Light Aircraft Association

I have recently fitted an ICOM IC-A220 radio (8.33kHz capable) and have been having some troubles with the squelch control. When auto squelch is selected I regularly get continuous background noise for minutes at a time with periodic relief when somebody actually transmits. Sometimes the radio auto squelch seams to work okay, other times its quite intoleratble and there is no obvious pattern to its annoying behavior.
Selecting manual squelch appears to do nothing despite adjusting the manual level from -10 to +10. You just get continual back ground noise. Cycling the radio (off and on) makes no difference either.
The radio tray and wiring have not been changed, a perfectly working ICOM IC-A200 was removed from the control panel and the IC-A220 slipped into the existing tray.

I have heard the squelch on the ICOM IC-A220 has got some problems and people have been returning them. What are other peoples experiences? Have ICOM got a fix and is anybody in a position to report if the fix was successful. Regards Gary Smith.

It isn't the intercom squelch is it ? I had the same thing on my Trig radio until the penny dropped that in my noisy aeroplane the intercom was effectively on all the time - soon as I got that adjusted ( which is separate from the radio squelch ) everything quietened down to what I was expecting.

Richard, I think you are confusing VOX and squelch. VOX or Voice Operated Switch, opens the mic when you speak loud enough and should be off when hearing just engine noise. It is part of the intercom. Squelch sets the threshold at which white noise in the airwaves is passed through.

Gary, that does sound like a unit fault to me.

Thanks Ian - I always thought of it as intercom squelch rather than gain / sensitivity. Good stuff this learning.

Hello Gary,
Did you ever resolve this issue?
I installed an ICOM IC-A220 before Christmas and have similar behaviour but I can stop the noise by selecting full +10 manual squelch. It seems to be caused by something in the hangar but as the ground is so wet I have not dared take the aircraft out to the middle of the strip to test. There is also a USB power supply mounted close by on the panel that I am suspicious of generating electrical noise.
Thanks for any help, Alan.

USB power supplies are notorious for generating noise, it would be easy to prove by disconnectig its input. I would do that first.