IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM - Squelch not working on one frequency

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Squelch not working on one frequency

Printed From: Avidyne
Category: Avidyne General
Forum Name: IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM
Forum Description: Topics on Avidyne's IFD 5 Series and IFD 4 Series Touch Screen GPS/NAV/COM
URL: http://forums.avidyne.com/forum_posts.asp?TID=2274
Printed Date: 25 Jun 2025 at 3:21am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com

Topic: Squelch not working on one frequency

Posted By: SteveMcD
Subject: Squelch not working on one frequency
Date Posted: 24 Oct 2021 at 12:21pm

Here's a weird one. Yesterday I flew nine hours from Florida to Ontario, IFR, so many frequencies. Squelch worked as expected until I switched to 119.400, then it seemed like a stuck mic on frequency, but no one else commented. I checked on COM2, no problem, back to COM1/540, problem still there. It would occasionally stop, but was static 95% of the time. I switched to COM2 while on that frequency, then played around with the 540. My (not exhaustive) testing showed that the static issue occurred only on 119.400. When I left the area, I resumed using COM1, which was normal again. Shortly after, I landed for fuel, so the 540 got power-cycled. Maybe that would help.

All was good until, near home, I wanted to monitor a nearby airport frequency which was on 119.400. Sure enough, the static issue reappeared. (I have used that nearby airport's frequency many times without issue, so it seems to be a new behaviour.)

My troubleshooting eliminated:

SQ was off: I checked it multiple times and verified in Aux Audio settings. Turning it on/off made no difference.
SQ failed totally: only 119.400 was affected.
A problem in the incoming transmission: COM2 was not affected, issue recurred at the later station on that frequency.

119.400 worked locally before, so that's one change. Anything I missed?

Replies:

Posted By: Jmack
Date Posted: 24 Jun 2025 at 4:46pm

I was sorry you didn't get any responses to your post. I have the same problem and hope someone will respond with their thoughts.

We use 122.875 for local air to ground communications and I have never had any problems with that frequency until last week. Both my IFD540 and IFD440 have continuous noise on that frequency as if the squelch has been turned off. None of the other planes on the frequency with me are experiencing the noise. I turned the custom squelch on in the maintenance screen and turning the squelch all the way to 80% did not quiet the noise. The problem exists only on that one frequency, and is there with engine running or shut down, and other electrical equipment on or off.

Jmack

-------------
John
A36

Posted By: SteveMcD
Date Posted: 24 Jun 2025 at 6:14pm

Sorry you've had the issue. It did go away on its own, one day I flew near that tower on 119.400 and all was well.

I redid my panel and sold the 540. Long story, it's all Garmin now. It's shiny and modern with a great autopilot, but the 540 had a bunch of nice features that Garmin is missing. The FMS format is much better than the menu format. Enjoy your 540!

Steve