forbidden atomic lines in high latitude aurorae the excitation processes are evaluated on the basis of optical and observations calculations show that electron densities occur in bright high latitude aurorae a summary is given of the various excitation and de activation processes which may occur and an attempt is made to decide which of these will be of major importance 9920 atmospherics with long trains of pulses the waveforms of atmospherics having long continued trains of pulses and the systematic modifications associated with time of recording storm distance and the presence of a low frequency component are described their interpretation is discussed and the results of analysis assuming the simple ionospheric reflection mechanism are presented estimates of reflection height and storm distance show the applicability of the theory to the temporal parameters of the waveforms and the origins of two groups of atmospherics having calculated ranges are considered the variation of pulse amplitude with reflection order is shown to lead to the channel during the later stages of the return stroke although difficulties arise in reconciling this concept with considerations of the magnitude and orientation of the horizontal elements 9921 multistage amplifier output impedance based on the result that the ratio of the net amplification to the parallel output impedance of a simple amplifier is the same with and without voltage feedback a simple expression is obtained relating the parallel output impedance to the amplifier constants for the multistage amplifier with overall feedback the design of an amplifier with a gain of and a parallel output impedance of is discussed briefly 9922 silicon power rectifier handles fused junction rectifier with a junction area of is mounted in a copper radiator with a slotted periphery high power handling capacity is obtained by use of forced air cooling characteristic curves are shown 9923 direct voltage stabilizers in the range with particular reference to degenerative systems the maximum usable loop gain depends on the frequency response of the system in practice loop gains of the order of are possible the effects of mains voltage and load current fluctuations are reduced by this factor reference elements are reviewed but electron energy analysers give comparable stability with smaller size and current drain 9924 a voltage stabilizer a motor operated variac type of stabilizer is described in which the voltage sensing unit contains only one valve of cold cathode type and incorporates biasing to hold the output voltage near the centre of the control range the output is maintained at the correction rate is 9925 relay time division multiplier a simple valve less multiplier for use in analogue computers is described 9926 three dimensional analogue computer the tridac is an electronic hydraulic machine developed for the royal aircraft establishment for solving problems in radar and guided missile operation it occupies of floor space uses and consumes under peak conditions individual mathematical operations are performed with an error of full scale the basic analogue quantity is a voltage and the basic element is a amplifier with a gain of the order of stabilized by association with an amplifier 9927 the calculation of the latent roots and vectors of matrices on the pilot model of the 9928 resistance network analogues with unequal meshes or subdivided meshes a general method for deriving the finite difference approximations to the partial differential equation which is solved by resistance network analogues is applied to find the resistance values and the currents which have to be fed in for and networks with unequal mesh sizes two ways of subdividing a network into finer meshes in the ratio are then given and a network subdivision in the ratio is described experimental tests have shown that these subdivisions introduce negligible errors into the measured field distributions 9929 a phonic wheel generator for position indication in digital computer magnetic drum storage the design is discussed of a variable reluctance phonic wheel generator for frequencies above the final form comprises a rotating slotted disk and polarizing permanent magnet placed centrally between two pickup heads pickup output as high as has been attained the system has been adopted in the type computer 9930 calculation of the magnetic field in the ferromagnetic layer of a magnetic drum the variation of the field with permeability air gap layer thickness and other factors is investigated assuming the ferromagnetic layer to be of low permeability spinel material while the problem is nonlinear the linear approximation is satisfactory in some cases numerical computations are presented for the drum used in the swedish computer besk 9931 extension of the generalized phase diagram method for studying the stability of linear systems extension of work reported previously a rule for interpreting the phase diagram leading to a simpler method of application is described the damping necessary to ensure stability is investigated by a graphical method an analytical method is developed using a characteristic algebraic equation with real coefficients 9932 automatic production for electronics a review of the techniques and design factors 9933 the influence of electrical current on the contact between metals experiments are reported in whic two blocks of gold were pressed together in such a way as to localize contact in a single region and current pulses were passed whose duration was chosen in relation to the time constants of the contact so as to produce the effect of a continuous current the constriction resistance between the blocks was measured before and after passage of a pulse from these values the changes in the contact area were calculated the results indicate that below a critical value of current the contact area is unchanged but above this current value the contact area is increased by passage of current 9934 a versatile output transformer for surge generators description of a tapped toroidal transformer designed to match the generator to a wide range of values of load impedance without altering the form of the surge 9935 microwave discriminator stabilization of test bench a discriminator for stabilizing a reflex klystron operating at is discussed a small portion of the klystron output is applied to a cavity resonator and the sum and difference of the resonator response and the incident signal are used after detection and amplification to provide the control voltage for the keystron reflector electrclosed loop automatic phase control the method described of designing a phase control system for an oscillator is based on an application of techniques of servomechanism analysis 9936 wafer coil development for inductive components the automatic production of coils made of insulated metal foil instead of wire is described the roll of foil is sliced into thin wafers which can be connected in series to obtain the required inductance physical and electrical characteristics are similar to those of wirewound coils closer spacing of turns is possible than with printed circuit techniques 9937 transductors with four limbed cores transductors with four limbed cores have characteristics which differ from those of conventional transductors in their symmetry with respect to control current changes such transductors are suitable for increasing the sensitivity of non polarized relays and may be operated by either signals the suppression of response to negative signals is also possible with four limbed transductors and this may be used to reduce swamping effects in push pull magnetic amplifiers subjected to large signals inputs 9938 accurate linear bidirectional diode gates discussion of switching circuits to be controlled by square wave voltages with gates of several milliseconds bridge arrangements of two four and six diodes are described operating factors considered include amplitude of control voltage gain constancy of gain signal characteristic backward leakage through the diodes and effects of unbalance series parallel and series parallel combinations are illustrated the use of a series parallel arrangement of gates for processing radar data is described 9939 the capacity and field of a split cylindrical condenser when the conductors differ in length the transformation using the usual notation of jacobian elliptic functions gives the complex potential at any point in the plane for the case of a plate of width raised to a potential symmetrically placed between two semi infinite plates at zero potential at distance apart from this the field and the capacitance of the system are obtained by the method of inversion by comparing the results with those of a previous paper two algebraic identities for the elliptic integrals and are obtained 9940 the charging and discharging of nonlinear capacitors capacitors with semiconductor photoconductor or electroyltic dielectrics involving space charge polarization are discussed and a formula is derived for the characteristic the charging and discharging processes in such a capacitor are compared with those for a capacitor in which is control voltage for the klystron reflector elec an increasing exponential function of the time variation of the differential capacitance of the space charge type during charging and discharging is investigated and is compared with the behaviour of a linear capacitor exhibiting a distribution of relaxation times 9941 the relation between time and frequency functions with practical examples of the calculation of the transient response of linear transmission systems 9942 tje practical calculation of transient response for arbitrary attenuation and phase distortion phase characteristic is determined from a given attenuation frequency curve by bodes method the locus of the complex transfer coefficient is approximated by fourier series the calculated coefficients are used to evaluate the response function for the case of unit pulse and unit step input as an example the transfer functions are determined for three different amplifier characteristics in a receiver the accuracy of the method in giving the general shape of the transient response curve is verified using samulons method an appendix contains formulae for calculating the fourier coefficients required and tables of the functions sin and sin applying in cases and respectively 9943 equivalence of two terminal networks simple procedure is indicated for synthesizing or recognizing or recognizing equivalent two terminal networks containing three or more circuit elements 9944 comment on networks terminated in resistance at both input and output theory presented previously for lattice networks is supplemented by indicating a method for obtaining or terminations 9945 displacement of the zeros of the impedance due to incremental variations in the network elements a method is presented for evaluating errors introduced in the analysis of networks by assuming that the elements are purely reactive 9946 response characteristics of a linear system with third order transfer function the rise time and delay time of a low pass system on application of a step function input are calculated using elmores formulae conditions for minimizing these times are determined for functions with three poles and two zeros the pulse transformer is treated as a numerical example the calculations are supported by experimental results as long as consideration is restricted to no overshoot conditions 9947 radio frequency phase difference networks a new approach to polyphase selectivity 9948 forced oscillations in nonlinear systems with two degrees of freedom analysis is given leading to the establishment of criteria for the stability of oscillations in circuits coupled by mutual inductance 9949 image parameters of filters with one or two cut off frequencies and notes on the decomposition of the transfer coefficient a table is given of formulae for the image transfer coefficients and image impedances of high pass band pass and band stop filters methods of expressing the transfer coefficients as the sum of the transfer coefficients of the basic sections are explained though the band stop case cannot be included the filters are considered to be without loss and without mutual inductance 9950 narrow band filter composed of quadripoles the design of filter circuits for very low frequencies is discussed oscillograms illustrate the suppression of noise superposed on a signal for theory of quadripoles see also 9951 transient operation of low pass and high pass lattice filters an expression is derived for the admittance of the lattice filter terminated by its characteristic impedance functions using a new inverse transformation method the unit step response of some low pass filters and the unit function response of some high pass filters are determined a simple method is indicated for determining the response to an arbitrary voltage 9952 direct coupled waveguide filters filters are considered of the type comprising chains of cavity resonators with a common iris separating adjacent cavities design methods based respectively on impedance considerations wave matrices and equivalence between the waveguide filter and the lumped element filter are described for determining the susceptance of the irises and their separation theory is given for the case of mismatching and formulae are derived for parallel and cascade couplings a four channel branching system for frequencies ranging from to is described 9953 ferrite attenuators in helixes directional attenuation has been observed using a cylinder fitting closely round a helix attenuation frequency curves are shown for two values of axial magnetic field and attenuation magnetic field curves are shown for frequencies of and the directional effect is considerably higher than indicated by elementary theory the reason for the discrepancy is discussed 9954 ferrite phase shifters in rectangular wave guide propagation theory is developed for a nonreciprocal device with asymmetrical arrangement as described by losses in the ferrite being neglected the dependence of the phase shift on the thickness of the ferrite slab on the degree of asymmetry and on the intensity of the transverse magnetic field is investigated the field configuration in the guide is shown diagrammatically for some special cases a modification with two symmetrically arranged ferrite slabs and antiparallel magnetic fields is also discussed 9955 design of aperiodic oscillator circuit with inductive quartz crystal the discussion is illustrated by a numerical example of an oscillator using a valve and suitable in the or band 9956 a new self excited square wave transistor power oscillator the basic circuit uses a push pull arrangement of power transistors in conjunction with a transformer consisting of a centre tapped primary centre tapped feedback and output winding and a single source an explanation of the operation and oscillograms of waveforms obtained are presented good efficiency is obtained over a frequency range the range has been extended up to with reduced efficiency application to conversion of power is discussed 9957 class amplifier and oscillator design charts are presented for simplifying the design procedure using a method based on that of 9958 mixing preamplifier a circuit for mixing signals from several photocells has diodes connected in the grid circuit of the separate input valves so as to avoid signal attenuation which would otherwise result from the parallel arrangement of these valves 9959 travelling wave tube system having m ultiplied gain advantage is taken of the wide frequency band of travelling wave valves to obtain increases gain by heterodyning the output to a different frequency and then feeding it to the valve again the system is useful in microwave relay stations where it is in any case necessary to change the carrier frequency to prevent feedback from the transmitting aerial to the receiving aerial 9960 gramophone and microphone pre amplifier the equipment is designed primarily for use with the amplifier described previously separate input stages and gain controls for gramophone and microphone channels are followed by a mixing circuit the full output of can be obtained with harmonic distortion for sinusoidal inputs ranging from to about with microphone and from with gramophone 9961 the use of double triodes in high gain low frequency amplifiers the type of amplifier stage employing a double triode is described in which one triode section provides a high dynamic load resistance for the plate circuit of the other an amplifier utilizing three such stages and possessing a gain of the order of is described 9962 infrared spectrophotometer amplifier an amplifier for use with a low impedance bolometer is described with complete circuit diagram the amplifier input is of the order of at a frequency of corresponding to a power input of the overall amplification is the methods used to reduce nouse valve microphony are discussed 9963 on the integral width of cascaded tuned amplifiers a formula is derived by which the overall integral bandwidth of an amplifier containing a number of noninductively coupled circuits is expressed in the effective quality factors of the separate resonance circuits the quantity can also be expressed in the integral widths of the separate circuits for two or three stages very simple relations are found 9964 a new circuit for balancing the characteristics of pairs of valves both static and dynamic characteristics of a pair of valves are balanced by adjusting the heater voltages by means of a potentiometer of a few ohms resistance in series with the heater supply circuit 9965 derivative controlled magnet amplifiers a two stage circuit for a low level fast response unit is described the first stage acts as derivative amplifier amplifying average increments of signal voltage per half cycle of power supply voltage the second stage acts as integrator amplifying and summing the output voltage of the first stage if the negative feedback applied to the first stage is delayed by a low pass filter the total time constant of a system incorporating the amplifier can be effectively reduced 9966 magnet amplifiers with inductive load the instability region in the control characteristic curve is discussed and a method of avoiding operation in this region suggested 9967 characteristics of magnetic amplifiers for industrial use a specification for standard units for regulator applications is drawn up the relative importance of the advantages and disadvantages of magnetic amplifiers is considered in detail for pre amplifiers limited range regulators motor field current regulators ward leonard drives amplifiers have a faster response than other types but at extra expense and with added complication 9968 pulse relaxation amplifier a low level magnetic amplifier the principles of operation are explained linear amplification can be obtained for an input signal of in a amplifier delivering an output of variation of the temperature between ans of the supply voltage by resulted in a maximum zero drift of less than over a two week period the gain varied by change of the supply frequency 9969 diode amplifier outline of the properties and applications of amplifiers based on the reverse transient phenomenon associated with the high degree of carrier storage in an junction diodes thr frequency of the power supply must not be less than that of the modulating signal such amplifiers can be used as pulse repeaters in flip flop circuits or as wide band flat response amplifiers faster operation can be obtained with than with diodes 9970 a new system of logarithmic units a general discussion of the subject treated by green 9971 correlation of amplitude and phase fluctuations in wave propagation in a statistically inhomo geneous medium the cases considered are the correlation of fluctuations of amplitude and phase at a single receiving point and the correlation of amplitude pr phase fluctuations at different receiving points in the case of large sized inhomogeneities the correlation between the amplitude or phase fluctuations extends over a range of the same order as the correlation between the random inhomogeneities of the medium itself 9972 surface distributions of fixed charges and poynting vector in a system of permanent volume currents theoretical study of conditions in a hollow cylindrical conductor 9973 present state of theory of electric breakdown in solid dielectrics a survey the theory of the first stage of dielectric breakdown the loss of electric strength can probably be given best in terms of a kinetic equation for electrons in a solid the effective cross sections of ionization for low energy electrons the probability of scattering of medium energy electrons by the vibrating lattice and the effective cross section of recombination must be determined the theory of the second stage the actual breakdown has not as yet been given it is suggested that the cause of the breakdown could be connected with processes leading to the production of a shock wave analogous to that occurring in the breakdown of gases at high pressures references include over to russian literature 9974 mechanism of discharge between plane plates the problem is considered using the diffusion theory of the positive column with a term added to take account of the character of the discharge measurements show that the electron temperature is higher than in a discharge under similar conditions a theory is proposed which explains the dependence of the running potential on frequency 9975 effect of secondary electrons on initiation of discharges initiation of discharges between parallel electrodes in inert gases was investigated at pressures of using a frequency of and magnetic fields up to two effects due to a transverse magnetic field were observed decrease of breakdown potential and suppression of a glow discharge the former is due to the cyclotron effect the maximum reduction of occurred at a field strength where is the frequency of the electric field the latter is shown to be due to prevention of the secondary electron resonance effect observed in a longitudinal magnetic field and noted by in his work on the secondary electron multiplier 9976 effect of moving striations on microwave conductivity of a coaxial discharge experiments were made with a discharge tube arranged so that part of the discharge path fills a gap along the inner conductor of a coaxial line the results indicate a marked variation of the microwave conductivity as striations move past the gap the effect may be strong enough to use for switching purposes 9977 electron emission from metals under high energy hydrogen ion bombardment 9978 method of measurement of the velocity of high energy electrons formulae relating the beam voltage to the oscillation frequency in carcinotrons and loaded waveguide linear accelerators are used to determine the electron velocity the only apparatus required is a wavemeter together with a small line velocities approaching that of light are treated relativity effects are taken into account 9979 the similarity law of secondary emission measurements were made of the secondary emission yield factor for a number of materials under carefully controlled conditions particularly with respect to clean target surface results then agreed well with the experimentally obtained universal curve a formula for which is also given 9980 determination of the proportion of reflected electrons in the secondary electron emission from copper and gold an experimental determination is reported the retarding field method of was used with primary potentials of the secondary electron yield was corrected for the space charge effect at a primary potential of and a retard ng potential of the percentages of reflected electrons in the total secondary electron yield are and respectively the percentages are respectively the results are presented graphically and are tabulated 9981 galvomagnetic and thermomagnetic effects in a plasma 9982 experimental determination of the energy distribution of thermoelectron beams an investigation using the lenard retarding field method is reported this method gave results accurate to within for electron energies in the range results indicate that a maxwell distribution occurs only at low beam currents and densities no direct dependence was found on cathode temperature space charge at the cathode or control potential a depence was observed on current density and to a lesser degree on current intensity deviations from maxwells distribution could not be attributed to errors in calculation collisions with the residual gas spectrometer effect of the emitter transverse resistances of cathode or local anomalies of the work function positive results were obtained by relating the electron energy distribution to longitudinal space charge oscillations produced by the shot effect shifts of the energy distribution are due to changes in the work function and the development of a potential barrier near the cathode 9983 deduction of magnetic interaction in exchange model of ferromagnetic metal 9984 quantum theory of magnetostriction of ferromagnetic single crystals theory is developed for crystals with hexagonal or cubic symmetry at low temperatures results indicate that magnetostriction is connected with the magnetic interaction of electrons and also give the temperature dependence of magnetostriction constants in the case investigated 9985 the perfectly conducting ring subjected to high frequency currents and magnetic fields detailed analysis of the interaction of current and field for a ring of circular cross section with current flowing in a conductor along its axis carryii g a c 9986 a derivation of maxwells equations for a vacuum by means of an energy quantum model propagation phenomena such as interference and diffraction can be explained by means of quantum theory if the energy quanta are assumed to have finite volume the magnitude of this volume is estimated from consideration of the energy received by a dipole in a field of strength 9987 theory of the trentini absorption grid exact theory is developed for absorption of a normally incident wave by a loaded grid placed near and parallel to a conducting surface the case when a dielectric intermediate layer is present is also considered 9988 eitaromcoated spheres in the region of the first resonance calculations based on methods developed previously indicate that a dielectric coated conducting sphere can be made to have a greater scattering cross section than an uncoated conducting sphere of the same overall diameter this was confirmed experimentally using technique described by results of calculations and measurements are shown graphically a physical interpretation is presented 9989 electromagnetic wave propagation in bounded electron beams equations in appropriate form are solved subject to boundary conditions chosen in accordance with a particular uniqueness theorem which is proved modes of propagation in a waveguide completely filled with an electron beam are determined 9990 a simple high temperature microwave spectrograph equipment for operation in the frequency range is described based on the stark modulation effect 9991 determination of thickness and optical constants of thin films theory is given relating the thickness and optical constants of very thin metallic films deposited on glass to the reflected and transmitted light intensities wolters theory is discussed 9992 the physics of experimental method the statistical interpretation and mathematical manipulation of experimental results and the natural limits of measurement are treated electrical measurements electronic devices and vacuum techniques are among subjects for discussion examples of appropriate instrument technology are included 9993 radio astronomy a survey of techniques and results 9994 the remnants of supernovae as radio sources in the galaxy a critical survey is presented of recent work on the sources of galactic radio emission at metre wavelengths observations indica e that remnants of supernovae may account for some of the sources and radio emission may be due to collisions of gas at high velocities results of flux density calculations at are tabulated 9995 novae and radio noise calculations show that radiation generated when two nova shells are emerging should be observable in the early stages 9996 an analysis of bursts of solar radio emission and their association with solar and terrestrial phenomena solar radio emission records on seven frequencies in the range were studied over a period of months the analysis which includes a number of histograms shows that many of the properties of bursts change with frequency a study of the time delay between bursts on different frequencies revealed that bursts often occur first a simultaneous up and down movement of ionized material from the level of zero refractive index at that frequency is postulated it is found that bursts were more frequent than flares fadeouts and crochets and that they almost always accompanied these effects the commencement of bursts appears to be simultaneous with that of flares and crochets but precedes that of fadeouts by about two minutes in addition there is a rough correlation between the intensity of bursts flares fadeouts and crochets 9997 a symposium on meteor physics at jodrell bank report of the symposium held in at which papers were presented these include several on radio echo investigations ionization and excitation and one paper on a possible mechanism of production of galactic radiation 9998 theory of the meteor height distribution obtained from radio echo observations shower meteors sporadic meteors 9999 distribution of coronal flares as a function of latitude during the course of the solar cycle distributions consistent with the commencement of the new sunspot cycle have been observed 10000 notes on the sunspot cycle analysis of a long series of sunspot cycles based on a period and illustrating the negligible gravitational effect of the planets 10001 practical methods of harmonic analysis for geophysical problems use of fourier series for resolving the diurnal variations of geophysical elemements is discussed rapid methods of analysis based on ordinate and ordinate schemes are described 10002 magnetic observations at quetta during the total solar eclipse of 10003 an intuitive description of the chapman ferraro theory of the inital phase of a magnetic storm the main mathematical results of the theory are derived from a simple consideration of the dynamic characteristics of a stream of ionized particles in a magnetic field 10004 transients of magnetographs blankstantaneous values from recordings 10005 relation between atmospheric ozone and storms comparison of records indicates that the ozone concentration in creases during storm times the increase occurs suddenly on the average hours before the first discharge 10006 measurement of atmospheric humidity up to kilometers 10007 scale heights and pressures in the upper atmosphere from radio echo observations of meteors methods are described for determining pressure and scale height in the altitude range making use of theory developed by kaiser 10008 notes on the atmospheric refractive index in canada from aircraft meteorologocal soundings values of the refractive index calculated from soundings made in connection with a shoran survey are compared withstandard values 10009 the latitudinal and seasonal variations of the absorption of solar radiation by ozone calculations indicate that the length of day and the solar altitude factor are sufficient to give the major features of the ozone solar absorption 10010 short period variations in the ionosphere a comprehensive review is presented of methods and results of ionospheric research short period fluctuations are discussed in relation to theories of layer formation 10011 procedures used to improve the quality of ionospheric data data from field stations are regularly dealt with by the ionospheric data quality control group of the upper atmosphere research section at the an outline is given of the procedures used with special reference to the detection of errors 10012 statistical analysis of echo further investigation of the echo from above the normal night timee e layer an analysis of data for the period indicates definite peaks in the percentage duration of these echoes at the equinoxes and a positive day recurrence tendency no definite correlation has been found with sunspot numbers magnetic storm data or e 10013 electron densities in the ionosphere a fresh interpretation of data obtained from rocket measurements bassed on a breakdown in the independence of propagation of the magneto ionic components of a signal transmitted from the rocket gives an electron density curve in agreement with records 10014 continuous electron density measurements up to electron distribution at altitudes from was determined accurately from measurements made during a rocket flight at using records the electron density curve was extrapolated to the maximum electron at density increased rapidly between in the region densities were in general lower than the maximum slight gradient variations in the lower ionosphere are probably the major cause of large variations of virtual height sporadic echoes are apparently due to partial reflections from high gradient regions 10015 spread over washington analysis of records for the period diurnal curves for seasons and years throughout this period are similar with spread occurring more frequently in winter than in summer and equinox values usually midway between those for summer and winter solstices sample data from six other stations show different characteristics phenomena at watheroo merit further study 10016 atomic nitrogen as a constituent for region three temperature height models are considered the nicolet mange model the possible upper limit of temperature height gradient and an intermediate model for these particle concentration with height the rate coefficient of reaction with height and the height and concentration of maximum ionization are critically discussed and computed the level of maximum ionization produced by photo ionization of atomic nitrogen lies between depending on the model considered the concentration of atomic nitrogen at the height at which diffusive separation takes place need not be assumed to be greater than hence atomic nitrogen could contribute at least in part to the layery ionization the possibility of ionization of atomic oxygen at the third ionization potential is briefly discussed 10017 a consideration of the electron disappearance in the layer of the ionosphere factors influencing the electron concentration and conventional theories of recombination and attachment are reviewed nocturnal diffusion can account for only a small variation of concentration but its effect on the altitude of maximum concentration is not necessarily negligible statistical analysis indicates that the influence of pressure on the nocturnal variation of electron concentration is unexpectedly small while that of temperature is large analysis of the monthly mean values indicates that attachment rather than recombination is the mechanism responsible for the electron disappearance the influence of layer movements though not large is significant further evidence in favour of the attachment theory is obtained from consideration of distribution and from a comparison of the nocturnal concentration variations at two sites theoretical considerations favour a process of electron removal in which collisions between atomic ions of oxygen and excited molecules of nitrogen produce molecular ions of nitrogen which in turn recombine with electrons 10018 a theoretical investigation of the ionospheric electron density variation during a solar eclipse the investigation reported previously by is extended to the general case of where is the apparent diameter of the moon and that of the sun a uniform distribution of radiation over the solar disk is assumed convenient formulae are derived for the minimum electron density and for the time of occurrence of the minimum for a partial eclipse of magnitude an approximate expression is derived giving minimum electron density as a function of with an error of the average ionospheric sounding equipment 10019 thunderstorms and sporadic e ionization of the ionosphere a study was made of the increase of ionization during severe squall type storms which are a feature of the weather in bengal in the pre monsoon months march may the transmitter frequency was gradually increased as the squall approached and the frequency at which the echo disappeared was noted the observations were repeated every four minutes results are shown graphically for two typical cases values of as high as were observed compared with the average no storm value of 10020 three phase static inverters power spacing vehicle equipment a three phase output at is obtained from a dc input of by means of si controlled rectifiers 10021 the physics of computer elements the general principles of acoustic electrostatic magnetic optical and superconducting storage systems are discussed magnetic or superconducting devices show the greatest promise for future high speed applications 10022 control pulse generation for a digital differential analyser circuit details are given of a transistorized unit which generates control pulses by a pulse division method involving some unusual processes 10023 thin films as elements for automatic computers a review covering the application of thin film storage devices including the cryotron to data processing techniques 10024 high speed logic circuits using diode logical networks and current switching amplifiers the use of diode networks as an alternative to transistors in logical networks is considered the circuits are versatile and economical but require associated amplifiers and are likely to have a limiting switching time of about 10025 output coupling networks for use with logical circuits of the emitter current switching type zener diodes coupling networks required to transfer the collector voltage swing in emitter current switching circuits to earth level are considered the disadvantage of low coupling efficiency of passive output coupling networks is considered in comparison with the versatility which they give to standard logical elements 10026 reliability of electronic components four papers based on contributions to a discussion meeting on contributions to a discussion meeting on circuit components and materials held by the nachrichtentechnisch gesellschaft in stuggart technological measures for improving the reliability oy of components lifetime investigations on capacitors the effect of humidity on the electrical characteristics of capacitors the unreliability of electronic equipment and its causes 10027 recent advances in microminiaturizatio reliable components and cooling techniques 10028 silicon epitaxial microcircuit a si microcircuit formed by vapour phase deposition techniques is described an eight layered epitaxial structure was formed which was capable of oscillation in different modes shunting capacitive and resistive leakage effects are discussed 10029 the design and performance of high precision audio frequency current transformers conventional multilayer current transformers are found to have large high frequency errors details are given of precision single layer transformers which cov range 10030 application of boolean notation to the maintenance of switching circuits concise notation by boolean algebra of the operations in the maintenance schedules of complex switching circuits is used to simplify testing and fault location 10031 high stability ferrite pot cores describes a range of assemblies suitable for laboratory use and for bulk production of stable inductors 10032 analysis of ferrite core switching for practical applications an analytical expression describing the switching process is derived which is suitable for practical circuit design measurements confirm the results of calculations 10033 more matrix driver employing magnetic amplifiers a high frequency magnetic amplifier with high efficiency good signal noise ratio and high output power has been developed 10034 low impedance capacitor design with special application to filters methods of reducing series inductance of conventional capacitors are investigated measurements of capacitor characteristics are discussed and an improved method of connection for filter capacitors is described 10035 the reactive behaviour of nonlinear negative differential resistors nonlinear negative resistance two poles may have a reactive component when forming part of a given relaxation oscillator circuit 10036 a general steady state analysis of power frequency relations in time varying reactances this analysis produces the manley rowe results as special cases an energy coefficient is derived which specifies the behaviour of an individual frequency transformation the modes in which an individual transformation can operate are described and related to a wide range of varying reactance devices 10037 the calculus of deviations applied to transistor circuit an network analysis network analysis is simplified by the method described rules are given for solving various transistor problems including the distributed parameter network 10038 some considerations on optimum filters an explicit formula is derived which gives the pulse response of a filter for signal detection in o noise where the known signal is expressed in the form of a trigonometric polynomial 10039 the design of all pass low pass and band pass filters with a tchebycheff type approximation of constant group delay 10040 replacement of a cascade of unequal asymmetric quadripoles of equal iterative impedance by one quadripole 10041 the cascade connection of nonreversible quadripoles 10042 the synthesis of active and passive filters by the root locus method 10043 active filter element and its application to a fourier comb a theoretical analysis is given and constructional data are presented for a variable q variable frequency band pass filter using transistor amplifiers stable q operation is possible over q factor range of for frequencies up to 10044 the applicability of active filters to the measurements of the frequency spectra of pulses the use in frequency analysers of active filters comprising amplifiers with double t type rc networks results in higher q values at low frequencies than is possible with stagger tuned lc circuits the error assessment given by seeger and stablein of is also applicable to this type of circuit 10045 synthesis of transformerless active n port networks 10046 a circuit with several stable state using tunnel diodes the circuit has four stable states the time required for a change of state being of the order of it can serve as a fast pre storage device for a multichannel analyser or as the basic unit of an associated address scaler 10047 a tunnel diode univibrator and pulse height discriminator an adaptation of the tunnel diode oscillator circuit above and its operation in conjunction with a biased backward diode see are described applications in pulse shaping and fast coincidence technique are noted 10048 a fast amplitude discriminator the circuit has a discrimination range of with a threshold stability within the output is a positive pulse in amplitude with rise time and duration 10049 new ways to trigger avalanche pulse circuits 10050 reversible decimal counters circuit design for both binary and bi quinary scales of notation is discussed 10051 tunnel diode binary counter circuit 10052 investigation of the single ended push pull amplifier theoretical and practical design aspects of various versions of this type f af amplifier are considered 10053 a quick method for calculating transistor amplifier circuits by neglecting the parameter calculations on transistor amplifiers can be greatly simplified this is applied in calculations of feedback temperature stability and noise 10054 calculation of mixing processes in transistor stages at low frequencies on the basis of the equivalent circuit diagram extension of the theory given in of august to transistor mixer circuits and to distortion effects in them 10055 nonlinear distortion of transistorized amplifiers sources of distortion are examined and methods are suggested for minimizing their effects 10056 designing amplifiers with nonlinear feedback design criteria for the use of a nonlinear feedback loop with a transistor amplifier are given increase of dynamic range and an exponential response can be obtained 10057 design theory of optimum negative resistance amplifiers an examination is made of amplifiers obtained by imbedding a linear active one port device in arbitrary three port devices the optimum gain bandwidth formula synthesis procedure and design curves are given for this and other amplifier configurations 10058 amplification through stimulated emission the maser an account of the physical principles underlying two and three level maser action is given and expressions for noise factor are derived recent maser applications in radio astronomy systems are noted 10059 general analysis of optical infrared and microwave maser oscillator emission the equations governing coherent emission are generalized amplitude modulation of the signal is to be expected and this can be used for communication purposes 10060 cross doping agents for rutile masers the electron paramagnetic resonance spectra of rutile doped with ta nb and ce have been examined at liquid helium temperatures ta and nb appear to be suitable for securing a short spin lattice relaxation time 10061 a new microwave power amplifier a method is suggested in which one electrode of a lecher or coaxial line is made electron emissive a signal propagated down the line produces an amplified current in the anode 10062 nonreciprocal parametric amplifier circuits two circuit configurations are given which do not use a circulator but which have similar properties to the single port reflection amplifier with a three port circulator 10063 staggered operation of doubly resonant parametric amplifiers a broad bandwidth is achieved by staggered operation of doubly resonant variable capacitance parametric amplifiers in the band 10064 on parametric excitation with current saturable inductances a a parametric amplifier circuit with an abrupt nonlinearity is described a method of analysis of relaxation oscillations leads to a physical understanding of the cycle of oscillations and quantitative relations the stability problem is also solved 10065 minimum noise figure of the variable capacitance amplifier a discussion of the minimum noise figure of variable capacitance diode amplifiers on the assumption that the series resistance is the only parasitic element some experimental figures are given for dsb operation at and universal curves are included which illustrate the effect of changing network parameters and component temperatures 10066 a solid state analogue to a travelling wave amplifier an attempt to improve the dispersive properties of multi diode parametric amplifiers was made by placing stacks of varactor diodes inside an l band helix bandwidths of and a noise figure of were obtained a low noise microwave quadripole amplifier 10067 travelling wave analysis of a class of parametric amplifiers based upon the hill equation 10068 electric fields and currents in dielectrics a general solution is given for the distribution of electric field and charge carrier concentration in a dielectric between two metallic contacts when field emission and thermionic currents flow from the cathode 10069 potentials in a conductor of varying cross section the importance of the eigen hall effect of in masking the bernoulli voltage in experimental measurements is pointed out 10070 rectification effect in gaseous discharges in crossed magnetic and electric fields description of an experimental crossed field diode consisting of two coaxial electrodes of stainless steel tube the inner electrode being filled with a ferrite stack separated by pieces of soft iron results obtained with a hydrogen filled tube under a pressure of show that the system is more efficient if the magnetic field is localized near the inner electrode in this manner 10071 the theory of secondary electron emission of metals 10072 complex conductivity of some plasmas and semiconductors the complex conductivities of plasmas and semiconductors have been calculated for several cases where the collision frequency can be expressed as a power function of the energy from the result some characteristic parameters of the plasma originally investigated by spitzer are estimated the problem of determining the relaxation from a non symmetrical dispersion is discussed 10073 couette flow of a fully ionized gas considered as a two component fluid 10074 experimental study of the diamagnetism of gaseous plasmas with electron and nuclear spin resonance techniques 10075 energy conversion mechanism in a bounded magnetized current carrying plasma for a finite plasma coupling exists between quasi transverse em waves and quasi longitudinal space charge waves this can lead to an energy transfer between the kinetic energy of drifting plasma and em energy this mechanism may be useful for heating a thermonuclear plasma using the runaway electrons certain types of clf radio noise can als be explained 10076 emission of submillimetre electromagnetic radiation from hot plasma in zeta the first results are reported of experiments using spectroscopy in the far infrared mm 10077 oscillations of a plasma in a static magnetic field the dielectric tensor is calculated and used together wi h the solutions to the propagation problem at zero temperature to allow for thermal effects 10078 the theory of plasmas in the presence of magnetic fields on the basis of boltzmanns equation the complete theory of a stationary cylindrical plasma is obtained allowing for the presence of the intrinsic magnetic field and of an additional longitudinal magnetic field 10079 statistical mechanics of ferromagnetism spherical model as high density limit the conjecture of the validity of the spherical model of is examined and justified 10080 measurements on resonators formed from circular plane ad confocal paraboloidal mirrors a measured of was obtained and results were in agreement with those of fox and relating to optical masers 10081 cherenkov radiation in a dielectric tube waveguide an experimental arrangement for measuring the radiation is described and results are given high s interaction resistances can be obtained at the expense of physical size and mode interference 10082 shift of the shadow boundary and scattering cross section of an opaque object 10083 near zone back scattering from large spheres theoretical treatment of back scatter from a perfectly conducting sphere for short wavelengths the back scatter cross section is modified considerably as the receiver approaches to within a few radii and becomes the cross section of a flat plate for a receiver very near the sphere 10084 reflection and transmission of conductive films a more general relation for the reflection and transmission coefficients is given for the case of oblique incidence and perturbations due to frequency dependence and displacement currents are considered a formula is also derived for thick films 10085 microwave zeeman effect of free hydroxyl radicals the theory of the zeeman effect in levels of light diatomic radicals is extended to the general intermediate coupling case and used for detailed analysis of observed paramagnetic resonance absorption spectra at of the products of an electric discharge in low pressure and vp vapour 10086 on the theory of cross relaxation in maser materials the cross relaxation rate is calculated by the method of moments taking into account the effect of the crystal line electric field 10087 phonon masers and the phonon bottleneck a calculation shows that the transfer of energy from the electron spin system can set up a stimulated phonon emission leading to maser action 10088 corkscrew a device for changing the magnetic moment of charged particles in a magnetic field a helical field source is described which produces a monotonic increase or decrease in the transverse energy of a particle moving initially in the uniform field along the helix axis 10089 higher random phase approximations in the many body problem the usual random phase approximation combined with an equations of motion technique for the many electron problem is extended yielding many of the known results of series summation methods in a straight forward manner the method should apply to other types of many body problems as well 10090 a variational approach to correlation in an electron gas a periodic electron density is allowed and it is proved that there exist one particle states energetically more favourable than the usual plane wave orbitals 10091 digital radiometer 10092 radio emission from the cygnus loop a high resolution study of the cygnus loop has been made at and the results are compared with the optical features estimates of the thermal and nonthermal radio emissions are made 10093 secular variation of the flux density of the radio source cassiopeia a observations at support the evidence of hogbom ad shakeshaft of a decrease of about per annum in the flux density of cassiopeia over the last years 10094 the microwave temperature of venus solar corpuscular radiation may maintain an ionosphere on venus and the variation in observed brightness temperature may consequently be a function of zenith angle 10095 the source of radiation from jupiter at decimetre wavelengths part time dependence of cyclotron radiation 10096 radio emission from the perseus cluster two small components of the perseus cluster separated by have been identified they may be physically related in a similar manner to that of the two emitting regions in cygnus a 10097 the effects of betatron accelerations upon the intensity and energy spectrum of magnetically trapped a particles the effects of change of magnetic field on th energy spectrum are calculated 10098 characteristics and fine structure of the large cosmic ray fluctuations in november report and discussion of observations of solar cosmic ray increases on and november the former occurring at a gi time of a sharp forbush decrease 10099 balloon observations of auroral zone x rays x rays are detectable about of the time large increases occur during geomagnetic disturbances 10100 seasonal variations of cosmic ray intensity in polar regions 10101 analysis of a type of rough trail meteor echo the characteristics of b type echoes are examined in detail the rough trail may be due to fragmentation of the dust ball type of meteoroid 10102 the height variation of the ambipolar diffusion coefficient for meteor trails both the two station and the split beam measuring techniques were used it was concluded that the atmospheric scale height during winter at a height of above jodrell bank is km 10103 delayed propagation of solar cosmic rays on september an analysis of balloon rocket and ground level observations reveals tht the delay between the flare and the arrival of solar protons increases with decrease in proton energy 10104 rocket observations of solar protons on september the results of nuclear emulsion and gm counter c observations are used to derive the integral and differential spectra for protons of energy arriving at the top of the atmosphere 10105 magnetic disturbances and the earths magnetic field storm time changes in the earths magnetic field could induce currents in the earths core which interact with the steady field this produces a nett unidirectional current at the end of the disturbance which penetrates gradually down to the core and has a decay time of a million years this current could be responsible for maintaining the steady field 10106 solar corpuscular showers and families of geomagnetic storms investigation of the effect of corpuscular showers in producing magnetic storms and magnetic disturbances during which the corpuscular shower pass near the earth without enveloping it 10107 the ring current geomagnetic disturbance and the van allen radiation belts the negative phase of a magnetic storm is ascribed to the formation of a ring current at a distance about four earths radii from the earths centre the magnetic field due to the current is calculated and compared with observational results 10108 radiation measurements during the flight of the third space rocket preliminary analysis of results of instrument recordings made during the flight of the rocket between the and october 10109 secondary electron emission and the satellite ionization phenomenon electron emission from a satellite and the electron density variation near it due to bombardment by neutral particles are considered 10110 sputtering as a possible mechanism for increase of ionization in the vicinity of low altitude satellites an increase in ionization above ambient may occur at distances of up to mean path from the satellite ionization potentials of the injected atoms ar to those of the ambient species the probability of any collision leading to ionization should exceed with the model proposed for the mechanism to be of interest 10111 the effect of atmospheric rotation on the orbital plane of a near earth satellite theoretical formulae are derived for the rotation of the orbital plane and change in orbital inclination of a near earth satellite due to the influence of the atmosphere 10112 satellite determination of heavy primary cosmic ray spectrum a preliminary report of the heavy nuclei cosmic ray flux observed aboard explorer is given 10113 drop out phenomenon observed in the satellite transmissions irradiation of the quartz oscillator in during passage through the horns of the outer van allen belt may explain drop outs sudden decreases of observed signal strength 10114 sideband correlation of lunar and echo satellite reflection signals in the range measurements are described and records of signal variation are illustrated with lunar reflections a correlation of was obtained between sidebands with separation the correlation of signals reflected from echo baloon with sideband separation was better than that of lunar reflections with separation 10115 production of carbon in the upper atmosphere before decaying very fast neutrons originating from disintegrations by high energy cosmic ray particles may collide with nitrogen t atoms to produce and this neutron capture should result in carbon and boron atoms and traces of cyanogen gas being present in the upper atmosphere while by products of the mechanism may contribute significantly to the formation of the inner radiation belt 10116 studies of the e layer of th ionosphere part electromagnetic perturbations and other anomalies departures from the predictions of simple theory in observed e layer behaviour are attributed to perturbations arising from the motor effect of the s system of currents flowing there the main effect is to raise near noon in low latitudes and reduce it in high latitudes the departure of from proportionality to and other anomalies are also discussed 10117 note on the role of small layers with irregular surfaces in the formation of sporadic e layers irregularities in the refractive index of the troposphere have been represented by a model which has now been adapted to the e layer the reflection coefficients calculated using the model are of the right order of magnitude 10118 irregularities in the e layer of the ionosphere correlation analysis shows no systematic elongation at cambridge in contrast to the ew elongation of auroral and elongation of equatorial type of e there is q wide range of sizes in the scale of the irregularities in the diffraction pattern on the ground 10119 consideration of the f layer in the ionosphere a graphical statistical description of the diurnal seasonal and annual variations of at kokobunji and information on the relation between and 10120 diurnal variation of f region drifts at waltair the results of f region drift measurements for the four seasons in the years are given 10121 equatorial spread f at ibadan nigeria spread f characteristics are closely related to the height of the layer the irregularities may be due to hydromagnetic disturbances which are increasingly attenuated at lower heights 10122 variation in height of anisotropy and random drift velocity of the irregularities in the ionosphere correlation analysis shows that the axial ratio of the anisotropy ellipse and the random change factor are both greatest for waves reflected from heights of 10123 possible identification of atmospheric waves associated with ionospheric storms the onset time of an ionospheric storm is defined as the time of first increase at and the velocity is determined by measuring the time delay at godley head north of campbell island the mean northward velocity for eight well defined storms was found to be in the range and may correspond to the velocity of a neutral gaseous wave as indicated by the johnston island nuclear explosion disturbance 10124 a method of calculation of profiles from ionospheric curves 10125 a new method for the analysis of ionospheric records a method is given for a calculating the real heights of reflection in the ionosphere from the observed virtual heights the real height is assumed to be a polynomial in the plasma frequency 10126 general expression for the group refractive index of the ionosphere a general expression for the group refractive index of the ionosphere is found in which wave frequency electron density and collision frequency magnetic field and direction of propagation are variables 10127 a solution of the integral equation a method involving power series expansions is given for solving the integral equation one advantage of the method is the use of a set of master curves which applies for all stations 10128 a study of he variations in a daily ionospheric index of solar activity a table of daily values of sec at slough is given for the short term variations in from july december are examined by statistical methods and it is shown that these variations are related to changes in the sun 10129 a long term variation in the relationship of sunspot numbers to e region character figures the statistical relation between sunspot number and monthly mean values of at slough suggests that from onwards there has been a decrease in the value of corresponding to a given sunspot number 10130 solar flare effects in the f region of the ionosphere increases in were observed during flares in and which were accompanied by increases in sea level cosmic ray intensity sm similar increases in are reported in november at two stations and simultaneous falls in isoinic heights of were also observed 10131 sporadic e phenomena associated with the high altitude nuclear explosions over johnston island marked increases in e occurred near latitudes and s and are attributed to the explosions 10132 magnetic effects in the f region of the ionosphere night time values of f at stations in the south of africa are found to decrease with increasing values of the equivalent planetary daily amplitude the magnetic control of night time ionization could account for the day to day correlation of values the relation of ionospheric and magnetically quiet days is discussed 10133 automatic ionogram scaler an instrument has been designed which projects an ionogram on to a screen the parameters which are read off are recorded simultaneously on punched tapes and in typewritten form the tape can be used to produce punched cards if required 10134 active high frequency spectrometers for ionospheric sounding part determination of true height from the virtual height of reflection a new method for determining true hi height is described of august ad its application to daytime and nighttime soundings discussed 10135 a new type of ionospheric drift recorder a method of eliminating photographic and pen recording of fading signals and the laborious calculations a tape recorder is used to introduce a variable time delay into one aerial feed when this delay equals that of the received signals a minimum is obtained delays of have been measured 10136 day to day and station to station correlation of ionospheric f region critical frequencies the correlation of simultaneous values at stations separated by in a north south direction is found to have a semi diurnal variation the phase of which varies with season results at a single station show an important autocorrelation for values at the same time on consecutive days and this is ascribed to magnetic effects 10137 year to year changes in the winter anomaly in ionospheric absorption the mean anomalous component in a given winter is linearly related to the mean magnetic c figure for the same winter 10138 some characteristics of solar corpuscular radiations which excite abnormal ionization in the polar upper atmosphere statistical data on the time delay from the occurrence of a major flare until the onset of polar absorption have been studied it is suggested that particles ejected from the sun may be trapped in a corpuscular cloud which may later intersect a magnetic line of force along which particles can travel to reach the earth 10139 the coupling between the protonosphere and the normal f region in the protonosphere above about the distribution of protons is determined by diffusion rather than chemical processes this region is independent of diurnal changes in the ionosphere 10140 continuous recordings for the determination of the vertical gradient of the refractive index in the free atmosphere report on measurements made by equipment mounted at six different levels on a twoer to determine the correlation between the refractive index gradient and field strength fluctuations over a radio link path 10141 the radio refractive index gradient over the british isles airborne microwave refractometer measurements made in the british isles confirm that the quantity varies exponentially with height the variations in the parameters are less than those in the usa there is a high correlation between the surface value of and the average decrease in the refractive index in the first kilometre of altitude 10142 a criterion for thunderstorm theories results on the charging and external currents of the same storm favour the classical theory rather than the convection theories 10143 aurora and airglow from colour film observations summary of experience using colour film records 10144 investigation of auroral echoes part ratios of measured echo signal strength at and showed that the frequency dependence of the reflection e coefficient is qualitatively e plained b by either an inverse law partial reflection from large surfaces or an exp law scattering from field aligned irregularities 10145 narrow band atmospherics from two local thunderstorms were studied reception frequencies of and were used with power bandwidths in the range duration peak amplitude mean field strength and mean power flux were calculated results conflict with some theories of the origin of atmospherics 10146 on the extremely low frequency spectrum of earth ionosphere cavity response to electrical storms a comparison of the observed and calculated spectra in the range 10147 simultaneous observations of clf noise at hobart and macquarie island the noise sources seem to be small in size and to have different locations at and kcs 10148 dispersions of multiple stroke whistlers analysis of igy records at durban indicates a increase in the dispersion of successive components of multiple stroke short whistlers which supports the current jet hypothesis of whistler generation 10149 theory of nonlinear control a review of work in various fields of nonlinear control 10150 stabilized eht supply unit for photomultipliers provided the load is substantially constant the circuit will produce an output voltage of with an error not exceeding during mains fluctuations of 10151 spectral response of solar cell structures measurements on si cells with the pn junction to below the surface show that the short wave response is relatively increased by making the junction close to the surface and the long wave response by making it deeper effects of rough and smooth surfaces were also studied 10152 on the lectr cal pa am ters of some types of s lenium rectifier 10153 variable precision regulated low voltage high current supply for large electromagnets circuit details are given of a power supply with combined electronic and magnetic amplifier control delivering currents of at with regulation and ripple values 10154 design and application of a digital differential analyser the principles of operation and limitations of a digital incremental computer are given and fields of research in which its accuracy and speed would be useful are suggested 10155 full binary adder with one tunnel diode three resistors and one tunnel diode in a wheatstone bridge network give both sum and carry outputs 10156 a program for finding the zeros of a polynomial by analogue computer 10157 a magnetic associative memory a computer storage system is described in which data flow in and out on the basis of content rather than location a small experimental model of the system using ferrite cores is also described 10158 a probability distribution analyser utilizing electrostatic storage the instrument has a linearity within and analyses input waveforms of frequency 10159 a universal nonlinear filter predictor and simulator which optimizes itself by a learning process after a discussion of some cybernetic principles a machine is described which by a process of successive runs on an input function ultimately produces a target function with least error the machine incorporates a tra k tape recorder and analogue multipliers of a novel piezomagnetic type which perform multiplications per second with errors not exceeding and 10160 a cathode ray tube output for a digital computer a variety of displays can be programmed and are photographed by a camera controlled by the computer 10161 alphanumeric characters the available characters are displayed by the splot deflection method at a rate of sec a full description of the systems with block and circuit diagrams is given 10162 logarithmic compression of binary numbers this to bit converter uses bits for the most significant figures and bits to indicate the position of the binary point accuracy is within 10163 step by step design techniques for multilayer thin film networks performances of various circuits incorporating thin film passive networks and those with conventional components are compared 10164 magnetics in doppler signal data extraction doppler radar data extraction problems such as detection integration and interrogation using devices with magnetic cores are discussed 10165 a magnetic device for high speed sensing of small currents the structure and operation of the ferror device are described it comprises a bar of low coercive force square loop ferrite with two holes transverse to the long axis the material around the holes acts as a pair of toroidal cores whose switchable flux may be controlled by a solenoid current 10166 the vibrating capacitor theory and application 10167 the energy properties of nonlinear reactance circuits there will be a conversion of power at one frequency to power at another frequency if one frequency is a rational fraction of the other or if at least one intermodulation frequency exists 10168 a network theorem the problem of determining the transfer impedance between a generator emf at one end of a resistance terminated ladder network and the load current at the other end is simplified by splitting the circuit into two sections 10169 on scattering matrices normalized to complex port numbers a terminal network with generators having complex impedances is considered 10170 a review of methods of linear network analysis in the steady state parts the establishment of an independent set of network variables permits various methods of network solution the four terminal network and the use of reference parameters are also considered 10171 wide band impedance transformers an analysis of networks consisting of cascades of lumped circuit sections of graded impedance level 10172 a property of passive lossless quadripoles and its application in the design of ladder filters the validity of formulae giving the values of elements of various filter structures is established by expressing the insertion loss as a function of the iterative parameters of a fictitious network 10173 using jacobians for frequency selective networks the advantages of the use of jacobians for synthesis of networks to give a specific frequency response is demonstrated with a simple network 10174 computation of mechanical filters filter design procedure and data are summarized 10175 active low pass rc filters a method is described of synthesizing the overall response of active cascaded low pass filters using simple rc ladders and buffer amplification 10176 tunnel diode down converters different circuit analyses are compared 10177 the dynamics of a subharmonic oscillator with linear dissipation a mathematical analysis is made of the dynamic behaviour of subharmonic oscillators parametrons assuming a nonlinear reactance but a linear dissipation or resistance 10178 present state of millimetre wave generation and amplification a review of techniques particularly those based on the use of conventional microwave valves 10179 pull in frequency of the phase controlled oscillator the pull in frequency derived by goldstein and confirmed experimentally by byrne is lower than that recently derived by rey of january 10180 additional negative resistance oscillation modes several class c modes are considered 10181 voltage variable capacitors make a relaxation oscillator the controllable frequency range is 10182 random pulse generator tests circuits encodes messages the shift register generator uses high speed logic circuits in producing complicated pulse sequences up to bits in length 10183 testing the linear distortion of transmission systems by means of rectangular pulses and application of this method for explaining the differential equalization used in magnetic tape equipment 10184 generation of nanosecond carrier pulses at x band with tunnel diodes 10185 tunnel diode ring counter 10186 multiaperture core counters tive nondestructive storage read out description of a counter circuit and its use in a missile guidance control system 10187 rf gate with carrier suppression a gate is described with a carrier suppression ratio db the ungated cw signal is continuously available circuitry leakage measurements and screening techniques are described 10188 frequency multiplication by large factors by means of the oscillation build up method frequency multiplication by factors of several thousands can be achieved with the oscillator described which is pulse controlled at the fundamental frequency and produces a harmonic spectrum of few components during the build up of oscillations 10189 methods of pulse selection to produce accurate timing marks from standard frequencies counter circuits are given which are suitable for the production of low frequency timing pulses independent of phase fluctuations in the frequency dividers of crystal clocks 10190 a matrix representation of linear amplifiers expressions are developed for the transfer matrices of combinations of bilateral and unilateral networks and of some passive and active networks including r feedback amplifiers 10191 designing for low level inputs difficulties arising in low level input instrumentation and methods of checking and evaluating the performance of such equipment are given 10192 interstage design for stagger loaded amplifiers a family of low pass butterworth amplifiers each stage having a different load impedance is described the resulting stagger loaded amplifier has high gain and large band width an example shows half power points at and and a mid band gain of 10193 the theory of negative feedback voltage amplifiers a modification of the standard method of analysis taking account of the fact that the attenuated feedback voltage cannot always be subtracted directly from the input voltage in practice 10194 dc amplifier with particularly high zero level stability a push pull circuit for drift compensation in dc amplifiers is described and details are given of its practical application and performance 10195 contribution on the dynamic plate load amplifier a method is described for improving frequency and phase response of the type of amplifier considered in of brown 10196 single ended self balancing magnetic amplifiers for changing the effective impedance of ink recorders 10197 common emitter amplifier the medium frequency performance of common emitter amplifiers is examined in terms of the simple equivalent circuit for a transistor formulae enabling the best type of transistor to be selected are derived 10198 transistor cascode circuit improves automatic gain control in amplifiers an improved method with circuit details for applying agc to transistor if tuned amplifiers is described the effects of changes in the transistor parameters with change of operating point on the q factor and the centre frequency of the tuned circuits are minimized 10199 a theoretical comparison of average and spot noise figure in transistor amplifiers 10200 investigation of the performance of coupled cavity maser type amplifiers part a general formula is developed to determine the equivalent noise temperature and gain stability of several elementary structures by comparing these results interesting features of multicavity masers are demonstrated 10201 travelling wave maser with instantaneous bandwidths more than twice the intrinsic line width of ruby were obtained by stagger tuning the applied external magnetic field 10202 parametric circuits with nonlinear reactances and resistances equivalent circuits of nonlinear reactances and resistances ar derived for calculations on parametric amplifiers expressions giving the circuit voltages are tabulated for parametric amplifiers up converters and down converters of the dynatron type and the non linear capacitance type 10203 sensitivity of the degenerate parametric amplifier although the noise temperature of a degenerate parametric amplifier is half that for a nondegenerate amplifier the minimum detectable signal is only better because the post detector noise fluctuation increases by a factor 10204 noise measure of distributed negative conductance amplifiers the modification required to the noise measure for circuits in which the characteristic impedance has a reactive part is given 10205 the noise temperature of cascade connected amplifiers a formula is derived for the noise temperature of a cascade connected amplifier with negative conductances as active elements this permits a simple graphical representation of noise characteristics examples are given of parametric amplifier stages and the influence of isolators and circulators on noise temperature and bandwidth is discussed 10206 parametric amplification with a low frequency pump the degenerate form of a three frequency parametric amplifier is considered 10207 an l band travelling wave parametric amplifier a gain of over a band around has been achieved 10208 reactance diodes and their application in wide band waveguide amplifiers 10209 noise in beam type parametric amplifiers 10210 parametric coupling between the transverse waves on and m type beams 10211 transduction of noise theory of a generalized travelling wave coupler 10212 selective high frequency amplification with tunnel diodes the design of a vhf fm tuner using tuner using tunnel diodes is detailed 10213 minimum noise figure of the negative resistance amplifier using esaki diodes the minimum noise figure is determined for a nonreciprocal single stage amplifier and the result is extended to cover multistage amplifiers a noise figure of about can be achieved for high gain single stage or multistage amplifiers 10214 semiconductor diode circuit provides gain the forward reverse characteristics of a diode can be used to provide amplification see of the characteristics of a circuit operating with power supply frequency considerably higher than the signal frequency are noted 10215 noise measure of lossy tunnel diode amplifier stages the influence of circuit losses and the diode series resistance on the noise figure of tunnel diode amplifiers is considered the calculation is repeated for a stage parallel circuit 10216 a saturable core modulation integrator a circuit is discussed which illustrates the use of saturable core reactors for operating directly on a modulation carrier use is made of the ability of a saturable reactor to convert a voltage integral to a magnetic flux and store it until required 10217 constant resistance modulators zobels constant resistance networks are interpreted in terms of constancy with time when the elements of the network are time variable and simultaneously in the same network the original conception of constancy with frequency when the elements are frequency variable may be realized the application to rectifier modulators is examined 10218 requirements regarding electrical squaring circuits and practical possibilities for the realization of square law characteristics the design of square law detector circuits for use in the measurement of rms values is discussed and the characteristics of various types of circuit using diodes or amplifier v valves are examined 10219 squaring circuits with staggered diodes with the circuit described a square law characteristic can be synthesized over a range of about ge diodes give better results than those obtained with thermionic valves 10220 crystal biasing improves millimetre wave detector at improvement in noise figure could be obtained by suitable biasing 10221 variational method for transport parameters in electron conductors the method described results in a simplification and clarification of calculation procedure 10222 derivation of the boltzmann transport equation for inelastic collisions a quantum mechanical treatment similar to that developed by kohn and luttinger for elastic collisions of for fermi dirac particles the scattering in the collision terof the transport equation is restricted to unoccupied states only 10223 negative resistance and hot electrons characteristics of ho electrons are analysed for negative resistance regions electrons in a homogeneous semiconductor are assumed to interact only with acoustic phons and charged centres of heavy mass which could be ionized impurities or heavy holes 10224 electron bunching in the multipacting mechanism of high frequency discharge electron bunching is analysed by an extension of simple multipacting theory 10225 electronic and ionic current at the cathode of a hollow cathode discharge the fractions of electronic and ionic current densities in the discharge are estimated the possibilities of other electron emission mechanisms are discussed 10226 instability of a plasma with an anisotropic distribution of ion and electron velocities investigation of the propagation of magnetohydrodynamic waves in an infinite a rarefied plasma a kinetic treatment leads to an increase of the instability region compared to that obtained in the quasihydrodynamic approximation 10227 fluctuations in a multicomponent plasma a theory of fluctuations in a plasma consisting of electrons and one kind of ion below is generalized to apply to several species of ions 10228 electrostatic sound wave modes in a plasma the ratios between the frequencies of the peaks observed in the anode voltage fluctuations in discharge tubes agree with those calculated using a simple theory of radial modes 10229 coupling mechanisms between longitudinal and transverse waves in a plasma the possible coupling mechanisms are deduced on the basis of fundamental plasma equations the existence of a nonlinear internal coupling effect is proved which can cause em radiation 10230 enhanced diffusion and oscillations in weakly ionized plasmas 10231 average forces in electromagnetic systems for ar a linear and loss free system it is shown that the time average force can be expressed in directly measurable circuit theory parameters 10232 a supplement to a study of electromagnetic point point sources a supplement to a previously published paper establishing that there are only two fundamental fields which can effectively be replaced by a point source corresponding to a distribution concentric about its origin 10233 cherenkov radiation for a dipole moment in a medium with spatial dispersion treatment of electric and magnetic dipoles in an isotropic nongyrotropic medium radiation from a ring current in such a medium is also considered 10234 radiation by charged particles passing through an electron plasma in an external magnetic field coupling between the longitudinal plasma wave and the transverse em wave modifies the nature of the radiation at particle velocities greater than that required for the excitation of plasma waves a non cherenkov type of radiation will occur 10235 incoherent microwave radiation from a plasma in a magnetic field the microwave emission from a plasma in a magnetic field is calculated theoretically using kirchhoffs radiation law for cases when characteristic waves do not couple within the plasma experimental observations of radiation temperatures and cyclotron radiation line breadth and shape are cited to illustrate applications of he theory to experiment 10236 classical electrodynamic equations of motion with radiative reaction the classical theory is reviewed previous objections to it are shown to be largely invalid 10237 radiation from fast particles moving through magnetic materials under certain conditions of frequency and angle of observation ringing of the spin system occurs differences from the normal cherenkov effect are discussed also the possibility of using the effect as a neutral magnetic moment detector or as a probe of magnetic materials 10238 wave propagation in an inhomogeneous waveguide analysis of the propagation of acoustic waves in a waveguide whose properties vary along its length the theory developed is applied to the propagation of acoustic and em waves in natural waveguides which may extend to distances of km and more 10239 study f of the electromagnetic field produced bya magnetic doublet in the presence of two medi separated by a plane surface a rigorous treatment for the general case of a doublet with its axis at any angle to the surface between the media the effects of special media are also considered 10240 the reflection of electromagnetic waves at a plane metal surface covered with an absorbing layer the reflection coefficient is calculated as a function of for an em wave incident perpendicularly on a thin absorption layer numerical and graphical methods are given for the evaluation of layer parameters which make the reflection coefficient as small as possible over a wide range of 10241 a note on the back scattering of a circular disk asymptotic series are obtained for the back scattering cross sections of an acoustically hard disk an acoustically soft disk and a perfectly conducting disk 10242 the diffraction of electromagnetic waves at rectangular apertures in plane metal screens an approximation method of calculating the diffraction field is applied to the case of rectangular apertures results are compared with those obtained experimentally 10243 diffraction by an elliptic cone two greens functions are derived for the reduced wave equation in the exterior or interior of an elliptic cone 10244 a note on the back scattering by an infinite strip the first few terms in the asymptotic series of the back scattering cross section of an infinite strip lying in a plane perpendicular to the direction of propagation of an em wave are calculated for all angles of incidence 10245 scattering of a surface wave by a discontinuity in the surface reactance on a right angled wedge an examination of the em field produced when a surface wave travels along the front face of a right angled wedge and is c scattered by the tip 10246 an experimental study of bistatic scattering from some small absorber coated metal shapes the absorber coating reduces energy scattering in the back hemisphere but increases the energy scattered in the forward hemisphere 10247 mechanisms of double resonance in solids 10248 ferromagnetic relaxation part theory of the relaxation of the uniform precession and the degenerate spectrum in insulators at low temperatures scattering by surface polishing imperfections equalization of degenerate mode populations and raman scattering are considered theoretically and compared with experiment 10249 theory of magnetostatic modes in long axially magnetized cylinders the characteristic equation determining the eigen frequencies of the magnetostatic modes is derived from the equations of motion and the boundary conditions 10250 instability of spin waves and magnetostatic modes in a microwave magnetic field applied parallel to the dc field two methods of calculating the instability threshold are described a plane wave analysis strictly applicable only in an infinite medium and a more rigorous theory in which the boundary conditions at the surface of the sample are taken into account 10251 the role of phonons in paramagnetic relaxation theory is given for the coupled spin lattice bath system with nonequilibrium phons experiments fail to indicate the presence of such phonons 10252 observation of forbidden resonances in optically driven spin systems 10253 thermal tuning of ruby optical maser 10254 radio techniques and space research a brief review of the papers on radio topics presented at the british ir convention 10255 the stability of force free magnetic fields the condition is derived for a force free magnetic field to exercise a stabilizing influence on an equilibrium configuration several cases are given for which the condition is satisfied 10256 the technique of radio astronomy review of applications of radio techniques in modern astronomy including radio telescopes interferometers and echo equipment 10257 results of radio astronomy review of the field of radio astronomy measurements particularly with regard to solar observations 10258 radio astronomy various measurement techniques in the hree main fields of research are described and their limitations discussed 10259 the radio telescope interferometer at the royal radar establishment two mobile and steerable radio telescopes with parabolic reflectors in diameter are used either separately or in conjunction as an interferometer the system is designed to operate in w wide frequency range down to cm 10260 a new source of centimetre radio waves during observations carried out at pulkov observatory on march on a new rf source of energy was detected in the galactic plane the co ordinates being and 10261 lunar occultation of a radio source by observation of the times of disappearance and reappearance of a radio star behind the moon the position of the source can be obtained with great accuracy taking into account all sources of error the estimated position is probably correct to within of arc 10262 solar radio astronomy in taly the development of radio astronomy outside and inside italy is traced and details are given of installations at the astrophysical observatory at arcetri some results of observations made there are illustrated and discussed 10263 observations of solar radio noise during august solar rf noise during the noise storm in august showed that the intense amplitude scintillation does not appear to extend down to frequencies as low as and that the storm both began and ended before the m storm did so 10264 very low frequency modulation of discrete frequency solar noise bursts measurements of type and type bursts at and show envelope fluctuations which were examined over the range the observed narrow band structure is illustrated 10265 a relation between solar radio emission and low energy solar cosmic rays 10266 characteristics of the ngc radio emission observations carried out with the puk pulkov radio telescope of virgo a showed that the angular extensions of he rf source on are smaller than those determined by mills on cm brightness distribution depended essentially on wavelength 10267 radiation measurements of kilometres altitude at equatorial latitudes the relative fluxes energy spectra and angular distributions of electrons and protons determined during three flights are reported the electron spectrum appears to be softer than that expected from a neutron beta decay origin 10268 effect of hydromagnetic waves on the lifetime of van allen radiation protons hydromagnetic waves with frequency less than and amplitude at two or three earth radii are capable of removing all high energy outer belt protons maximum energy in about day if an albedo neutron source is assumed for the inner belt protons the calculated proton flux as a function of radial distance from the earth agrees well with pioneer results 10269 cosmic ray phenomena during the november solar disturbances cosmic ray data for high and middle latitude stations are examined to investigate the interaction of a solar flare increase and forbush decrease 10270 the spectrum and propagation of relativistic solar flare particles during july an examination of cosmic ray data reveals two increases of solar protons for which the time vr variations are quite different this difference is attributed to a change in the interplanetary field 10271 a theory of radar reflection from the moon and planets relations between the surface statistics of an irregular radar target and the angular power spectrum and autocorrelation function of the reflected signal are derived the spatial correlation function is also computed the theory is used to investigate the small scale structure of the moons surface 10272 meteorites and meteors a general outline of the field of meteor studies with a few details of meteor tracking equipment at the microwave centre in florence and results obtained there 10273 the distribution of meteor masses for sporadic meteors and three showers distributions of maximum line densities in meteor trails are derived from radio echo data for sporadic and shower meteors 10274 attachment processes in meteor trails the effects of electron attachment to neutral particles on the characteristics of long duration meteor echoes are considered two body and three body attachment processes produce differing effects and these are compared with observations 10275 the characteristics of persistent sporadic meteor echoes for sporadic meteors whose trails have an electron line density greater than electrons the observed distribution of meteor echo duration cannot be explained by power law distributions there is no significant seasonal or diurnal variation in the mass distribution of the meteors examined 10276 a possible explanation of th long duration radar echoes of ionized trails in the upper atmosphere in ionospheric regions where the plasma frequency is near the frequency of the incident wave the local wavelength of the latter is very long and the destructive interference of the fields scattered from the dispersed trail is less effective 10277 volume density of radio echoes from meteor trails in radar type reception the echo density is evaluated taking account of trail orientation the meteor evaporation process and the characteristics of the transmitter receiver system used for back scatter reception 10278 volume density of reflection points of meteor trails in radio links the procedure developed for back scatter systems above is applied to the case of forward scatter links 10279 geomagnetic crochet of november discussion of the geomagnetic and ionospheric effects of a large solar flare 10280 a possible explanation of observed at high geomagnetic latitudes an explanation of is given in terms of hydromagnetic waves propagating along the geomagnetic field lines 10281 the scientific uses of earth satellites a survey is given of the effect of the use of artificial satellites on measurements relating to the gravitational field the atmosphere the upper ionosphere magnetic fields near o the earth and in interplanetary space and the zones of trapped radiation 10282 on simulation studies of motion of bodies in ionized atmosphere the problems involved in laboratory model studies on satellite motion in an ionized z atmosphere are analysed scaling relations obtained satisfy the conditions for aerodynamic magneto hydrodynamic and electrodynamic similitude flight conditions corresponding to the earths upper atmosphere can be simulated by suitable scaling of he test model 10283 on the long period lunisolar effect in the motion of the artificial satellite formulae for the determination of long period effects caused by the sun and moon on the motion of satellites and the stability of their orbits are developed 10284 rapid variations of the rotation period of the second soviet artificial earth satellite with respect to the transverse axis a table is given of data on the rotation period during march april 10285 determination of the vertical distribution of ozone by satellite photometry june 10286 density of the upper atmosphere determined from satellite orbits and its variation during calculations from the orbits of satellites in the height range show a decrease in density as the sunspot activity declined between and the influence of latitude on density and the large day to night variation above are also considered 10287 satellite sounder and telemeter chart ionosphere electron density a satellite borne ionosonde is described which is to be launched into a orbit by the usa measurements will be made on six log spaced frequencies between and by transmitting pulses of each frequency in turn crossed dipole receiving aerials are connected in phase quadrature and the receiver is arranged to receive echo pulses of one polarization and then pulses of opposite polarization a transistorized transmitter gives z peak power of with pulse length data will be recorded by the satellite and transmitted on command to ground stations 10288 the atmospheric density in the earths ionosphere and exosphere the atmospheric density distribution in the exosphere and the f layer as determined from satellite observations is plotted and causes of density fluctuations with height are briefly discussed 10289 rate of ion atom interchange conclusions about the rate of conversion of atomic ions into molecular ions in the ionosphere are reiterated and an alternative suggestion of june is discounted 10290 density fluctuations in a plasma in a magnetic field with applications to the ionosphere general expressions are derived for the fluctuations in density of electrons ions and net charge in a plasma in thermal equilibrium in an external magnetic field coulomb interaction and two body collisions are taken into account the total scattered power and doppler spectrum is calculated for incoherent scatter from the ionosphere at with a radar at mcs the total power is unaffected by the magnetic field but resonance peaks at multiples of the ion gyro frequency appear in the spectrum when the radar beam is within of orthogonality with the field lines 10291 extensions of the chapman theory of layer formation an attempt has been made to establish some of the theorems necessary for the extension of the chapman theory of layer formation to the case where a spectrum of ionizing radiation acts on an atmosphere with any temperature profile some invariant properties of the electron production function have been established and they have proved useful in estimating the temperature and temperature variations in the ionosphere 10292 theory of electrostatic fields in the ionosphere at polar and middle geomagnetic latitudes analysis of the elongated es fields which provide the coupling in the dynamo motor concept of the e and f regions the es field is taken to be of arbitary horizontal scale and numerical solutions are determined for the attenuation of the field wi h a horizontal scale as small as or can extend from to height with a reduction of only about but the coupling efficiency is critically dependent on ionospheric conditions 10293 photoionization heating in the f region of the atmosphere an estimate of the total f region heating due to photoionization is made based on a comparison of theoretical and observed models of several atmospheric parameters the heat flux due to photoionization is estimated to be approximately erg cm sec which would be a major if not predominant source of heat in this region 10294 observations on the ionospheric f layer at night part height of maximum ionization critical frequency and semi thickness of f layer at night measurements taken at cambridge england agree with those for other stations the scale height determined from the semi thickness of the layer is too small when compared with rocket and satellite observations 10295 group and phase velocities of a travelling disturbance in the f region of the ionosphere the disturbances cause gross distortions of ionogram records and have a velocity of about min they are associated with sporadic e patches having a velocity of about which is the phase velocity of the disturbances 10296 on vertical drift velocities of the f layer vertical drift velocities in the f layer are deduced by evaluating the equation of continuity of electron density and compared with observed movements some correlation is found 10297 a statistical study of ionospheric drifts measured by the radio star scintillation technique the method gives the ew component of the drift velocity throughout the day this component is commonly found to reverse suddenly near but the complementary reversal occurs at a less definite time during the following day 10298 rocket measurements of flayer electron density and their interpretation theoretical considerations about the shape of the electron density profile near the f peak are compared with data obtained from rockets of march the results are consistent with day and night temperatures of about an respectively numerical values of the loss coefficient and other parameters are given 10299 an ion trap measurement of the ion concentration profile above the f peak the results of a winter evening rocket flight give the ion concentration from to and indicate a constant scale height above 10300 an annual variation of the density of the upper atmosphere of the earth the various causes of the fluctuations of upper air densities see of june which result in observed changes of satellite orbits are discussed the possible influence of interplanetary matter and of an interstellar wind is mentioned 10301 active high frequency spectrometers for ionospheric sounding part numerical recording of delay times equipment for the automatic determination and printing of echo heights in numerical form is described 10302 active high frequency spectrometers for ionospheric sounding part methods of automatic determination of true height the direct evaluation of profiles from the echo delays measured a the output of an ionosonde is proposed three digital and three analogue methods are discussed and block diagrams given 10303 density in a planetary exosphere 10304 evidence on the laminar nature of the exosphere obtained by means of guided high frequency wave propagation radar pulses at were transmitted in the direction of the earths magnetic field from washington dc delayed echoes were found on many occasions from distances between and km each echo remained at a constant range a possible explanation is given 10305 orientation of polar auroras observations of homogeneous arc auroras at three antarctic stations are presented and show a diurnal variation of orientation thus supporting the observations of weill vol 10306 the east west drift of auroral forms determined from all sky camera films 10307 thickness of an active auroral curtain 10308 models of auroral ionization part auroral ionization models and their radio reflection characteristics several general models of auroral ionization are developed by considering the ionization as an assembly of scattering centres it is possible to include a unified treatment of weak scattering and critical reflection 10309 models of auroral ionization part applications to radio observations of aurora the radio reflection characteristics are examined in the light of the theory developed in above critical reflection at implies electron densities up to electrons cm the observations are consistent with the electrons elongated in the ratio of or parallel to the field lines and a few metres in diameter perpendicular to the field 10310 atmospheric noise levels from to kilocycles per second a comprehensive series of observations on atmospheric noise in california and florida for frequencies below is described and analysed the diurnal variation for loop orientation is a minimum in the interval at both sites and minimum noise levels are found to occur between and the latter result is in agreement with the theory of wait of 10311 a study of whistling atmospherics part occurrence results of igy whistler observations at brisbane adelaide hobart and macquarie island are presented and the seasonal diurnal and latitude variations of incidence of occurrence are discussed 10312 a study of whistling atmospherics part diffuseness diffuseness defined as the average time duration of whistler energy on a fixed frequency is found to be twice as large for long as for short whistlers to be independent of season and time of day and to be linearly related to geomagnetic latitude and whistler dispersion 10313 observations of hydromagnetic emissions a frequency time analysis of geomagnetic pulsations was made in the range for the period november the oscillations were observed simultaneously in california and nevada and were probably influenced by solar flares which occurred before and during the dates mentioned 10314 two hop whistler mode echoes received at seattle 10315 complex plane charts for obtaining closed loop frequency responses in linear control systems summary of graphical methods for plotting complex plane charts 10316 outside coil magnetic head improves high frequency recording high resolution is obtained as a result of smaller air gaps and an improved field configuration 10317 replacing sine wave sources with solid state inverters a series magnetic amplifier f or a saturable reactor is used following a solid state inverter to give a modified square wave output such that the heater and direct voltages available are the same as would be obtained from a sinusoidal ac supply 10318 converter efficiency and power output of a tunnel diode relaxation oscillator a simple dc ac converter is discussed 10319 control of frequency and phase displacement in transistor converter circuits by means of rc networks a new type of adjustable frequency transistor converter is described in which the operating frequency is controlled by a rc network and is independent of the direct voltage power regulation by means of rc phase control of a pair of transistor converters is discussed 10320 controlled rectifier produces quarter megawatt pulse power circuit details are given of pulse generator equipment using solid state devices as active elements a pnpn si controlled rectifier acts as the switch and two layer and four layer diodes are used in the trigger generator 10321 recent developments in selenium rectifiers an account of phenomena occurring during the construction and operation of different types of se rectifier 10322 a note on transistorized ripple filters a smoothing circuit providing optimum efficiency over a wide range of load currents is described 10323 digital computers annual review of developments in computer design with descriptions of recent installations and tabulated performance data 10324 notes on the structure of logic nets an elementary approach to a theory of the role of structure in logic nets 10325 the main store of a digital differential analyser a description of the performance and circuits of the main store of corsair 10326 a potential microwave compu er element a bistable oscillator frequency script system is described which uses a tunnel diode as the active element a switching time of the order of cycles is required for resonance frequencies of operation at has been demonstrated and operation at is suggested 10327 new thermally variable bead resistor the unique characteristic of ion doped is illustrated a bead in diameter dissipated in still air 10328 equivalent circuits of coils with distributed capacitances the equivalent circuit comprises an ideal coil a certain number of positive capacitances two in the case of a coil with one winding and an additional capacitance which can be either positive or negative depending on the relative magnitude and the exact distribution of the various parasitic capacitances 10329 on the core gain of the magnetic amplifier cores new definitions specific core gain and core gain are suggested and the relation of these to the power gain of an amplifier is discussed 10330 an experimental study on the ampere turn gain of ordinary saturable reactors measurements show that great improvements in performance of dc instrument transformers can be obtained by slightly increasing the effective ratio of primary to secondary turns and applying a properly rated ac bias circuit 10331 on the linear circuit aspects of cryotrons an expression is derived for the gate resistance of a cryotron in the transition region 10332 variable conductance sampling switch weighted sums are produced of discrete samples from continuous voltage waveforms by varying the rate at which the integrating capacitor can charge the switch has been operated randomly and cyclically at rates between and sec 10333 the silicon cryosar the main difference from the ge cryosar of is that negative resistance characteristics are obtained using crystals with uncompensated impurities as a computer element the device has been switched in about and has a maximum minimum voltage ratio as high as 10334 ire standards on solid state devices definitions of terms for nonlinear capacitors 10335 on some aspects of matrix calculus applied to local oscillation in nonlinear circuits the application of matrix methods to the analysis of oscillating circuits with an impressed signal of lowamplitude is considered the representation of amplitude and phase modulation in co ordinate form is illustrated and examples are given of the use of these methods in problems of oscillator stabilization 10336 elliptic functions in network synthesis the jacobian elliptic functions are used to solve the approximation problem of network synthesis a unified design chart for image parameter filters elliptic function filters and phase difference networks is shown and tabular and graphical data emphasizing extreme parameter values are given 10337 shaping of distributed rc networks an improvement in the attenuation factor of a phase shift network from to appears to be possible if the conventional uptapered section network is replaced by a tapered distributed network 10338 graphical procedures for solving the approximation problem of electrical filters three graphical methods of synthesizing filter response characteristics as the sum and difference of functions of similar geometric form are explained the methods are theoretically equivalent but have different fields of application for english version see 10339 optimum matching of symmetrical low pass and high pass filters application to low pass and high pass ladder filters using piezoelectric crystals a filter structure is suggested which is especially suitable for use with crystal elements advantages and disadvantages of this and similar structures are discussed 10340 tunable rejection filters an analysis of the requirements for a rejection filter is used in the design of some practical circuits tunable over half an octave and covering the hf band 10341 vhf broad band variable group delay equalizers the two designs described are for links using telephony channels or line subcarrier colour television telephony channels or line subcarrier colour television 10342 application of graph theory to the analysis of active and mutually coupled networks a unified graphical approach applying the concept of the mathematically equivalent circuit of as it relates to the indefinite admittance matrix of a multipole 10343 stable low noise tunnel diode frequency converter an initial wide band converter with local oscillator frequency and intermediate frequency had unity conversion gain and a radiometer noise figure of 10344 self oscillation in a transmission line with a tunnel diode a theoretical analysis of the circuit is given together with experimental results the self oscillation can be explained as a periodic solution of the linear wave equation with a nonlinear boundary condition 10345 broadening of the spectrum of an oscillator due to noise a formula is derived for the frequency broadening due to random thermal noise in a nonlinear circuit 10346 pulling phenomena in valve oscillators a general theory of pulling effects is derived on the basis of band filter theory these effects are calculated as a function of detuning and degree of coupling between similar and dissimilar oscillator circuits a mechanical analogue of a pulled oscillating system is described 10347 varistor network controls voltage tuned oscillator an af phase shift oscillator with varistors as the variable elements has almost constant output over a range of and low harmonic distortion 10348 locking of a two circuit oscillator the addition of a second tuned circuit improves the amplitude frequency and phase frequency characteristics of a locked oscillator the effect of coupling conditions on stability is s discussed 10349 recent development of quartz crystal units for telecommunication a new method and equipment devised for manufacture and development of crystal units in the range and associated apparatus are described 10350 tunnel diode one sho and triggered oscillator th one tunnel diode flip flop described by kaenel of june which requires a bidirectional pulse can be made to operate as a triggered oscillator the switching mechanism of the schmitt trigger circuit using transistors equivalent circuits and characteristic curves ar derived results of measurements are given for comparison by the addition of an identical circuit with modified bias 10351 the tunnel diode pair the composite characteristic of the twin circuit is considered and its application in the design of astable monostable and bistable multivibrators is illustrated trigger requirements and effects of loading can also be determined 10352 a low level linear rundown circuit for pulse height to pulse width conversion a two transistor device consisting of a constant current generator and an emitter follower circuit is described experimental and theoretical analysis of the circuit are in good agreement 10353 tunnel diode fast step generator produces positive or negative steps the generator produces pulses of about duration having a rise time of at recurrence frequencies up to 10354 the collector coupled complementary pair the astable mode gives phantastron type waveforms with peak to peak voltages almost equalling the supply voltage the bistable md mode gives thyratron type characteristics 10355 fast coincidence circuits using avalanche transistors the circuit described has a resolution time of and an efficiency of results of tests made with a pulse generator and a pair of photomultipliers are reported 10356 an automatic self checking transistor counter with digital display 10357 a fast binary counter a transistor binary counter employing seven flip flops is described its operation is dependent only on the switching time of one flip flop which may be 10358 a tripler circuit using a capacitance diode mathematical analysis of a frequency tripler circuit and derivation of an equivalent circuit the results of the analysis and of measurements on a practical circuit are compared 10359 the pulse response of a delay line an expression is developed for each element of the network and a solution is obtained in the form of a convergent neumann series 10360 zener diode creates logarithmic pulse amplifier amplification over three decades is achieved by using as the logarithmic device a zener diode to which a small resistance has been added to straighten the characteristic curve 10361 note on the series correction of wide band amplifiers a variation of the series inductance correction circuit is considered in which the load resistance is connected across the output and the circuit designed for either maximally flat transfer impedance or maximally flat input impedance inconvenient ratios of input t output capacitance can be avoided by using a cathode follower stage 10362 a new magnetic controlled rectifier power amplifier with a saturable reactor controlling on time 10363 problems relating to transistor power amplifiers the design of transformerless af output amplifiers is considered and a graphical method for determining transistor thermal stability is given 10364 a circuit for the compensation of voltage drift in the input stage of a direct coupled transistor dc amplifier in the circuit given the temperature drift of the base emitter voltage has been compensated almost to the theoretical limit 10365 differential amplifier with regulator achieves high stability low drift a transistor dc amplifier suitable for missile tl telemetry systems is described 10366 narrow band amplification with transistors contribution to of with authors reply 10367 field swept maser oscillation the application by singer and want of september of their analysis of maser oscillations to experimental results of the author is criticized they attribute the oscillations to energy exchange between cavity and emitting sample th radiation envelope is however largely determined by the zeeman field sweep rate due to a different mechanism 10368 paramagnetic maser oscillator analysis an equation for the output waveform is derived and numerical solutions obtained using a computer good agreement with experiment is given for steady state and field swept oscillators 10369 project echo the dual channel travelling wave maser details of the ruby material isolator and amplifier package construction are given an instantaneous bandwidth of and effective noise temperature of were obtained and the gain was sufficient to override the noise of the following stage 10370 parametric amplifiers theoretical comparison of gain bandwidth noise and stability of the negative resistance amplifier and upper or lower sideband converters experimental results are also reported for english version 10371 the wide tuning range of backward travelling wave parametric amplifiers a method is indicated of increasing the range beyond that suggested by staus vol 10372 theory of nonreciprocal circuits with equal input and output frequency using nonlinear semiconductor elements the quadripole equations and transfer gain are derived for nonreciprocal amplifiers which consist of tunnel diode or parametric diode converter stages in cascade connection see also of january matching and decoupling problems are considered for various circuit configurations 10373 signal and noise characteristics of diode reactance amplifiers for the uhf region examples are given of mixer circuits straight amplifiers and a travelling wave amplifier using parametric amplifier techniques the problem of matching by means of nonreciprocal elements or by bridge circuit i also dealt with 10374 noise and stability of negative conductance amplifiers calculations of lowest noise figure attainable from stability considerations are in agreement with results of an earlier analysis of but the lowest possible noise figure is obtained at the expense of stability 10375 project echo lower side band up converter for satellite tracking radar the amplifier is pumped at and although regenerative it has been made conditionally stable by careful mechanical and electrical design the overall noise figure is gain and bandwidth 10376 a tunnel diode slot transmission amplifier a negative conductance waveguide transmission type amplifier consisting of a tunnel diode mounted within an s band waveguide end plate slot has been built operating at a frequency of with a bandwidth of and gain no measurements have yet been made of noise figure 10377 the matching problem of the ring type and double push pull modulator with filter termination at both ends detailed discussion of an impedance matching method for obtaining optimum frequency response and minimum attenuation 10378 a ring modulator with integrated filters a losslrdd four terminal frequency translating network is proposed which avoids using a transformer between rectifiers and filters 10379 theory of photoexcitation in solids the theory of optical absorption by photo excitation is reviewed and further investigated a distinction is made between oblique and vertical transitions 10380 tunneling from an independent particle point of view calculation of wave functions for tunnelling problems with applications 10381 radio frequency breakdown controlled by drift of electrons in an inhomogeneous magnetic field measurements of breakdown rf electron field versus magnetic field were made at pressures between and in and the breakdown field varied as the inverse square root of the magnetic field as predicted by theory 10382 experimental evidence for beam plasma interaction in a low pressure argon discharge 10383 broadening of a beam of electrons by the space charge a recurrence formula is developed for computing the broadening of the beam 10384 filamentary structure produced by an electric current in a plasma an electric field parallel to a magnetic field in a plasma at low pressure produces a current which is confined to a filament simple formulae are given for the cross section of the filament and the current in it 10385 space dispersive properties of plasma 10386 interaction of fast electron beams with longitudinal plasma waves equations are derived for the variation with time of the plasma wave spectral density and the fast electron distribution function for arbitrary velocity distributions 10387 waves in a rarefied ionized gas propagated transverse to an external magnetic field three modes of plane waves in which the perturbed magnetic field is parallel to the external magnetic field can be propagated transverse to the external magnetic field in a collision free and fully ionized gas in the hf limit the three modes behave respectively as em electron sound and ion sound waves 10388 concerning the disturbances produced by a body moving in a plasma formulae derived for the disturbance of electron density are used to calculate the effective cross section for the scattering of em waves at this disturbance in particular cases 10389 electrohydromagnetic waves in a fully ionized gas part the appleton hartree dispersion formula for magneto ionics is generalized to include the effect of heavy ions the ratio of particle energy to magnetic field energy in a wave of arbitrary frequency is determined a band of frequencies around the plasma frequency is found for which waves are attenuated location of these bands would enable the interplanetary magnetic field and electron density to be estimated 10390 the statistical mechanics dynamics and magnetohydrodynamic of plasmas a system of equations is established in particular to denote the movement the current and the compression tensor of an ionized gas these are applied to partially and completely ionized gases and used to obtain the general equations of magneto hydrodynamics propagation modes of different types of wave are determined 10391 on plasma oscillations with special emphasis on the landau damping and the gross gaps in the frequency spectrum a linear theory of oscillations of the form in a collision free electron plasma in an external magnetic field is given 10392 collective motions in a plasma due to magnetic interaction the existence of collective modes due to the static magnetic interaction between the current elements represented by the moving electrons has been investigated 10393 plasma density fluctuations in a magnetic field a continuation of earlier work in which the frequency spectrum was derived for the spatial fourier transform of the electron charge density fluctuations in a plasma the effects of a constant magnetic field in an arbitrary direction are considered a theoretical basis is provided for analysing back scatter experiments and intensities are derived a function of the real frequency variable for the case of thermodynamic equilibrium 10394 hydromagnet a self generating liquid conductor electromagnet the exciting current is generated by forcing a liquid conductor radially inwards across an axial magnetic field the tangential current thus generated adds to the initial applied field 10395 emergence into vacuum of the cherenkov radiation produced by longitudinal waves in a medium the em radiation of an electron moving into a vacuum from a medium with spatial dispersion is considered under certain conditions in addition to the transition radiation there is cherenkov radiation from longitudinal waves in the medium at large distances from the interface this radiation is a spherical wave confined to a narrow range of frequencies near the plasma frequency 10396 coherent generation of microwave power by annihilation radiation of a prebunched beam millimetre wave radiation at the level has been produced by the creation and annihilation of a tightly bunched electron beam a proposed extension of the method based on optical techniques is intended to produce power in the submillimetre region 10397 the problem of diffraction of electromagnetic waves at a perfectly conducting plane ring theoretical treatment of the diffraction of plane em waves assuming a ring of internal radius and width much greater than the wavelength integral equations for the shadow currents are given from which the total current flowing in the screen is determined 10398 diffraction of a plane wave by a unidirectionally conducting half plane the problem is formulated in terms of an integral equation specifying the screen function whose solution is obtained by the standard wiener hopf procedure expressions for the fields and the current induced on the half plane are given 10399 a note on the diffraction of a scalar wave by a small circular aperture 10400 kinetic theory of reflection of electromagnetic waves from a moving plasma mathematical analysis of the reflection of em waves from a plasma moving in a space in which the phase velocity of the waves is less than the velocity of light 10401 scattering of microwaves from a cylindrical plasma in the born approximation part formulae are derived for the angular distribution function and the effect of special distributions is considered 10402 some properties of resonance line shape functions mathematical discussion of the broadening of spectral lines 10403 shift of nuclear quadrupole resonance frequency by electric field a linear shift in the line in is observed when a field of several is applied parallel to the crystal axis the line shape becomes asymmetric and is attributed to unresolved line splitting 10404 linear effect of applied electric field on nuclear quadruple resonance a linear stark effect is observed in the line in and crystalline powders as predicted theoretically 10405 linear effect of applied electric field on magnetic hyperfine interaction 10406 angular variation of axial spin hamiltonian eigenvalues in strong magnetic field the expressions for the energies of transitions between levels with strong field quantum numbers m and m the tables give the values of the coefficients containing and for a range of values of these parameters 10407 a proposal for a tunable source of radiation for the far infrared using beats between optical masers 10408 theory of quantum oscillators in a multimode cavity the distribution of power in the various modes in the steady state operation of an optical maser is studied 10409 shhsrroposed technique for modulation f coherent light a frequency shift of the coherent light output proportional to the strength of an electric field applied to a ruby laser provides a system for fm of the output 10410 studies in cosmic radio noise at bungalore the techniques in use at banalore for a radio survey of the sky and the disturbed sun at and are described 10411 interpretation of cosmic noise measurements at from satellite and the analysis given is based on the assumption that observed variations in signal strength were due to three causes variation of radiation resistance o the aerial with the dielectric constant of the surrounding ionosphere restriction of the angular aperture at the aerial due to ionospheric refraction and polarization and variation of cosmic noise power over the sky 10412 oscillations in the refraction of radio waves emitted by the sun radio astronomy observations at sunrise in november and december at wavelengths of and showed a periodic variation of ionospheric refraction with uniform change of zenith distance of the sun this variation is analysed in terms of sunspot activity and the motion of cellular waves in the ionosphere see of 10413 lunar temperature measurements at 10414 distribution brightness in extragalactic radio sources measurements have been made at both on and base lines with a resolution of about interpretations are given of the asymmetry observed in sources 10415 the radio source hercules a interferometer observations were made at on the two components of the intense source the separation in declination is 10416 central component of the radio source centaurus observations made ith a variable spacing interferometer at and show that the radiation originates outside the wide dust band 10417 flux and energy spectra of he protons in the inner van allen belt 10418 energy spectrum of electrons trapped in the geomagnetic field solutions of the fokker planck equation for th electron distribution function are obtained by reducing the equation to an eigenvalue problem the spectrum obtained with a source of decaying albedo neutrons is at variance with the observed result 10419 characteristics of the van allen radiation zones as measured by the scintillation counter on explorer results were obtained over a period of four weeks from a counter recording fluxes of electrons above and protons above a geomagnetic storm which occurred about a week after launching the satellite produced an immediate increase in the counting rate large fluctuations in particle intensity were observed at the d edge of the outer van allen belt during the storm which were closely related to simultaneous geomagnetic activity 10420 on meteor ablation in the atmosphere improvements to the usually adopted theory are given and approximate expressions suggested for the fundamental equation of ablation of low velocity meteors 10421 reduction of meteor velocities from continuous wave radio records an analysis of the reduction technique used at ottawa shows that in velocity measurements any statistical bias was positive and less than 10422 some studies of geomagnetic micropulsations recordings made at four stations in australia are analysed the period of the continuous type of oscillation increases with latitude and also varies diurnally the damped trains of oscillations occurring mainly near midnight are followed by magnetic bays with an average delay of about min effects observed during magnetic storms are discussed 10423 some features of magnetic storms in high latitudes ionospheric currents in high latitudes during magnetic disturbances are deduced from magnetic data lists of disturbances during and prior to the igy are given 10424 the national program for lunar and planetary exploration an illustrated description of the ranger and other planned spacecraft 10425 excitation of plasma waves by bodies moving in ionized atmosphere an ionized cloud formed in front of a rapidly moving body excites waves by interaction with the ambient plasma extraordinary em waves are generated in the presence of a suitable weak magnetic field 10426 on the interplanetary magnetic storm pioneer a magnetic field of to was detected by pioneer perpendicular to the sun earth line during periods of intense solar activity between march and april quiet time fields of were observed on other occasions 10427 magnetic storms in interplanetary space as observed by pioneer v a positive correlation is found between the interplanetary field measured at the satellite and the planetary magnetic index during the flight of pioneer from launch on march to the end of april magnetic storms at the satellite occur at the same time as earth storms although there is a slight delay towards the end of the period of telemetry 10428 satellite flashing light system to provide increased accuracy of the determination of the position of a satellite a coded flashing light system could be carried design details are given 10429 effect of an oblate rotating atmosphere on the orientation of a satellite orbit for inclinations of in particular significant rotation of the major axis in the orbital plane occurs due to the atmosphere 10430 atmospheric phenomena noted in simultaneous observations of events occurring in three typical revolutions of sputnik are described measurements were made on the transmissions i signal drop outs due to transmitter failure were noted and another type of signal decrease was attributed to localized absorbing regions regions of the ionosphere causing scintillation were also identified they have an extent in the horizontal plane of several hundred km 10431 methods of calculating atmospheric densities from satellite orbit data formulae relating atmospheric density to the rate of change of period of a satellite as obtained by various workers are reviewed and are shown to be in sufficient agreement to meet practical needs 10432 ray paths from a cosmic radio source to a satellite in orbit a satellite above the maximum can receive radiation on frequencies that are totally reflected by the ionosphere two effects of reflection in the upper part of the ionosphere are discussed focusing and interference both occur particularly when s a satellite enters or leaves a region in which it can receive radiation from a point source in space 10433 measurement of solar x radiation the x ray emission measuring equipment to be carried in skylark rockets and the satellite is described both x ray flux and spectral shape are to be investigated 10434 local electron densities deduced from the faraday fading of satellite transmissions using measurements during two consecutive transits in the analysis it is assumed that during the period of revolution of the satellite the relative gradients of the local electron density are constant at he same altitudes and the changes in density above the maximum are the same as those within the f layer daytime observations of in september have been analysed 10435 scintillations and the latitude distribution of ionospheric irregularities evidence is given in support of kents interpretation of the rapid fading of earth satellite signals of mawdsleys alternative explanation of scattering by field aligned irregularities of is not confirmed by experiment 10436 radio tracking of artificial earth satellites 10437 tracking and display of earth satelli es 10438 charged particles in the upper atmosphere a comprehensive review of collision processes involving charged particles in he upper atmosphere 10439 structure variations and measurements of the earths ionosphere and exosphere a survey of present knowledge and work being conducted at the technion israel institute of technology haifa 10440 the distribution f minor ions in electrostatic equilibrium in the high atmosphere a simple discussion of the factors which govern the distribution of ions in diffusive equilibrium the scale height of the predominant ions is twice that of the corresponding neutral constituent and the concentration of a minor light ion can increase with altitude 10441 comments on tidal winds in the high atmosphere the accuracy of published data on tidal wind variations are discussed on the basis of computations of the indices of the probable error circle variations with seasons and elevation are real although their magnitudes may be unreliable 10442 diffusion in the ionosphere a review of some recent work work by gliddon and kendall of shows considerable support for the hypothesis that f and f regions are produced by the same source of ionization 10443 the lunar variation of the virtual height of the normal ionospheric e layer above fribourg a semi diurnal lunar variation of has been detected with a maximum at lunar time 10444 theory of overhead nonblanketing sporadic e sequences of curves are calculated for an e layer in which a horizontal stratum of irregularities thick is slowly descending the results are very similar to recorded sequences of ionograms showing sporadic e 10445 observations on the ionospheric f layer at night the law of electron loss in the f layer at night electrons in the f layer are lost by attachment like processes the loss coefficients are of the form where is the height at which and is the scale height of the loss coefficient assuming the loss coefficients are attributable to loss rates in chemical processes values correspond to those of molecular oxygen and nitrogen 10446 equatorial spread f in relation to post sunset height changes and magnetic activity the seasonal dependence of the correlations is found and the data are considered in relation to maryns theory of the formation of spread see of 10447 on the relation between magnetic storm and ionospheric disturbances that occurred on sept th patterns of dense e blackouts and f layer disturbance in the northern hemisphere are compared with the current systems of geomagnetic disturbance at different stages of the storm with the development of polar cap blackout several hours before the sudden commencement of the storm a current system was produced in the polar cap region during the main phase blackouts and e coincide with strong currents at auroral latitudes 10448 upper atmospheric turbulence near the level an examination of observations of a sodium trail produced by a veronique rocket in the upper atmosphere 10449 hydrogen atoms and ions in the thermosphere and exosphere the structure of the atmosphere between and is discussed in terms of various models for a further note on the temperature in the exosphere 10450 variable conditions of the terrestrial exosphere the well known features of atmospheric density variations as deduced from satellite observations are discussed data for at least ten satellites show evidence of an annual variation in atmospheric density with a minimum in july the amplitude of the variation increasing with altitude 10451 exospheric electron density variations deduced from whistlers new data on electron density are presented density is approximately proportional to the strength of the earths magnetic field an unexplained annual variation in which the december value is nearly twice that in june 10452 altitudes of the night airglow radiations observational methods for obtaining the layer heights of airglow emission are briefly reviewed and results derived from ground measurements rocket flights and kinetic temperatures are discussed 10453 attempt to measure night helium glow evidence for metastable molecules in the night ionosphere a rocket experiment intended to measure the intensity of night time he glow wavelengths and gave negative results but provided some evidence for the existence of metastable molecules above km 10454 some auroral observations inside the southern auroral zone 10455 guiding of whistlers by the magnetic field a mechanism is proposed which explains the wideband noise observed during whistler reception a particle moving with velocity where is gyrofrequency and is plasma frequency causes a wave to be propagated along the earths magnetic field all frequency components of the wave travel with the same velocity see of january 10456 the dispersion of s whistlers compared with the geomagnetic latitudes of their sources observational results are presented which indicate that the geomagnetic latitude of lightning discharges is a factor determining the dispersion constant of the related whistlers 10457 project echo antenna steering system the use of basic orbital information to generate aerial steering instructions for project echo is discussed a digital method is described in which predicted pointing data is transmitted by teletype to the aerial site then stored and subsequently used when required in real time to control the aerial drive mechanism 10458 project echo boresight cameras cameras are attached to the project echo transmitting and receiving antennas at holmdel for recording the position of the satellite an exposure of sec at was used at frames sec 10459 an analytical expression for describing the write process in magnetic recording 10460 video tape analyser tape frequency response noise contribution drop outs and rate of wear are determined and an assessment is made of the decline in picture quality due to repeated playback 10461 spectral response of solar cells theoretical response curves are derived by an analysis including the effects of carrier diffusion and drift due to the electric field in the surface region 10462 solar cells for communication satellites in the van allen belt the power output of solar cells on satellites is degraded by radiation damage on passing through the van allen belts methods of overcoming this are discussed 10463 power supplies for space vehicles a comprehensive review of types of power systems energy sources and power converters and an examination of the problems associated with development as power supplies for space vehicles 10464 commutation and destructive oscillation in diode circuits an investigation of these phenomena in si rectifiers and a study of how commutation may cause destruction of unprotected cells 10465 a fatigue free silicon device structure by using hard solder instead of soft solder to make joints in the device raptures are no longer produced by cyclic thermal stress 10466 passive voltage and current stabilizers using a bridge network the residual voltage variation which occurs when a zener diode is used as a stabilizer is removed by using a wheatstone bridge network 10467 transistorized current stabilizers for electromagnets of medium power to methods of computing the characteristics and determining the stability are given 10468 cathode coupled cascode stabilizer circuit in a negative hv power supply the peak to peak ripple was less than and a change in line voltage gave less than change in output 10469 high speed analogue digital converter details are given of a fully transistorized unit for the conversion of pulse amplitude data to numbers of pulses use is made of a tunnel diode transistor combination in the blocking oscillator circuit to produce oscillations at a frequency of or mc the overall dead time of the converter is reduced by times 10470 optical erasure of el pc and neon pc storage elements a new method of selective storage and erasure using optrons is described a single light source of constant intensity with emission within the sensitivity range of the photoconductor will latch optrons with short pulses and erase them with long pulses 10471 obtaining nondestructive read out with ferroelectric memories the development and initial tests of a monomorphic polycrystalline ba titanate storage cell used as a three or four terminal device 10472 the magnetic flux counter the principle and application fof multistable magnetic storage systems are discussed 10473 feedback amplification improves hall effect multipliers a transistor feedback amplifier supplies a field coil current in phase with the input signal a dc component is added to increase the common mode signal rejection 10474 a microsecond ferrite core memory a storage capacity of bits is achieved with an instruction repetition rate of 10475 switching processes in dc circuits with nonlinear resistance and nonlinear inductance normalized differential equations are derived for the analysis of switching processes involving nonlinear resistances with semiconductor or valve type characteristics 10476 design of wide ba d shielded toroidal rf transformers details of transformers for use with magic or hybrid junctions in the frequency range 10477 determination of core size in pulse transformer design the construction of a design chart is described and its application is illustrated 10478 toroids of square loop ferrite material as switching elements a differential equation is derived wi which described magnetic reversal processes in square loop ferrites neglecting the effect of eddy currents the application of this analysis to practical switching circuits is considered 10479 tunnel diodes increase digital circuit switching speeds tunnel diodes are used with transistors in high speed switching circuits suitable for pulse generator operation 10480 application of karnaughs mirror symbols to transfluxors a transfluxor symbol is proposed which is based on the system used by karnaugh of for magnetic core switching circuits 10481 an analysis of a cylindrical cavity with radial vanes the procedure involves the use of variational methods for obtaining successively better approximations to the resonance frequencies and the field configuration 10482 an analysis of the travelling wave cavity the masured response of a travelling wave cavity differs from that predicted by simple theory an internal mismatch can explain the observed response 10483 rules for the verification of the stability of normal linear negative feedback systems the stability criterion and rules are formulated and the rules to polar diagrams and curves of the system function is described 10484 a filter system with favourable pulse characteristics analysis of filter performance under pulse conditions on the basis of the distribution of poles and zeros of the transfer function a practical filter circuit is derived and the pulse amplitude calculated 10485 mechanical filters with flexural coupling the use of flexural coupling between longitudinal resonators makes possible the construction of very small mechanical filters for operating around the characteristics of such a system are calculated and two practical examples are given 10486 the design of filters with the aid of the catalogue of normalized low pass filters filter design by the insertion loss method is facilitated by the use of tables prepared with the aid of an electronic computer see of the design of tchebycheff type and cauer parameter low pass filters is considered in detail 10487 diagrams for the design of double tuned band filters with arbitrary coupling the design curves and equations given are based on filter parameters which can be obtained directly by measurement in the filter circuit 10488 insertion loss of electromechanical coupling filters the insertion loss is defined and design formulae are derived for minimising this loss 10489 experiences with mechanical band filters problems arising in the construction of electromechanical filters are discussed and some practical types of filter are described 10490 a crystal filter of increased bandwidth and its synthesis the method given in of june is applied to a lattice type filter with a crystal in each bridge arm 10491 a differentiating equalizer with transistors the equipment described is designed for emphasizing the upper frequencies of the video signal band withou phase distortion 10492 a synthesis procedure for an n port network the method is based on the bott duffin procedure for two port networks 10493 bistable systems of differential equations with applications to tunnel diode circuits a mathematical theory is developed for nonlinear circuits with at least two stable steady states the theory is applied in detail to circuits containing one or two tunnel diodes 10494 new wide range oscillator technique a modification of the wien bridge rc oscillator circuit is used in an instrument with a range of 10495 crystal stabilized tunnel diode oscillators theory and design procedure is given for a oscillator with frequency stability of parts per million per 10496 one tunnel diode binary comment on of june and authors reply 10497 an analysis of the modes of operation of a simple transistor oscillator an analysis predicting two modes of oscillation a two terminal transit time mode and a three terminal mode 10498 transistor precision pulse shaper with short recovery time the circuit is designed to minimize the effects of temperature changes and individual variations in transistors the pulse duration varied by for a temperature range of and by in ten similar circuits 10499 a neuristor prototype a description of an electronic lumped element model of the neuristor proposed by crane sept 10500 some circuit applications of avalanche devices applications of pnpn avalanche diodes in analogue computers process con rol oscillography and telemetry are discussed 10501 study of a diode bridge nanosecond resolution coincidence circuit a highly stable circuit is described which can provide a resolution down to 10502 frequency components in the output of a harmonic generator driven by the sum of two sine waves a frequency analysis is given for the output of a generator which emits a constant amplitude pulse at each zero crossing of the input voltage consisting of the sum of two sine waves raised to an arbitrary dc level 10503 a random pulse generator with variable mean rate method of producing a random pulse train with predetermined statistical properties 10504 amplifier for the generation of accurately controlled microsecond pulses a description is given of a pulse amplifier whose output voltage can be accurately controlled by the setting of a ten turn potentiometer the output amplitude and pulse lengths are variable up to and respectively 10505 designing hybrid dc amplifiers to withstand missile environments the amplifier comprises one valve and si transistors and is based on the goldberg principle for dc drift correction 10506 actual noise measure of linear amplifiers a new noise measure is proposed which includes the noise contribution from the load it is of particular use in comparing amplifiers whose terminations are not necessarily optimized 10507 automatic gain control for super regenerative amplifiers the circuit gives stable operation for long periods and maintains output pulses constant over a range of input signals 10508 nonadiabatic behaviour in a low frequency beam type maser characteristics are discussed theoretically when the adiabatic focusing approximation travelling wave maser using chromium doped rutile the active material is of small cross section and is connected to standard size x band waveguides by dielectric tapers performance figures quoted show appreciable gain per unit length with a very large tunable bandwidth obtained without the use of any external sh slowing structure 10509 maser action in emerald the successful operation of a single cavity reflection type maser amplifier at using synthetic emerald is reported 10510 maser action in ruby by off resonance pumping population inversion peaks have been observed using a pump frequency as much as from the centre frequency the experimental results are discussed and explained 10511 the maser and its application to satellite communication systems the properties of the travelling wave maser with a comb structure are discussed with particular reference to the frequency range performance is estimated and compared with a parametric amplifier in a practical aerial system 10512 a tunable reactance type straight amplifier for the uhf range an experimental variable capacitance amplifier tunable in the range with a pump frequency of is described with a bandwidth the noise figure is better than that obtainable with a conventional earthed grid triode amplifier 10513 gain saturation in a travelling wave parametric amplifier there is a periodic transfer of power along the line between signal idler and pump frequencies see of the resultant reduction in gain with increase of signal strength is shown graphically 10514 parametric amplification with transistors a note on the operation and characteristics of a parametric amplifier using transistors operating beyond cut off frequency 10515 microwave amplification in electrostatic ring structures 10516 on the cascaded tunnel diode amplifier a mid band equivalent circuit of an artificial transmission line is described for use with tunnel diodes in cascade amplifiers see only one diode is needed in each stage and the shunt resistor is an ordinary passive component 10517 the electrostatic field in metals particularly at a surface against an insulator 10518 quantum theory and transverse galvanomagnetic phenomena a quantum theory of electrical conduction in crossed electric and magnetic fields is given for the limit of very weak scattering 10519 a gas discharge generated by micro waves which glowes free in space at the focus of a closed ellipsoid of revolution better results were obtained than in earlier experiments 10520 electric field induced anisotropies in an inhomogeneous plasma anisotropies in electron diffusion and conductivity can be produced in the absence of a magnetic field 10521 nonlinear time dependent plasma oscillations the laplace transform technique used to solve the the problem of the first order motions in an unbounded rarified electron plasma is modified to solve the problem to arbitrarily high order 10522 some boundary value problems involving plasma media a plasma consisting of a neu ral mixture of electrons ions and molecules in the presence of a constant magnetic field possesses a dielectric constant which is in the form of a tensor exact solutions of boundary value problems involving such media are obtained for two dimensional configurations explicit results are given for the reflection coefficients of stratified plasma in planar and cylindrical geometry 10523 radiation in a plasma part cherenkov effect a linear continuum theory in which the em and electroacoustic waves set up in a plasma by arbitrary change and current sources are found from maxwells equations the results are similar to those of pines and bohm or although the latter start from the particle viewpoint 10524 contribution to the theory of mode conversion maxwells equations are formulated for three dimensional riemann space the propagation of a lecher wave without mode conversion is considered 10525 diffraction of a plane electromagnetic wave at a circular ferrite cylinder german version of paper published in 10526 scattering of electromagnetic waves from concentric infinite cylinders the solution for the scattering of radiant energy in the form of electromagnetic waves by concentric isotropic infinitely long circular cylinders is given for the incident energy travelling perpendicular to the cylinder axis 10527 theory of resonance absorption of energy by a rotating solid 10528 use of a different type of fluorescent material as an optical maser a device is suggested which is based on the stokes shift associated with absorption and emission bands created by point defects in solids such as kcl preliminary calculations indicate that such a device can be made to operate 10529 generation of optical harmonics analysis s is given together with a description of experimental observation of the second harmonic produced by projecting an intense beam of light through crystalline quartz 10530 stimulated optical emission in fluorescent solids part theoretical considerations 10531 stimulated optical emission in fluorescent solids part spectroscopy and stimulated emission in ruby 10532 fluorescence and optical maser effects in 10533 electron trajectories in a nonuniform axially symmetric magnetic field the equations for motions for electrons in a sinusoidally varying magnetic field have been solved a device for converging a hollow cylindrical electron beam designed and built on the basis of the solutions gave measured area convergences of to 10534 energy bands in the presence of an external force field anomalous velocities the theory of field modified energy bands is extended to include the effect of weak scattering forces the modified current operator is found to contain terms giving anomalous currents the theory of these currents is developed and their relation to the spontaneous hall effect in ferromagnets is considered 10535 spectrum of galactic radio emission a discrepancy between theoretical and experimental values of the radio spectral index is discussed new observations at are consistent with the value previously obtained 10536 radio star scintillations and the auroral zone scintillations at over a year period are analysed the dependence on the altitude of the source was much stronger in than in the scintillations probably arise in regions of the atmosphere which migrate southwards when solar activity is high 10537 radio spectrum of jupiter review of the results of radio observations from to the present 10538 the solar noise burst of november a description of the noise received at and 10539 spectral characteristics of type solar radio bursts an explanation of the appearance of radiation only at fundamental and second harmonic frequencies and the frequent splitting observed in these lines is given 10540 decimetre radio bursts concurrent with solar type radiation measurements taken during a type burst show that radiation at can originate in a part of the suns atmosphere widely different from the source of radiation 10541 coincidence of the explosive phase of solar flares with solar noise bursts comparison of commencement times of solar noise bursts with those of the observed explosive phase of solar flares shows good correlation 10542 amplitude and angular scintillations of the radio source cygnus a observed at boulder colorado comparison with records from a suitably placed ionosonde shows correlation between scintillations and spread f but no with e the angular dependence of scintillations shows that the ionospheric during the day slow irregular variations of angle occur and are attributed to large scale lens like irregularities 10543 intensity variations in outer van allen radiation belt count rates observed with explorer during stormy periods october december indicate a decrease outside earth radii during the main phases the lower cut off values on the counters are for protons for electrons the proportion of soft radiation increases during periods of increased intensity 10544 some effects of diamagnetic ring currents on van allen radiation a qualitative theoretical model is proposed to explain the depletion of the outer van allen belt during the main phase of a storm the theory incorporates a magnetic tail on the dark side of earth a ring current centred at earth radii and local betatron acceleration and deceleration of van allen and solar pz particles 10545 energy spectrum and angular distributions of electrons trapped in the geomagnetic field count rates taken during a sounding rocket flight to km are used to derive distributions of pitch angles at various heights and the energy spectrum the latter was found to be constant above km electron flux for energies at apogee was sec 10546 the observed outer belt electron distribution and the neutron decay hypothesis the electron flux distribution along a line of force of range in the equatorial plane is compared with a curve based on the neutron albedo theory of electron production there is sufficient disparity between the two curves to suggest that other sources of electrons must exist 10547 unusual increase in the cosmic ray intensity on november observations at arctic and antarctic stations show a statistically significant anisotropy 10548 radar scattering cross section applied to moon return 10549 the latitude dependence of radar meteor shower observations a simplified method of assessing the relative significance of meteor showers is described which leads to good agreement between surveys in both hemispheres 10550 head echoes from meteor trails head echoes are often reflected from regions up to in length which may persist for many seconds after the passage of the meteor the consequences of this fact are discussed 10551 solar x rays measurements of the intensity of solar x rays made during the past eleven years using rockets are reviewed and a useful table showing intensities as a function of wavelength and solar activity is given 10552 preliminary data on solar extreme ultraviolet radiation in the upper atmosphere a rocket borne monochromator was flown in august the intensity of the solar spectrum from was scanned in sec at a series of heights up to km tables of the intensities extrapolated to a height above the earths atmosphere are given together with absorption cross sections and t other useful information for completeness similar tables are given for wavelengths outside the range covered by the august measurements 10553 secular variations of short lived sunspots 10554 geomagnetism in relation to aeronomy a brief review dealing with quiet day and storm variations and associated current systems the motion of particles trapped in the radiation belts and phenomena in the outer atmosphere 10555 geomagnetic variations between november and november 10556 on the reflection and refraction of hydromagnetic waves in ionized gas reflection and refraction of hydromagnetic waves at a plane boundary between two semi infinite homogeneous media of anisotropic electrical conductivity are considered for the case of a steady uniform magnetic field perpendicular to the plane difficulties in obtaining solutions when the field is at other angles are demonstrated 10557 electric currents associated with geomagnetic disturbances in the auroral zone currents of the order of have been observed at lerwick during bay type disturbances a west to east maximum occurred between and zero current at and an east to west peak was measured at about midnight the west to east current was at the level of the f layer and the east to west current near e layer level 10558 the diurnal variation of k indices of geomagnetic activity on disturbed days in 10559 analysis of satellite data from an analysis of the orbit of satellite atmospheric density variations have been isolated which are tentatively ascribed to third harmonic tides 10560 errors in orbital predictions for artificial satellites of earth 10561 atmospheric densities at heights of km atmospheric densities determined from changes in the orbits of earth satellites are discussed 10562 determination of atmospheric densities from satellite observations a discussion of the errors arising from various factors involved in the determination of upper atmosphere densities from satellite drag measurements 10563 proceedings of the fourth afbmd stl symposium advances in ballistic missile and space technology the text is given of papers on various aspects of rocket and satelli e techniques including instrumentation space guidance and computers for papers on space communications 10564 proposed satellite techniques for performing a high resolution survey of the radio sky at medium wavelengths the reception pattern of a short dipole above the f layer is modified by refraction in the ionized medium the properties of this pattern are discussed and satellite experiments using this phenomenon are suggested 10565 satellite borne instrumentation for observing flux of heavy primary cosmic radiation 10566 cosmic ray measurements in the uk scout satellite the main purpose is to measure accurately the primary cosmic ray energy spectrum and the changes in it due to modulation by the interplanetary magnetic field gm counters and a cherenkov counter will be used 10567 radiation and other environmental effects on satellites transistor failure in a satellite spending an appreciable part of its life in the inner van allen belt seems likely after several years solar cells cannot be effectively protected from hard radiation 10568 lyman radia ion the role of lyman in the ionization of the d region is discussed nocturnal observations of lyman which lead to the concept of the hydrogen geocorona are reviewed 10569 theory of electrostatic fields in the ionosphere at equatorial latitudes an analysis is made of the elongated es fields required to provide the the e and f layer coupling in the dynamo theory for equatorial conditions the attenuation of the es field is found to be large implying very small coupling for fields with horizontal wavelengths of a few km most of this attenuation occurs at heights near the e region for an analysis in non equatorial regions see of october 10570 apparent reflection heights and reflection properties of the ionosphere above tsumeb south west africa determined by means of pulses in the frequency band from to the results of nighttime ionospheric measurements made during the period august march are analysed to determine the electron density distribution below the f layer at least three ledges in the electron distribution were regularly observed at heights between and and in the lower e region the occurrence of e layers was also noted 10571 comparison of absorption coefficients of the ionosphere from pulse amplitude measurements and field strength recordings ionospheric absorption was measured by two methods vertical incidence soundings at field strength measurements over an oblique incidence path in length at mcs threse frequencies are such that in both methods the heights of reflection are equal the absorption coefficients determined using the two methods have a correlation coefficient of for both daily and monthly mean values and are related to ez each other by the square of the effective frequency 10572 the ionospheric disturbance of november and changes in ionospheric absorption as shown by are discussed 10573 nocturnal and seasonal variations of equatorial spread f a classification of spread echo patterns based on the distribution of relative amplitude within the echo is described the variations in spread f index at waltair geomag are compared with those at kodaikanal 10574 measurement of ionospheric drift by radio star observations the incidence of scintillations is greatest in the hours before sunrise at puerto rico it is not correlated with spread f or e the drift results show that the ionosphere irregularities causing scintillation are elongated along the lines of force of the geomagnetic field and that drift rather than random changes is the main source of scintillation 10575 a method of estimating ionospheric absorption heights from recovery times rapid recovery from absorption occurs when the ionizing source is suddenly cut off from a plot of ionospheric relaxation time against height an estimate can be made of the height of the absorbing layer which is in good agreement with measurements made by the three frequency riometer method 10576 ionospheric absorption on november the results obtained using riometers in canada are described 10577 ionospheric absorption and solar activity in intermediate latitudes measurements of the absorption of cosmic noise were made at athens on and analysis of the data allowed the components of the total absorption due to the f and d layers and the extra component to be estimated 10578 ionospheric current systems of ten igy solar flare effects the current systems consist of two vortices one on each side of the magnetic equator the m northern vortex is centred west of the southern one and is more intense in local summer than the southern one the asymmetry in the vortices can be described in terms of an ionospheric current system 10579 ionospheric critical frequencies and magnetic parameters of the day before the correlation between and at capetown and local magnetic activity was calculated the correlation is greatest when the magnetic indices for the previous day are used this is true both when and means of are used in the correlations 10580 connexion between micropulsations and the ionosphere measurements made at christchurch england and ascension island distant show that pulses occur simultaneously at both stations but the same coherence s not observed for pulsations 10581 atmospheric ion compositions measured above wallops island virginia preliminary data for heights between and obtained from two rocket flights are given and compared with results of previous determinations 10582 ionospheric information deduced from the doppler shifts of harmonic frequencies from earth satellites measurements made near the end of the life of sputnik have indicated the presence of appreciable ionization at a height of in the daytime and have revealed the existence of ionospheric irregularities below 10583 height of nighttime f layer irregularities at the equator satellite transmissions propagated through the irregularities produce a diffraction pattern from whose velocity the effective height of the diffracting screen may be determined irregularities are elongated with axial ratio at least along the earths magnetic field and lie between and above the base of the f layer 10584 the determination of the absorption of the ionosphere from pulse amplitude observations equipment for measuring ionospheric absorption by means of vertical incidence soundings is described it operates at or with pulse width variable between and details are given of the polarimeter receiving circuit see also above 10585 on the validity of some approximations to the appleton hartree formula 10586 investigation of ionospheric absorption on at waltair 10587 the fading of radio waves reflected vertically from the ionosphere during magnetic storms correlation analysis is applied to the spread rapidly fading reflection observed at cambridge during magnetic storms the drift velocity is usually large and towards the west and the direction of elongation of the diffraction pattern shows that the ionospheric irregularities are aligned with the earths magnetic field 10588 the electrically short antenna as a probe for measuring free electron densities and collision frequencies in an ionized region the in integral equation method is used to obtain expressions for the admittance of an electrically short centre driven dipole or base driven monopole when immersed in a conducting dielectric the conductivity and permittivity of the medium can be calculated from measurements of the admittance of the aerial immersed in the medium and in air 10589 an analogue solution of the continuity equation of the ionospheric f region an electromechanical analogue computer is used to solve an idealized f layer continuity equation the results show how the layer above the f peak is mainly controlled by vertical diffusion of ionization and below the peak by the production and loss processes the machine can also simulate the effect of a solar eclipse 10590 effects of corpuscular emissions on the polar ionosphere following solar flares during the events of july and september ionospheric absorption was more intense in the sunlit portion of the polar cap after the september event there was strong auroral absorption a geomagnetic storm and a decrease in f layer ionization none of these occurred after the july event 10591 ionospheric reflections below kilometres during polar cap absorption events vertical incidence observations on at scott base lati ude showed particle reflections from heights below during two polar cap absorption events the results are correlated with measurements made in space vehicles during the same periods 10592 electron densities in the outer ionosphere deduced from nose whistlers 10593 some comments on obtaining electron densities in the exosphere using nose whistlers 10594 variations of emission in the upper atmosphere a review of experimental data with consideration of excitation mechanisms and relations with other airglow emissions 10595 a simultaneous study of the and emissions of the night airglow at poona results of measurements made in early 10596 hydrogen emissions during the period november 10597 power density requirements for airglow excitation by gyro waves an array of dipoles radiating a gyro wave with a mean power of would produce an easily observable enhancement of the nocturnal airglow overhead within a solid angle of square degrees 10598 temperatures deduced from aurora and airglow spectra several experimental results are combined to give a temperature profile between and km 10599 observations of auroral ionization during the period november auroral luminosity and radar echo amplitude at and were observed 10600 three frequency measurements of auroral absorption the ratio of the measured absorption of cosmic noise during auroral events was measured on two pairs of frequencies near assuming that the electron collision frequency as a function of height is known the height at which the absorption occurs can be estimated heights of were usual for intense auroral events but lower heights were observed for cosmic ray events 10601 auroral observations by radar in terre adelie observations made during the southern summer show a correlation between the geomagnetic latitude of the echoes and the k value for full report 10602 auroral radar observations at during the period of the november solar event 10603 extension of nose whistler analysis a method of analysis is described which gives the nose frequency and the time delay to the nose when the nose is not directly observable 10604 servo system design for balloon borne star trackers the telescope pointing equipment can operate over a dynamic light range of the average pointing error being within seconds of arc 10605 magneto optical readout of magnetic recordings this technique is based on the rotation of the plane of polarization of a light beam reflected from a magnetized surface 10606 power supplies for space vehicles available unconventional power sources are reviewed in the light of possible future requirements 10607 silicon power rectifiers the processes involved in preparing single crystal si are outlined and details of design production techniques and characteristics of si rectifiers are given 10608 theory of majority decision elements various problems concerning a single majority decision element are considered 10609 majority decision functions of six variables see also 10610 a fourier transform generator parts 10611 the address system and increment store for a digital differential analyser 10612 digitizer to tape punch coupling unit the output in twelve binary digits of a digitizer is briefly stored before operating a high speed five track tape punch 10613 study of the application of the hall effect in the construction of logic circuit elements 10614 the use of thin films for computer storage 10615 diode steering increases speed of magnetic memories by using the recovery time of junction diodes for half selection of the same word during the second half of a read or store operation a cycle time is achieved in a magnetic storage system with word capacity 10616 design of logic circuits using thin films and tunnel diodes switching circuits which have operated successfully are described and designs suitable for a wide range of logic functions are suggested 10617 resistance as dissipation into many reactive circuits landau damping and nyquists noise theorem nonradiative dissipation is not a loss of energy but its dispersal into a large number of degrees of freedom resistance can be simulated by purely reactive elements this lead to an understanding of landau damping and nyquists noise theorem 10618 techniques of microminiaturizatio the techniques of evaporated film and semiconductor solid state circuit design are described and their merits discussed 10619 metal transfluxors the choice of materials for and the design of a three aperture transfluxor of are considered 10620 transient response of grounded emitter switching circuits analysis of the effects of collector capacitance and load resistance a ramp input voltage is assumed which is close to the practical case than a step function 10621 the representation of branched circuits on an analogue computer extension of earlier work of to cover another class of branched network 10622 the effect of driving electrode shape on the electrical properties of piezoelectric crystals formulae are derived for the electrical admittance of a piezoelectric crystal in terms of its resonant frequencies and static and dynamic capacitances the results are applied to the investigation of the effect of electrode shape on the resonance spectrum and the capacitance ratio of the crystal 10623 the expanded reactance series resonator erser a description is given of a circuit element wherein the bandwidth between the infinities of a series resonant circuit can be exchanged for increased steepness of the reactance slope through resonance 10624 time varying networks an analysis is presented of some significant developments in the last decade in the theory of time varying networks 10625 nonsymmetrical properties of non linear elements in low and high impedance circuits 10626 on cyrator networks the attenuation and image impedance characteristics of four terminal networks using nonreciprocal elements are considered in networks incorporating gyrators it is possible to obtain finite attenuation in one direction and infinite attenuation in the other 10627 nonrealizability of the complex transformer a proof is given to show that for a particular case the complex transformer cannot be realized 10628 high frequency broad band impedance matching the design initial adjustments and performance of a confluent band pass filter are discussed and specific examples covering frequency ranges of and are given 10629 an adaptive communications filter a filter is described which is optimum for a completely random communication signal 10630 generating random noise with radioactive sources the system comprises a radio active isotope mixed with a light emitting phosphor and a type photomultiplier tube it was designed for application with a repetitive analogue computer and provides both a random telegraph wave with a mean count rate of and gaussian noise with a power spectrum 10631 the generation of variable square pulses in the nanosecond range a generator is described which is capable of producing pulses of duration variable between and with pulse rise and decay between and of pulse height within correction 10632 pulse analysis the mathematical apsects of the determination of the response of systems by pulse techniques is discussed with particular reference to many of the practical problems involved in applying the techniques 10633 radar boxcar circuits suing nuvistors transistors and zeners two versions of a waveform sampling device with zener diode biasing are described which give a signal noise ratio at room temperature 10634 amplifiers with band filter coupling the design of multistage amplifiers with flat or tchebycheff type response is considered design formulae and response cuf curves are given 10635 transistor amplifier stages with prescribed gain and sensitivity a design procedure is developed for circuits meeting prescribed gain and sensitivity criteria in terms of anticipated operational variations and available component data 10636 an engineering approach to the design of transistor feedback amplifiers a technique is developed for amplifier design which produces very accurate expressions for the transmittance without requiring any quantitative information about the transistors 10637 the dielectric harmonic amplifier a controllable harmonic generator circuits incorporating ferroelectric capacitors for producing harmonics of power frequencies are described applications as amplifiers or controllable frequency changers are mentioned 10638 lossy coupling in parametric amplifier a method of analysing a two resonant circuit parametric amplifier with a lossy coupling branch 10639 experiments with nonreciprocal parametric devices a report is given of the behaviour of two nonreciprocal parametric devices one device is a unilateral amplifier and the other is a circulator 10640 the helix parametric amplifier a broad band solid state microwave amplifier the amplifier uses a helix as a slow wave distributed interaction structure and has variable capacitance solid state diodes distributively coupled to the helix gains above have been obtained in the region 10641 generalized coupled mode theory 10642 phase inverters utilizing controlled superconductors two arrangements for phase inversion in a controlled superconductor push pull amplifier are illustrated 10643 transient response of fm signals practical investigation of distortion introduced by networks and lines into a signal when its frequency suddenly changes the effects of filters coaxial terminations and resistive and rc networks are considered 10644 linear frequency discriminator a method of distortionless demodulation of lf fm signals with large deviations is described circuit design and performance are discussed and analysed to determine conditions for maximum linearity 10645 electrical conduction phenomena in anisotropic media part strongly convergent solutions of linear operational equations particularly of blochs integral equations 10646 a note on the relativistic boltzmann equation and some applications the relativistic equation in the absence of collisions is derived and applied to the case of a velocity modulated drifting electron beam 10647 electron trigonometry a new tool for electron optical design a method is developed for predicting the image formation in electron optical systems as a substitute for trajectory tracing it is based on approximating axial potential distributions by linear or parabolic segments linear sections are replaced by equivalent drift tubes of appropriately scaled length parabolic sections observe certain triangle rules for the sum of three phase angles of flight applications of the method in the design of magnetic and combined lens systems are illustrated 10648 the theory of secondary electron emission of metals part of 10649 average kinetic energy of diffusing particles in discharge and electron tubes for particles flowing under a concentration gradient or across a region of a small field in the body of a gas the mean kinetic energy of particles with a maxwellian velocity distribution is 10650 the origin of plasma waves in strongly ionized gases the development of plane waves in a gas plasma without external fields is considered 10651 plasma engineering part applications of plasma uses of plasma are considered in the fields of thermonuclear research thermonic and magnetohydrodynamic power conversion propulsion and electronics the generation and heating of plasma and measurement of its parameters are described in parts of 10652 cavity method for measurement of high electron densities in plasmas conventional microwave cavity techniques may be used to measure electron densities considerably above that corresponding to plasma resonance at tht the particular microwave frequency employed 10653 observations of ionic sound waves in plasmas ionic sound waves were produced in a spherical plasma six different gases were used and a relation between the lowest fundamental frequency and atomic mass was found 10654 new form of plasma dispersion formula usable for analogue computing a correction term is derived which takes into account the influence of a magnetic field 10655 representation of propagation parameters for the plasma in a magnetic field the effect of a dc magnetic field on the properties of a uniform plasma for the propagation of em waves is described using three dimensional models see also of 10656 study of electromagnetic wave polarization in magneto plasmas by a matrix method of crystal optics a method o is given of studying em wave propagation through magneto plasmas which is appropriate to microwaves 10657 alfven waves in partially ionized gases the conditions for formation of an alfven wave are determined and fundamental equations are derived to describe the electrodynamic behaviour of the ionized gas 10658 electromagnetic surface waves on a plane interface surface waves are defined as waves exponentially decreasing on both sides of a plane interface the relations between the propagation parameters and the material constants are derived in a general case which includes media with different magnetic permeabilities 10659 fundamental solution of the vectorial wave equation in spherical coordinates two families of vectors are determined which under certain conditions together form an orthonormalized system tied to the geometry of a sphere 10660 vertex generated waves outside metallic wedges the waves generated by a magnetic line source placed at the vertex of a wedge of high conductivity and arbitrary angle are studied the effect of a dielectric coating on the wedge is examined and the propagation of surface waves considered briefly 10661 the low frequency scattering by a perfectly conducting strip previous approximate solutions have not been satisfactory as no expansion parameter suitable for all terms has been found results of an analysis suitable for thin cylinders and arbitrary angles of incidence are given 10662 induced and spontaneous emission in a coherent field previous theoretical work on the interaction of molecules and em fields in a resonant cavity is extended to take account of large perturbations 10663 splitting of electron spin resonance lines by an applied electric field 10664 linear effect of applied electric field in electron spin resonance 10665 second order effect of spin orbit interaction on the paramagnetic resonance spectra of ions with a single electron 10666 some operating characteristics of flash pumped ruby lasers 10667 repetitive hair trigger mode of optical maser operation 10668 charged particle trajectories in static electric and magnetic fields relative expressions are derived for the curvature and torsion of a trajectory in terms of electric and magnetic field distributions 10669 an examination of the steady state model in the the light of some recent observations of radio sources the unsatisfactory nature of the theoretical model is demonstrated by a comparison of predictions with observational results 10670 an investigation of the clustering of radio stars an examination of two recent surveys produced no evidence of clustering and an upper limit of could be set to the percentage of sources which occur in clusters 10671 the number flux density relation for radio sources away from the galactic plane observations at have been used to derive the number flux density relation for sources situated at galactic latitudes 10672 radio astronomy from space vehicles the usefulness of a radio receiving system in space is considered satellite experiments at frequencies outside the range are suggested 10673 counts of extragalactic radio sources a formula is derived for the cumulative totals of class radio sources and compared with observational measurements 10674 some attempts to detect linear polarization of galactic radio emission from the spur at evidence from measurements at suggests that the theory of does not adequately explain the spur shaped feature of radio emission 10675 slow drift solar radio bursts harmonic frequency ratios solar longitude dependence and frequency drift rates 10676 latitude dependence of a forbush type decrease 10677 radiation measurements in the slot between the van allen belts to an altitude of kilometres 10678 longitudinal dependence of radiation belt scattering and primary auroral particles 10679 world wide distribution of diurnal variation of the neutron intensity of cosmic rays data from stations throughout the world for the period to december have bee analysed to detect possible latitude and i diurnal effects in periods averaged over six months 10680 drift rate in a dipole field expressions are found for drift rate and period and the results are applied to the drift of trapped electrons and protons in the geomagnetic field 10681 the distribution of trapped particles in a changing magnetic field the changes in distribution which result from various changes in the field parameters are calculated 10682 dynamics and structure of the outer radiation belt an analysis of electron measurements made in explorer is presented in terms of four time independent parameters of the outer van allen belt the belt has two peaks of intensity e max amd e max during a storm coincides with dipole lines of force max is used as a tracer to follow changes in the magnetic field some changes are accounted for only by invoking an irreversible energy gain or loss in the belt the peaks are observed to move radially inward during a storm and peak electron intensities fall by about 10683 radar contact with venus in the ussr in april a transmitter and receiver operating at about were used in conjunction with an analysing and integrating system which enabled both the range of the planet and doppler spread of received signals to be determined 10684 radar measurements of the planet venus by means of radar equipment operating at a new value for the astronomical unit was determined accurate to and the rotation period of venus was estimated as days 10685 amplitude distribution for radio signals reflected by meteor trails part vhf signals are propagated to distances of by reflection from meteor trails a probability distribution for the envelope of the received signal is derived for the case of reflections from numerous small meteors coincident with residual signals from infrequent large meteors 10686 auroral effects on the earths electric field abnormal conduction currents at the earths surface are interpreted in terms of currents generated in the atmosphere during three aurorae 10687 interaction of west ford needles with earths magnetosphere the influence of drag forces on the west ford needles is studied and is shown to be predominant at heights above 10688 sun earth relations and associated periodicities a periodic analysis shows that magnetic impulses tend to recur at three day intervals and that the interval between a flare and a magnetic impulse is about days 10689 some relationships between short wave fade outs magnetic crochets and solar flares statistical analysis indicates a strong association between sudden sw fade outs and magnetic crochets no significant difference could be found in fade out type between those fade outs associated with flars of importance greater than two and those with flares of importance less than two 10690 on the geomagnetic effect of the solar eclipse of february at genoa in english 10691 an idealized problem of plasma dynamics that bears on geomagnetic storm theory an idealized problem is solved a cylindrical sheet of neutral ionized gas is projected into a magnetic field which is aligned along the cylinder axis and varies as where is the distance from the axis for a magnetic field comparable in magnitude with that of the earth the sheet would be stopped at earth radii for storm and at earth radii for storm 10692 interpenetration of two ionized gas clouds counter streaming resulting from the collision of two ionized gas clouds is unstable the double stream forms small clouds of space charge which may be the cause of geomagnetic storms and the radio noise of colliding galaxies 10693 rocket measurements of the magnetic field above new mexico absolute total intensity was measured in a rocket at heights up to and compared with the intensity predicted by spherical harmonic coefficients 10694 measuring the doppler frequency shift on satellite transmissions the use of a phase locked oscillator for observation of doppler shift in transmissions in the range is described and the effect of signal modulation on the accuracy of measurements is illustrated by examples 10695 theory of an accurate intermediary orbit for satellite astronomy 10696 on the long period lunar and solar effects on the motion of an artificial satellite part the theory of lunisolar effects on artificial satellite orbits is presented in a form suitable for numerical integration and for the development of the perturbations into fourier series with numerical coefficients 10697 a comparison of theory and observation of the echo satellite a comparison is made between theoretical and observed changes in the perigee height of echo due to radiation pressure the change in atmospheric drag gives information on densities in the height region 10698 infrared circuits in tiros satellites a channel radiometer for measuring parameters relating to the earths heat balance and horizon sensors to determine spin rate and orientation are described 10699 determination of the earths gravitational potential from satellite orbits from the motions of the orbital planes of four satellites values for the second fourth and sixth harmonics in the earths gravitational potentials have been obtained allowance is made for atmospheric lunar and solar perturbations and the results are compared with those of other authors 10700 radioactivity produced in discoverer by november solar protons 10701 latitude and diurnal variations of air densities from to as derived from the orbits of discoverer satellites an analysis of orbital information obtained from nine discoverer satellites shows that variations in air density between day and night in the region curves of daytime density plotted against height indicate the possibility of a region of local heating at which disappears at night 10702 courier communication satellite 10703 chemical heating above the polar mesopause in winter 10704 the electron content of the ionosphere in winter observations of the faraday rotation of moon reflected radio waves at two closely spaced frequencies are described accurate values were obtained for the total electron content of the ionosphere for many hours on successive days 10705 the total electron content through the entire ionosphere by the faraday rotation technique a linear relation between total electron density anc and is demonstrated which presents a possible method of determining variations in intensity of solar ionizing radiation 10706 the conductive chapman layer the shape of the electron production function when ionizing radiation acts as an atmospheric heat source is given for atmospheres in mixed or diffusive equilibrium 10707 studies of the new ionospheric model the original model is perfected on the basis of profiles and results obtained from moon echo and radar scatter observations 10708 wind systems in the mesosphere and lower ionosphere 10709 study of horizontal drifts in the e region of waltair results obtained over a period including the steady hr and hr components found by harmonic analysis are presented other drift results an the e region drifts deduced from variations are quoted for comparison 10710 height gradient of horizontal drifts in the e region over waltair a value of is obtained between and see also 10711 evidence of some geomagnetic control on the layer the bifurcation of the noon f layer is found to be related to geomagnetic latitude 10712 analysis of the transition region from a detailed study of profiles the atmospheric scale height and the relative values of production rates and loss coefficients are deduced 10713 effect of electron ion collisions in the f region of the ionosphere on the absorption of cosmic radio noise at ahmedabad changes in absorption associated with magnetic storms riometer measurements at a frequency of have been compared with calculated values of total nondeviative absorption due to collisions with neutral particles with ions which occurred below maximum and the differences ascribed to absorption occurring baove the layer maximum the results show a depletion of electrons above the f maximum on the day following a sudden commencement and are compared with satellite observations on particle fluxes in van allen belts during storms 10714 riometer observations during a solar eclipse an average decrease of ia the absorption of cosmic noise transmitted via the d region was observed during the total eclipse of october 10715 solar flares and association with the lower ionosphere short wave fade outs and are adopted as ionospheric parameters the statistical relations between these and solar flares and solar rf emission are studied the analysis includes flares from class down to class the number of fade outs is correlated with flare activity and with radio noise increases 10716 a model of solar flare induced ionization in the d region the energy distribution of the x radiation in the range was estimated from rocket measurements during a class flare on august simultaneous measurements of cosmic noise at showed the changes in d layer absorption during the flare the absorption can be accounted for by assuming a recombination coefficient of about and an electron density profile which varies linearly from at 10717 possible solar flare effects in the f region of the ionosphere sudden changes in are suggested as being due to the effects of travelling disturbances in the layer and not to solar flares of in reply the authors point out that on november a sudden change in occurred simultaneously at stations apart which invalidates munros hypothesis also a change in occurs only when the height of the peak of the layer at the time of the flare is less than km 10718 rocket measurement of a daytime electron density profile up to results are compatible with ground based and satellite derived measurements 10719 first pulsed radio soundings of the topside of the ionosphere preliminary report on a rocket test of the fixed frequency system to be used in a satellite while the rocket was above the f layer pulse echoes were observed at and from the ordinary ray and extraordinary ray reflection levels below unexpected phenomena were spread and field guided echoes near the and reflection levels and local spread echoes at 10720 an annual and a semiannual variation of the upper air density fluctuations in the acceleration of several satellites are analysed see also 10721 satellites and the earths outer atmosphere the structure of the atmosphere as determined by recent experiments is discussed 10722 world maps of during the igy maps showing contours of are reproduced for each month of the year and are based on measurements made during the igy when solar activity was very high constant local time maps are given for and those for a given universal time refer to the hours 10723 transresonant electron acceleration describes a mechanism additional to that of helliwell for the acceleration of van allen electrons by whistlers non relativistic electrons would be accelerated by whistlers of about field strength the mechanism depends on the whistler frequency doppler shifted by the electron velocity passing through the electron gyro frequency 10724 diurnal variation of high latitude auroral frequency on magnetically quiet and disturbed days the frequency of occurrence as a function of time of day is plotted separately for three sectors north and south of the senity and centred on the zenity quiet and disturbed days are considered separately the frequency distributions differ from each other and can be interpreted in terms of the movement of the auroral zone relative to the station at nord greenland 10725 energy spectrum of atmospherics and attenuation of different low frequencies with distance supplement energy spectrum curves of atmospherics produced at known distances are derived from simultaneous measurements on four frequencies in the range of curves of attenuation for the range are similar to the theoretical curves of budden 10726 a note on whistlers observed above the ionosphere whistlers were observed between september and december in satellite vanguard between heights of and of these occurred between and indicating low ionospheric absorption at night 10727 terrestrial extremely low frequency noise spectrum in the presence of exponential ionospheric conductivity profiles expressions are derived which are derived which are applicable to a nonhomogeneous ionosphere the exponential model gives slightly lower resonant frequencies and less damping of the resonant peaks than a sharply bounded model of agreement with measurement is improved 10728 a study of ionospherics at macquarie island a systematic study of radio emissions of natural origin recorded at one station is presented and the generation of these ionospherics is considered on the basis of an extension of the cherenkov radiation model 10729 stanford pacific naval laboratory conjugate point experiment good correlation was found in the times of occurrence of em phenomena observed at high latitude conjugate locations 10730 a nonlinear integral equation from the theory of servomechanism 10731 improved high power dc converters design and performance details of several new circuits are given 10732 cathode coupled cascode stabilizer circuits comment on of and authors reply 10733 methods and possibilities for automatic character recognition review of methods with references 10734 selection of analogue variables by means of idealized diodes diodes the circuits proposed for the selection of maxima and minima in analogue computer applications introduce only very small errors near the points of discontinuity of the functions 10735 ferrite cores as logical elements properties are discussed and the operation of a typical circuit is analysed 10736 persistent current memory circuit difficulties predicted by crittenden et al with regard to the use of in persistor switch elements are disproved by results obtained with persistatron elements made of thin films 10737 high speed memory uses tunnel diode circuit the unit operates at and has a capacity 10738 a transistor binary digital logic system a system of digital logic is described which uses as a basic unit a circuit consisting of two transistors in a bistable arrangement with a novel method of obtaining an output which indicates which of the two stable states the unit is in 10739 a proposal for uniform symbols of logical connections a system of symbols for representing logic functions id described and its application illustrated by examples 10740 electrical noise in carbon film potentiometers noise characteristics are studied as a function of parameters such as the speed of rotation of the sliding contact and the load current 10741 transfer characteristics of permalloy tape toroidal cores of small tape thickness and with square hysteresis loop analysis of core characteristic allowing for the previous history of the core and for inertia effects the treatment is similar to that used by chen and papoulis of and 10742 q factor anomalies in series coupled ferrite rod inductances an examination of the variation of the q factor of a coil divided into two series coupled parts positioned at different points on the core results are discussed with reference to high q oscillatory circuits and in particular the efficiency of ferrite rod aerials 10743 the equivalence of one class of networks with magnetic branches and one class of kirchhoff networks with magnetic elements toroidal core networks equivalent to transfluxors are derived 10744 superconductor transition switching time measurements using a superconductive radio frequency mixer 10745 high speed silicon computer diodes as rf switches 10746 transformer drive for switching transistors a note on design problems and the preferred circuit arrangement 10747 the cryosistor a field effect controlled impact ionization switch a new three terminal device is described in which the impact ionization of impurities in ge at is controlled by means of the depletion field effect of a reverse biased junction the localized nature of the ionization should permit the construction of numerous independent cryosistors on a single ge wafer 10748 signal flow graphs of a linear system a method is proposed for the construction of a signal flow graph based on a nonessential node concept 10749 linear signal flow graphs introduction into the principles and use of the topological method of signal flow graphs 10750 spectral response of a nonlinear device application of fourier series expansion with a bessel function substitution 10751 the cascading of symmetric quadripoles the transformation into a single bridge circuit of cascade connected bridge circuits proved is applied to cascade connected unequal quaripoles 10752 nonlinear investigation of a parallel integrator with the aid of an approximation of first order algebra 10753 stepped waveguide transformers and filters a review of recent developments in the synthesis of stepped quarter wave transformers and half wave filters is given a recent paper by holte and lambert of is discussed 10754 catalogue of power law and tchebycheff type filters from order tables are given extending the earlier catalogue of 10755 optimum matching of symmetrical low pass and high pass filters application to low pass and high pass ladder filters using piezoelectric crystals appendices to earlier paper 10756 low pass and high pass ladder filters using piezoelectric crystals and designed by the image impedance method for single cut off frequency filter structures several design methods are suggested see also of 10757 the tuning fork a two stage mechanical band filter a tuning fork coupled to electromechanical transducers is considered as a quadripole with band pass properties 10758 x band electronically variable attenuator the attenuator described comprises a pair of matched crystal diodes with variable external bias mounted in a symmetric stripline structure 10759 the switching on of a resonant circuit with controlled reactance investigations of the build up transient characteristics of a variable reactance oscillator parametron 10760 one tunnel diode flip flop hf behaviour the switching speed of the circuit discussed in of is determined the use of the circuit as rf detector and high speed counter is suggested 10761 boxcar integrator with long holding times a detailed description of the circuit with component values and performance data 10762 microwave harmonic generation by ferrimagnetic crystals a cavity resonant at both and was used the generation of second harmonics was in good agreement with theory a figure of merit for a ferrimagnet is defined 10763 some types of low noise amplifier a discussion of the advantages and disadvantages of vacuum tubes transistors masers parametric amplifiers and tunnel diodes used in the construction of low noise amplifiers for the frequency range some experimental results are given and frequency ranges suggested for the devices 10764 the linearized transfer function of a phase locked loop containing an if amplifier 10765 the design of wide band power amplifiers for the steady state condition 10766 vacuum tube networks 10767 the stability of narrow band transistor amplifier stages a stability criterion is derived on which a method of phase neutralization is based 10768 comment on a theoretical comparison of average and spot noise figure in transistor amplifiers comment on 10769 comments on design theory of optimum negative resistance amplifiers comment on 10770 thermodynamics and statistical mechanics of a three level maser the analysis gives results which agree with those obtained by solving the rate equations explicit expressions are also obtained for the internal energy heat capacity and entropy the calculations are extended to include spontaneous emission and cross relaxation as well as the usual thermal relaxation 10771 magnetization nutations in maser oscillation pulses the maser equations of are shown to give similar time dependent magnetization and magnetic field patterns to kemps equations of for similar boundary conditions and circuit parameters 10772 characteristics of an ammonia beam maser the design construction and operating characteristics of a maser are described with particular reference to the use of the line threshold oscillation conditions and tuning effects are calculated theoretically and compared with observed performance 10773 maser oscillation observed from maser at the maser described in of has been rebuilt and maser oscillation obtained at 10774 a band parametric amplifier with large bandwidth a bandwidth of at was achieved using a single varactor diode 10775 unidirectional lower sideband parametric amplifier without circulator the amplifier described has the characteristics of a circulator system in respect of matching gain noise figure and non reciprocity but has inferior bandwidth 10776 theory of parametric amplifiers and converter amplifiers of resistance type the investigations cover nonlinear reactance and tunnel diode circuits with particular reference to down converters of the type described by et al 10777 an electronically tunable up converter a lower sideband up converter with a single varactor diode is described 10778 the effect of large pump voltage on tunnel diode down converter performance lower noise factor and increased stability can be achieved through the application of relatively large pump voltages the effects are predictable by a theory incorporating a suitable power series representation for the diode characteristic 10779 the use of square wave carrier currents for supplying ring modulators systematic tests show the advantage of square waves for modulator carrier supply the application of transistor circuits for generating the square waves by frequency division and multiplication eliminates unwanted frequencies without the use of filters 10780 rectifier modulators stray capacitances in modulators of nominally purely resistive type always increase the conversion loss sets of experimental results and a normalization procedure are discussed the circumstances in which it is desirable to tune out the stray capacitances by means of inductances are assessed 10781 nonlinear distortion in the amplitude demodulation of small alternating voltages by means of thermionic and germanium diodes 10782 hyperfine interaction due to orbital magnetic moment of electrons with large g factors 10783 microwave measurements on a high frequency excited gas discharge waves were transmitted through the discharge vessel and amplitude and phase changes were measured as a function of the anode voltage of the plasma producing hf generator horn radiators were applied to the ends or sides of the vessel and the direction of polarization was varied 10784 reflection of an electron beam from high frequency fields experimental verification of time average forces due to an rf field acting on charged particles is obtained by measuring the transmission of an electron beam through the high frequency fields of a cavity by adjusting the external dc magnetic field so that cyclotron resonance is approached it is possible to reflect high energy beams that is of microwave power completely reflected a beam agreement between experiment and theory was close 10785 anomalous electron double diffraction description and discussion of an effect observed in tandem foils of and 10786 production of direct voltages in a rarefied gas tube excited by a high frequency electric field an investigation of the influence of the coil position and hf excitation voltage on the direction of current flow through the discharge tube 10787 electron energy distributions in plasmas the cathode regions in helium neon and argon electron energy distributions in striated positive columns of inert gas discharges have been measured and the effects of impurities on these distributions and on the uniformity of the column discussed 10788 microwave study of non ionizing shock waves the interaction of microwaves with gaseous plasmas is used to study weak shock waves in low pressure gases 10789 on radiations from plasma in a static magnetic field microwave radiometer measurements at of extraordinary waves radiated at right angles to the magnetic field show resonances in accordance with the theory of gross 10790 leakage in a steady state of a plasma with two temperatures confined by a magnetostatic field an extension of earlier work to the case of unequal electron and ion temperatures 10791 triple resonance phenomenon in plasmas a triple resonance effect may occur under certain conditions for a em e wave propagated in an ionized plasma in the presence of a steady magnetic field the effect is demonstrated experimentally and the difficulties encountered and techniques employed in the experiment are described 10792 the absorptivity spectrum of a uniform anisotropic plasma slab the absorptivity spectrum of a plasma slab is computed for waves propagating parallel and normal to an applied static magnetic field for various electron densities electron collision frequencies and slab thicknesses peaks in the absorptivity occur at frequencies near the edges of the stop bands within which little energy can enter the plasma because of reflection at the first boundary 10793 oscillations in a plasma in a weak magnetic field previous work by kato is extended using discharge tubes with high emission cathodes and vapour at lower pressure 10794 plasma oscillations in external fields for a weak electric field the usual method of analysis valid for zero field can be applied the formation of ion waves and their time variation are considered 10795 thermionic emission from spherical metallic particles the build up of positive charge on a particle due to loss of electrons in the absence of space charge is predicted quantitatively 10796 localized magnetic states in metals the conditions necessary for the presence or absence of localized moments on solute atoms containing inner shell electrons are analysed in terms of a simplified model and stability conditions are discussed 10797 vavilov cherenkov effect and bohr radiation produced by a beam of charged particles in a dispersive medium an extension of earlier work with particular reference to instabilities and coupling effects 10798 electron beam excitation of a fabry perot interferometer energy is extracted from a modulated electron beam by injecting the beam diagonally t through dielectric between the plates of the interferometer an output power of about at has been obtained 10799 high frequency diffraction by a sphere a procedure suitable for investigating diffraction produced by a convex body with rotational symmetry illuminated by a high frequency plane wave is discussed and applied to the case of a sphere 10800 on the theory of the diffraction of a plane wave by a large perfectly conducting circular cylinder the boundary value problem is treated for the case of an incident harmonic plane em wave on a cylinder of radius much greater than the wavelength the method used is a straight forward application of a fourier integral transform analysis to a boundary value problem 10801 diffraction of a plane wave by an almost circular cylinder the two dimensional problem of an incident e plane wave is treated the method of solution is based on infinite fourier transform techniques an analysis involving a watson transform is also given in an appendix 10802 experiments on the diffraction of microwaves at plane lattices investigations were carried out at using a horn radiator and artificial dielectric lens the two dimensional lattices were formed by balls circular disks or dipoles 10803 scattering of microwaves from a cylindrical plasma in the born approximation part earlier work is extended to the case of a plasma scattering the spherical waves radiating from an electric dipole 10804 the absorption of electromagnetic waves in a wide frequency range by a thin homogeneous layer with losses the frequency bandwidth of absorbers using a single homogeneous lossy layer is investigated for conditions of vertical incidence with a very thin layer it is possible to achieve a frequency coverage over a range of 10805 energy transfer within a spin system experimental investigations are described of the nature and efficiency of the transfer within a nuclear spin system of energy absorbed from an external rf magnetic field 10806 magnetostatic modes of a ferromagnet slab the characteristic modes of a thin slab magnetized in its plane are obtained in the magnetostatic limit 10807 excitation of spin wave resonance by microwave phonons in a thin ferromagnetic film a series of standing spin waves can be excited by phonons of the same frequency as the spin waves but at wavelengths considerably larger than the magnon wavelength 10808 lasers part devices and systems an illustrated review of the operation o of various types of laser device 10809 the pulsed ruby maser as a light amplifier using a ruby maser oscillator as a light source a net gain of two was observed 10810 power output characteristics of ruby laser a theoretical treatment giving values for the efficiency of operation 10811 probabilities for the neon laser transitions 10812 measurement of the relaxation time by modulation of the radio frequency field and detection of the he variation of magnetization with the controlling field an extension of the method described by whitfield and redfield of is proposed using a much higher modulating frequency under these conditions variations in the signal induced in the pick up coil may be used to determine three methods of detecting the signal are examined 10813 corbino disk predicted changes in magneto resistance in a flat annular disk in a magnetic field are in rough agreement with experiment 10814 on the theoretical limitation of a radio telescope in determining the sky temperature distribution theoretically sky coverage is not intrinsically limited by the aerial power pattern provided that both electrical and mechanical scans are used but there is a practical limit due to noise and power pattern 10815 radio telescope interferometer 10816 the possibility of observing features of galactic radio emission from a satellite borne radio telescope the experimental conditions for the required degree of focusing are discussed the receiver should sweep a frequency range of with a bandwidth of in a satellite established in a nearly circular orbit at a height of 10817 on the apparent long term negative correlation between scintillations and spread f a close examination of the experimental situation relating to chivers observations shows that the result is not unexpected 10818 interferometric studies of type solar bursts of continuum radiation on and type emission at occurs at a height less than while the source has an angular diameter less than and no motion at the height is greater than the diameter is or greater and the source has a large movement 10819 the radio emission from normal galaxies a study of spirals at 10820 preliminary observations of the polarization of radio sources on a wavelength of a consideration of measurements made with crossed aerials on several radio sources shows that the radiation from virgo a is probably due to synchrotron emission 10821 standard errors at harmonic analysis on cosmic ray data 10822 changes in the diurnal hour of maximum of the cosmic ray intensity the evidence from ottawa churchill and resolute supports a year cycle in the hour of maximum intensity at ottawa and perhaps churchill while at resolute it follows k 10823 time variation of cosmic ray intensity in the antarctic region atmospheric temperature effect from the annual change in the amplitude of the diurnal variation variations in isobar level are inferred and compared with radiosonde data 10824 time variation of cosmic ray intensity in the antarctic region part unusual increase differences in the characteristics of unusual increases between north and south polar stations suggest the existence of anisotropy in solar particles from deflection in solar magnetic clouds 10825 variations of the cosmic radiation in november 10826 balloon measurement of solar cosmic rays at fort churchill canada during 10827 the lifetime of radiation belt protons with energies between and m the charge exchange lifetime of protons in the val allen radiation belts is calculated using experimentally measured cross sections these values are compared with estimates of coulomb scattering lifetimes 10828 predictions of cosmic ray storms from geomagnetic data the need for simultaneous high altitude soundings and ground observations during cosmic ray storms is established the times of the sudden commencement of a geomagnetic storm and the forbush decrease of cosmic ray intensity show insufficient correlation for accurate predictions to be made 10829 sweep frequency observations of meteor scatter bursts the duration of the signals as a function of frequency agrees closely with the theoretical inverse square relation 10830 ground conductivity determinations at low radio frequencies by an analysis of the spheric signatures of thunderstorms the experimental and analytical techniques are described a detailed comparison of predicted and experimentally observed waveforms indicates that the effective conductivity can be determined to a precision of one or two significant figures application of the techniques for evaluating the reflection and transmission properties of the lower ionosphere is suggested 10831 a provisional ground conductivity map for canada the derivation of the map is discussed results are given of propagation measurements over the great lakes region to determine the conductivity of fresh water areas 10832 the effects of energetic trapped particles on magnetospheric motions and ionospheric currents distortions of stable belts of particles in the earths magnetic field due for example to the interaction of new groups of particles or to the compression of the earths fields by a neutral stream could result in a system of ionospheric currents and magnetospheric motions of the form assumed by axford and hines 10833 sq and ocean a theory of electromagnetic induction is derived and applied to the induction by sq in a vast ocean 10834 magnetic field micropulsations and electron bremsstrahlung enhanced magnetic micropulsation activity in the auroral zone has been observed to coincide with the increased intensity of bremsstrahlung from energetic electrons 10835 the stability of the interface between the solar wind ad the geomagnetic field surface magnetometer data are presented as evidence of the stability of the interface between the solar wind and the geomagnetic field hydromagnetic waves are assumed to be generated by fluctuations in the energy density of the solar wind rather than by turbulence or gross instability at the interface 10836 note on hydromagnetic propagation and geomagnetic field stability the use of surface magnetic data in estimating the conditions in the exosphere s is criticized inferences from suf surface magnetometers are not consistent with measurements obtained from space probes 10837 a unifying theory of high latitude geophysical phenomena and geomagnetic storms a convection system set up in the magnetosphere by viscous interaction between the magnetosphere and a solar wind or by other sources could account for a wide variety of observed high latitude geophysical phenomena and storm time variations 10838 total atmospheric ozone and geomagnetic activity 10839 note on the autocorrelation coefficient of and its relation to regions results of ward for the period april march are consistent with the theory of the existence of long lived regions on the sun autocorrelation functions plotted for other periods are given by ward 10840 a simple method for the supervision of the orbital period of artificial satellites a graphical method of detecting changes in orbital period on progression charts 10841 infrared and reflected solar radiation measurements from the tiros meteorological satellite 10842 observations on the possible influence of cosmic radiation on transistor life in space satellites the concentration of cosmic radiation in the van allen belts and the possible effect of this on transistors in communications satellites are discussed with reference to observational results 10843 solar flare tritium in a recovered satellite unusually high ritium content present in samples of recovered discoverer satellite is interpreted as due to flux of incident tritons from a solar flare 10844 an hf radar search for possible effects of earth satellites upon the upper atmosphere the radar used had a frequency of peak power of and aerial gain the results showed no evidence that backscatter anomalies observed were caused by earth satellites 10845 orbiting spectrometer plots solar x rays pulse analyser and counter circuits in the scout satellite for investigations in the wavelength range are described 10846 bursts during the last few periods of 10847 ionospheric contributions to the doppler shift at vhf from near earth satellites 10848 effect of major meteoric showers on the densities of the upper atmosphere preliminary analysis of density data obtained from satellite measurements at about and indicates density increases during major showers 10849 note on a mechanism for the vertical transport of ionization in the ionosphere vertically travelling gravity waves can produce corresponding vertical movements of dense layers of ionization which are formed at alternate nodes of the wave system the combined effects of coexistent standing and travelling waves are considered 10850 determination of electron density profiles in the ionosphere neglecting the influence of the magnetic field a rapid method is described for determining nighttime layer electron density given base height critical frequency and factor though less z accurate than other methods it is not dependent on the quality of ionograms 10851 determination of electron density profiles in the ionosphere taking account of the earths magnetic field an addition to the original theory 10852 on the index of refraction in the ionosphere the forces acting on an electron in an ionized gas are enumerated it is confirmed that in the ionosphere the lorentz polarization force is annulled by the effects of electron ion collisions and that the refractive index is given by the sellmeyer formula at radio frequencies 10853 a statistical study of lower atmospheric ionospheric coupling the departures of the daily values of from the monthly median were compared with the calculated large scale vertical motion in the atmosphere at heights up to km no association between the two parameters was found at five stations in canada and the usa 10854 the interpretation and synthesis of certain spread f configurations appearing on equatorial ionograms computer ray tracing to thin irregularities in the equatorial ionosphere explains three classes of spread f from synthesized ionograms it is possible to deduce the position size and drift velocities of patches of irregularities 10855 a waveguide interpretation of temperate latitude spread f on equatorial ionograms the striated nature of frequency spreading on equatorial ionograms is tentatively explained by energy trapping between thick field aligned ionospheric irregularities 10856 excessive ionization in the lower ionosphere and instabilities in the outer radiation belt absorption anomalies in the lower ionosphere are interpreted on the basis of recent observations of aurorae and the van allen belts the analysis of long term measurements indicates a strong dependence of the ionization effects on sunspot activity 10857 atmospheric scale height as a modifying influence on linear trend of region electron density with sunspot number twelve month running average values of noon maximum electron density and true height of the layer at christchurch are plotted against twelve month running average sunspot numbers for the period a departure from linearity is apparent above a sunspot number of it is suggested that increases in scale height near the sunspot maximum were large enough to modify the increase in the rate of ion production with a consequent relative decrease in maximum electron density 10858 electron ion recombination coefficients in nitrogen and oxygen microwave determinations of electron density decay during the afterglow following ionization of gas in a cavity and simultaneous identification of the afterglow positive ion current by an rf type mass spectrometer provide information from which recombination coefficients can be assigned to particular positive ion species 10859 vertical drift of the f layer during negative geomagnetic bay disturbances disturbances are taken to be negative when and are not both positive observational results are compared with theoretical findings as in previous investigations of the agreement between geomagnetic and ionospheric observations is poor 10860 determining local concentrations of charged particles in the ionosphere and interplanetary space russian work in the determination of electron concentration by radio wave dispersion measurements and charged particle trap experiments is described 10861 the use of probing electrodes in the study of the ionosphere measurement of electron concentration and temperature and ion mass spectrum concentration and temperature by a satellite borne langmuir probe is considered 10862 the calculation of the electron density in the ionosphere from elevation angle measurements on artificial satellites when a transmitting satellite travels below the peak of the f layer measurements of the angle of arrival of the received signal show a minimum the value of which is related to the local satellite electron density 10863 a new versatile ionospheric recorder the main features of a cheap portable panoramic recorder are outlined 10864 the effect of collisions on the propagation of radio waves in the ionosphere 10865 the interpretation of critical frequency measurements during winter daylight hours on magnetically quiet days day to day variations of hourly values of may be due mainly to the presence of travelling ionospheric disturbances hence values are only reliable to within the resulting errors in estimated are also discussed 10866 the graphical distribution of the harmonics of the annual variation in the critical frequency of the layer at noon the annual change in noon at stations has been represented in terms of the first and second harmonics and a constant term the term the first harmonic usually has the same sign in both north and south hemispheres and in the origin of the winter anomaly in the northern hemisphere the amplitude of the second harmonic is greater than expected 10867 the dependence of the fluctuations of the atmospheric refractive index on meteorological parameters results of measurements with a microwave refractometer measurements were carried out with the refractometer described in of suspended from a tower 10868 the excitation of airglow by means of radio waves the theoretical possibility of producing an artificial airglow in a weakly ionized gas is investigated and the feasibility of generating this effect in the ionosphere is discussed see also 10869 theory of auroral bombardment the theory covers the drift motions of particles in a dipole field perturbations of the pitch angles produced by local magnetic and electric fields the growth of electrostatic potential and perturbations of drift motions by magnetic disturbances and electric fields 10870 on the statistical properties of optical and radio aurora an investigation of latitudinal and diurnal variation of auroral forms and the correlation between optical and radio aurora 10871 solar flare effects on and atmospheric radio noise solar flares have been analysed and a positive relation between them and short time noise power decreases has been found the most significant noise fade outs occurred when the sun was ovr one of the major noise centres contributing to the noise at the recording station 10872 definition and measurement of the mean field of pulse type atmospherics the mean effect on a receiver with tuned circuits and linear detection of short pulses at is very similar to that of an em field with an effective electric component eing the effective height of the aerial for the aerial for the frequency to which the receiver is tuned 10873 use of coherent memory filter in spectral measurements of atmospheric whistlers 10874 a study of the playback process of a magnetic ring head a simplified gap loss function is given for the case of finite parameters for tape and head 10875 superconductive computers factors involved in present and future use of super conductive components are assessed new approaches to the design of superconductive storage systems are reviewed 10876 forming semi permanent memories with metal card storage presence or absence of a metal shield between two closely spaced coils has a large effect on their mutual inductance the principle is used to build a read only memory whose content is determined by thin metal cards 10877 the transfluxor as analogue storage device 10878 tentative recommendations for the definition z and testing of the dynamic performance of analogue to digital converters methods of classifying specifying and testing shaft position and analogue voltage digital converters are suggested 10879 the reliability of components in satellites the effects of the special hazards on component design and development for space vehicles are reviewed 10880 new phase and frequency comparison circuits a method is described for producing a rectified voltage which is a function of the phase and frequency difference of two alternating voltages it is particularly suitable for pulse shaped waveforms and its application for synchronizing systems in television receivers is examined in detail 10881 vacuum deposited metal film resistors detailed description of the problems and procedure involved in the production and testing of film resistors 10882 noise performance in tin oxide resistors noise measurements show up resistor defects not found by standard tests 10883 on the process of flux reversal in multiaperture ferrite cores experimental results for two aperture cores are presented and a model is suggested to represent the flux state within a two aperture core for various winding circuit combinations 10884 silicon junction diodes as variable capacitors expressions are given defining barrier width and junction capacitance and methods of measuring the latter are suggested various applications of diode capacitors are described the temperature dependence of the capacitance is a hanicap 10885 resistance and frequency variations due to unwanted modes in quartz crystals a numerical relation is shown to exist between the peak resistance increase and peak frequency departure caused by an unwanted mechanically coupled mode the value provides a useful means of estimating frequency departures and determining whether a particular crystal is satisfactory 10886 circuits with nonlinear resistance an extension of the study of series circuits with diodes of to the behaviour of parallel combinations of circuit elements each circuit containing a diode as a nonlinear resistance 10887 the calculation of the numerical values of the elliptic functions for tchebycheff type filters formulae suitable for handling by automatic computers are derived for the solution of jacobis elliptic functions 10888 restrictions on the natural frequencies of an network theory is developed suitable for application in the synthesis of passive and active networks 10889 tunnel diodes for low level triggers a sensitive low level circuit uses a tunnel diode to drive a schmitt trigger 10890 simulating nerve networks with four layer diodes a note on the operation of a neuristor model 10891 efficiency of frequency multipliers using charge storage effect in general highest efficiency is obtained by cascading lower order multipliers based on the depletion layer effect but the power rating of the charge storage type is considerably higher 10892 a tunnel diode wide band frequency doubling circuit 10893 generation of microwave harmonics in an electrodeless discharge at low pressure methods of producing rf harmonic power in an ionized gas are reviewed and an experimental arrangement is described which shows improved efficiency at a fundamental wavelength of 10894 three level maser action in gas part theory of multiple quantum transition and doppler effect in three level gas maser 10895 cross relaxation effects in a ruby l band maser at low magnetic fields the reversals of maser h behaviour on cooling from to are explained in terms of cross relaxation transitions involving triple spin flips 10896 parametric circuits with nonlinear inductances in the lower frequency range extension of earlier analysis of to cover nonlinear inductances and their application in amplifiers up converters and down converters results of experiments using a ferrite core as nonlinear element at af are discussed 10897 a travelling wave variable reactance type parametric amplifier a full description of the amplifier previously noted in of 10898 a resonant slot parametric amplifier brief description of a varactor diode amplifier for operation in the range 10899 an extremely wide a band tunable s band parametric amplifier the range covered is by mechanically tuning the pump circuit and shifting the frequency of the pump source by the latter means alone the amplifier can be tuned over a band 10900 a dc pumped amplifier with a two dimensional field structure 10901 stability criteria for a tunnel diode amplifier analysis of a type of circuit also considered by hines 10902 a tunnel diode frequency multiplier with gain the multiplier described is based on the nonlinear negative resistance characteristic of a tunnel diode and shows a voltage gain for the second and third harmonics 10903 a simple phase detector a phase sensitive detector is described for use when the reference and variable signals have a common terminal 10904 crystal detectors to cover the frequency band 10905 an audio frequency phase modulator using pulse techniques the range of phase shift of the carrier is and departure from linearity as a function of the magnitude of modulation input is less than 10906 the movement of charge carriers in gases with crossed electric and magnetic fields the cases discussed are static magnetic field with alternating electric field at right angles both fields static and both fields alternating synchronously 10907 theory of impurity resistance in metals part the many body theory developed in a previous paper of is extended to include all corrections resulting from electron electron interactions 10908 self trapping of an electron by the acoustical mode of lattice vibration when the coupling constant between the electron and acoustic mode vibration exceeds a critical value the effective mass of the electron increases discontinuously and the electron takes a localized self trapping state as an eigenstate 10909 transient effects in peltier coolers addendum to 10910 new derivation of the vacuum breakdown equation relating breakdown voltage and electrode separation 10911 practical calculation of the defocusing influence of the space charge application to relativistic electron beams 10912 interaction of a modulated electron beam with a plasma report on theoretical and experimental investigations of the interaction between a microwave modulated electron beam and a mercury arc discharge and of the interaction between a modulated electron beam and a slow es wave on a plasma column 10913 transport equations for plasmas in strong external fields coupling of plasma particles to a strong electric field can greatly exceed their mutual coupling and this is shown to lead to a vlasov type transport equation 10914 values of the transport coefficients in a plasma for any degree of ionization based on a maxwellian distribution values for electrical conductivity for any degree of ionization steady magnetic field and various electron neutral collision laws are presented other transport coefficients are tabulated the analysis uses the fokker planck and boltzmann equations 10915 generation and application of highly ionized quiescent cesium plasma in steady state plasma densities at greater than ionization have been obtained by the method described 10916 plasma physics an elementary review a summary o of the role of plasma physics in current scientific research 10917 the electrical conductivity of a partially ionized gas analysis taking account of both electron particle and coulomb type collisions but neglecting the effects of inelastic collisions and a steady magnetic field 10918 oscillations and noise in low pressure dc discharges a review of experimental investigations of oscillations and fluctuations which occur spontaneously or through excitation in low pressure hot cathode plasmas methods of reducing these effects are discussed 10919 antiferromagnetic susceptibility of the plane triangular ising lattice the antiferromagnetic susceptibility of the plane triangular ising lattice is calculated in terms of a power series for all temperatures 10920 the magnetic field in the vicinity of obliquely magnetized cylindrical bodies the field distribution has been calculated and plotted for three different cases of oblique magnetization 10921 magnetization curve of an infinite cylinder calculations are made for an infinite ferromagnetic cylinder with negative uniaxial anisotropy 10922 the reciprocity theorem of electromagnetic theory an examination of the work of several authors in order to present the theorem in the clearest way with emphasis on the physical hypotheses which are the basis of the principle 10923 magnetohydrodynamic waves in cylindrical waveguides and toroidal resonators investigation of small amplitude magnetohydrodynamic waves in rectangular and circular waveguides and of standing waves in a toroidal resonator 10924 radiation from a modulated electron beam with a plasma background expressions are derived for the electromagnetic radiation of current modulated electron beams which emerge from a plasma simple expressions are derived in the case where the dielectric constant of the plasma is zero or infinity 10925 diffraction of electromagnetic wates by sound waves the diffraction amplitude is calculated from borns approximation results of measurements on microwaves affected by a standing sound frequency and polarization of the em waves 10926 transmission and reflection of electromagnetic waves at a plasma boundary for arbitrary angles of incidence a plane em wave horizontally or vertically polarized incident at an arbitrary angle on a flat plasma boundary is investigated numerical results showing variation of attenuation and phase power entering the plasma and ellipticity of the reflected wave are presented 10927 some features of the transverse propagation of high frequency waves in a magneto active plasma mathematical analysis based on the kinetic equations of nonrelativistic theory for a simple case of transverse wave propagation in a uniform plasma located in a constant magnetic field the effect of electron collisions with other particles is neglected 10928 magneto ionic theory for a fully ionized hydrogen plasma the effects of electron proton and electron electron collisions on the real refractive index and the absorptivity are evaluated for electromagnetic wave propagation in a fully ionized hydrogen plasma under the influence of an external magnetic field the appleton hartree magneto ionic formula as generally applied to the solar ionosphere is retrieved in a limiting case with the conventionally adopted expression for the effective electron proton collision frequency electron electron collisions are significant only in the realm of gyro resonance where they diminish the absorptivity due to electron proton encounters 10929 frequency conversion in a microwave discharge analysis of the nonlinearity of a microwave discharge between two closely spaced parallel plates of dimensions small compared to parametric amplification in a discharge is briefly considered 10930 interaction of microwaves in gaseous plasmas immersed in magnetic fields experimental investigation of the interaction of two or more em waves guided through a magnetoplasma medium with particular consideration of em energy transfer and its effects 10931 measurement of the refractive index of lucite by recoilless resonance absorption details are given of a method of modulating the frequency of a monochromatic em wave by varying the optical pathe length between the source and detector in the application described a small frequency shift in radiation is detected by recoilless resonance absorption 10932 electron paramagnetic resonance for metals with two conduction bands 10933 ferromagnetic relaxation part the role of four magnon processes in relaxing the magnetization in ferromagnetic insulators the effect of the exchange induced four magnon process should be observable in parallel pumping experiments four magnon processes arising from dipole cubic anisotropy and exchange coupling are not very effective in relaxing the uniform precession 10934 contribution to the study of ferrimagnetic resonance curves theoretical considerations techniques for measurement of magnetic parameters and results of experiment are discussed 10935 relaxation equations for two magnon and magnon phonon processes in ferrimagnetic resonance equations giving the relaxation behaviour of the magnetization in the case of ferrimagnetic resonance are derived from quantum mechanical rate equations for spin wave magnons 10936 detection of spin magnetization variation in a two level maser oscillator a neutron irradiated sample containing about spins was mounted in a rectangular plastic cavity resonator with field sweep excitation oscillations were detected which established the existence of variations of 10937 three level maser action in gas theory of multiple quantum transition and doppler effect in three level gas maser discussion of the multiple quantum process for the off resonance condition the intensity of the emission produced is calculated using perturbation theory as well as the more general javans theory the doppler effect is analysed from semiclassical and quantum mechanical viewpoints 10938 lasers devices and systems parts an illustrated review covering communications range finding and detection military and computing applications and methods of modulation scientific medical and other devices part 10939 proposed harmonic generator or mixer for optical frequencies limitations of the mixer suggested by laine of are discussed and s simpler alternative device using liquid caesium is described 10940 observation of optical maser oscillation in ruby a note on experimental results obtained using multiple dielectric layers as mirrors in the maser cavity 10941 mode characteristics and coherence in optical ruby masers a discussion of a series of interference experiments in which oscillations are shown to occur at several different frequencies corressponding to various numbers of half wavelengths between the reflecting ends of the ruby 10942 a ruby laser exhibiting periodic relaxation oscillations generated by the optical maser described may make it useful for ranging applications 10943 design of a helium neon gaseous optical maser constructional details of the optical maser described in of 10944 coherent light amplification in optically pumped vapour using the strong line to produce a population inversion in the vapour a gain of is predicted for a cell 10945 signal to noise ratios in photo electric mixing the possibility of using photoelectric mixing for the linear amplification and frequency conversion of coherent optical signals is considered 10946 a new application of the faraday magneto optical effect for diagnostic measurements of transient magnetic fields by a combination of streak and optical interference fringe techniques with the magneto optical method described it is possible to determine field geometry space time distribution of electron number density in a high density plasma and line integrated variations of magnetic field 10947 radio frequency discharges in magnetic fields report on investigations of discharges in with the magnetic field normal to the rf electric field 10948 drift velocity of a charged particle in an inhomogeneous magnetic field a class of magnetic fields is defined for which the drift velocity may be calculated exactly 10949 energy band structure of solids from a perturbation on the empty lattice 10950 instability of antiferromagnetic screw type structure of an electron gas an analysis by the self consistent field method of a screw type structure in a free electron gas such as that proposed by overhauser proves that it is always unstable the susceptibility of such a gas is also derived by the same method 10951 on the origin of radio emission from cosmic clouds the balance between absorption and stimulated emission for free free transitions in a gas plasma can lead to a negative as well as a positive effective absorption coefficient and hence to amplification of the spontaneous emission 10952 the australian national radio astronomy observatory a brief description of the inauguration of the observatory at parkes and of its first instrument a steerable paraboloid 10953 report of the advisory panel on radio telescopes special reference is made to the feasibility and cost of constructing a beam aerial operating at 10954 operation at the medicina station of a radio telescope a description of an interferometer type radio telescope which consists of a cylindrical parabolic aerial long and wide at the focus of which are full wave dipoles 10955 a radio survey of the galactic plane at a frequency of parts of discrete sources observed most lie within of the galactic plane and about are thermal continuum observations show large scale features which can be interpreted in terms of a spiral model of the galaxy if independent distributions for thermal and nonthermal emission are postulated 10956 recent decametre wavelength observations of jupiter saturn and venus observations made during show that only jupiter appears to emit extensive nonthermal radio noise 10957 presence and correlation of fine structure in jovian decametric radiation results obtained from spaced receiver observations of noise storms of jupiter showed correlation of fine structure components having durations of the order of hundredths of a second for receiving sites apart 10958 solar emission at millimetre wavelengths solar flux density measurements at indicate that the radiation is primarily from the photosphere and corresponds to the thermal radiation from a black body at 10959 some solar studies on the occurrence of type solar bursts of continuum radiation type solar emission in the frequency range occurs in two phases the first usually observed at frequencies higher than appears to be emitted low in the chromosphere from a source of angular size the second occurs high in the corona with a source size or more 10960 thermal radio emission from the transition layer chromosphere corona two models of the transition layer are computed using new values of emission and absorption coefficients comparison with recent observations shows that the models predict decimetre wave emission with reasonable accuracy 10961 the radio brightness distribution on the sun at from combined eclipse and pencil beam observations radio bright regions appear to overlie the optical plages faculaires at a height of about and show similarity in size shape and relative intensity a higher peak temperature and gradient for the limb brightening was revealed 10962 the spectral components of major solar radio events characteristics of solar radio events are listed together with the associated flare and ionospheric data the distribution of storm associated flares over the sun and the variation of storm occurrence with sunspot cycle are noted 10963 observations of radio sources at wavelength observations of radiation from cas tau orion nebula and are described 10964 stimulated emission of the fine structure line of hydrogen in diffuse nebulae 10965 radio sources and clusters of galaxies the result is given of a comparison of positions of radio sources in the catalogue with positions of rich clusters of galaxies see also of 10966 a note on the unusual variations of cosmic ray intensity during the period november to unique features of cosmic ray observations are described including effects on the earths magnetic field and effects produced by the interplanetary magnetic field well defined solar particle trapping regions appear to exist in the inner solar system the preferential arrival of particles from directions well to the west of the sun is discussed 10967 an analysis of the solar daily variations of the primary cosmic radiation measured with the igy neutron monitor network the results of a harmonic analysis of monthly averaged data from world wide monitoring stations show no asymmetry in amplitude or time of maximum for the northern and southern hemispheres 10968 diurnal variation and forbush decrease an examion of the depressions which often precede the largest forbush type decreases by less than 10969 the primary cosmic ray electron flux during a forbush type decrease balloon observations indicate a decrease of in the electron flux during a forbush decrease it is suggested that the primary electrons are of galactic and not of solar origin 10970 spatial distribution of electrons from neutron decay in the outer radiation belt the spatial distribution of electrons in the outer radiation belt is calculated theoretically assuming as a source the decay products of albedo neutrons there is moderate agreement with satellite results 10971 coordinates for mapping the distribution of magnetically trapped particles 10972 measurements of cosmic rays on geophysical rockets the rocket equipment and the results obtained during one flight are described 10973 radio wave scattering from the lunar surface measurements on the angular scattering properties of the lunar surface at are described for angles of incidence at least scattering is independent of over the range of 10974 the radar cross section of the moon reply to criticism of the theory of scattering from the moons surface proposed in 10975 magnetohydrodynamic interpretation of sunsport activity 10976 sunspot cycles a discussion of problems met in attempting to forecast sunspot conditions a simple analysis is made of data from the complete cycles so far recorded 10977 the theory of electric currents in the magnetosphere in the brief theoretical treatment given the plasma of the magnetosphere is replaced by a particle gas with diamagnetic properties 10978 interaction of west ford needles with the earths magnetosphere and their lifetime a discussion of the effects of the charge built up on the needles passing through the magnetosphere the uncertainty of the lifetime of the needles is illustrated by calculations showing that they may re enter the atmosphere in any period from a few months to a century 10979 rapid geomagnetic fluctuations an investigation of oscillations at in the earths magnetic field measured in the archipelago of stockholm between july and june 10980 formation of the geomagnetic storm main phase ring current the main phase ring current is supposed to be generated by heating the exospheric gas by hydromagnetic shock waves the more energetic component consists of protons a flux hydrogen atoms should be observed at the base of the exosphere and the decay time of the ring should be less at sunspot minimum than at sunspot maximum by a factor of three 10981 spectrum of hydromagnetic waves in the exosphere the influence of the earths gravitational field on hydromagnetic wave propagation is discussed and the limiting conditions for the propagation of the various modes in the exosphere are considered 10982 travelling pressure waves associated with geomagnetic activity records obtained at washington frequently indicate the occurrence of travelling pressure waves with periods of during intervals of high geomagnetic activity 10983 variations of the earths exosphere and geomagnetic disturbances during the geomagnetic storm of september geomagnetic data and observations on trapped particles in the outer radiation belt have been studied and a simple model of the state of the exosphere during the main phase of the f storm has been proposed 10984 missile and space electronics applications of electronics in future space projects are described a schedule of launchings for the next years is given 10985 determination of illumination conditions and periods of an artificial satellite in shadow and in sunlight a method of determining the illumination conditions of a satellite is described and a brief analysis of the paths of th first three soviet satellites is given 10986 influence of the earths oblateness on the rotational motion of an artificial satellite the equations of motion are set up and the small oscillations of the satellite relative to the orbital system of coordinates are studied 10987 variations in the positive ion concentration with altitude from data of mass spectrometry measurements on the third satellite mass spectrometer measurements of the ion concentration are compared with measurements of electron concentration obtained from radio observations of the first and third soviet satellites and with measurements of positive ion concentration obtained with positive ion traps installed on the third soviet satellite 10988 irregularities in atmospheric densities deduced from satellite observations results of observations of atmospheric drag on satellites indicate a pronounced diurnal bulge lagging behind the subsolar point erratic fluctuations of the atmosphere above due to solar radiation and irregular perturbations of the upper atmosphere associated with magnetic storms 10989 a theoretical model of temperature variations at the surface of an orbiting satellite 10990 winds in the upper atmosphere results are given of a five year study of winds at heights of obtained from radar observation of ionized meteor trails diurnal and seasonal variations are described in detail 10991 radar investigations of the upper atmosphere the parameters of the radar transmitters to be used with the two parabolic reflectors at defford near malvern are given and possible experimental investigations of ionization are discussed 10992 a working model for the upper atmosphere the validity of a model by nicolet is examined and some comparisons made with that proposed earlier of 10993 fluctuations of electron density in the ionosphere discussion of turbulent fluctuations in the lower ionosphere where the frequency of ion collisions with neutral particles is large compared to the larmor frequency 10994 theory of electrostatic fields in the ionosphere at polar and middle geomagnetic latitudes discussion of paper by spreiter and briggs of and criticism of daggs theory of the formation of irregularities in the f region of and 10995 two methods of detecting ionospheric disturbances describes rapid visual methods for detecting f region disturbances by the distortion of traces on ionograms 10996 simultaneous study of drifts at different levels in the ionosphere by the spaced receiver method by comparing drift speeds in the and regions the effect of a lower layer on upper layer drift measurements is deduced and drift gradients are estimated 10997 the varying electron density profile of the f region during magnetically quiet nights local height changes of about lasting for are illustrated the general increase in height before midnight and the pre sunrise decrease are found to be independent o of season severe vertical movements induced by a magnetic bay were not accompanied by spread echoes 10998 the heat balance of the f region and the saturation effect as the input of solar ultraviolet radiation to the f region increases with increasing solar activity the volume rate of production of ionization increases to a certain point and thereafter decreases 10999 the morphology of lunar semidiurnal variation in near solar noon within about of the magnetic equator the phase of the lunar semidiurnal variation in is almost opposite to that observed elsewhere the amplitude of the variation is greatest at the equator and near magnetic latitudes where it is about of 11000 further evidence of a long term variation in the relationship of solar activity to the ionosphere there is evidence that since there has been a decrease in the amount of ionization in the layer for a given sunspot number a similar conclusion was reached for the e layer 11001 round the world sound waves produced by the nuclear explosion on october and their effect on the ionosphere at sodankyla microbarograph and ionosonde recordings of the explosion are described disturbances due to direct travelling waves and round the world waves were detected on each instrument 11002 increase of ionization associated with geomagnetic sudden commencements increases of cosmic noise absorption in high latitudes seem to be associated with certain types of ssc 11003 measurements of electron concentration in the ionosphere up to altitudes of carried out during the international geophysical year by means of radio wave transmissions from the geophysical rockets of the academy of sciences ussr the determination of electron density distributions from measurements of radio wave dispersion and the faraday effect are examined the results of three rocket flights to altitudes of in are described 11004 generalized appleton hartree equation for any degree of ionization and application t the ionosphere the equation derived is applicable to any variation of electron collision frequency with electron speed and any degree of ionization results for the ionosphere are compared with experimental data e layer results can be explained by assuming a electron temperature several times higher than the gas temperature 11005 the absorption of radio waves in the ionosphere with respect to geomagnetic current control and other proposed me models a critical survey a critical survey is given of the work of appleton and piggott of bandyopadhyay of and rumi serious errors arise because of the neglect of deviative absorption in the e region 11006 properties of the outer ionosphere deduced from nose whistlers analysis of nose whistler data shows that the electron density in the outer ionosphere is proportional to the geomagnetic field strength with a annual variation 11007 auroral investigations during the winter seasons and their bearing on solar terrestrial relationships the results of spectral investigations of aurorae at oslo and tromso 11008 some results of investigations of aurorae and night airglow during the igy and igc a review of ussr results and a discussion of their interpretation 11009 circular symmetry in the geomagnetic plane for aurora phenomena projections of circles in the geomagnetic equatorial plane on to the earths surface along the real geomagnetic field lines are compared with published observational data for the northern and southern auroral zones 11010 a morning discontinuity in the orientation of the quiet auroral arcs 11011 on the association of radio reflections with optical aurora the observations provide no basis for assuming that optical and radio aurora are independent phenomena 11012 the azimuthal distribution of ultra high frequency radar echoes from aurora partial analysis in range and azimuth of radar echoes at with diameter paraboloid aerials contours of constant echo occurrence are different in the two periods before and after midnight 11013 determination of radar auroral heights with the prince albert radar 11014 measurement of very low frequency atmospherics at bonn report on measurements in the frequency range close agreement was found with earlier results obtained by of 11015 propagation characteristics of whistlers trapped in field aligned columns of enhanced ionization whistler data are examined using ray theory to deduce properties o field aligned ducts in the outer atmosphere 11016 electromagnetic radiation from solar corpuscular streams some objections are raised to a paper by mac arthur of and theory is developed for the case of superlight motion when the particle velocity is greater than the phase velocity of the emitted waves 11017 correlation between low frequency radio noise and magnetic and cosmic ray storms measurements at poitiers and limeil show that vlf radio noise starts about after an ssc a maximum being reached about after the ssc the maximum noise occurs at the maximum of cosmic ray storms 11018 geomagnetic activity and the reception of whistlers in polar regions data on whistler reception at scott base antarctica are discussed the frequency of occurrence of whistlers shows a diurnal variation and decreases with increasing geomagnetic activity 11019 some ionospheric results obtained during the international geophysical year 11020 some thermal considerations on the use of solar cells in space vehicles the radiation balance of solar cells in space is discussed for different configurations of the cell assembly and different orbits surface coatings are considered 11021 a cryotron memory cell an improved versatile storage cell consisting of three cryotrons and one superconductive loop is described 11022 high speed logic circuits using common base transistors and tunnel diodes 11023 digital function generation with torsional delay lines a torsional magnetostriction delay line has small magnets to replace the usual control taps since the magnets do not load the line a large number of taps each equivalent to one bit may be used with one common output 11024 envelope feedback in an audio frequency amplitude modulator the amplitude modulator is designed to transmit solution information when a composite computing scheme consisting of an analogue computer and a network analyser is used to solve problems concerning generator and load transients 11025 the logic potential of molecular electronics in the multicollector transistor methods of applying the techniques of molecular electronics to form logic circuits are discussed with emphasis on the two collector transistor of the logical effects of more collectors are briefly considered 11026 microsystems and molecular electronics a special issue containing nine papers describing the need for microsystems and designs for modular and solid state circuits the last three papers are abstracted separately 11027 microsystem circuit analysis a general method for analysing film type networks based on the theory of indefinite matrices is presented simple rules are developed for generating sub networks from a given four terminal network 11028 a fatigue test for printed wiring boards and through connections a krouse flat plate fatigue testing machine was modified to take the larger specimens to be examined typical test data are presented in the form of strain cycle life diagrams 11029 developing the hall generator equivalent circuit the basic phenomena occurring in the device are described in matrix form and an equivalent circuit is derived by matrix manipulation current gain voltage gain and input impedance are found in terms of the equivalent circuit parameters 11030 nonlinear and controllable inductances made of thin and magnetic films the inductance considered which may be used for parametric amplification takes the form of a thin ferromagnetic film in a magnetizing coil the effect of film premagnetization on the inductance value is calculated experimental results obtained for a coaxial oscillator system are compared with theory 11031 ferrite core current steering comutators and ring counters commutating circuits are described which steer well defined current pulses sequentially along a number of paths and simplified design formulae are given 11032 duality relations between threshold type switching functions and their application to problems of synthesis 11033 thin film capacitors using tantalum oxide dielectrics prepared by reactive sputtering a note on the method of preparation and measured characteristics 11034 the transient response of linear passive networks to phase modulated signals some simple networks are stimulated by a sinusoidal signal phase modulated by a step input analytical solutions are verified experimentally and with an analogue computer 11035 parametric behaviour of an ideal two frequency varactor an analysis in which pump and signal voltages of large amplitude are allowed and the complete varactor characteristic is used with linear signal termination the ratio of signal to pump frequency must be where is an integer all possible operating modes are identified 11036 a synthesis procedure the synthesis of symmetrical reactance networks with equal terminations is considered from the insertion loss characteristic the impedance which the half circuit presents at the axis of symmetry is derived from network theory and the complete circuit is obtained by back to back connection of the two halves 11037 the representation of ladder network parameters through continued fraction polynomials euler polynomials are used to derive concise expressions for the transmission parameters of linear ladder networks in terms of the branch and terminating immittances a generalized form of the polynomials is helpful in the design of reactively coupled multiple tuned narrow band pass filters 11038 band pass filters having quasi symmetrical attenuation and group delay characteristics description of design procedure and report on experimental results 11039 integrating and differentiating circuits applications to filtering and to z acoustics the basic circuits and the effect of successive operations on speech and music signals are considered a detailed study is made of an if band stop filter derived by linear combination of differentiating and integrating circuits its applications in a distortion meter selective amplifier and df oscillator are described 11040 harmonic generation and frequency mixing in ferromagnetic insulators calculations are made of second harmonic generation and second order frequency mixing for small ellipsoidal samples with loss included in the landau lifshitz form examples are given and a simple case of third harmonic generation is discussed detailed calculations are given elsewhere 11041 background noise in oscillators with rf pushing an extension of previous work to include non linearities in which the frequency of oscillation is a function of oscillation amplitude 11042 an indirect method for the exact solution of the oscillator equation by establishing the characteristic of the oscillator in the phase plane exact solutions of the nonlinear differential equation involved can be found the characteristics of these solutions are discussed for english 11043 transfluxor frequency memory a transfluxor is used as the frequency control component of a magnetically coupled multivibrator 11044 sawtooth generator with almost infinite linearity the miller integrator using junction transistors is analysed maximum linearity is achieved with the transistor operating without feedback in an earthed base circuit practical circuits for generating various sawtooth waveforms are given 11045 an analysis of the dc design considerations of a transistorized schmitt trigger parts design difficultes are reduced by establishing first the necessary and second the desirable requirements so that the number of variable parameters is mu minimized 11046 voltage controlled wide range oscillator the variation of the small signal impedance of a junction diode with bias is used to give a voltage controlled phase shift 11047 study of transients in similar electrical networks the transient characteristics of equivalent networks obtained by frequency or impedance transformation are analysed for english version 11048 new high speed counter divider the unit will count and divide by any number up to at operation at frequencies up to should be possible 11049 a self indicating magnetic scaling system using electro deposited nickel iron film cores details are given of a magnetic decade scaling system in which direct count indication is obtained by using the external magnetic fields of the storage cores themselves with the electro deposition technique described the difficulty of getting sufficiently close coupling between the film and the associated driving and sense coils has been overcome 11050 theory design and performance of maximum efficiency variable reactance frequency multipliers the maximum efficiency with a given nonlinear element and circuitry is predicted from the analysis and circuit configurations for improved efficiency at a given harmonic are indicated 11051 choice of collector load resistance for minimum harmonic distortion a graphical method for calculating the optimum load to minimize harmonic distortion in transistor amplifiers 11052 the earthed collector circuit as an amplifier withe high input impedance the earthed collector circuit configuration is analysed and expressions are obtained for its input impedance and frequency response calculated and measured results are compared and circuit stability limits are discussed 11053 wide band amplifiers tuned or aperiodic using transistors up to stabilization of circuits against varying ambient temperature frequency compensation in aperiodic amplifiers design of distributed amplifiers and gain control of tuned amplifiers are examined 11054 adiabatic rapid passage in ruby at wavelengths performance data are giten on a two level ruby maser operating at with a modulated magnetic field and using the crystal as a resonant cavity as an amplifier it has a gain of and bandwidth as an oscillator it has an output of 11055 a solid state push pull maser in the millimetre wavelength region maser oscillation from to was achieved with doped rutile using push pull pumping at a short experiment on cross relaxation effects was also formed 11056 magnetic perturbation of an ammonia maser on the line theoretical curves of frequency change as a function of the perturbing field are given for a line maser fluctuations of the field by are shown to give an error of about 11057 dependence of magnetic coupling constant of ammonia on the inversion state theoretical studies indicate that in a maser the magnetic coupling constants of the upper and lower inversion states are different resulting in the observed dependence of frequency on magnetic field 11058 double beam maser as a primary frequency standard 11059 theory and design of wide band parametric converters a circuit theory approach using z linear time varying capacitance with a linear passive network 11060 diffused silicon mesa diodes for use in refrigerated parametric amplifiers 11061 analysis of fast wave couplers for transverse field beam type parametric amplifiers 11062 the application of beam cooling to quadrupole amplifiers 11063 quantum fluctuations and noise in parametric processes part a quantum mechanical model for parametric interactions is used to evaluate the effect of the measuring amplifying process on the statistical properties of radiation parametric amplifying process on the statistical properties of radiation parametric amplification is shown to be ideal in the sense that it allows a simultaneous determination of the phase and number of quanta of an electromagnetic wave with an accuracy which is limited only by the uncertainty principle frequency conversion via parametric processes is whown to be free of zero point fluctuations 11064 rapid modulation of microwaves on a coaxial line with the aid of ferrites a signal on a coaxial cable has been modulated to a depth of at resonance absorption in a magnetized ferrite tube threaded on the core of the cable is varied by a coil round the tube the modulating field is chosen to operate about a mean value on one flank of the resonance curve 11065 decreasing the threshold in fm by frequency feedback the feedback action of the demodulator is taken into account in determining the threshold calculated values agree well with experimental data 11066 an automatic frequency controlled phase shift keyed demodulator the principles of demodulators with binary phase shift keying are reviewed design equations are given which indicate the trade off relations between pull in range noise bandwidth and lock up time experimental results are given 11067 correlation in the fluctuating outputs from two square law detectors illuminated by light of any state of coherence and polarization the correlation is found by treating light fluctuations as a random process the expression takes a particularly simple form when the light is spectrally pure two special cases are applicable to the hanbury brown twiss effect of and to correlation experiments with light from optical masers 11068 thermally stimulated emission and conductivity peaks in the case of temperature dependent trapping cross sections original theory is extended and a method is proposed for determining by a single experiment the ionization energy and temperature dependent cross section of a trapping level 11069 stimulated emission into optical whispering modes of spheres stimulated emission into optical whispering modes of a spherical sample of has been observed light produced by the stimulated emission is radiated tangentially from each point on the surface of the sphere the experimental results have been interpreted in terms of the electromagnetic analogue of the rayleigh theory of the whispering gallery 11070 modes in sequences of e lenses an investigation of the modes of propagation of coherent light iht in a sequence of lenses 11071 quantum theory of free carrier absorption quantum theory becomes equivalent to classical boltzmann theory for photon energies small compared to carrier energies 11072 collective behaviour in solid state plasmas theoretical investigation of the nonlinearities in plasma wave instability applied particularly to the possibility of observing this effect in scattering mechanisms may prevent observation 11073 instabilities of a cylindrical electron hole plasma in a magnetic field the stability of an electron hole plasma carrying current parallel to a magnetic field is investigated instabilities are predicted and the calculated values of electric field magnetic field and lowest oscillation frequency are compared with available observations agreement is reasonably satisfactory 11074 hall effect in impurity conduction the existence of a nonvanishing hall effect in the impurity conduction regime of a semiconductor is demonstrated the theory is based on a three site transition process and in particular on a magnetic field dependent contribution to the jump probability between two sites 11075 a microwave plasma discharge striae produced in argon by high power radiation are described and illustrated their maximum length was and widthmm 11076 time lags associated with ultra high frequency gas f breakdown an investigation of the time lags associated with gas breakdown in correctly profiled parallel plate gaps at a frequency of 11077 magnetically confined cold cathode gas discharges at low pressures a theory is developed taking account of the effects of space charge in inverted and in normal magnetrons and in penning structures discharges of much greater intensity may be expected in normal magnetrons than in inverted magnetrons 11078 electron energy distribution measurements in gas discharges accuracy of the distribution determination using the method of druyvestyn is improved by differentiating the langmuir probe signal and filtering mains frequency noise from the output the second differential coefficient is obtained by graphical differentiation 11079 brillouin flow in relativistic beams a solution is closed form in a cylindrical geometry is derived in the limit of low beam temperature 11080 exact solution of the one dimensional bunching problem a solution is derived for the bunching of an infinite electron beam modulated by an infinitesimal gap the solution is valid when no overtaking occurs 11081 theory of the potential well produced by multipacting electrons very low pressure regime theory of ion behaviour in an electron well 11082 the transverse electric noise from an electron beam the measurement of transverse noise provides a means of investigating scattering phenomena 11083 analysis of double stream interactions in the presence of a finite axial magnetic field couplings of fast and slow cyclotron and space charge waves between two electron beams and between an electron beam and a plasma are analysed 11084 fluctuations in a plasma ion electron temperature relaxation the rate of relaxation calculated on the basis of the fluctuation dissipation theorem assuming interaction between the ion and the fluctuating electric field caused by the surrounding electrons is found to agree with the result obtained considering interactions with individual electrons 11085 the behaviour of a plasma under the influence of a standing electromagnetic wave in the absence of a constant magnetic field the physics of the radial confinement of an ionized plasma in an em field are examined for a cylindrical cavity excited in the modes 11086 electroacoustic coupling at the boundary of an ionized medium an analysis is developed to explain the production of a reflected sound wave and a transmitted modified sound wave at the boundary of an ionized medium when an em wave is incident at the boundary in the presence of a transverse magnetic field 11087 a proposal to use microwave cavities to study the surface properties of high density plasmas the method is based on the resonance properties of a cavity containing a highly conductive axial plasma rod 11088 a method of measuring the potential distribution in a cylindrical rf cavity containing plasma an ion beam is directed through the plasma and the position velocity and direction of the beam at the points of entry and exit are determined by varying the input parameter the potential of a particular point inside the plasma can be computed 11089 magnetocompressiona disturbance in a tepid plasma the examination of steady state pulses travelling at right angles to a magnetic field in a cold plasma is extended to a tepid plasma a linear and quasi nonlinear analysis is given from which it is shown that pulses exist when the disturbance speed is supersonic 11090 a method for measuring the conductivity in a high electron density plasma the interaction between the solenoidal electric field and a circular cylindrical plasma column is used as the basis for the design of a pulse operated bridge suitable for transient measurements of conductivity in high density plasma 11091 the ferromagnetism of the plane lattice inconsistencies in the results of the theoretical treatment of ferromagnetism at low temperatures on the basis of the heisenberg model are discussed 11092 theory of direct exchange in ferromagnetism a unique definition of is applied to the following cases on a heisenberg atomic model hydrogen functions orbitals of the iron series a pair of iron series atoms in a configuration it is found to be negative in all cases the conclusion is that the direct exchange model is inadequate or inappropriate 11093 mechanical damping due to magnetic processes the causes of magnetic damping are analysed with reference to theoretical and experimental investigations by various authors the technical implications of these effects are discussed 11094 anisotropic curie temperature a theoretical treatment showing how the curie temperature in an anisotropic ferromagnet varies with the direction of magnetization 11095 momentum and energy of waves elementary arguments of conservation of energy and momentum are used to derive expressions for the formal momentum angular momentum and energy of a plane wave in a moving medium 11096 high frequency diffraction by a wedge with a linearly varying surface impedance an asymptotic representation valid both in the illuminated and shadow regions is derived for the scattered field due to an incident plane wave and its properties are analysed as a function of the rate of variation of surface impedance 11097 absorption of electromagnetic radiation by an electron gas using the greens function formulation of the many body problem the total absorption cross section for a photon by an electron gas is calculated in the high density limit 11098 pulsed x band epr spectrometer a description of the design and operation of an electron paramagnetic resonance spectrometer for observation of spin echoes in the submicrosecond time domain 11099 radio frequency spectrometer with bidirectional square wave frequency modulation modulation is effected by means of a voltage controlled si capacitor coupled to the oscillator tank circuit if the frequency deviation is greater than the line width the absorption line will be displayed with full available intensity and good shape by careful adjustment of the relative amplitude of the positive and negative going deviations incidental amplitude modulation in the rf detector output component can be eliminated this method should be applicable to other types of spectrometers 11100 spectrometer for the frequency range to the instrument incorporates a hartley type marginal oscillator with continuous frequency sweep and frequency modulated at a repetition rate of cs 11101 a stark effect microwave spectrograph with high resolving power description of a spectrograph incorporating a carcinotron as microwave source and using stark effect modulation 11102 optical maser characteristics of in 11103 optical maser action of in a barium crown glass a glass optical maser using ions and operating at room temperature is described a number of sharp lines are emitted in a range centred about a 11104 on the resonant frequency modes of ruby optical masers using a high resolution spectrograph in conjunction with a fabry perot interferometer of high resolving power shows the output from an optical maser to consist of lines at higher input energies more modes are excited 11105 the kinetics of moving phase boundaries in ferromagnetic ferroelectric and superconducting materials the inadequacy of previously published theories is discussed a phenomenological model is considered in which a phase boundary is represented by a thin sheet of the material in an intermediate state 11106 inverted nature and significance of negative mass landau levels 11107 the magnetic susceptibility of an electron gas the cluster expansion of the quantum mechanical grand partition function is obtained for a gas of interacting charged particles in a uniform magnetic field and applied to calculate the susceptibility of an electron gas for small fields 11108 measurement of interplanetary electron density from the earth radio astronomy techniques for density measurement in free space the solar corona and the lunar electron atmosphere are discussed and a solar wind plasma model is examined 11109 the measurements of random radio frequency fields by the use of short electric and magnetic dipoles a note on the relation between measured noise voltages at the terminals of a short aerial and the temperature of the radiation field with reference to satellite measurements of sky brightness of 11110 future large radio telescopes 11111 the australian radio telescope 11112 bursts of centimetre wave emission and the region of origin of x rays from solar flares seven solar flare events are discussed x ray emission is found to be closely associated with emission less closely with emission some implications are considered 11113 the radio emission from normal galaxies observations of irregular and early type galaxies at and a general discussion of the results 11114 extragalactic radio emission at report and discussion of some results of an interferometer survey of the sky at hobart tasmania 11115 radio emission from cassiopeia on wavelength 11116 time variations of directional cosmic ray intensity at low latitudes comparison of daily variation of the intensity of cosmic rays incident from east and west time variations of east west asymmetry interpretation of solar daily variation and changes of east west asymmetry a report of investigations conducted at ahmedabad during and 11117 on a short lived cosmic ray decrease on november 11118 observations of the van allen radiation regions during august and september the capetown anomaly and the shape of the outer belt the position of the relative minimum in the u outer belt as found by explorer differs significantly from the position calculated for particles affected by the capetown anomaly part of 11119 geomagnetically trapped electrons from cosmic ray albedo neutrons the energy spectrum for outer belt electrons derived from a neutron albedo source is calculated the spectrum peaks at whereas rocket results indicate no such peak there is fair agreement above only the small fraction of electrons above can be accounted for by a neutron albedo source the capetown anomaly is found to give only a relative minimum in the equatorial plane compared with the observed 11120 solar proton impact zones the trajectories of charged particles in a magnetic dipole field are calculated numerically and applied to data on the relative number of impacts in the northern and southern geomagnetic hemispheres depends strongly on season low energy protons are focused into i small impact areas on the earth 11121 supernovae as cosmic ray sources a theory explaining the origin of primary cosmic rays is proposed 11122 cosmic ray evidence for a ring current reduction in cosmic ray cut offs at minneapolis during the main phase of a magnetic storm is attributed to a ring current the data are used to determine the moment and radius of the ring surface magnetic disturbances are a function of it is shown that the ring shrinks during the main phase cosmic ra evidence for a quiet day ring current is discussed 11123 radar observation of venus observations were carried out by the radar system using an diameter aerial the value of the astronomical unit obtained from these measurements is in satisfactory agreement with values derived by other observatories see also of january 11124 the determination of the incident flux of radio meteors part sporadic meteors the theory relating the radio echo rate to the incident meteor flux is extended to the case of sporadic meteors results for sporadic meteors and several showers are presented part of 11125 the identification of meteor showers with application to southern hemisphere results results of recent radar measurements of meteor showers at christchurch new zealand are combined with previous visual and radar surveys to develop a composite picture of meteor activity seven showers are confirmed appearing in all three surveys another six to nine are probable being identified in two 11126 radar reflections from the sun at very high frequencies preliminary report of measurements made at using a frequency offset keying technique and transmitted power of the results complement those obtained earlier at of 11127 determination of the nature of the earths distant magnetic field when singly ionized an alkaline earth element such as be is a strong resonant scatterer of solar radiation released in a gaseous state at a distance of earth radii or by atom bomb at about above the magnetic pole it could be used to mape the geomagnetic field in the vicinity of the earth 11128 evidence of low frequency hydromagnetic waves in the exosphere damped waves with periods of several minutes are found in the auroral zones since their polarization is essentially elliptical they are interpreted as low frequency hydromagnetic waves propagated along the magnetic lines of force 11129 equatorial electrojet in ghana the variability of the diurnal range of the vertical magnetic field component observed at tamale ghana is explained by changes in position and intensity of the electrojet 11130 hydromagnetic interpretation of sudden commencements of magnetic storms a model is proposed in which the impact of solar plasma on the geomagnetic field generates a shock wave the compressional shock wave propagates to the earth as a longitudinal hydromagnetic wave in low latitudes and generates transverse hydromagnetic waves in the exosphere which propagate to high latitudes along the field lines a reversed impulse at latitudes above is explained in terms of the direction of the magnetic perturbation vector at the top of the ionosphere 11131 the magnetic field of a model radiation belt numerically computed the magnetic field of a model ring current belt is calculated numerically over the earths surface the field of the ring current is nearly uniform although the diamagnetism of the belt produces an insignificant irregularity in the disturbance field in auroral latitudes 11132 scientific research recently carried out by means of veronique rockets experiments on the physics of the high atmosphere a report of measurements made in a recent series of tests the rocket and associated telemetry equipment are described 11133 a year of photographic observations of artificial satellites at the astrophysical observatory of asiago results of the first years observations commencing september are tabulated 11134 ionospheric limitations on attainable satellite potential consideration of the potentials attainable by a satellite in the ionosphere when continuous streams and pulsed streams of charged particles are ejected from it 11135 the motion of an artificial earth satellite in the normal gravitational field of the earth mathematical treatment of satellite motion neglecting air resistance and gravitational anomalies results can be applied to the calculation of satellites orbits at high altitudes 11136 analytical approach to the perturbation problem for an artificial satellite 11137 the effect of atmospheric oblateness on a satellite orbit 11138 the stability of the hour satellite perturbations of the orbit by the sun earth and particularly the moon are investigated using a method of numerical integration 11139 effects of the earths magnetic field on the orbit of a charged satellite the main effect of the earths magnetic field on a charged satellite is to cause the node to precess for the west ford needles the precession amounts to about 11140 the effects of atmospheric refraction on angles measured from a satellite 11141 electron temperature measurements on the explorer satellite the diurnal variation of electron temperature at altitudes of is obtained from a modified langmuir probe experiment temperatures range between and 11142 the canadian defence research board topside sounder satellite the satellite is designed to measure the characteristics of the ionosphere above the region of maximum ionization it will be placed in a circular orbit miles above the earth inclined at and precessing westward the sounder will cover the frequency range in sweeps on command from ground stations two telemetry transmitters will operate at frequencies near 11143 identification of sporadic e from low frequency sweep polarization records reversals in the direction of rotation of the polarization ellipse are interpreted s using the wave theory of reflection from a thin sharply bounded layer in the ionosphere 11144 the seasonal anomalies in the f region the seasonal variations in noon critical frequency and in the occurrence of f layer bifurcation are ascribed to changes in the electron loss coefficient these are related to a seasonal variation in frequency of occurrence of travelling disturbances and a connection with atmospheric tides is proposed 11145 horizontal diffusion and the geomagnetic anomaly in the equatorial f region equations relating to the diffusion of f region ionization parallel to the earths field are stated and used to discuss low latitude phenomena one implication of the analysis is criticized in the adjoining note which attempts a qualitative description of the role of diffusion in the equatorial f region 11146 determination of drift movements of the ionosphere at high latitudes from radio star scintillations an apparent reversal in drift direction of the component in three aerial radio scintillation measurements at tromso is discussed it can be explained by assuming the diffracting medium to consist of elongated blobs with the main direction lying along the projection of the geomagnetic field lines as seen from the radio source 11147 solar activity effect and diurnal variation in the upper atmosphere an examination is made of the characteristics of the solar activity variations in upper atmosphere density and it is suggested that a source of heating from the solar wind must be involved as well as solar ultraviolet heating to explain the observed effects 11148 sudden increase in the ionosphere region ionization associated with solar flares five v cases are reported in one case the attachment coefficient was estimated from the ensuing decay the result was somewhat higher than the value indicated by ratcliffe 11149 ionospheric currents responsible for sudden commencements observed at the geomagnetic equator the height and strength of the line current which would account for the sc at two equatorial stations is calculated for storms the height is found to lie between and is independent of the local time of sc a more realistic sheet current model is examined and is found to be insensitive to height an explanation of enhanced at the equator is given 11150 man made heating and ionization of the upper atmosphere 11151 doppler studies of the ionosphere with vertical incidence a description is given of a method for determining whether observed doppler shifts are due to changes in height of reflection or to ionization changes in the lower ionosphere 11152 polar ionospheric spread echoes and radio frequency properties of ice shelves records from three stations in the antarctic and one drifting stations in the antarctic and one drifting station in the arctic show that downward radiation from an ionosonde aerial is reflected from sea water under the ice an interference pattern is established from which it is possible to determine the thickness and dielectric constant of the ice and the direction from which ionospheric spread echoes arise 11153 a study of the enhanced ionization produced by solar protons during a polar cap absorption event the electron density height profiles produced by solar protons are examined theoretically the cosmic noise absorption expected from these profiles are compared with experimental data particular attention is paid to the sunrise and sunset periods the presence of o alone is insufficient to account for the observations at these times 11154 polar cap absorption following the solar flare of july the absorption records at saskatoon and ottawa during the pca event showed short term recoveries of the cosmic noise level which were associated with auroral disturbances it is suggested that these recoveries were due to a magnetic screening of the particles causing the pca events 11155 minor pca events during march two polar cap absorption events are described in detail 11156 interrelations among the upper atmosphere disturbance phenomena in the auroral zone an analysis of data from syowa station antarctica reveals a numerical relation between the intensity of the line the maximum electron density of ionization and the magnitude of the horizontal disturbance vector 11157 ionosphere review a comment on ionospheric conditions including a note on probable sunspot activity up to the end of with special reference to effects on long distance communication 11158 lunar time variation of oxygen green line in the night airglow it is suggested that the lunar time variation in the intensity of the line is due to the tidal influence on the density of oxygen atoms near the level 11159 collision processes in the aurorae and ionization in the auroral zone a review of present knowledge which includes the stopping power of air the charge changing in proton beams and ionization processes 11160 rocket measurements of auroral radio absorption the variation of ionospheric absorption with height was studied by measuring the signal strength of a transmission from the ground the results from a flight on october indicated that most of the absorption occurred between and th peak being in the region 11161 direct measurement of charged particles associated with auroral zone radio absorption rocket observations of electrons with energy and protons with energy are described during ascent the electron flux showed large and rapid fluctuations which are consistent with a columnar structure while the proton intensity was relatively steady an estimate is made of the integral electron energy spectrum and the angular distribution of both electrons and protons are examined 11162 whistler dispersions for a model of the ionic distribution in the exosphere an investigation into the dispersion of whistlers for a range of exospheric temperature latitude and ion content 11163 theory of stochastic linear systems with gaussian parameter variations a theory of linear systems with randomly varying parameters id is developed under the assumption that the parameter processes are gaussian processes obtained by linear filtering of white noise a theory of mean and mean square stability is given and applied to an circuit with randomly varying capacitance an error in a previous analysis is corrected 11164 high stability temperature controller for transistors the control system uses two servomechanism stages which are electrically independent but thermally in series an outer annular block is made to provide initial temperature control of the inner block which is thermally stabilized within itself 11165 single turn recording heads results of an experimental approach to the development of a single turn head for a magnetic drum storage system are noted optimum values of drum plating thickness gap width and write current are shown in gtaphs 11166 voltage stabilization by means of trigger tubes several cold cathode trigger tube circuits are described which give effective stabilization against fluctuating input voltage and current drain 11167 the dsk system of fuel cell electrodes a description of various cells which have been constructed and experimental results 11168 the pascal a fast digital electronic computer for the philips computing centre a description of the design and operation of the computer which is a binary parallel machine of single address type with a word length of bits it incorporates five different kinds of storage system including special plug board and modification units 11169 the rectangular loop ferrite core as storage device for data processing installations outline of principles underlying the storage mechanism and magnetization reversal process with details of typical characteristics and dimensions of cores for use as storage elements 11170 magnetic film rods provide high speed memory the application of rod elements of in the development of a word bit per word storage system with a cycle rate is described 11171 planar transistors in microwatt logic circuitry the application of the uhf si transistor to logic circuits at very low power is discussed a four stage shift register is described which operates at per transistor stage 11172 pattern recognition review of the principles of pattern recognition on the basis of information theory references 11173 printed circuits made without drawings a ring matrix technique is described for rapid production in the laboratory of a circuit negative which is readily modified 11174 the helitran two designs of rf transformer with continuously variable turns ratio forming a nearly perfect voltage divider are described a helitran can simplify the design of the variable conductance control of three terminal bridges with a transformer ratio arm 11175 coil capacitances and inductances of single layer cylindrical coils for different current voltage distributions over the coil 11176 possibilities of realizing logic boolean functions by means of rectangular magnetic networks the network consists of idealized transfluxors with rectangular hysteresis loop 11177 using hall generators as contactless commutators a sampling rate in excess of is achieved by feeding a signal voltage into one input of a hall generator and a switching waveform into the other amplification must be used to recover the signal loss but only one amplifier is needed regardless of the number of inputs 11178 designing tunnel diode circuits using composite characteristics with tunnel diodes connected in series certain relations between their peak and valley currents and their final voltages can be satisfied so that the composite curve has peaks valleys and stable positive regions the use of this type of characteristic for binary addition scaling and encoding is described 11179 solid state optoelectronic commutator matching electroluminescent photoconductor arrays can be packed into a volume per switching element the noise from an eight channel binary output commutator is bandwidth compared with an upper signal limit of 11180 the edge effect of a capacitor of finitely thick plates with application to magnet design conformal mapping is used to determine exactly the fringe capacitance and field strength distribution of a thick plate capacitor general formulae and curves are given the application to magnet systems intended for high frequency devices is described 11181 novel microwave resonator a cavity resonator designed at the national bureau of standards based on fabry perot interferometer technique consists of two perforated sheets of meta square forming the ends of a box microwave energy beamed on one end with correct end spacing produces a resonance q of about 11182 symmetric quadripoles further detailed description of the transformation of symmetric quadripoles and the cascade connection of bridge circuits to form filters 11183 analysis and synthesis of antimetrical networks an extension of previous work on symmetrical reactance networks of to reactive ladders with resistance terminations 11184 a realization of the error curve system the filter analysed by of is discussed in terms of kupfmullers system theory 11185 transfer characteristics of electromechanical coupling filters as a function of the coupling element the effect of manufacturing tolerances to respect of diameter and length of mechanical transmission line elements is investigated 11186 a contribution to the synthesis of resistive three ports algebraic and topological treatment of a special case of three port network synthesis for italian version 11187 fundamentals of linear graphs and their applications to networks without transformers the application of linear graph theory to the analysis and synthesis of passive networks ad matrix methods of solution are described 11188 the switching on of two oscillator circuits which are coupled by an externally controlled reactance case of the parametric amplifier extension of earlier investigations of february to the case of coupled resonant circuits 11189 investigation of the possibilities of a nonreactive parallel connection of two oscillators in the short wave range scattering matrices are used to calculate the characteristics of three and four port networks and a comparison of their suitability for parallel connection is made application to waveguide circuits is discussed 11190 defining the coherence of a signal 11191 an analysis of a class of variable frequency sinusoidal oscillators using a single active element an analysis is given of a class of oscillators requiring a single active element with an electronically variable mutual conductance the oscillation frequency is directly or inversely proportional to two experimental circuits are described and compared with theory 11192 an investigation of nonlinear distortion in grid modulated oscillators caused by the bottom bend of the static valve characteristic 11193 review of the present state of crystal control and frequency synthesis description of basic circuits constituting various frequency synthesizing systems 11194 one tunnel diode flip flop report on the operation of a circuit similar to one given in with oscillograms showing triggering and switching modes 11195 an astable four region multivibrator the multivibrator operation of a four region semiconductor structure is analysed and its temperature instability is discussed results obtained with a five region structure are also given 11196 pulse compression without dispersive networks pulse compression by means of a three dimensional correlator using light modulation is described the application to radar systems is discussed 11197 saturation effects in ferrite frequency doublers operating in the uniform precession mode three distinct saturation mechanisms occurring in ferrite frequency doublers are described an approximate nonlinear equation of motion including the effect of the reaction field is obtained and solved for a particular case 11198 a variable ultrasonic electro optical delay line and a new ultrasonic optical effect in fused quartz a variable delay line for rf pulses is described in which unpolarized light is modulated by the rf signal passing through a quartz bar and is detected by a photomultiplier the operation of the system is unexplained 11199 quartz delay lines the state of the art a summary of available information on geometry performance ad applications of ultrasonic delay lines 11200 transient phenomena in ruby maser a note on time lags observed in the build up of oscillations in a pulsed three level maser operating at with pump frequency 11201 on the problem of pulsed oscillations in ruby masers the nonlinearity necessary for the existence of a pulsed mode of operation is shown to be due to the interaction between the electrons and the distant nuclei 11202 double beam masers as primary frequency standards 11203 origin of noise in a ferromagnetic parametric amplifier further measurements on a ferromagnetic parametric amplifier with longitudinal pumping indicate that the exceptionally high noise figure previously reported is not thermal in origin 11204 an extremely low noise nondegenerate parametric amplifier preliminary note on an experimental amplifier which was operated at room and liquid nitrogen temperatures a system noise temperature was achieved 11205 microwave carrier modulation demodulation amplifiers and logic circuits applications of parametric amplifiers are described in wide band video modulation demodulation amplifiers and ultra high speed logic circuits with possible repetition rates of the order of 11206 the tunnel diode superregenerative amplifier the simplicity of the circuitry required and the characteristics of tunnel diodes make superregenerative amplifiers very attractive for applications where high gains are required the noise performance of maser and parametric amplifiers is superior 11207 progress in field emission work function measurements of atomically perfect crystal planes 11208 the penetration of an electron beam through a plasma part general considerations amplifications and overstability the problem is treated from the point of view of the double stream amplifier the resistive and inductive envelope amplifier and stability theory 11209 the orbit of a charged particle in a constant magnetic field and a sinusoidal electric field explicit expressions are obtained for the particle orbit assuming that the effect of the electric field on the particle is merely to produce a perturbation on the motion which it would describe in the absence of th field 11210 experimental demonstration of the phase shift of electron waves by the magnetic vector potential report on investigations with an electron optical interferometer see also of 11211 the noise temperature of a plasma using a current source method an expression for noise temperature is derived identical with that for plasma radiation temperature derived by bekefi et al but valid under more general assumptions the application of the expression is not confined to transparent plasmas 11212 dielectric constant of plasma the definition of dielectric constant used by gallop et al is criticized on theoretical grounds in reply the authors point out that the definition is justified on experimental evidence relating to the particular conditions under discussion 11213 emission absorption and conductivity of a fully ionized gas at radio frequencies classical and quantum mechanical calculations are compared yielding the emission spectrum of free electrons in the coulomb field of positive ions 11214 backward waves on isotropic plasma slabs if the relative dielectric constant of the plasma becomes negative backward surface waves can be developed on a lossless homogeneous and isotropic plasma slab 11215 magnetic effects in a plasma column irradiated with microwaves the radius of gyration of a plasma column is determined by imparting a coherent circular orbital motion to the electrons in the column at its principal resonance frequency this is accomplished by irradiating the column with two incoming waves of the same frequency but out of phase when the electric fields are correctly aligned a magnetic moment is developed 11216 magneto fluid dynamics papers presented at the symposium sponsored by the international union at theoretical and applied mechanics in co operation with the national academy of sciences and te the national research council held at williamsbug virginia and washington dc in january of 11217 the propagation of slow electromagnetic waves in plasma cable a phase difference method of measurement is described which enables the propagation parameters of a travelling wave in a plasma to be determined including the direction of phase and group velocities 11218 on the axial echo area of the cone sphere shape initial results of a study of the back scattering from a cone sphere are given comparison is made between the measured and calculated axial echo areas of a cone sphere 11219 two magnon processes in ferromagnetic relaxation a theory is developed from the assumption that all magnons of equal energy are so tightly coupled that they may be considered as a unit in any process involving degenerate magnons 11220 propagation of spin waves theoretical considerations show that coherent spin wates can be propagated in a ferrite material if the microwave field penetrates no more than a distance into the specimen 11221 infrared oscillations from and masers results obtained from the operation of these masers are given trains of damped oscillations were observed 11222 continuous operation of the p optical maser preliminary report on the experimental apparatus and results achieved continuous operation was maintained for about 11223 lasers review of recent developments and applications 11224 theory of relaxation oscillations in optical masers a theoretical explanation is given of the intense short spikes observed in the output of optical masers of a simple formula is derived for the time interval between them and the rate at which they decay to a constant level 11225 visual display of isolated optical resonator modes in a laser cavity is described two concave mirrors forming a nearly spherical cavity are used 11226 coupling of laser rods interference was observed between the oscillations produced in two parallel ruby laser rods coupled by a prism results indicate that the coupling of independently pumped lasers is feasible 11227 measurements of the laser output measurements of energy output were made by means of a simulated black body absorber the accuracy of the system was sufficient to measure a minimum energy of joules a plot of laser output as a function of pump input energy is reproduced 11228 propagation in laser crystals an example is given of ring structure in a far field pattern from a laser this may be absent but fringes may still be obtainable from a two slit system 11229 stimulated light emission by optical pumping and by energy transfer in organic molecules observations of stimulated light emission in organic glass matrices are described particularly in glass containing ap approximately of benzophenone and of naphthalene in which energy is absorbed by the naphthalene in which energy is absorbed by the benzophenone and transferred to the naphthalene 11230 optical mixing a report of the observation of the sum frequency of two ruby laser beams of different frequencies in the region incident simultaneously on a crystal of triglycine sulphate 11231 mixing of light beams in crystals plane light waves provided by an intense unfocused beam of a ruby laser are used to produce second harmonic radiation in a kdp crystal 11232 effects of dispersion and focusing on the production of optical harmonics the generation of blue light by the incidence of red light from a ruby laser upon quartz and kdp is examined particular attention is giten to the variation in blue light intensity with crystal orientation 11233 nonlinear optical effects the possibility is discussed of producing harmonic generation and mixing at infrared and visible frequencies by means of radiation from optical masers 11234 some radio astronomy techniques a review of modern techniques 11235 spectral observations of solar radio bursts slow drift bursts and coronal streamers the characteristics and origin of slow drift bursts spectral type are determined from data recorded in the frequency ranges and at fort davis texas during the pr period october december the equipment used is described in part 11236 mechanism of cosmic ray storms inferred from some statistical results a statistical analysis of results obtained during a four year period including the igy relating to the propagation time of cosmic ray storms and the heliographic position of solar flares 11237 the day period of cosmic radiation the existence of a persistent day periodicity of the intensity of cosmic radiation is proved from an analysis of recordings at huancayo peru and halle germany 11238 trapped proton and cosmic ray albedo neutron fluxes a rocket borne emulsion stack was launched at to an altitude of a proton energy spectrum above was calculated and its shape near interpreted by assuming a minimum in the cosmic ray albedo neutron spectrum 11239 absolute electron intensities in the heart of the earths outer radiation zone previous estimates from geiger counters of the electron flux above are shown to be too large by a factor of the high count rates are due not to electron bremsstrahlung but to directly penetrating electrons of energy 11240 time variations of the energy spectrum of solar cosmic rays in relation to the radiation hazard in space results from a number of solar cosmic ray events are used to estimate the highest level of integrated proton flux likely to be encountered 11241 particle motion in the equatorial plane of a dipole magnetic field for the motion of a high energy particle in a dipole field a correction to the usual drift velocity is given the new result must be used when the radius of gyration of the particle approaches the scale of the field 11242 ionized gas and fast electrons in the vicinity of the earth and in interplanetary space measurements made during the flight of the second soviet space rocket are described it is concluded that the electron flux in the second radiation belt does not exceed evidence is also provided for the existence of a third outermost belt from the earths surface 11243 observations of the van allen radiation regions during august and september part the inner belt ionization chamber and gm counter data from explorer are used to obtain the two constants in an assumed energy spectrum for inner belt protons of the form electron fluxes of low energy are estimated from scintillation counts 11244 the detection of electrons with energies of approximately in the upper atmosphere fluorescent sreen indicators on the third soviet satellite recorded electron fluxes at altitudes up to over the southern region of the pacific ocean the depence of electron and energy fluxes on direction relative to the earths field is examined it is suggested that the energy flux is sufficient to cause heating in the f region 11245 bifurcation of the outer van allen belt and related auroral phenomena the two parts of the outer r belt are associated with two separate regions of auroral activity 11246 irregular lunar reflection polarization changes noted in the presence of aurora observations made during a lunar experiment carried out between sagamore hill and jodrell bank show fast irregular changes in signal polarization while a visible aurora occurred on one leg of the bistatic path an explanation is given 11247 a new technique for investigation of meteor echoes at uhf the application of radar doppler measurements to the study of meteor echo characteristics is described 11248 solar protons and particles from the september a report of balloon observations at minneapolis during a series of major solar flares 11249 on the frequency of occurrence and amplitude spectrum of the geomagnetic field pulsations the results of investigations of geomagnetic micropulsations observed at the soviet flux measurement stations during are presented diurnal variations of amplitude and of frequency of occurrence of micropulsations having different periods are investigated 11250 theoretical determination of the form of the boundary of the solar corpuscular stream produced by interaction with the magnetic dipole field of the earth 11251 new experimental evidence of the effect of magnetic storms on the magnetosphere new methods of whistler analysis of have been used to study the effect of magnetic storms on the time delay at whistler nose frequencies during the late phases of magnetic storms these time delays are reduced there is evidence that these changes in delay represent changes in the electron density in the magnetosphere 11252 the first italian launch of a sounding rocket for atmosphere research review of technical problems and the organization and equipment employed for a sodium cloud experiment carried out from sardinia on january results are given and discussed 11253 the classification of the motions of an artificial earth satellite about its centre of mass an analysis is given of aerodynamic and gravitational perturbations taking account of orbital repression the aerodynamic effects due to retardation of the satellite rotation are not considered 11254 on the secular variations of the elements of satellite orbits 11255 on the long period effects in the motion of an artificial satellite caused by the ellipticity of the earth effect of ellipticity of the equator on hour nearly circular satellite orbits 11256 predicting the lifetimes of artifical satellites in theory and practice possible errors involved in calculating life times from simplified formulae are considered and methods of error reduction are suggested 11257 preliminary results f of radiation measurements from the tiros meteorological satellite measurements of visible and infrared radiation are pree presented together with television pictures of cloud patterns values of radiation fluxes and albedos are derived 11258 use of z mode propagation for observing cosmic radio noise from earth satellites the use of z mode propagation for reception of signals from satellites above the height of maximum ionization density gives an effective improvement in angular resolution stability of radiation pattern and pencil beam configuration 11259 energy detector for satellites a description of a detector used in explorer and inun to measure the integrated energy flux of low energy electrons and protons 11260 electron temperature evidence for nonthermal equilibrium in the ionosphere measurements of ion density and electron temperature from four rocket flights by dumb bell shaped johnson malter type probes are presented the method of analysis is described in detail with examples electron temperatures about double the gas temperatures were found from to 11261 electron distribution in the ionosphere over trivandrum the results are given of a analysis of profiles obtained from records on selected quiet days during june september 11262 the behaviour of the lower ionosphere near sunrise in the lower d region a temporary increase in electron density is predicted at the time of ionospheric sunrise a decrease in the height of reflection of clf waves and a decrease in the signal strength of waves at sunrise are quoted as evidence for the existence of the temporary layer 11263 the determination of d region electron densities from observations of cross modulations the bailey and martin expressions for cross modulation are not sufficiently accurate new expressions have been derived and used to determine d region electron densities near sunrise a nearly uniform layer is created almost simultaneously between and there are no striking changes during the rest of the day 11264 ionospheric effects associated with the solar flare of september 11265 effects of nuclear explosions on the ionosphere an increase of about in the electron density of the f layer over lindau was observed at the time of transit of the shock wave from the megaton yield nuclear bomb over novaya zemlya on october relevant ionograms and data are illustrated 11266 the relation of magnetic micropulsations to electric current and space charge systems in the lower ionosphere from observations made in using a large wire loop theory is developed to suggest that micropulsations in the range are associated with absorption of auroral particles in the ionosphere and in the range are the result of the absorption and reflection of hydromagnetic waves in the lower ionosphere 11267 total electron content of the ionosphere over singapore during a magnetic disturbance observations made during a disturbance characterized by a negative phase show a corresponding decrease in total electron content of the ionosphere 11268 spread f and geomagnetic activity on magnetically quiet days the occurrence of spread f at trivandrum near the geomagnetic equator is regular it begins after sunset reaches a peak at and falls off slowly towards morning on stormy days the frequency of occurrence is lower and the behaviour is less regular the effect of storms is least in summer some of the observations are in agreement with the theory of martyn 11269 rocket measurement of the upper ionosphere by a radio propagation technique an example of measurement of the electron density profile up to by means of the tso two frequency technique is presented including the determination of inferred scale height and temperature of the upper ionosphere a correction procedure is outlined necessary for the determination of local electron density data 11270 diurnal variations in the ionosphere deduced from satellite radio signals observations of the faraday fading rate at sydney australia from have been used in a simple way to obtain diurnal and seasonal electron content variations secondary maxima occur at in both seasons and in winter the diurnal variation in winter is several times greater than the summer variation these values are compared with the variations in 11271 quality control of ionograms description of an instrument for making quick accurate checks of receiver and display characteristics 11272 some observations of ionospheric absorption at geomagnetic conjugate stations in the auroral zone the boundary of the polar cap absorption regin appears to extend to the same effective magnetic latitude in the northern and southern hemispheres during auroral events the absorption generally occurs simultaneously at the nearly magnetically conjugate stations of farewell and campbell island 11273 world maps of contour maps based on local time and diurnal variation showing the percentage of have been constructed from ionospheric datz data obtained during 11274 the electron density distribution above the peak and associated atmospheric parameters theoretical models of electron and ion distributions are discussed 11275 upper atmosphere helium ions available data are consistent with an atmospheric model in which a layer of helium ions at least thick separates the ionosphere from the protonosphere 11276 a correction to the exospheric electron density estimate using the nose whistlers of march a reinterpretation of the data gives electron densities about four times larger than those previously deduced 11277 on the orientation of auroral arcs the diurnal variation in the direction of quiet arcs at kiruna is similar to the theoretical variation expected r from alvens theory the average arc direction near the auroral zone seems to be determined for a given time by projections of circles in the geomagnetic equatorial plane on to the earths surface along the geomagnetic field lines 11278 the morphology of the auroral displays of parts a study is made of all sky camera records from a network of stations in alaska and from an array of stations extending from sub auroral latitudes to near the geomagnetic pole the subjects considered include the time and latitude dependence of incidence azimuthal alignment direction of horizontal movement of auroral forms and the relation of these subjects to magnetic disturbance 11279 argus radar returns in conjugate area the concept of orthogonal reflection from aurora and field aligned ionization is used to explain the apparent movement of the radar returns 11280 west east motion of an auroral zone x ray event a west east motion of an auroral zone x ray event was observed late in the magnetic storm of june time delays between x ray burst at balloon altitude and increases in ionospheric absorption of cosmic radio noise indicate that velocity components along the auroral zone of are present in this type of event 11281 midnight fall in atmospherics activity on band at poona on of nights there is a fall in activity which is explained in terms of a sudden decrease in the number of sources of atmospherics which occurs when the evening peak in thunderstorm activity crosses the west coast of africa the fall is greater during magnetically disturbed periods 11282 dispersion of whistlers the whistler dispersion d is found to have diurnal and seasonal variations the seasonal variation depends on geomagnetic latitude variations of d with geomagnetic and solar activity are also discussed 11283 whistlers and solar activity a high negative correlation between whistler activity and sunspot number has been found for the years in japan 11284 recording of electrical signals of particularly low frequency during the solar eclipse of february recordings of atmospherics in the range observed at bonn and munich at the time of the eclipse are reproduced the characteristics immediately after the eclipse are similar to those normally obtained at sunrise 11285 variation of the dispersion of radio whistlers during magnetic storms the whistler dispersion shows a special decrease at poitiers after the commencement of an intense magnetic storm the decrease is not observed for lesser storms this is possibly due to the existence of favoured paths which move to lower latitudes as the storm intensity increases 11286 a possibility of the generation of vlf emissions in the earths outer exosphere 11287 investigation of the magnetic recording process with step functions 11288 ht supply units for television receivers equipped with silicon diodes a short survey of semiconductor rectifiers is given and design parameters for rectifier circuits and rc smoothing networks are discussed 11289 an explanation of the superior radiation resistance resistance of type base si solar cells calculation of the effect of electron flux on the minority carrier lifetime in the base region gives results which agree well with measurements of actual damage 11290 current limited rectifiers a description is given of a class of rectifier circuits that limit their output current to a specified maximum applications are suggested 11291 heat to ac conversion using thermoelectric generators and tunnel diodes single cell generators operating between and produce of electric power the dc output of at is converted to high voltage power by using a high current tunnel diode as a dc ac converter 11292 an electroluminescent fixed store for a digital computer a method of reading information from such a store is discussed and the operation of a matrix containing digit positions is described 11293 circuit protection for a transistorized magnetic core memory the system protects the storage elements against fault currents as low as even though the normal operating current is 11294 minimum size and maximum packing density of nonredundant semiconductor devices the essential active region in semiconductor devices is already close to minimum size further miniaturization of these devices must come from reduction in the size of nonessential parts 11295 modular circuit construction circuits are constructed on a wiring board consisting of a laminated base board pierced with a regular matrix of holes see also of 11296 some considerations on s square loop magnetic core circuits domain wall motion theory is introduced to correct the simple analysis for determining the driving impedance of a ferrite core the results for peak output voltage are not changed by using the domain theory 11297 force free coils and superconductors a discussion of the prospects of building superconducting high field coils based on a force free construction technique which are suitable for operation in the range 11298 superconducting solenoids graphs are presented wit which permit the application of a method based on the fabry formulation for the approximate optimization of superconducting solenoids 11299 a sequence switching unit for measurement of ionospheric drift 11300 switching elements consisting of photoconductors and triggered neon lamps the properties of combinations of photoconductors with normal and triggered neon lamps are discussed some requirements of the lamp characteristics are given 11301 circuit designers improve practical applications of solid state devices a review of some of the low noise amplifiers and microwave power sources using solid state masers tunnel diodes and varactors featured at the solid state circuits conference philadelphia 11302 theoretical analysis of an inter digital resonator with radial vanes general expressions are derived for calculating to successively better approximations the resonant frequencies of modes perturbed by the vanes and anode examples of calculations are verified experimentally 11303 lumped impedance network transformation given the mz matrix of a network having pairs of terminals an equivalent network involving transmission lines with junction points is discussed 11304 on the network with the minimum number of coils necessary and sufficient conditions for maximizing the degrees of freedom of an network which contains a given number of inductances and resistances and an arbitrary number of capacitances are established a method of determining the transfer function of a tchebycheff type band pass filter with a minimum number of coils id described 11305 the reduction of unsymmetric quadripoles between different terminal resistances to symmetric quadripoles 11306 the calculation of build up processes in networks with stagger tuned individual circuits and large relative bandwidths the response to switching on transients of two and three stage networks is calculated 11307 terminal impedance and gain of the series to parallel transitionally coupled circuit 11308 a study of the phase and filter properties of arrays of parallel conductors between ground planes 11309 crystal filter design a universal design graph gives filter characteristics of any quartz unit and termination the technique described is specially suitable for multi channel applications 11310 theory and examples of application of a circuit element with distributed resistance and distributed capacitance the component considered consists of a ceramic plate of high dielectric constant with a resistive coating on one side and a highly conductive coating on the other side this circuit element is equivalent to an infinite number of cascade connected filter sections applications discussed include a low pass and a rejection filter and a frequency control element for an oscillator 11311 low q band pass filters a lossless filter design is modified to preserve the relative discrimination between a wanted frequency and an unwated band when the filter elements are lossy 11312 variable pass a band rc filter 11313 jaumann structures with capacitive tapping for band pass crystal filters symmetric and dissymmetric capacitive tapping of a band pass filter transformer is considered and a method of obtaining a maximum capacitance ratio in the branch to be replaced by a crystal is developed 11314 the influence of the differential transformer on the attenuation characteristic of differential bridge filters 11315 duality of nonplanar electric circuits without the use of ideal transformers a method of constructing the dual of any linear lumped nonplanar network which does not include magnetic coupling is given without using ideal transformers 11316 a hall effect microwave mixer a signal frequency current and a magnetic field at the local oscillator frequency produce a hall effect emf at the if across a semiconducting plate the minimum conversion loss achieved is 11317 a survey of very low frequency oscillators methods of generating frequencies below for vibration work and for testing servomechanisms are outlined the major characteristics of instruments are tabulated 11318 a high stability transistor oscillator for the design development construction and testing of a oscillator are described power output is stable within and frequency within ove the temperature range 11319 spikes on chopper transistor waveforms the effect of load resistance and capacitance on spike feed through is investigated and the amplitude and rise and fall times are derived a spike test for chopper transistors is recommended 11320 avalanche pulse generators a method is given for optimizing the switching time and the pulse repetition rate of avalanche transistor operation 11321 a fast counter for adding and subtracting randomly related pulse trains the circuits shown have a high speed of count propagation through a binary or binary decimal counter and are able to deal with random pulses on each line irrespective of the degree overlap or separation of the pulses 11322 pulse counting and fast scaling transistor circuits a review of scaling circuits and some typical designs 11323 millimetre wave harmonic generation in ferrites a ferroxcube doubler driven at a fundamental of was found to have a minimum conversion loss of when the output waveguide was polarized parallel to the input 11324 microwave harmonic generator capable of frequencies in excess of the device contains argon at atmospheres which reduces the are produced between cathode and anode to a small cathode spot the microwave signal driving the arc is a continuous wave of about an output of at the harmonic of the drive input is obtained 11325 gain and in phase suppression of symmetric and unsymmetric differential amplifiers the equivalent circuit of the differential amplifier is given and the operating parameters are calculated 11326 transistor differential amplifier the design concepts of and experimental results obtained from a drift compensated cross coupled amplifier are discussed 11327 thermal feedback in a dc transistor amplifier thermal feedback is applied via resistance windings around two transistors of a balanced input stage it is only effective at very low frequency and it reduces dc drift experimental results are given 11328 optical pumping of masers using laser output using ruby with a total ion concentration of about an inversion of approximately between levels and and for several hundreds of microseconds is predicted which should give stimulated emission at apparatus is being made to demonstrate this 11329 reduction of the noise figure of an amplifier by a negative conductance in its input circuit the lowest noise figure is obtained when the negative conductance is infinitely great in practice a minimum noise figure exists only if the lowest permissible value of stability or bandwidth is given 11330 quasi cascaded parametric amplifier a description is given of a circuit based on the resonance modes of a single sample which should significantly improve the power gain of current suhl type amplifiers 11331 parametric energy conversion by nonlinear admittances circuits employing nonlinear resistances and capacitances are described which can yield unconditionally stable up conversion gains considerably in excess of the output input frequency ratios the down conversion loss can be made simultaneously high 11332 broad band parametric amplifiers by simple experimental techniques maximum use is made of the parasitic elements of the varactor diode and simple measurements enable the diode unit with the best characteristics to be chosen the pass band characteristics of diode mount combinations are also measured single channel gain band width products approaching have been achieved 11333 nondegenerate x band amplifier the parametric amplifier described uses a pill varactor diode it has a gain of and a noise figure of with more pump power greater gains should be relizable at bandwidths equal to or slightly less than 11334 the efficiency of electrostatic quadrupole amplifiers 11335 parametric amplifier improves troposcatter system design details are given of an amplifier operating at which improves the performance of an existing communications receiver 11336 tunnel diode straight amplifier as low noise preamplifier stage for the uhf range the signal and noise characteristics are investigated of a conventional triode amplifier with a tunnel diode circuit as preamplifier stage and experimental results obtained at and are found to agree well with theory for similar investigations on a diode reactance preamplifier see 11337 the problem of nonlinear signal distortion in ring modulators theoretical and experimental investigation particularly of third order distortion 11338 self reactance modulation in telemetry oscillators design formulae are given for predicting the frequency characteristics of vhf and uhf transistor oscillators 11339 microwave modulation of light using the kerr effect modulation of light at and is achieved by applying a superimposed and microwave field to a kerr cell which is incorporated within the high electric field region of a resonant cavity 11340 drift mobility of an ionic impurity in an electric field 11341 on the theory of surface states a new method is proposed for calculating shockley type surface states 11342 thermoelectric phenomena associated with electron field emission the equilibrium temperature distribution in an ideal metal rod one end of which is subjected to an intense electric field is studied the application of the system as a heat pump is considered 11343 an analytical solution for the effect of space charge in cold cathode gas discharges by using a simple mathematical model an analytical solution for the varney space charge equation is obtained this is in good agreement with the exact solutions computed by ward 11344 current build up in neon gas discharges at small overvoltages the increase is exponential the time constant is calculated theoretically assuming that the discharge is sustained by secondary emission from the cathode caused by ions and metaastable ne atoms there is good agreement with experiment 11345 perturbation of electron flow a perturbation analysis of single stream quasi static non relativistic electron flow is developed based on the nonlinear equation for the velocity field 11346 the frequency of nonlinear plasma oscillations the frequency of plane standing waves of electrons moving through a back ground of infinitely heavy ions is independent of amplitude if the electron velocity is a unique function of position this is not true for spherical and cylindrical plasma oscillations 11347 wave propagation in a partially ionized medium theoretical treatment of the propagation and damping of low frequency waves in an infinite uniform partially ionized medium in a longitudinal magnetic field tso two longitudinal modes one an acoustic wave and two transverse uncoupled modes are identified 11348 demonstration of classical plasma behaviour in a transverse magnetic field a demonstration that the removal of the internal electric field halts the streaming of the plasma transverse to the b field 11349 notes on the effect of noise on langmuir probe characteristics the effects of periodic fluctuations of electron temperature random current and space potential are considered in many cases the electron concentration will be underestimated 11350 x band measurement of shock tube plasma temperature the radiation temperature of a plasma behind a hypersonic shock wave is measured using a microwave receiver results indicate that the temperature is approximately 11351 resonances of a microwave cavity partially filled with a plasma the resonance characteristics of a cavity containing a cold plasma of arbitrarily large density are studied theoretically and experimentally in addition to the modes of an empty cavity a new class of modes is found 11352 possible sources of energy of ion oscillations in high and ultra high vacuum two mechanisms are proposed to account for plasma oscillations arising in electron beam amplifier devices 11353 theory of ferromagnetism and the ordering of electronic energy leve s the ordering of the energy levels of a system of interacting fermions is considered mathematically 11354 stability of one dimensional ferromagnetic microstructures all nonuniform one dimensional structures are found to be unstable reasons for the stability of three dimensional structures are given 11355 magnetic decay in a hollow circular cylinder the rate of decay is found t depend on a dimensionless constant which is a function of the inner radius and outer radius of the cylinder numerical values of have been computed for various ratios 11356 propagation of a plane electromagnetic wave in a plasma at cut off and beyond a complete solution of maxwells equations for two typical density distributions is used to demonstrate the limitations of the geometrical optics hypotheses for thin plasmas 11357 the influence of positive ions on the propagation of electromagnetic waves in magnetized plasmas theoretical investigations covering a wide range of frequencies up to gyro frequency for the case of a homogeneous infinite plasma and a plasma confined by conducting walls with propagation at various directions relative to the applied magnetic field 11358 the propagation of centimetric electromagnetic waves in an absorbing medium of parallel wires experimental and theoretical investigation of the attenuation and wavelength of a plane wave in an artificial dielectric consisting of infinitely long parallel thin poorly conducting wires forming a regular rectangular lattice 11359 measurement of a high refractive index for transmission of microwaves through a plasma propagation of signals between two aerials apart in the afterglow of a argon discharge was studied a strong magnetic field was applied propagation of the whistler mode was noted and satisfactory agreement with the appleton hartree equation was obtained 11360 spectral diffusion decay in spin resonance experiments a theory of stochastic processes affecting spin resonance is given 11361 the theory of ferromagnetic resonance expressions based on a temperature difference greens function are derived for the susceptibility tensor some general properties are established which are independent of a specific hamiltonian form the energy damping of a spin system is also considered 11362 optical maser characteristics of in observations show that fluoresces strongly at and at sim stimulated emission has been found in the infrared fluorescence line at and 11363 optical maser characteristics of in observations of in show that the three groups of lines characteristic of appear but the precise position of the individual lines is altered slightly 11364 colloquium lasers and coherence phenomena the text is given of the following communications to the colloquium organized by the societe francaise de physique in paris on a me mathematical definition of coherence experimental study of the light emitted by a ruby laser influence of various methods of optical excitation on the populations of energy levels of ions in ruby semiconductors and their possible use in lasers possibilities of semiconductor lasers 11365 laser and two photon processes the possibility of observing two photon processes using a ruby laser is considered theoretically 11366 proposal for modulating the output of an optical maser the strong magnetic field associated with a modulating beam is used to rotate the plane of polarization of a plane polarized beam from another maser which then passes through an analyser and emerges modulated in amplitude 11367 output power and possible continuous operation of ruby lasers pink ruby was used in an arc imaging furnace capable of concentrating of energy as blue green light with starting voltages between and average output power in a pulse ranged from to the threshold of continuous operation was nearly achieved 11368 scattering losses in optical maser crystals an account is given of the extinction losses resulting from the optical scattering on small foreign particles within the maser crystal in an attempt to explain the wide variation of maser threshold 11369 gaseous optical maser with external concave mirrors the construction and operation of a helium neon optical maser is described the discharge tube is sealed at both ends with optically flat windows at the brewster angle to the beam axis 11370 nonlinear interband and plasma effects in solids the theory takes into account the band properties of the crystal as well as its symmetry 11371 a catalogue of radio sources between declinations 11372 studies in cosmic radio noise at bangalore from the results of a survey at bangalore see of a value of is obtained for the spectral index of background radiation 11373 scintillations of radio stars and satellites during intense magnetic disturbances during periods of intense magnetic disturbance it was sometimes found that the radio star scintillation index increased with frequency possible explanations are discussed 11374 interferometers for a radio astronomy a general review of current techniques applied at several major laboratories 11375 systems for simultaneous image formation with radio telescopes to avoid point by point scanning in radio astronomy an optical and an ultrasonic method of forming instantaneous images are considered practical systems with useful sensitivity and resolution will require further technical development 11376 the galactic radio spectrum down to an analysis of results of a number of surveys at frequencies between and 11377 a high resolution galactic survey at report of a survey of an extensive strip of the southern milky way using a mills cross with beam 11378 evidence for the transfer of corpuscles to distant parts of the sun following a solar radio burst microwave and optical observations of solar bursts suggest secondary distant areas of disturbance 11379 forward scatter of radio signals via meteor trails and short lived solar radio bursts certain features of reported solar rf bursts may be due to the reflection of broadcast signals from meteor trails in the radiometer aerial beam 11380 design of radio telescopes for extragalactic surveys design formulae are given for ensuring that the number of sources resolved is equal to the number detected long wavelengths have several advantages 11381 hydromagnetic waves and the trapped radiation effects on protons above the proton belt previous results are extended by allowing the waves to travel at instead of parallel to the geomagnetic field parts of and 11382 the cosmic ray flare effect parts a new method for finding the angular dependence of the flare cosmic rays is described and applied to the anisotropic part of the solar event the observations are used to study the interplanetary magnetic field and to compare the relative merits of the theories of gold and parker 11383 a theory of radar reflections from the moon and planets comment on of and authors reply 11384 radar observations of meteor echoes at a frequency of mc during the maximum of the germinid shower of december meteor echoes were observed at in all cases echoes were obtained from the same meteor trials at these were of the long duration type associated with linear electron densities greatly in excess of cm 11385 decomposition and comparison of time series of indices of solar activity 11386 the shape of the geomagnetic field boundary under uniform external pressure the shape of the cavity separating the geomagnetic field from the inteplanetary plasma is calculated numerically for an idealized model in which the plasma pressure is assumed to be constant over the surface of the cavity 11387 the interaction of the terrestrial magnetic field with the solar corpuscular radiation a previous calculation of on the shape of the interface between the solar plasma and the terrestrial magnetic field is recomputed to obtain a second order approximation 11388 computation of the bounding surface of a dipole field in a plasma by a moment technique the cavity formed by a plasma free dipole magnetic field in a field free stationary plasma is determined by a numerical method a possible extension of the theory to determine the shape of the cavity produced in the solar wind by the geomagnetic field is indicated 11389 world wide changes in the geomagnetic field current systems are drawn to depict world wide changes and the mode of propagation of these changes is studied 11390 the solar and luni solar harmonic components of geomagnetic variation at san fernando 11391 fluctuations in the geomagnetic horizontal field fluctuations in the range and having durations from a few minutes to were studied they seem to be world wide in their occurrence and their amplitude depends on local time and the current other features have been deduced from the data 11392 short range spatial coherence of geomagnetic micropulsations with a separation of the coherence was high measurements were made in a geologically uniform region and the z component of the micropulsations was small 11393 auroral zone geomagnetic micropulsations with periods of to seconds the results of one years observations at college alaska are presented and compared with other data 11394 on the earth storms some of the problems to be considered in studies of storms in the upper atmosphere and outer space of the earth are outlined stability of solar corpuscular stream collision with the interplanetary plasma causes the nonmagnetized stream to lose electrons the resulting space charge is neutralized by the change in density of the interplanetary plasma and the stream remains stable interaction between the solar corpuscular stream and the ezrths magnetic field the heating of exospheric gas caused by the compression of the magnetic field during the initial phase of a storm is not sufficient to account for the main phase the main phase might however result from the penetration of particles under the influence of a fluctuating magnetic field polar magnetic storms with special reference to relation between geomagnetic disturbances in the northern and southern auroral zones comparisons are made between the northern and southern zones on the basis of the s field patterns indices and individual disturbances at magnetically conjugate points the correlation coefficient for minute average values of disturbances at baker lake geomagnetic and little america geomagnetic interrelations among the upper atmosphere disturbance phenomena over the polar regions observations at syowa during the period january are used to examine the detailed correlations between geomagnetic disturbance visual aurorae and ionospheric blackouts or sporadic e energy and flux of corpuscular streams impinging the earths atmosphere an examination is made of the energy and flux of the corpuscular streams responsible for the ionospheric blackouts in the polar cap the unusual displays ad ionospheric effects in the auroral zone and the red aurora observed at lower latitudes 11395 statistics of geomagnetic storms and solar activity 11396 an economical satellite launching technique for conducting radio research in space a simple and inexpensive launching technique for economical radio research is described which employs an aircraft and rocket combination to place a satellite into orbit the paper reviews the progress to date and indicates performance potential 11397 satellite data analysis an analysis of data shows a temperature peak at and an density oscillation 11398 experimental evidence for the presence of helium ions based on explorer satellite data 11399 orbiting ultraviolet system will map stars and the skys radiant intensity an outline of camera calibration equipment and the command and telemetry systems for project celoscope 11400 orbital acceleration of satellites during geomagnetic disturbance approximate analysis d is developed to show that joule heating of the lower reaches of the ionosphere by geomagnetic currents is a major factor in the modulation of thermospheric densities which causes fluctuations in the orbital acceleration of satellites 11401 infrared radiometric instruments on tiros 11402 tiros radiation experiment and its physical significance the five channel radiometer which scans the earth by satellite rotation is described a mz map of the radiation received by the channel sensitive to wavelength is compared with a conventional weather chart 11403 law of electric conduction for waves in the ionosphere the law of electric conduction has been derived as for transver waves propagated along a strong external magnetic field in a slightly ionized gas the results have been applied to waves in the ionosphere 11404 a note on the group refractive index of the ionosphere for zero collisional frequency a difference between the general expressions for the group refractive index derived by unz and murty and khastgir of is due to an error in sign in the former 11405 recombination in the upper ionosphere at sunrise and before noon the loss of electrons in the f layer will occur as a result of dissociative recombination of the recombination coefficient will increase linearly with temperature and the rate of production of electrons will be proportional 11406 lunar daily variation of horizontal drifts in the ionosphere at waltair the amplitudes and phases of the hourly harmonics of the drift in the e and f regions are given for the four seasons 11407 the phase speed of a travelling disturbance in the f region of the ionosphere and its comparison with group velocity the phase speed of an f region disturbance is observed to be about half the group velocity of km 11408 on the mean temporal variations of electron density at a fixed height of the f region a sunrise dip in the diurnal variation of deduced from puerto rico data may possibly be explained by a reversal in the ionospheric wind the diurnal variations of the f layer may be due to loss rate changes resulting from the presence of no between sunrise and sunset 11409 increases of ionization in the layer and solar corpuscular radiation every reported large increase in ionization during a flare has been associated with an increase in corpuscular radiation examination of further data should lead to an exa explanation of corpuscular acceleration processes 11410 a theory of sfe current systems a study of the development of the current system of the solar flare effect after a sudden increase in the electrical conductivity of the ionosphere facing the sun based on the theory of electromagnetic induction 11411 information on the ionizing radiation of solar flares from the ionospheric absorption effect the additional ionization is produced in a thin layer at height and the attachment coefficient is sec the radiation flux deduced from the ionospheric changes agrees well with rocket measurements the spectrum of the ionizing radiation is probably mainly line emission near 11412 the equatorial sporadic e layer and the electrojet data from three chains of stations near the magnetic equator but at different longitudes have been studied and from them it has been possible to deduce information about the extent of the electrojet its seasonal changes and its variations with sunspot number and longitude 11413 a source of energy for the ionosphere joule heating by electric currents associated with geomagnetic variations is normally sufficient to account for the heat flux in the low latitude ionosphere 11414 the relationship between and magnetic phenomena a general seasonal relation between and is shown to be similar over a wide range of latitudes and also for both daytime and nighttime data 11415 analysis of probe characteristics in drifting plasma for a spherical langmuir probe moving relatively to a plasma the ion sheath is deformed positive ion densities determined from rocket measurements in the ionosphere for certain sheath configurations have been compared with simultaneous observations of density deduced from curves agreement is good 11416 satellite observations of electron content at the magnetic equator daytime values of electron content near are obtained 11417 variations of scale height in the upper atmosphere analysis of satellite orbital data suggests a decrease of the density scale height in the upper atmosphere from to which is attributed to a drop of in the average temperature at km 11418 the heights of ionospheric irregularities in the auroral zone signals from sputnik were received at points spaced by the heights of irregularities giving scintillation were found to range from to with occasional higher values 11419 a sequence switching unit for measurement of ionospheric drift in a modification of the three receiver system a unit switches the input of a single receiver between three aerials the output signal of each aerial being displayed simultaneously with vertical separation on a cro 11420 a study of layer effects as observed with a doppler technique frequency changes in the radio waves arriving at boulder colarado from are measured the frequency dependence of these changes is shown to give information about the heights of ionospheric disturbances 11421 a new method of space exploration by radar using incoherent scattering discussion of incoherent scattering by spatial fluctuations in electron density and a review of theoretical and experimental results emphasis is on the properties of the ionosphere 11422 stability of a simplified geocyclotron model a treatment of the phase stability of the geocyclotron a mechanism for accelerating electrons in the outer ionosphere 11423 the radio refractive index of air a review paper containing references the constants in the classical debye expression for the radio refractive index are discussed together with the errors incurred in using standard meteorological data model atmospheres and radio climatology are also discussed 11424 sferic observations of the severe weather on may records obtained with the ephi system of are presented and discussed in relation to certain weather and propagation factors 11425 diurnal power variation of the earth ionosphere cavity modes and their relationship to world wide thunderstorm activity 11426 on the design of small economical radio frequency eht supplies particular attention is given to the design of the high voltage transformer the type of stabilized eht generator described is suitable for operation at frequencies greater than 11427 satellite power supply has variable pulse width a detailed circuit description of a short circuit proof dc to dc converter of high efficiency with an input voltage of the output voltage is held at a power out of 11428 solar batteries for the use as the power source of unattended uhf repeaters 11429 pattern detection and recognition both processes have been carried out on an ibm computer which was programmed to simulate a spatial computer the programs tested included the recognition process for reading handlettered sansserif alphanumeric characters