Garmin GNC 355 comm issue

[FlyBoyAndy]

A few months ago we had a GNC 355 installed and the system works great except that we have had intermittent comm problems. I can’t find anything specific with that model having comm issues, but someone mentioned to us that they have heard or read about there being some.

I was flying today using the comm and said to my partner we should have gotten handed off and he said I haven’t heard anything for a while. I called approach on that system, and he came back with I was trying to contact you. Not sure how we kick started it with that transmission but it started working.

We then experienced it again on the ride back.

Does anyone have a 355 or 375 and experienced intermittent comm issues? Is it a Garmin thing. I just have to think it’s a connection issue.

 

[FlyBoyAndy]

Sorry spell check got me Garmin not Harming.

 

[Ryan Klems]

Sounds like once you are far enough from the station, the transmissions aren't opening the squelch circuit. So perhaps the squelch is set improperly on the unit. This could potentially be an antenna issue as well, or perhaps a connection, but the squelch is easiest to check. Power up the unit in to configuration mode (hold down the inner knob while powering the unit on), Then tap where it says Setup, then COM, take a picture of that page and post it.

 

[FlyBoyAndy]

Will do.

 

[FlyBoyAndy]

Sounds like once you are far enough from the station, the transmissions aren't opening the squelch circuit. So perhaps the squelch is set improperly on the unit. This could potentially be an antenna issue as well, or perhaps a connection, but the squelch is easiest to check. Power up the unit in to configuration mode (hold down the inner knob while powering the unit on), Then tap where it says Setup, then COM, take a picture of that page and post it.

Here's what it looks like...

 

[Edward Dearborn]

Here are my 355 settings confirmed by the Garmin dealer as default post installation.

Search PoA for Garmin 355 setting issue. I think I started a thread 12 months ago. Another PoA first identified the issue and I was able to recreate. Long story short, default settings get dropped and the reversion values result in poor communication. May not be related to your issue but worth researching here.

 

[Ryan Klems]

I definitely think your squelch is way too high. A good setting on the GTNs is around 15% on RX squelch and 0% on carrier squelch. I’d give that a try. If you find it’s breaking improperly you could move them up higher, but I think that’d definitely be limiting longer range reception.