Astrolite pilot's headset - trying to get it to work !
I bought this unused headset a few years ago. It has standard 300 ohm earphones each side and an amplified electret microphone. The earphones work perfectly but the mic/amp combo doesn't. I've plugged it into my ICOM handheld and when I press the PTT, all I can hear is a nasty squealing. I've tried adjusting the pot on the down lead terminal board (I assume this is the gain adjustment) but this only alters the pitch of the squeal ! I have tried a Sennheiser headset with an amplified electret mic and older Airlite 71s and Astrolites with carbon and amplified dynamic mics. They all work perfectly well. Does anybody know what the problem(s) might be ?
Thankyou all.