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

[luv2flypilot]

I noticed that I was having a hard time hearing some of transmissions of other aircraft while practicing touch and go's this weekend and believe it is a com squelch setting issue.  Squelch in the system com setup was set at 70 so I dropped it down to 50.  I have not had a chance to retest.  I assume I needed to set lower value and not higher value?  Also, what is the default com squelch value?  This system was already installed in the recent airplane I purchased and do not see the default value listed in the Skyview pilot guide or install manual.

 

[dynonsupport]

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 noticed that I was having a hard time hearing some of transmissions of other aircraft while practicing touch and go's this weekend and believe it is a com squelch setting issue.  Squelch in the system com setup was set at 70 so I dropped it down to 50.  I have not had a chance to retest.  I assume I needed to set lower value and not higher value?  Also, what is the default com squelch value?  This system was already installed in the recent airplane I purchased and do not see the default value listed in the Skyview pilot guide or install manual.

 

[jakej]

FWIW - I set the squelch levels during a climb (high power = the loudest it's going to get) & start at a very low setting so squelch is really open.  Then increase until ambient noise doesn't 'break' squelch anymore.  Speaking into the mic should then break squelch, works for me 

 

[stede52]

I'm having squelch issues with my new 425 which was also happening in the previous 425. In order to eliminate the noise I'm having to adjust my squelch between 70 and 90% during a single flight. At times I had the squelch down to 60 and then after 15-20 minute I would start hearing the noise again and would need to increase the squelch to 70 then 80 and then 90%. I was also able to reduce reduce the squelch back down to 60 for a while before the noise started coming back. When I initially installed the radio a year ago I had not problems and the squelch was set around 50 and then after about 8 months I noticed I was increasing the squelch more and more until last week I hit a high of 90% during parts of the flight in order to eliminate the noise. Any suggestions as to what to look for to solve this issue? Would a ground issue cause this kind of problem?

 

[jakej]

Steve,
Pm sent.

 

[cmgolden]

Steve,
Do you have electronic ignition, by chance? What kind of noise are you having? Loose spark-plug wires?

 

[mmarien]

It can also be cause by high alternator output. I sometimes get noise on the radio after a start when the alternator is outputting 30+ amps. The noise goes away once the amps come down to normal.

 

[stede52]

It can also be cause by high alternator output. I sometimes get noise on the radio after a start when the alternator is outputting 30+ amps. The noise goes away once the amps come down to normal.

If my alternator is not sending out high output during a period of time in which I was getting increased noise levels and squelch as high as 90% and then in that same flight I was able to reduce it to around 65% and then have it go back up again I'm not sure that would be an alternator problem. I did reduce rpms in flight and it made no difference.

 

[stede52]

Do you have electronic ignition, by chance? What kind of noise are you having? Loose spark-plug wires?

Chris, yes I do and I did check for loose wires, I'm going to be looking at the leads from electronic ignition and see if there are some problems there. I'm using Lightspeed Zulu PFX with LEMO plugs.

 

[n456ts]

It can also be cause by high alternator output. I sometimes get noise on the radio after a start when the alternator is outputting 30+ amps. The noise goes away once the amps come down to normal.

Have you checked your alternator for excessive A/C voltage output?

 

[mmarien]

Have you checked your alternator for excessive A/C voltage output?

Getting of topic, but out of curiosity I went back through the last couple of years of screen shots. The voltage is a fairly stable at about 14.4 volts. There were a few at 13.9 volts. The common thing among the 13.9 volt readings is the air time. It's 2+ hours. I checked a flight with Savvy Analysis and the voltage had a continuous drop from a start to end of a long flight. The AMPS doesn't vary much from 17 AMPS. Except after a start it reads higher for a few minutes.

Apparently there is a lot of activity this side of the AMPS shunt that doesn't show up on the AMPS gauge. These shots were taken consecutively. The AMPS is steady at 17A but the flow is in and out of the battery depending on the draw of the equipment.

Any thoughts on why the voltage steadily drops?

 

[n144sh]

I love the Dynon COM radio functionality and it works well. One thing I would like to see is the capability to adjust the squelch without going into the setup menu.

 

[n456ts]

No, I'm talking about A/C voltage, not DC voltage. I'm hinting that you should check the health of the rectifier. You must check it directly at the alternator with a DVOM and under the highest load you can give it.

 

[mmarien]

No, I'm talking about A/C voltage, not DC voltage.  I'm hinting that you should check the health of the rectifier.  You must check it directly at the alternator with a DVOM and under the highest load you can give it.

Thanks for the tip. Found an article about it.

http://www.avweb.com/news/maint/182896-1.html

 

[n456ts]

http://www.avweb.com/news/maint/182896-1.html

I would suggest not following the way they suggest checking. What they suggest is pretty crazy and will mislead many.

 

[mmarien]

Perhaps, but the article pointed out a couple the causes of the noise. One was the diodes in the rectifier as you suggest. The other was just poor electrical connections. I found a couple loose connections between the alternator and battery when I was troubleshooting a starter problem a while ago. I can't remember any noise since then so I may have inadvertently solved the problem.

The starter on the other hand went back to Sky-Tec. Not that I minded the intermittent no start as I got the cute FBO girl to hold the brakes while I hand propped. It didn't lead to any long term relationships so I sent the starter in for repairs.

 

[stede52]

Hey guys, I just realized and confirmed it that my PTT wire was not a shielded wire. Aircraft Spruce built the wire bundles and they put in two single unshielded wires for the PTT connection and when I installed it it didn't register that it should have been shielded. The static happens with or without the engine running, I pulled breakers to see if I could isolate the issue and the only time the static went away was when I pulled the com or intercom breaker. I'm hoping its the PTT wire that needs replacing, I'll keep you posted.

 

[dynonsupport]

Steve,
The PTT wire does not need to be shielded. This is highly unlikely to be the issue.

 

[stede52]

Dynon Support, you are correct It didn't change anything :-[

 

[stede52]

I FOUND MY STATIC PROBLEM!!!! About 4-5 mos ago (which is why I didn't have the problem 6 mos previous to that :) I installed an extended battery for my GoPro, I also installed a charge line so I could charge that battery with aircraft power. This wire had a female 5V USB socket on the end. I ran the wire up the windshield post and along wing root to the back seat which was precisely where my antenna cable was routed in another sleeve. I disconnect the charging line from the buss and my radio went silent, no more static. I had everything wired right before I decided to put in that charging cord and battery for the GoPro :-[
I'm a happy camper again ;D ;D