SV-COM-25 Squelch Adjustment

[madb1rd]

I am still greatly dissatisfied with the squelch control of the SV-COM-25. I have to keep it at 67 to prevent unsolicited squelch breaks but this setting causes it to cut out many, often critical transmissions. I can't hear other airplanes on the ground at my airport less than 5000 feet away, w/direct line of sight. The two mods were done, which helped a little and everything I've done to measure and verify correct antenna operation shows it is working. And the problem varies. If I set it at 60 it works much better and may not break for a while, but then starts, or behaves differently on differing frequencies.

It appears to transmit much further than it can receive which also indicates the antenna is fine.

The inability to adjust squelch without going into layers of setup is negligent in design and is adding to the frustration with this problem.

Every other aspect of the Skyview works flawlessly. And I know others are having similar issues.

 

[rlallen1]

Ditto. I have had to increase my squelch rather high too. Really not sure why this is, but should be an area for Dynon to improve the product on.

 

[airguy]

I have not had to adjust my squelch from the original factory setting in my plane, but I have seen one interesting thing that might shed a little light on the issue. I have noticed that the Dynon Comm will occasionally have a spotty squelch break like you are describing only at higher frequencies in my airplane. I have a local center frequency at 133.70, and I've noticed that sometimes, definitely not all the time but occasionally, I will have the Dynon comm break squelch constantly on/off like you describe on 133.70 and similar frequencies in the high end. If I switch the frequency to my comm 2 (Garmin 430W) it does not break the squelch. Pulling the squelch full open to listen to the background does not indicate any actual transmissions to cause it to break squelch. Turning the Dynon comm frequency down when this happens does stop it, usually around 132.0 it is gone completely.

In my case it's apparent that I've got some type of interference at the high frequency end, which makes me suspect the antenna and/or the coax, since it only affects one radio. Your theory is that it might be the radio also, which I honestly hadn't considered yet but it is certainly possible.

 

[madb1rd]

Per airguy's post: yes I would say that the issue with squelch breaking is worse higher up the band but the real issue is not giving me the transmissions that are clearly being made and can be easily heard when manually toggling RX on. I don't know what the radio uses to discriminate between white noise and actual transmissions but other radios seem to do a better job.

 

[turbopilot]

Just finished an episode of squelch breaking which I ultimately traced to a USB power supply I use to power IOS devices in the cockpit.

 

[jakej]

They are a common cause of audio issues - best when troubleshooting is to disconnect everything at the beginning or one at a time to find the culprit

 

[madb1rd]

I couldn't agree more, USB filtering is piss poor. I run small USB batteries to charge/run the IOs, completely isolated from the AC electrical system. I do have the ability to charge the second battery while the other is in use and it does not seem to change the squelch equation any.

I may try turning everything off except the Skyview and radio to see if that changes anything. I think I've tried this but... memory does not serve me all that well.

 

[jakej]

I'd disconnect those too, although they are isolated it doesn't prevent them from generating "noise", if any, being injected into the audio.