RF Feedback??

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

Don

I too have had issues with my icom A210. Don't get me wrong, I really love this radio in my Speedster and plan to purchase another for my Classic 1200 project. Ocassionally when transmitting, I get an interuption in the sidetone will a series of loud beeps. I have to wait for the beeps to stop and then retransmit. Other aircraft complain that my transmission is unreadable. 99.9% of the time my transmission is crystal clear. I've discussed with an icom rep.....no help. I use a lightspeed with noise cancel and never suspected that as my problem. I'll pay more attention when it happens again. This problem rarely happens so it's impossible to duplicate. Thanks for sharing your bit of information.

Paul

Don, Many of us feel your pain as electrical problems are sometimes hard to track down. I take it everything was working well and then started giving problems? Think about any changes / additions you may have made to the plane prior to the occurrence (IE, did you do an annual, take things apart, change the battery in the controller (if it has one), etc... If you haven't already done so, check the antenna connections to both the radio as well as the antenna. The PTT switch may be failed. Do you have a co-pilot PTT and have you tried it?
How about trying a different headset? If no squeal w/ a different headset, then problem found.
All things you may have already done...just things coming to mind. I would also suggest joining the Yahoo Group Aero Electric Connection. Many guys on that group with great advice and experience. Search the archives and it might give you a few ideas.
Best Wishes,
Dan

Hi Dan
The only changed thing is reinstalling my transponder that was out for repair. Transponder is shut off though.
I have found the issue. It is some type of interference from the ANR controllers causing the feedback if the controller is held too close to the PTT wires. Both head sets are new within the past year.I borrowed a friend`s headset (same model) and it does the same thing. Batteries in or out, intercom on or off, engine running or stopped,NO difference.I replaced both PTT switches, re-routed the PTT wires to the sides as opposed to running in the consul. If I use an old passive DC headset there is no feed-back.
All I have to do is keep the controllers AWAY from the stick area!
Anyone with a similar issue maybe try this as well.
I am on the other site as well and will try them.
Thanks
Cheers
Don