| NIHRAC (K3YGG) NIH Building 13 Room G-903 Bethesda, MD 20892 |
Emergency Communications Center NIH Building 11 Room 308 phone: 301 496-5311 |
NIHRAC Web site http://nihac.info.nih.gov/nihrac/k3ygghp.html
The next meeting will be held at noon on Thursday April 2, 1998 in the Emergency Communications Center (ECC) located on the third floor of Building 11. We will make final plans to provide volunteer communication support to the scheduled Clinical Center power outage on Saturday, April 4.
The meeting was called to order by President Walter Stewart at 1208 p.m. The minutes of the February 5, 1998 meeting were accepted after adding that the meeting adjourned at 110 pm.
Members attending the meeting were Jim Hobbs AA3DN, Bill Hook W3QBC, Albert Lock KA3WCF, Larry Martin W3IBO, Andy Mitz WA3LTJ, John Muller W3QF, Frank Putnam N3ZPQ, Dan Reggia N3ENT, Chuck Sherman N3WTO, Harold Simon N3PXK, and Walter Stewart WM3Z.
none
On Tuesday evening February 10, Bob Haslack and Bill Hook operated K3YGG and MEMA Unit 48 during the monthly communications exercise. Messages were copied on amateur and MEMA VHF frequencies. For the March 10 exercise John Muller and Harold Simon will operate, with Bill Hook on call as the backup.
A total of ten members and guests gathered at O'Brien's Pit Barbecue for a pleasant evening meal and to informally discuss amateur radio and other subjects. Attending the event were Steve Carroll N2DDI (who travelled around the Beltway to attend), Robin Hobbs N3NTW, Jim Hobbs AA3DN, Joy Hook ex-WN3WWN, Bill Hook W3QBC, Esther Muller, John Muller W3QF, Dan Reggia N3ENT, Chuck Sherman N3WTO and Mike Thomas WB3LHT.
Following their appointment as auditors at the February 5 meeting, Dan Reggia and Bill Hook prepared a report of NIHRAC's income and expenses in 1997. A copy of their report was mailed to members along with the February meeting minutes. Additional copies are available in the ECC.
Jim Hobbs distributed copies of the design review he and Larry Martin had prepared for the emergency power battery cart project that had been shown at our last meeting. Their report is attached to these minutes. In summary, the cart should perform as expected.
A discussion followed as to whether a voltmeter and dummy load (to estimate battery condition) should be included in the package. It was agreed that an exceptionally rugged meter and high wattage dummy load would be needed. The estimated price of $1000 was considered to be too low until it was learned that cost-free labor might be provided by the shop that built the demonstration unit. Off-the-shelf rather than custom-built components could be also be used to reduce the cost.
It was stated that for other emergency preparedness groups to be able to duplicate the device, there is a need for detailed drawings. While Al Taylor has prepared some of the documentation there is work yet to be done in this area. A discussion followed as to whether we should consider this as only a second prototype or a product with a design suitable for duplication by others. Jim Hobbs opined that preparing full documentation might increase the cost significantly.
It was suggested that rather than purchasing the parts with cash from the club treasury, it might be possible to obtain support from a source at NIH. Larry Martin suggested that the Clinical Center would likely benefit from the availability of a portable, 12 volt, 100 amp hr power source.
Bill suggested that we could approve the construction of the battery cart now. Then, if no other source of funding was found, vote later to expend funds from the NIHRAC treasury. Accordingly, a motion was made, seconded and passed to approve but not presently fund the construction of an emergency power battery cart.
The expenditure of club funds for other equipment was next considered. These items are listed below along with the action taken.
1) An expenditure of $1500 was approved to purchase a Kenwood TS-570D HF transceiver plus accessories to include a 500 Hz CW filter and Astron 20A continuous/25A intermittent switching power supply. A suggestion that we spend $300 additional for the TS- 570S model with 6-meter capability was not approved.
2) The purchase of a Kenwood TS-50S portable HF transceiver plus automatic antenna tuner was not approved. This item had been proposed primarily for digital use by the PHS-1 DMAT while in the field. However, because their future in HF operations is uncertain, it was considered unnecessary to purchase this item now,
3) A Kantronics KAM-Plus all-mode controller had been also proposed for HF digital use by the PHS-1 DMAT. Its purchase was not approved for the reason given above.
4) A heavy duty replacement for the defective rotator for the NIHRAC log-periodic beam antenna is needed. An estimated $540 had been budgeted for this item. However, it was deemed prudent to carefully determine what the physical requirements are for turning and braking this antenna when mounted on Building 11. We also need to know more about what rotators are currently available and their costs. Walter Stewart, John Muller, Chuck Sherman and Jim Hobbs volunteered to serve on a committee to evaluate the present beam antenna. After it is determined what is needed we will vote on an expenditure.
As of March 5, renewal forms from 10 full members and 7 affiliates have been received. Renewals should be received by March 31, 1998. Those not renewing by April 30, 1998 will be deleted from the list of members.
David Dodell K7DSD, D.M.D., is an advanced class licensee living in Scottsdale AZ. He visits the NIH campus twice yearly, would like to support NIHRAC activities when he's available and has submitted his application for affiliate membership. David operates HF, 2 meters and 70 cm.
Andrea L. Stewart KB3CDK is the daughter of NIHRAC President Walter Stewart. She recently passed the Novice class exam and would like be an affiliate NIHRAC member. In the past, Andrea has been on hand to assisted her dad during NIHRAC activities including the B-CC YMCA Turkey Chase and Clinical Center power outage tests. It was agreed that NIH regulations concerning the presence of minors in NIH buildings would be adhered to during her participation in NIHRAC activities
The list of candidates presented at the February meeting by the Nominating Committee was unopposed. Andy Mitz made a motion that the officers who served in 1997 be thanked for their excellent work. The motion was passed unanimously and the following incumbents were reelected by acclimation.
- Walter Stewart WM3Z, President,
- Larry Martin W3IBO, Vice President,
- Albert Lock KA3WCF, Secretary-Treasurer, and
- Chuck Sherman N3WTO, Asst. Secretary-Treasurer.
The next power outage is scheduled for Saturday, April 4 from 100 to 330 p.m. A minimum of 12 volunteer operators are needed to cover the important posts. For this test, it has been suggested that we change our usual protocol as follows
- Net Control will be stationed at the Building 11 ECC rather than in the CC cafeteria. A second op should be present to assist.
- The primary frequency will be 447.925 MHz SIMPLEX. NIHRAC's YAESU FT-7200 or the DMAT Bendix-King Model EMH will be used at the ECC as a UHF base station.
- For UHF backup, the NIHRAC repeater (447.925 MHz) will be used.
- The NIHRAC two meter (145.29 MHz) repeater will be used as the talk-around channel and as a back-up to UHF operation. NIHRAC's Midland or ICOM meter transceiver will be used as the VHF base station.
- The PHS-1 DMAT's UHF handhelds need to be tested in an actual event. NIHRAC volunteers will be provided with a Motorola, Bendix-King or GE transceiver to use during the power outage.
Jim Hobbs suggested that Ross Merlin bring the demonstration model battery cart for use at the Clinical Center command post. Andy Mitz suggested that a permanent through-the-glass amateur band antenna be installed there.
The meeting adjourned at 1:10 p.m.
de ka3wcf and w3qbc
SPECIFICATIONS AS PRESENTED
Battery Type
Sealed Lead-Acid, meeting
"IATA"
standards (can go in airplane)
Battery Capacity 100 A-H
Circuit Breaker Rating 100 Amps
Estimated Cost of Parts $1000
Estimated Cost of Labor Unknown
PURPOSE OF SYSTEM
(from presentation at February 5, 1998 NIHRAC meeting)
This system was designed to serve as a UPS for 12 V radio equipment. It is
intended to be used in conjunction with a gasoline powered generator or commercial
120 VAC power, not in stand-alone service. It will effectively bridge the gaps in
power resulting from refueling a gasoline generator, or from power outages in commercial
power ranging from very brief up to several hours, load permitting. The capacity of
the battery/ charger system is supposed to permit use of an HF radio and a 500 watt
amplifier, as an example. Many other load possibilities exist.
ENGINEERING DESIGN REVIEW BY JIM HOBBS AND LARRY MARTIN
The battery's 100 Amp-hour rating is currently in question, since we do not know the rated
battery voltage at the end of its discharge cycle, and radio equipment may not function at
the voltage likely to represent the manufacturer's design discharge point. Also
unknown are the manufacturer's rated maximum discharge current and rated number of
discharge cycles. However, the size of this battery will probably permit it to fulfill the
design goals, with loads such as that in the above example.
A lot of thought went into the prototype's design. The output connections are numerous and easy to get to, and likely to be about as convenient as one could come up with. All output circuits are fused.
The system appears to be about as portable as one could make it, considering the bulk and weight of the components. The enclosures are rugged, but appear to not be weather resistant, although this is a minor issue, since the equipment it powers isn't weather resistant either.
By design, there is no metering included, nor is there a means for testing battery condition. A voltmeter would allow users to know approximately how much battery capacity remains. In the worst case, the meter could get broken in transport or use, but then the system is no less useful than it is in the present configuration.
The system should include a simple means to test battery capacity. This could be an integral part of the system, or an external device. It would have a load resistor and a device to measure the time it takes the battery to reach the minimum acceptable voltage for communication use from a fully charged state. By measuring this time, the actual Amp-hour capacity would be known. Such a testing device would greatly reduce the chance of system failure during use, since a bad battery would be discovered and replaced during routine tests. Alternatively, the battery could be replaced at scheduled intervals, likely to be much shorter than time to failure, but wide variations in actual battery life require relatively frequent replacement, increasing system cost.
Actual cost of the system depends greatly on the cost of labor to fabricate parts and assemble them. At typical machine shop and sheet metal shop rates, the fabrication cost could easily match the cost of materials. Assuming no volunteer assembly labor, this puts the cost at $2000, unless someone finds a machine shop willing to do the job for less than typical rates.
-----------
UPDATE 3/5/98, after receiving e-mail from Al Taylor dated 3/4/98
I understand that a shop is available to fabricate parts for this project at no charge, but that no mechanical drawings exist. Because one of the goals for this system is to stir interest among other organizations to build similar systems, it is necessary to have a full design package available. This includes a layout, parts list, full set of parts drawings, assembly drawings, schematics and wiring diagrams. Without such documentation, the system is not easily reproducible, and a second system would merely be another prototype. It is my recommendation that this design package be a required first stage of this project.
The full design package would facilitate a QST article, further increasing the likelihood of proliferation. I'm glad that Al Taylor agrees that using off the shelf enclosures is a good idea. This can greatly reduce design time, fabrication time and parts cost, while increasing reproducibility.
-0-