Current Events
2024
Members met at 11am. Dr. Higgins, W5EX, started with a Control Ops school followed by a business meeting. Mr. Jim Hooper gave presentation on RF Safety and the recent change in FCC regulations regarding documented Safety Studies at amateur station locations. Bart Huffman, KG5PGH, gave a talk on recent site maintenance.
Mid April, Uvalde Site Pulldown and Upgrade
Dink, WA5LNL filed the following report.
The complete Uvalde radio site and APRS digi was pulled down by Larry/EX and Tom/KC5L about During April, 2024. The upgrade is to replace the controller with a new Sierra (SRS Cube) and get the digi working again. New control cables for the SRS were made by Bill/WA5DSS/KRV. Everything was looked at to evaluate performance.
What we found:
All equipment was cleaned and we got 2- tablespoons of nice red dirt!
L1 (to SAT)
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CDM plastic covers were removed for extra cooling.
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A hole was put in the radio shelf so the blower can move more air (TX cooling).
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This was way-out. PL encode (tx) was ON and OFF. It would work sometimes. It would work well and I would go to eat, come out and find the PL OFF? Moving wires would not stop the PL. Turning the shelf vertical--PL would work all the time!
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The problem: 2- non soldered wires on the PL switch!!!
L2 ( to BKT)
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CDM plastic covers removed ( cooling)
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Hole made in shelf for better cooling on TX
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Old Motrac PL notch filter was removed on the Rx. ( filter now in controller)
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PL Rx switch was reversed.... ON was really OFF.
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Found broken +12v wire that powers the 5K audio board.
All radios were checked for frequency, deviation and frequency response (swept).
We found the Kenwood repeater ( TKR-850) clipping tx audio to 3.7 kHz. With a better audio
impedance match, we now have a full 5 kHz dev. with NO clipping.
APRS
Found the KPC3+ with its program gone (erased). KPC3+ reprogrammed and is working. A -10v power supply was rebuilt for the Wx station. We found the Wx station back-up battery shorted- now replaced.
Uvalde radios are ready for a return.
73's,
Dink, WA5LNL
May 18, Trip to George West
Trip report
Saturday(May 18), Bart/KG5PGH and Dink/WA5LNL team made a trip back to George West (GWS) to
reinstall the radios (links + repeater)and APRS packet station. The main purpose was to install a new SRS 'Cube' controller. All components were checked on the bench. It is a lot better to do this on the bench , than to take test equipment to the site.
Things done to the site equipment:
1. Astron RS-35, reset voltage to 13.4v.....was 12.1v
2. (4) CDM's, covers removed for cooling,frequency check, audio sweep,dev. check rx front end aligned
3. ( 2) bandreject duplexers checked
4. Filters were installed on the blower motors for less noise on the 12v power feed
5. New control cable was made for the Motorola 5K repeater
6. A platform was made for the Astron power supply to set 6" above the bottom of the cabinet so cool air can get through the bottom vent.
7. A fan was added above the Astron for cooling.
8. New SRS 'Cube' controller adjusted and set-up (1)repeater with (2) links
APRS:
1.tnc (PLX) was checked- battery -OK
2.weather station data was NOT working. Found outside instruments coated in a nice 'tower painted 'ORANGE' '
Replace outside instruments
Check out APRS Intertie digi station [ WX5II-15 ] with weather:
https://aprs.fi/#!lat=29.42410&lng=-98.49360
28°20.14' N 98°10.30' W
2023-07-29 23:50:47 - 2024-05-19 10:13:22
APRS/CWOP weather 2024-05-19 10:13:22: show weather charts
Temperature 85°F Humidity 67% Pressure 1008.4 mbar
Wind 135° 4.9 MPH (Gusts 10.1 MPH)
Rain 0.0 inches/1h 0.0 inches/24h
2317 Wx
George West
power 36W, antenna HAAT 160 ft, gain 1 dBi 135°,
range 21.9 miles, rate 4 packets/hour
[APMI03-5 via WX5II-12*,WIDE2-1,qAR,N5JLR-1]
73's
Bart,KG5PGH
Dink,WA5LNL
June 1, Grounding System Repair, Uvalde Muffin Hill
Trip Report
Hello, all: Some time ago, we were aware that our original top-of-rock grounding system at Uvalde Muffin Hill had been trashed during the removal of a group of satellite dishes thereon.
Yesterday, Dink and I returned with a fresh reel of #4 AWG bare solid copper, attaching hardware and our trusty AEMC ground impedance meter. Before breaking out the tools, we measured all accessible on-site grounds. A good ground measures < 25 ohms.
Two chemical grounds are in service near the west side entrance of the TV transponder building. These measured 205 and 250 ohms. We surmised that the chemical well has not received electrolyte fill-up for some time!
The mains power neutral (on the NE corner of building) consists of 3 rods driven at a 45 deg angle under the building. This location choice is a good one, since drip condensate from the building floor above might help keep the ohms low. Each of the 3 rods had a large gauge wire attached.
480 ohms
340 ohms
2.5 ohms with the meter reading "noise"
A north telephone pole butt plate ground, hooked to our neighbor, W5LBD (SK) radio box 45 ohms
A south telephone pole butt plate 365 ohms
Turing our attention to our radio cabinets, which are shelf-mounted on a telephone pole: We cleared the tangle of wire. We identified #4 insulated stranded copper wire to each of 2 cabinets, a wire going to the corral fence, and a wire going into the weeds and down the north face of the hill. A couple of wires went nowhere and were removed.
We carefully connected all wires together with large Kearney nuts, With all connected, but the south pole butt plate, we measured 35 ohms! We added a run of #4 to this pole. Now, the impedance was 0.9 ohms, which is undefined on our meter.
Conclusion: We have markedly improved the grounding on Muffin Hill!
We hesitated to hook on to the trifurcated mains power line neutral grounds. We can revisit this later, if necessary.
Further examination of the AC disconnect switch neutral is needed. We are uncertain how this is terminated.
(Dink also cleaned up weather telemetry cabinet entrance plumbing)
73, Larry, W5EX and Dink, WA5LNL
June 14-16, Dark Canyon, NM and Ft. Stockton
Field Notes
Last weekend saw a jovial joint work party at Dark Canyon, NM, part of the Jacks Peak Intertie. Group was headed by Mike, KB6JYF and included intrepid climber, Sean, KD6CUB, as well as Shannon, W9CSM, Paul KC5HCX and Mary (Michelle) as ground crew. Tim and I rode with Mike and Sean in Mike's Ford 4wd. A rough ride and then some! But beautiful mountainous country all the way.
Our mission was to restore a radio link to Intertie, Inc. at Ft Stockton, plus several chores related to overall function of the Dark Canyon system.
Sean mounted a new PcTel 10 dBd Yagi and LDF-4 feedline, donated by Intertie, plus a small vertical to replace the existing, but broken 443.750 repeater antenna. Sean spent a lot of time on that tower!
Mike came equipped with a very nice Anritsu antenna analyzer and a Telewave watt meter. All relevant transmission lines/antennas were rung out and power/VSWR reported. We saw no signal incoming at the Kenwood after functioning the FST site address. We then removed the receiver multi-coupler connection and substituted a freshly-tuned 6-cavity flat pack mobile duplexer. Still no response. 6 watts at the duplexer antenna spigot.
The link to Ft Stockton was checked with a new CDM tuned to the link channel. No joy from FST, even though , the day before, Tim and I successfully simulated the DKC link with a talkie across US 385 from FST station. At the time we noticed almost no signal off the back/sides of the Paraflector there. More on this below. Also, control, but no voice was seen on the simulated incoming signal. (More below).
Only after installing the LDF 4 on the PcTel Yagi, were we able to bump the FST repeater via our new Yagi, with a 25 watt CDM tuned to FST. All attempts at dial tone or voice failed. Dink, WA5LNL, heard nothing from San Antonio.
Mike then ran his own path-prediction software to show that we should have a 1 uV incoming signal. This is similar to my homework with Radio Mobile software. I got 0.57 uV with FST Paraflector (15 dBd) at 167 ft, but with a 12.5 dBd dual Yagi suggested at DKC. So, the path should work: maybe not LC all the time
Mike repaired a defective shack door hasp - time consuming task.
At the end of the day, Mike and I concluded that we did all we could do. I suspected that the FST Palomar squelch card COS line was switched off. In this state, you can function a site and get telemetry, but w/o voice throughput.
During our visit, Martin was receiving emergent medical care at an El Paso hospital. Yet, once home, he was able to coach us via an Internet kluge at Midessa.!!
We returned to quarters at El Paso and Carlsbad.
Sunday, Tim and I met Benny, KB5JXO, at the FST site. We quickly verified that the big Paraflector was spot on azimuth, in spite of a windstorm last week. Yes, the Palomar squelch card switch was OFF. Sliding it to ON, allowed voice contact with Dink . WA5LNL, in San Antonio, via the talkie-simulated DKC link channel and our alternate Alpine/NXU/Jacks interface. But no response from DKC.. We did confirm that FST is receiving 424.xxx and transmitting 429.xxx with correct PL.
We broke out our Bird watt meter. Zero watts out on 429.xxx /PL CDM transmitter! Enough RF to key my talkie across the street, but that's all. So that's why we hear nothing at Dark Canyon mountain!
Unresolved, still is FST link receiver sensitivity. (no IFR with us)
Conclusion. We still believe that the FST<>DKC link has a viable path.
We plan to tune a fresh pair of CDM's and duplexer, haul them to Ft Stockton and see if we're right.
73,
Larry, W5EX, with sincere thanks to Mike, Martin, and a terrific crew from El Paso, and to Benny, KB5JXO, Dink WA5LNL., and my copilot, Timothy.
August 3, Annual Meeting, La Fonda Alamo Heights, San Antonio
Members met at 11:15am. Dr. Higgins, W5EX, started with a Control Ops school followed by a business meeting. The Intertie, Incorporated Annual Report for 2023-2024 was distributed to all members present. Dr. Higgins also gave short technical presentations on Bentonite Grounding Technique, VHF Propagation Simulation and Transmission Line Return Loss Measurements. Everyone left the meeting with full stomachs.