one more very important thing: Do not use those cheap swr meters, here is why, 1, they usually have a plastic body. 2, the measurement device internally is not a true swr bar, it is a printed circuit and is only about 60% accurate. find a shop and or ask around for a meter that is from the 80's-90's with a true bar built in. also, don't use a base station watt meter, they are not designed for those applications.
Well, with the 20% tolerance slop you say is in CBs anyway, what's wrong with using the $25 SWR specials out there everywhere on the market? IOW, why use a scalpel to slice the baloney?
Any meter at the radio end of the coax is not to be trusted unless the coax is a certain *electrical* (not physical) length.
Used to see alot of these boxes in ltl linehaul daycabs, talked to one years back and he said they used em because they switched trucks everyday and most of them cheap day cabs they had didn't even have a fm radio much less a cb.. guessing that's changed now.
