GTN 650xi never breaks squelch

[FORANE]

Have a GTN 650xi
Main software version: 20.23
GPS/WAAS software version: 8.2
Comm software version: 2.02
Nav software version: 2.04

It never breaks squelch, ever. It receives well generally, but routinely with distant ATC frequencies it doesn't receive ATC transmissions unless I open the squelch. Simple fix I thought, just dial down the squelch settings in the setup menu. Tried that, dialed down all squelch levels to zero. It improved the issue, but still misses ATC transmissions unless I open the squelch and listen to constant static. When I do open the squelch those distant ATC transmissions are received very clearly.

Any ideas how to resolve this issue?

 

[Walt]

Have a GTN 650xi
Main software version: 20.23
GPS/WAAS software version: 8.2
Comm software version: 2.02
Nav software version: 2.04

It never breaks squelch, ever. It receives well generally, but routinely with distant ATC frequencies it doesn't receive ATC transmissions unless I open the squelch. Simple fix I thought, just dial down the squelch settings in the setup menu. Tried that, dialed down all squelch levels to zero. It improved the issue, but still misses ATC transmissions unless I open the squelch and listen to constant static. When I do open the squelch those distant ATC transmissions are received very clearly.

Any ideas how to resolve this issue?

Lay some mesh in the belly for a ground plane and mount the antenna externally.

 

[FORANE]

Lay some mesh in the belly for a ground plane and mount the antenna externally.

It has an external belly mounted Comant CI-122 comm antenna. Possible the ground plane is inadequate; it has 48 inch diameter wire in horizontal X shape as the ground plane.

 

[BlackhawkSP]

Have a GTN 650xi
Main software version: 20.23
GPS/WAAS software version: 8.2
Comm software version: 2.02
Nav software version: 2.04

It never breaks squelch, ever. It receives well generally, but routinely with distant ATC frequencies it doesn't receive ATC transmissions unless I open the squelch. Simple fix I thought, just dial down the squelch settings in the setup menu. Tried that, dialed down all squelch levels to zero. It improved the issue, but still misses ATC transmissions unless I open the squelch and listen to constant static. When I do open the squelch those distant ATC transmissions are received very clearly.

Any ideas how to resolve this issue?

I've had this same issue !! When the station I'm talking to is remote, I use my backup comm for receiving and transmitting to them. I also reduced the squelch level to minimum, an it didn't fix the issue..........

 

[Carl Froehlich]

Don’t do anything before you ring out the antenna and feed line with a real antenna analyzer. If you don’t have one, find someone that does and who knows how to use it.

Considering your post, after you verify the antenna system is not right (from the antenna analyzer) I’d first look toward poor coax BNC connections. Your (4) 24” ground plane radials should be more than adequate if they are properly connected to the antenna mount. Do not overlook the GNC-650 tray antenna connection. It is amazingly easy to inadvertently ground the coax center lead to ground if your are not careful with your soldering iron.

Carl

 

[Avanza]

AC 43-13-2B pg 26

If Com 2 is mounted under the aircraft, a
bent whip may be required to provide ground
clearance. Bent whips may not provide the best
performance because of proximity to the aircraft
skin. Signal reflection and obstruction is more of a
problem with such locations. Extension of the
landing gear or flaps may also impact belly mounted
antenna performance.

d. Composite or fabric covered aircraft that do
not provide a conductive mounting surface generally
require fabrication of a conductive surface (ground
plane) and bonding through the mounting screws.

e. Antenna performance can be severely
degraded from corrosion caused by moisture
accumulation where the antenna electrically bonds
to its ground plane. It is advisable to apply RTV
around the antenna edges to seal the antenna bond;
however, always ensure chemical compatibility
before using any sealant.

You could straighten the antenna slightly to get better performance.

Good luck

 

[Walt]

Better performance if you have the clearance.
(note: fwd ads-b antenna is no longer there)

 

[FORANE]

Thanks for the replies.

I have a SWR meter and can check that. It is strange though that the radio receives 5x5 once squelch is manually opened. Also, I have never received a complaint or any indications of my transmissions being less than good.

I have found another thread with the same issue on a GTR200B.
GTR200B not breaking squelch
https://vansairforce.net/community/showthread.php?t=195647
Multiple people reporting same issue...
This was resolved with a software update.

Are these the latest versions? (I am unable to locate this on the G site)
GTN 650xi
Main software version: 20.23
GPS/WAAS software version: 8.2
Comm software version: 2.02
Nav software version: 2.04

 

[g3xpert]

GTN Xi Software Version

Thanks for the replies.

I have a SWR meter and can check that. It is strange though that the radio receives 5x5 once squelch is manually opened. Also, I have never received a complaint or any indications of my transmissions being less than good.

I have found another thread with the same issue on a GTR200B.
GTR200B not breaking squelch
https://vansairforce.net/community/showthread.php?t=195647
Multiple people reporting same issue...
This was resolved with a software update.

Are these the latest versions? (I am unable to locate this on the G site)
GTN 650xi
Main software version: 20.23
GPS/WAAS software version: 8.2
Comm software version: 2.02
Nav software version: 2.04

GTN Xi Navigator software 20.31 is the most recent revision. You will find that software available for download here.

Was this installation working normally until recently or has this problem been present since initial installation?

Thanks,

Justin

 

[FORANE]

GTN Xi Navigator software 20.31 is the most recent revision. You will find that software available for download here.

Was this installation working normally until recently or has this problem been present since initial installation?

Thanks,

Justin

Problem has been present since installation.
Thanks for the link above.

And for Walt, which antenna is that?