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I am posting this for the benefit of newcomers to myGMRS. Folks entering the world of GMRS and repeaters often have early questions on this very subject and the question can often best be answered through the use graphics or video. I stumbled across the following video this morning that I found to be short, simple, and concise. So I post here for the benefit of new members of the myGMRS community. Enjoy. Michael WRHS965 KE8PLM

There are quite a few "board stuffers" here in the US since it is almost totally automated. They just load the reels of parts and set up the stencil and align/orient it. The CAD files give all the part locations. So there is more board assembly here than you might think. Most of the products I designed were all built over here... with some or many foreign parts of course. Most of our low-mid volume boards were populated right in Oregon. The blank boards themselves were more often fabricated in Asia. Caps and resistors are almost free but the boards themselves can get expensive... $2-$15 depending on size, # of layers, etc. We made educational science equipment so had all different volumes of products. Some things were almost entirely US made and other things entirely Chinese or Thai. It's a very complicated business. If you buy parts in the US then send them to China for assembly and bring them back the import duties get very complicated. You can end up paying duties twice on the same part. Then the finished products were sometimes sold to China and charged another duty. So we started keeping stock in China for sales there. (Yes, there are American companies selling electronics devices to China.) I would guess that hand held consumer radios are entirely made in Asia. The designs could be done either here or Asia... but likely China. The chip makers do most of the radio design since it entirely revolves around the chip for that function. Only the support circuits (power, control, etc.) are done by the maker. When I worked at Maxim (chip maker) many wafers were made in the US then tested and packaged into chips in the Philippines. I trained a couple of Filipino engineers in RF test back in the late 90's. We made a lot of cell phone chips back then. The chip designs were mostly done in the US Basically, I'm just saying its a very complicated picture. Hopefully somebody found this interesting. :-) Vince

The R1225's were famous for burning up if you ran them at high power. Someone probably did you a favor by turning down the finals to limit the power output. The sales brochure said they'd do a 50% duty cycle at high power, experience says that even at 25 Watts, anything close to a 50% duty cycle would kill them. Lots of the later Maxtrac/Radius mobiles that the R1225 series were based off of had a thermistor controlled limiting circuit that would turn down the power as the amp heated up - kind of a self limiting feature to keep the radio from burning itself up. I haven't dug into the manual for one of those R1225's in probably 15 years - so I can't say for sure that's what is causing the pull-back that you're seeing, but it seems like it might be. Make sure you're keeping the fan on & blowing cold clean air across the heat sink. Either way, if you want more than 20 watts out of your R1225 repeater, you should either get an external amp or go find a nice used MTR2000. I'd also say if you're trying to crank more than 20 watts out of your duplexer - what are you talking to? Portables at 4/5 watts? How far can they talk back in? Transmit power sounds sexy, but it's rarely the limiting factor in a repeater system.

I don’t know what the issue is, but the first thing that is running through my head is ‘Is the transmitter output truly remaining constant or is changing too?’ If the transmitter power is in-fact remaining constant while the insertion loss of the duplexer is changing, then perhaps a cable to or connection within the duplexer is warming and changing impedance. If the radio is actually changing, then we know the issue is related to the repeater. If the SWR is located at the radio and the duplexer characteristics that are changing while transmitting, would expect to see some subtle movement in the SWR. Just food for thought. Michael WRHS965 KE8PLM

Yes, it will. That is one of the major real-world functions that the lighting arrester serves. Contrary to its name, a lighting arrester does not protect you from damage from a direct lighting hit, but instead it shunts surges from nearby lighting and bleeds off static that occurs naturally during storms as well as other periods of high winds. BTW, welcome to myGMRS. Michael WRHS965 KE8PLM Edit: Here is a link to a document that explains how they work. https://www.polyphaser.com/News/DownloadFile?downloadGuid=52f23510-c294-40d8-889b-b63f1c6fdcb5

That's real nice, but on this forum, we generally try not to recommend people doing illegal things. Keep in mind that Baofeng UV-5 series and F8 series radios are not type accepted for use on GMRS, thus, you are in fact breaking the law. If you were running a Part 95 accepted 25-40 Watt radio such as a Kenwood, Motorola, or even a Midland MXT400 with a quarter-wave antenna on your roof, you would be able to easily reach the back of your convoy at 3-5 Miles, legally.