SonexBuilders.net

I have a Micro-Air 760 and the 403 intercom and also have the problem of noise on the intercom when talking to a passenger. Noise is acceptable while making transmissions.
Things I have tried so far:
Four different types of headsets
Sound damping in the cockpit to try to minimize noise
Exhaust mufflers to try to minimize noise

If anyone has any ideas I'd love to hear them.

Peter

Hi Pete.
Have you tried adjusting the side tone and mic gain for ambient noise? Page 11 in the manual describes where and how to adjust. http://www.microair.com.au/images/pdf/M ... lverN1.PDF

I had an older model Microair 760 in my Sonerai and had to tweak those. It was a little different to your setup. I didn't use a separate intercom, just switches to cut in the radio hot mic for intercom.
Cheers Steve

Still trying to figure just what is going on with the noise. So, try unpluging each headset mic cable in sequence, and listen to see if either one changes the noise. If so, then it is being injected by that specific mic, cable or connector. this info may well be an indicator of above mentioned mic gain being excessive also. I usually place the mic right against my lips to pervent the need of high mic gain.

Have you tried a Micmuff Peter.
www.aircraftspruce.ca/catalog/avpages/m ... cfer=19356
Worked ok in the Corby Starlet which is a lot noisier than the Sonex. As a trial before I bought one I simply cut the thumb off an old gardening glove and put a couple of holes in it.

Thanks for the ideas. Can't fly until I finish (and start) my 100 hourly but I'll give them a try. One of the other things I tried on an older headset was a mic that was specifically intended for a noisy environment. I think it helped a bit. For the past few years I have been using a Bose A20 set and I was under the impression that they use a couple of mics into a difference amplifier, but I think when one person talks on the intercom it opens both headset mics so maybe I need to try a different muff on the spare headset.

Peter