COMM CONFUSED?

I have had 4 years of flawless operation on my Garmin GPS/COMM 250XL.

Last week I noticed that while approaching my destination I could not clearly hear the tower due to static interference. The tower had the same problem hearing my transmissions. When I landed the tower said I can hear you fine on the ground. And vice versa.

This week I tested it on the ground with my wife using the handheld. Clear.
I then started the engine and tested it on the ground at different RPMs. Clear.
I then took off and tuned in the ATIS nearby and could barely hear due to static. I then flew back to my home airport and called my wife on her handheld while in flight, static again.

Landed and the comm was clear again. I'm now thinking it may have something to do with the Comm antennae.

What do the experts think? Any helpful suggestions would be appreciated.

It might be....

your MIC boom. I had this issue with my Quite Technologies headset. Everyone heard static from me in flight but on the ground it was ok. The MIC must be facing your mouth. At least on the Halo's you can't tell which way it faces unless you pull off the foam protector. Sure enough when I pulled the foam off of it the holes were facing out pulling in all the noise from the cabin. Turned it around and Whola, no noise anymore. Hope it is that easy for you.

Build9A
I am far from an expert but have had a somewhat similar experience. I?ve been beating myself up over this for a week and just discovered the problem this afternoon. My com is an ic-a200, I was getting static or fuzz that would overpower transmissions if above 1500 rpm, quite as a church mouse if under. It didn?t seem to matter if I was on the ground or flying, however. With a few radio checks I discovered, unlike your situation, I was not transmitting it and others could not hear it.

I had just finished my annual, removing/replacing inspection covers, crawling into every nook and cranny etc .etc. and was concerned I had disturbed a connection somewhere. Also, I had a slick mag subject a service bulletin and had to pull it from the engine and replace some parts, re install, time etc etc. I had a lot of possibilities which it could be and was stumped.

Long story short I found it to be the squelch on the intercom had evidently been moved during all my bumping around during inspection. I tore that plane apart looking for something complex and it was as simple and stupid as the squelch on the intercom.

Point is, don?t overlook the simple things. Check things one at a time.
1) Kill your alt field (if you have a switch) to eliminate the alternator
2) Mags one at time to isolate if one of them could be the problem
3) Move your headset around to different ports
4) Try a different headset/mic combo
5) Play with the squelch on both radio and intercom

Keep it close to the airport for safety reasons but if you are still flying and having the same problem with nothing but the engine running and the radio on, it must be coming from one or the other.

My .02
Doug
Rv-9a
N625DK
103 HRS

QT

This sounds promising. I, too, have the Quiet Tech headset. I'll check it out tomorrow. thanks, Jack

And to Doug: thanks for the suggestions, I'll go through them and hopefully between your suggestion and the QT one, I'll fix it.

rglick said:

your MIC boom. I had this issue with my Quite Technologies headset. Everyone heard static from me in flight but on the ground it was ok. The MIC must be facing your mouth. At least on the Halo's you can't tell which way it faces unless you pull off the foam protector. Sure enough when I pulled the foam off of it the holes were facing out pulling in all the noise from the cabin. Turned it around and Whola, no noise anymore. Hope it is that easy for you.

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