I think you need another set of eyes on the radios. Whatever is wrong, it's possible you're overlooking it and a fresh perspective might be able to figure out what's wrong. If you know someone knowledgeable that could take a look a the radios, I'd suggest doing that.I have used the stock antennas...not working; put on the new antennas (from Amazon), still not working; simplex works for maybe 100 feet, then nothing. They can hear me loud, but I cannot hear them when they try to talk back. I did try one of the new antennas on a Wouxum & works perfectly.
ALthough both radios had been stored inside climate contolled room for about two years, they did work when I stored them. Now, nothing but paper weights! I find it quite odd that both radios have the same issue.
Not sure if it is cost-effective to have them checked out and/or repaired.
Receiver will usually work in a strong signal (-10dbm from a nearby radio) but deaf to the "outside world". It's a well documented issue with ceramic filters and I have a stack of Kenwood 80 series mobiles made in 2006/2007 with the same issue. Deaf as a doornail on wide but work fine on narrow. Not worth fixing due to the labor involved.Hang on a second - you said in the very first post " In simplex, both transmit & receive perfectly. " If the ceramic filter was bad as they say, how did it receive on simplex but not the very same signal when you interrogated the repeater. ?