On my last flight about 3 weeks ago every time I engaged the PPT to transmit I got a loud "squeal". The tower could still hear me but said it sounded like I was calling from inside a tin can.
Anyway after much frustration (checking grounds,re-soldering,head scratching,etc) I believe I have found the issue.
I have an ICOM A210 and Lightspeed ANR headsets. Normally I just lay the headset controller on my lap when flying. (near the stick with the PPT).
Today I find that if the controller is moved around the cockpit when the PPT is engaged the squeal comes and goes in relation to how close it is to the stick! I suppose this is RF feedback??
The PPT wires, head set sockets, PPT wires are all shielded. I did not have this issue for the past year so I guess I must have had the controller laying a bit farther from the stick.
Any ideas?? How about a larger ground plane on the antenna? Foil wrap the controller? Ferret beads?? Are there any radio gurus out there?
Cheers
Don