I have a newly installed Dynon radio and intercom in a composite aircraft. Wiring is per the instructions with all grounds running through to the ground pin on the intercom. The intercom works well, loud and clear between pilot and passenger. Radio transmissions however have a distinct howl to them. It sounds like I'm talking into a metal bucket and ATC says my transmissions are garbled, and listening on a handheld I can hear the same howling that I'm hearing through the sidetone.
Suspecting an issue with the radio I contacted Dynon and they asked me to try transmitting with the intercom off. This I did and the transmissions are loud and clear both on a handheld and through the sidetone. So the intercom seems to be causing the problem. Dynon suggested running a ground wire (not sure what size (20 swg maybe?) from the radio tray and the intercom case - which I will try, not quite sure where on the intercom case I can attach it though. The panel attachment screws maybe?
I'd be grateful if any radio/electronics experts out there but be able to explain what might be going on. Thanks.
Suspecting an issue with the radio I contacted Dynon and they asked me to try transmitting with the intercom off. This I did and the transmissions are loud and clear both on a handheld and through the sidetone. So the intercom seems to be causing the problem. Dynon suggested running a ground wire (not sure what size (20 swg maybe?) from the radio tray and the intercom case - which I will try, not quite sure where on the intercom case I can attach it though. The panel attachment screws maybe?
I'd be grateful if any radio/electronics experts out there but be able to explain what might be going on. Thanks.
