What is default squelch setting of SV-COM-C25?

[jakej]

So glad you found the problem &, as discussed offline, the issue can be caused by other power supplies like USB's.  That's why it's important to turn everything off then turn on one item at a time to determine the cause of the interference 

 

[stede52]

So glad you found the problem &, as discussed offline, the issue can be caused by other power supplies like USB's.  That's why it's important to turn everything off then turn on one item at a time to determine the cause of the interference 

Jake, you were definitely a great help, thanks again for spending the time on the phone with me.

 

[stede52]

Me again, I've got another problem which I thought had gone away after fixing the static issue........NOT!, nothing is ever that easy! During the static issue I also had an faint but detectable buzzing sound which only happened when I pressed the PTT and talked. I checked both ends of the antenna for shorts and they were good, however, I noticed the center pin in one of the BNC connectors looked like it was not pushed thru far enough so I pushed the pin thru the BNC a little more and now when I pressed the PTT I get a loud high pitched buzzing every time I press the PTT, much louder and I don't need to talk to trigger it like before. I'm going to build a new antenna cable and see it it makes any difference. Any other ideas?

 

[jakej]

Hi Steve
I'd fix the antenna connections first, hopefully the Dynon transmitter has not been damaged.  Generally if you transmit without an antenna connected ( centre pin 'retracted' in your case) or a dummy load fitted there can be damage, the RF energy has to go somewhere & basically that energy would be reflected back.  Yours may be okay but fixing the antenna first is the priority. 
Refer to page 16-18 of the SV install manual rev Y, it talks about this.

 

[stede52]

Jake, I understand that can be a real problem, I just didn't know the pin wasn't protruding enough and I'm really not too sure about that either but it seemed the case because it did increase the buzzing when it was pushed in further. I'm hoping it didn't cause any damage. I'll let you know on the new BNC.

 

[stede52]

Once again I got some good news, it was not the antenna cable, I built a new cable and it did the same thing so I took a trip to Dynon,(I'm soooooo glad I live close). We determined it was some kind a ground issue in the box itself because when it was installed on the tray in the plane and I pulled on/torque the box itself the buzzing went away. Dynon gave me a test unit COM to try out and when I installed it the buzzing went away.

 

[mmarien]

Another source of static. I have two cigarette lighter plugs in my panel that I insert USB chargers. One I use for my iPad. Foreflight kills the iPad battery in about half a day so I keep it plugged in for most flights. The other I occasionally plug in my phone if I'm using it as a hotspot for my iPad or streaming music. I plugged both in yesterday and got some really bad static on my radio. In retrospect I had some bad static before on long flights that I couldn't figure out.

Turns out it's one of the the USB chargers. And it happened to be an expensive Duracell USB 2A cigarette lighter charger. The other no name USB charger didn't create any static in either cigarette lighter plugs or charging the phone or iPad. Worth checking if you're getting static on your radio.

 

[madb1rd]

Mark & Quote Quote
I think the default Squelch for the SV-COM-C25/X83 is 50%.

Increasing Squelch (in all radios) means that more "energy" (stronger transmitted, or received radio signal) is required before the squelch "opens" and you can hear the audio.

DEcreasing squelch means that less energy, a weaker signal (including noise) is required before the squelch "opens" and you can hear the audio.

Setting squelch is unique to each aircraft / radio unit / operator preference. You don't want to not miss any (significant) transmissions; to catch EVERY transmission, no matter how weak, set Squelch at 0... but then you're listening to noise whenever someone isn't transmitting a strong signal.

But you also don't want the squelch opening (annoying you) on noise and weak transmissions not intended for you. If you set Squelch to 100%, only the very strongest signal (like the tower transmissions while you're sitting on the airfield).

So... tweak between 0 and 100 until you have an acceptable compromise.


I continue to not be impressed with the SV-COM-25 because its squelch control does not seem to be able to discriminate well. When I set it to where it does not regularly break squelch on non-transmission noise it generally will not receive tower transmissions much over 20 miles. My GNS430 easily gets 50-70 mile ranges with the same antenna. I've had both updates done a few months ago and this helped increase range some but it is still not satisfactory in comparison to other aviation units.

And it does receive the transmissions when I override the auto-squelch so I'm reasonably sure reception is OK. I need to retest how far it will actually read with squelch set to 0. I'm fairly sure it's range is still quite a bit less than the 430 or the King 97A I have.

And this is true tested with different antennas, coaxes, and antenna locations. SWR was also checked and is good (1.4) so I'm not sure what to try next.

 

[mrdaud]

I too have issues with my SV-COM. Similar to madb1rd, with the squelch set high enough to kill the noise (about 60 - 70%), I miss calls from ATC when using flight following, sometimes shorter distance tower calls. Cable and SWR checks are good. I really like the SV-COM features, but have had to revert to my 430 comm as primary. No issues with the 430 comm.

 

[Dynon]

Can you guys shoot our support team a note directly at support at dynonavionics dot com? This definitely isn't the behavior we expect.

 

[sglynn55]

Back to the squelch setting number for the Dynon Radio. I just started flying mine with HDX and a Garmin 430 and I'm experiencing similar issue. I'll hear radio calls fine on the 430 but the Dynon Comm won't pick it up unless I press the knob and turn squelch on. I reduced the default squelch from 70 to 60 and it improved a bit. I guess I'll go to 40 and test.

What squelch setting are others using successfully?

Will the Dynon Radio receive as well as a Garmin 430?

 

[Raymo]

The default squelch level is 50. I had to bump mine up to 70 after installing LED landing lights in the wings, which do not use shielded wire and have no return ground. Everything still works well but the radio no longer breaks squelch when I turn on the landing lights.

Set it as low as you can and not have the RX break squelch with any electrical load.

 

[sglynn55]

I've been testing the last couple days/flights and lowered mine to 50 and now it seems to be sensitive enough with no anomalous behavior. I like it. Mine came set at 70 from Dynon.