Continuous Squelch Noise With SV-1000 Display On

[Dynon101]

I am getting a continuous squelch type noise when I have the dynon screens receiving ships power.

The Avionics system is two Skyview sv1000 displays, a dynon radio, a Garmin gtn - 650, and an sl15 audio panel.


The squelch noise is continuous regardless if the engine is running or not so I have eliminated any noise from the alternator system. And I have also disconnected any battery chargers so that the system is running only on airplane battery.

When I first fired up the system it sounded like the squelch was activated on a radio meaning the continuous White Noise sound was in the headsets and/ or the overhead speaker however when somebody would talk on the radio the white noise would go away and the transmission would come out completely clear.

I turned off the Dynon radio and I also turned off the Garmin and the sound continued so those sources of either noise and or squelch were eliminated.

I began pulling all of the circuit breakers out one at a time and the sound continued until I pulled out the circuit breaker that powers one of the  Dynon screens. The squelch noise stopped even though the backup battery was powering the display. Push the circuit breaker in and the noise started again...

So I can confirm that the only source of noise in the headsets is when the circuit breaker for the left screen is pushed in.

Has anybody experienced this problem?

Does anybody have any recommendations for troubleshooting in addition to what I have done thus far?
Thanks for any feedback, experience, and or suggestions!

 

[mmarien]

Re: Continuous Squelch Noise With SV-MAG Displays On

Sounds like a grounding loop. The ground for the SV display may be going through the audio system. Check the grounding for the screen that is causing the noise. It could be a loose connection or bad crimp. Quick way would be to pull the connector from the back of the screen and check that the ground pins (c37p21-22) are both connect to ground.

 

[Raymo]

Turn off your shop lights and test again. Ask me how I know

 

[Dynon101]

>Turn off your shop lights and test again. Ask me how I know

I know as well...Ask me how I know...

Yes all of the shop lights were turned off...AFTER...I discovered the first humming sound in the radios.

I have concluded that it is indeed the left side Dynon screen.

I also determined that the sound is dependent on the intensity of the illumination of the screen. Lower light is less noise and light light is more noise.

I will check my ground...ALL instrument panel grounds are connected to a single copper ground bus bar and then a 12 AWG cable goes to the battery negative cable (it is a composite airplane). I will check the crimps and the connections

 

[Dynon101]

Called a Dynon tech support.


He was stumped as well for a while and then after we did some troubleshooting he remembered a possible fix and then he was able to walk me through an internal squelch setting that is in one of the setup pages. I think it has solved the problem but I will wait on that definitive answer until I go and fly again but I think we got it!