“Military Radio” Field Day 2025 was another Field Training Exercise that I did on Mt Diablo, CA. As usual, I operated only military radio equipment in this national emergency communications preparedness exercise. It’s obviously perfect for the job.
Sponsored by the American Radio Relay League, upwards of 40,000 people in North America participate. Some Hams and Clubs also view this as a “contest” but I don’t participate like that. I don’t even keep a log of contacts beyond a scratch pad.
A few pix of LZ Shady:
It’s just a fun chance to exercise my equipment in the field with the opportunity to contact many other like-minded people also operating from field sites. I operated from Mt. Diablo State Park, 45 km east of San Francisco, as I have done many times in the past. Supported by my dedicated camping vehicle: the 1971 Stealth Bronco. It is well-equipped for this.
I operated for about 4 hours with this very hasty setup on site. The HF antenna was a 10 meter long horizontal wire strung about 3 meters above the ground, another 10 meter long wire was laying on the ground as an “RF Return”/”ground”. Simple, quick, Lo-Vis, inefficient, but it worked well.
It won’t out perform my preferred horizontal low dipole but I contacted many stations in CA, OR and UT on 40 meters CW (NVIS) and also Hawaii on 15 meters CW.
Below is the basic setup with the 20 watt PRC-174 HF man pack set at the picnic table. I operated this set exclusively on CW this time. I was not trying to make lots of contacts or hit long distances, just casual ops to exercise everything. No HF Winlink EMail this time.
That J-45 Knee Key works fine for short contacts but it will eventually make your leg turn Blue! Solution? Improvise, Adapt, Overcome.
(That spray can of DEET served 2 purposes)
I also ran my VRC-7/RT-70 VHF FM mobile set on 6 meters. It works great with other compatible military radios of the era and is somewhat compatible with modern narrow-band Ham radio equipment. From 2500 feet elevation (see dash altimeter below) I had a commanding view of central California and there were lots of stations on 52.525 mc FM.
That CW key on the RT-70 can key the PRC-47, GRC-9 (or TS-50 if necessary). CW mobile.
In addition to the PRC-174 and VRC-7 I also ran the 20/100 Watt AN/PRC-47 in the Bronco. I have it set up as a Grab&Go installation that is powered here by a 12V-24V converter off the vehicle battery. It is shock-mounted with foam pads and a bungee cord while it sits on that little fold-down operating table surface. While mobile or fixed-mobile it drives a bumper mounted MS-57 spring mount with 15′ of MS-xx mast sections. It can also be patched into external antennas such as dipoles when needed.
It works great on SSB although the CW signal contains some artifacts of the 400 cps HV power oscillator. For voice Ops I have 2 Amplifier-Modulator plug-in modules to run it on either USB or LSB as needed. It’s an easy, no “mods” occasional sideband mode change. USB for RATT, Mil radio voice nets, 5357 on 60 meters or LSB for casual ham ops.
The AN/GRC-9 mobile installation was also available as usual. However there is basically no AM activity on Field Day and it was a little hard to get to with all the camping gear stowed in here for transit. This is a great, reliable little AM/CW set from very remote camping spots when used with a dipole antenna. Powered via a DIY transistorized HVPS.
ARRL Field Day 2025 was a fun Op for me up here. No Grid, no Internet, no Wifi, no repeaters, no cell phones, no noise, no neighbors, no problem. Great views but no BBQ!
Got Comms? Yes. Mission Accomplished.
Get your military gear out in the field where it belongs and have fun. No Shelf Queens!
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See you at Winter Field Day 2026! https://www.n6cc.com/winter-field-day-2025/
For more details on the very capable PRC-174 take a look here: https://www.n6cc.com/prc-174-hf-manpack-radio-set/
Some more information on the AN-PRC-47 at N6CC: https://www.n6cc.com/the-prc-47-hf-ssbcw-transceiver/
AR
NNNN
Thanks for this Tim, I always look forward to updates on your adventures! You do cool stuff, and document it very well.
73,
Scott, kc8kbk
Hi Scott – Thanks.. Just trying to generate a little interest in Mil radio operation.
“If you’re not having fun – you aren’t doing it right”…LOL
Thanks for the report Tim, I was standing mid watches @ NAA this year during field day, your set up as always looks great.
Mark
Thanks for the awesome AAR
Thanks for doing FD your way
John ve3ips
Now to get my trc77 and prc25 ready for next year
Hi John – Looks like we share the same interest in “ham radio outdoors”! Your TRC-77 and PRC-25 do well out there, especially the TRC-77 on HF from the woods. Mine is almost always with me. Have fun and thanks for visiting..Tim
Tim – Thank you for taking your military gear into the field on Field Day. And thank you for documenting it so nicely so we can ride along!
I don’t think the leg-clamp key brackets have ever fit my leg. I love the idea but I have always been far bigger than the target leg size of those units. I don’t think I am alone in this as several militaries went to an adjustable canvas strap for leg-mounted keys. You can see several on my website at https://www.wd8das.net/keys.html
I recently made one from odds and ends I had with me here on Kauai. It is shown near the bottom of that webpage.
73 Steve WD8DAS
Hi Steve – Thanks! Your key collection is great – especially the DIY models. I made a “field expedient” paddle key for field ops using a Curtis 8043/4 CMOS keyer. Hacksaw blades work great! Thanks for visiting,, Tim
Tim,
FWIW, I managed to stuff two filters and a pair of miniature relays into my PRC-47 modulator. It will work with a bit of PCB modification and replacing the CW-FSK/Phone switch with a center-off toggle to select the filters.
No additional holes on the front panel and selectable SSB without having to open the unit.
The cover on the module does protrude just a bit, but not enough to keep it from fittin’
n3kcb
Hi Anthony – Yes those are useful mods and others have had success with them as well. Also a “variable tuning” mod which could be very useful especially on 60 meters. I have not gone that route as yet. Thank you for visiting and thanks for the ideas! Tim