ARRL Field Day 2024: In an effort to encourage more off-grid, portable field radio operation and exercises the following After Action Report is posted:
I used some of my usual military equipment from Mt Diablo State Park this year as in the recent past: “aPOTA”. “A Park On The Air” although very unofficial and unannounced. I operated Class 1BEB (1 transmitter at a time, battery operated, in the East Bay Section.) But I don’t “do” contests, or even keep a contacts log when in the field.
Battery powered, man-portable military radio gear makes this a simple and effective off grid and emergency communications exercise with like-minded people. Military radio equipment like this is rugged, easy to operate, reliable and historically interesting. Also “cool” as compared with modern commercial equipment which works well but can be fragile IMHO.
As in past “Boonie Ops”, I also ran the PRC-174 for some HF Winlink test messages to/from the Internet using the laptop PC and a Signalink radio interface.
That messaging was via an automated HF Radio/Internet interface gateway station in Reno NV, a 163 mile HF shot. This is very handy Internet EMail connectivity from The Bush. EMail your buddy: “I’m here, Get on the air!”
Included was the British Racal TRA-967/3 man pack transceiver running on 6 meters FM, 52.525 mc. The Picnic Table TOC – Field Day BBQ not included.
Using the J-45 “Knee Key”, I made a bunch of CW contacts (and then a few SSB voice with an H-250 handset) on HF using the PRC-174. It is a 20 watt man pack set, mounted on the ALICE Pack frame for humping it. Seen below with the whip antenna later tilted downward to enhance the NVIS effect for regional contacts.
I had good results inside central California on 40 meters with the antenna deployed like this for NVIS (also running a quarter wave ground wire). Propagation was otherwise very good. The tilted whip won’t out perform a low horizontal dipole, but this is easy and worked under today’s conditions.
Eg: Had a nice chat with Mike at Maritime Radio Historical Society station K6KPH in the Marin headlands, a 42 mile, midday NVIS shot. This was well out of ground wave range on 7050 kc CW.
The AN/PRC-127EFJ handy talkie was along for monitoring the local simplex and repeaters on 2 meters. This is the 3rd generation of the PRC-127; the “EFJ” model is made by EF Johnson and is keypad programmable. These were designed for use by Combat Support units and not technically “tactical” combat equipment. They can include P-25 digital and DES encryption as options as needed. A rugged, semi-COTS radio. (EFJohnson 5117)
I also had the PRC-47 HF transceiver as normally mounted in the Bronco. It can be easily dismounted for field-portable ops. It provides 20/100 watts of HF CW, RATT/RTTY or SSB, 2 to 12 mc. I have 2 modulator modules so I can switch between them for USB or LSB operation; just plug in the desired sideband. A military USB net or Field Day favorite. Fixed, portable or mobile.
The little fold-down operator table is handy when needed. With the patch panel I can connect the PRC-47 or GRC-9 to any number of antenna systems including the MP-57/MS-49/52 mobile whip, external dipoles or other wire antennas when fixed-portable.
On a related note: This Op was also a shakedown cruise for the ChiCom “MGGi” 12 volt-to-24 volt converter I bought via Amazon. See below. I would have preferred the US Mil. EMCU-116 converter to power the 24 volt PRC-47 from the vehicle 12 volt system but this was readily available and cheap at $36. I just installed it in the truck to evaluate it to power that radio. The efficiency, regulation and ripple “specs” looked good but Caveat Emptor.
This one is rated to deliver 20 amps, 480 watts; more than enough although its output is fixed at 24.0 Volts. A few more volts would be better but it does the job with the PRC-47 in high power mode just fine. So far it has proven to be RFI-quiet while in operation, always a concern with SMPS power supplies.
Note to self: The converter draws an idle current of 30 ma @ 12 volts with no 24 V load. It pulls 1.5 amps@ 12 volts to power the PRC-47 receiver @ 24 volts..
The Bronco is also wired to provide 24 volts for my other military radios such as the PRC-174 when operating “tailgate portable” at campsites.
Site selection is important! I stopped at this shady spot and then unloaded the truck in 100° + F heat. Whew. Upon initial power up checks I noticed a periodic loud raspy “DZZZZT” occasionally. Then I looked up through the dense tree cover. DOH! Too hot to relocate.
Next time I’ll be more careful in assessing the overall site suitability. Once noted and after I decided not to move, I elected not to install my usual wire antennas under this 3 phase HV line. This was not a show stopper but just an annoyance. Improvise, Adapt, Overcome.
Got Comms ? Yes. Mission Accomplished.
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For more information on the PRC-174, take a look here:
https://www.n6cc.com/prc-174-hf-manpack-radio-set/
More on the AN/PRC-47 look here:
https://www.n6cc.com/the-prc-47-hf-ssbcw-transceiver/
Details on the TRA-967:
HI Tim, thank you for the report on field day, the equipment sure looks great out in the field.
Hi Mark! It all works and is fun to use…
Thanks for visiting!
(and thanks for those parts you sent me awhile back…)
No Shelf Queens!
Tim
Hey Tim,
I totally spaced FD this year glad to see someone remembered. Nice setup looks like fun I’m still in the progress of getting parts together to run field operations with the PRC-515 one of these days I’ll get my act together.
I think maybe WINLINK dropped my account from lack of activity last time I tried to check in WINLINK wouldn’t let me send or receive emails.
73, Dave
W6MQI
Hi Dave – I could have likely hit your PRC-515 from my perch on the mountain – good LOS/Groundwave view in your direction.
I send myself a monthly Winlink EMail via HF just to remember how (!) but also to keep up with any software/system changes as they occur.
We are planning a lengthy camp/Recon trip up to the Sierra’s later this summer – will let you know. Cheers, Tim
Sounds good will update WINLINK so I’m current as well.
Later
Dave
W6MQI
Another great write-up! I always enjoy hearing about your adventures.
Thanks and 73,
Scott, kc8kbk
Hi Scott – Thanks for visiting..Just trying to encourage more field ops.
“If you’re not having fun you’re not doin’ it right…”
73, Tim
Fun taking a virtual tour of your gear — very unique.
Carol (LICW member)
Hi Carol – Maybe I worked your station! This old equipment is fun and reliable but heavy! hihi
Thanks for visiting, Tim