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Just basic Truck setup nothing special. Midland MXTA25 Antenna, outer shell cracked due to overlanding. with a Wouxun KG-XS20G Mobile radio. Keeping the Antenna Coax in place, just upgraded radio (KG-1000G) and Antenna (Tram 1173 NMO UHF Antenna) My Home Base station is a ICOM F6011 radio with a 50Foot Tower/Mast with 2x Comet GP-3 Antennas. About to add 2 more to it. Also have a BTech GMRS 50V2 to play with. And a few 20/25 Watt radios. My mobile overland repeater rig is 2xRadioddity DB25-G. Running a custom firmware my buddy and I compiled based on the radioddity firmware. Using a Raspberrypi as the interface controller. I'm a ex automotive Electrical engineer. So I like to play around with stuff trying to mod it or break it.

If you think using codes will "protect" you - then have at it. If you're really looking at things from a SHTF perspective, analog radios are problematic to begin with, especially if you're in a single frequency/channelized domain. If I have bad intentions, I really don't need to know specifically what you're talking about, I can pretty much determine how many different people I hear talking, and I can easily triangulate your signal to figure out where you are.

I have 2 different portable repeaters that are made from 2 radios per repeater. One uplink and one downlink. The pairs are literally bolted to each other. I have been doing this with multiple radios for decades and never had desense issues due to the pair being too close to each other. With quality coax and proper spacing between the receive and transmit antenna or a good mobile duplexer and your golden. I've taken the repeater up to the mountains, dropped them on a high spot with solar, batteries and and the up/down antennas separated by about 100 feet. At 20w I was getting 35-36 miles with 70%+ reliability coverage. The real benefit from shielding is in the cable. If you have cheap coax with loose braided shielding, its going to be much more prone to desense and interference in general. Especially compared to something like hardline.

I did eventually try to shield it to improve the signal but I could never really improve much.. From the beginning, with the two radios right next to each other with zero shielding, I was getting ~20 miles.

Though I'd take into account the dates... 1997 probably goes back far enough that most "real" GMRS gear WAS Part 90 equipment, 20 years before the Part 95 rewrite by the FCC. I believe the FCC has also removed the "categorical exemption" clauses. HTs fall into the SAR computation (antenna less than 8" from body) -- and that is complex enough (how much radiation does a <10cm /cube/ of flesh absorb) that it is basically up to the manufacturer to have the evaluation performed before offering the device for sale. Mobiles fall into MPE computation (antenna >8" away) and can be numerically modeled (see the ARRL RF exposure program). Mobiles -- used mobile -- are unlikely to have anyone from the general/uncontrolled population nearby for the averaging period used in the computations; that leaves the controlled population ("you" as the operator) with its averaging criteria.

I can't tell you how many MOSFETs I have blown. My wife will tell you I mess more stuff up then I fix at times.. I think I'm more at 60%fix and 40%broke.

just received my license four days ago. WRXW830. Looking forward to learning Robert

So i think what we have learned here today is that just because you experienced something does not mean everyone else will experience the exact same thing in the exact same way, especially when there are many variables at play such as coax type and length, electrical cable quality and lengths, terrain, different antennas, differently tuned duplexers, etc.. However, most importantly, today we learned that decreeing a fact based upon ones personal experience can make a person look like an "internet expert", aka "some people".

What countries recognize a US GMRS license? Which of those countries allow communications on the WARC bands with only a US GMRS license? If these questions cause you to become frustrated because you “don’t have a lot of time to talk about other things” you may have come to the wrong place. We’re all about talking about other things.

Your GMRS license only allows use within the United States. Likewise the FCC rules and regulations for GMRS only apply to licensed use within the United States. Security communications when traveling in other countries is a completely different subject that requires a good deal of planning and preparation before traveling (and probably input from local contractors.)