Pulling the knob out is the override for the squelch. That's not your
problem. By pulling the volume knob out, you are simply disabling the
squelch so that you hear whatever is being received. That would be a lot of
static with no real signal for the receiver to latch on to.

Turning that knob adjusts the volume of the received signal regardless of
whether the knob is in or out.

A typical scenario is to listen to ATIS, contact ground, contact tower, etc.
Listening to ATIS allowed you to make sure that your volume was up high
enough to hear responses from the tower. But, if you were at an airport that
did not have an ATIS, you might pull the knob out to make sure that the
volume is up high enough to hear any responses on CTAF as you leave the
area. Adjust the volume so that the static is at a tolerable level, then
push it in.

Or, if you are trying to pick up a weak signal (far away ATIS or ATC), you
can pull the knob out so that you hear whatever is transmitted as best you
can. Of course, there will be a lot of noise as well. If the received signal
is strong enough to quiet the noise, then it is probably strong enough to
break squelch too.

With the knob in for normal operation, the squelch is only broken when the
received signal exceeds the set squelch. If you are in a noisy area or your
installation is noisy, the squelch level needs to be adjusted. nrp posted
the correct information. The limit is set by a "hidden" adjustment.

For a demonstration of this, the ICOM and Vertex handheld radios have
similar capabilities. I'm sure others do too. I just know that those do.
There is a button on the side that can temporarily disable the squelch. To
change the squelch threshold, you have to go into the settings mode.

Ideally, you would adjust the squelch level down so that the normal noise
level breaks the squelch. Then take the squelch level up a number or two.
You want a quiet radio except when there is a transmission that is strong
enough to break squelch and be heard clearly.

If a transmission breaks the squelch but is too weak to be heard clearly,
then the squelch is probably too low. That goes for the handhled and for the
panel mounted. That sounds like what you are describing. Although, just
increasing the squelch level will also supress weak transmissions that you
might want to hear. Trying to make the installed environment as quiet as
possible is a good goal.

Time to get out a hex wrench and a jeweler's screwdriver...

-------------------------------
Travis
Lake N3094P
PWK


"Kensandyeggo" wrote in message
oups.com...
Thanks for the great replies. The ICOM radio's squelch is a part of
the volume control. You pull it out and hear the squelch and turning
the knob just adjusts the volume of it. If you push it in the squelch
noise stops. Doen't seem to me that the squelch is really controllable
except to change the volume of it, which also changes the radio volume.

I never knew about a squelch and gain controls on the back of the
radio. I don't have the manual with me. I'm now at a remote airstrip
where there is hardly any radio traffic, so I'll have to get someone to
transmit while I try it out.

I called Aircraft Spruces radio shop and got a little feedback from a
tech. He said to first check out my spark plug connections. He said
loosen them one by one and then retighten them. He said that's a
common cause of noise. And now that I think of it, I had the CHT wire
break and to fix it, one spark plug had to be removed, so I better
start with that one. I guess I could actually disconnect that one
plug and run the engine to see if the noise disappears. If that
doesn't work, he recommends a new ignition harness, which isn't too
painfully expensive. Thanks again for the help, especially forgetting
about using an external capacitor. Is that what those mag filters
basically are?