The Radio Information Board

I have an 820 that has a fluctuating audio issue when transmitting. I have an external controller going thru the rear 15 pin connector. All audio, IDs, TX/RX Audio, Courtesy Tones, Controller Voices... all things fluctuate at indefinite times. Seems to be the worst while the repeater is in use. TX Audio may be fine for the first minute or so after sitting dormant but it slowly drops down to hardly intelligible after being in use... perhaps its heat related? FWIW, When I use the internal Kenwood controller, there is NO audio issue. Everything is fine with the internal controller. Only when using the external controller...Perhaps Heat related in a separate audio path? I've ruled out cables and controllers. I've had this thing apart down to the chassis, with the front bezel removed and the front chassis mount folded down, and left it on the bench for a week to "play" with it. While monitoring another radio while I transmitted into the repeater, I had ZERO audio issues while this unit was "completely naked" so perhaps if it was heat related, the heat was able to escape?

Ideas here? Darndest thing I've seen and heard this year...

Josh W4ZZK
w4zzk (at) qsl (dot) net

Sounds like the external controller has a problem.