I Have encountered a situation with my radio/intercom/headsets which I still haven't figured out. I am wondering if any of you have any ideas on where to start on this one. Honestly, avionics I consider somewhat of a black art since I haven't had a lot of training. I can read wiring diagrams just fine - but I still can't see electrons too well.

Here is what happens; and I don't know if the radio, the intercom or the headset is to blame. There is a noise, similar to a squelch noise which is in the background only when transmitting and only when flying at moderate or better power settings. Receiving is just fine - always. Impressions can be deceiving, but the background noise seems to have something to do with the background noise in the cockpit - in other words - it is only there if there is a lot of noise in the cockpit. It does not seem to be RFI from the ignition nor from the strobes - I am real familiar with that from rental planes.

The radio is an Icom IC A200, the Intersom is a softcom panel mount and the headsets are older Softcom units which I have used in a lot of other aircraft (they are not the high tech noise reduction ones - they are the plain Jane ones).

I have replaced the headset phone plugs and cleaned up the jacks (jacks are new - but had some crud on them), checked the grounds and shielding - that seems to be OK.

Any Ideas are truly appreciated.

Didn't get a lot of flying this weekend - snow was horizontal and the birds were walking.....

Sincerely,

Dave S
St Paul, MN
Kitfox 7 Trigear