Hey Buly (and anyone else)

I’ve got an RST intercom and an ICOM radio (don’t remember the number but only 1 year old).  When the engine is off I can hear and Xmit fine. Turn the engine on and I can still hear fine (i.e. no noise) but when I key the mic there is a ton of noise in my headset and in the broadcast. It’s not high pitched just a mid-range noise.

I ruled out the alternator by taking the belt off – noise was still there.

 

So why noise only when I transmit? Any thoughts?

 

Joe Hull

Cozy Mk-IV #991 (Done Building! In Phase1 Flight Test - 0 hrs flown)

Redmond (Seattle), Washington