Janekom

Janekom

Well Known Member
Patron
Hope someone can help. New RV10, Two SV1000, G340 audio panel, GNC255A and GTR225.

Everything is working fine, but I have a soft crackling sound on the headsets as well as the speaker. This is on the ground with no engine. So when you fly you cannot really hear it. But I have now connected the music input of the audio panel and found that this crackling is just loud enough to mute the music for short intervals. I do not know what will happen in flight but wouldreally like the musice to work for all the boring test hours.

In order to try and isolate it I have done various tests and found that if I leave the radios on, but switch off the SV's and then on again, the noise starts the moment the screens are finished booting up and ready to use. Grounding of the avoinics and the SV screens are seperate on two terminals on the bulkhead behind the panel and are about 12" apart.

Did anyone else have this or can advise what to look for?
Much appreciated.
 
There is a lot of discussion on noise on the Dynon Forum, check on it. I eliminated most of the noise from my SV install.
 
Jan,
A few questions:

1) If you have a backup battery, does the noise stop when you pull the breaker for the screen but it's still running?

2) Do both SkyViews make the same noise?

3) Metal or composite panel?

4) If you have volume on your audio panel for the SkyView inputs, turn it all the way down and SkyView's volume all the way up

5) Grab a jumper cable (yes, from a car). Touch one black lead it to the back of SkyView, and the other end of the black lead to the case of your intercom. Does the noise change?
 
Thanks guys - I really appreciate the help.

I have done some more testing and has also slightly adjusted the mute level pot on the Garmin Audio panel. This controls the level at which the music will mute. Right now on the ground it does not mute the music and I will fly it first to see what happens.

I have also grounded J2, pin 15 of the audio panel that gives a x10 gain on the music input. So the music now sounds better and I do not have to go max volume on the little mp3 player. The down side of this is that when I now tap or touch the audio cable you can faintly hear that on the headset - the high gain I gues.

Below some answers/observations.

1) If you have a backup battery, does the noise stop when you pull the breaker for the screen but it's still running?
No - stays exactly the same.

2) Do both SkyViews make the same noise?
Yes. Another observation here. While I have left or right on (note only one) the noise is there, but the moment I switch on the second SV the noise stops for the time it takes for the second SV to boot.

3) Metal or composite panel?
Metal panel.


4) If you have volume on your audio panel for the SkyView inputs, turn it all the way down and SkyView's volume all the way up
Right now I have now disconnected the left hand Skyview screen's audio and grounded the audio input to the GNC255A. I have connected the AUX Audio input of the Garmin GNC255A to the left hand Skyview audio in order to get an audio in that will not mute. The RH Skyview screen does not have the audio connected. Yes I see the manual states that both should be connected. All this does not change anything.


5) Grab a jumper cable (yes, from a car). Touch one black lead it to the back of SkyView, and the other end of the black lead to the case of your intercom. Does the noise change?
Did that - grounded the SV case directly to the case of the Garmin 340. No change. Also used same wire to ground the SV case to my panel GND. No change.

Another observation nothing to do with this - when you switch on one SV tha fan/fans on the second one starts running even on a coldish winter morning like right now.

Again in summary - I will fly it now and see what happens. Maybe one cannot hear the noise while flying and the music might stay unmuted.

Lastly I just have to say that this is such a great product and it is such a priviledge to fly behind these airline like panels. :D:D
 
I know the question has nothing to do with our products but I'd like to suggest something:

"Crackling" or "Poping" noises in flight or on the ground with engine running are sometimes caused by static discharges. This happens in dry conditions (low humidity usualy) when air flows over metal surfaces that are not electrically connected to the airframe.
Look for radiators and other items in the engine bay as well - often items that are quite exposed to airflow but might be mounted on rubber vibration dampers etc.

The very best way to detect this is using a cheap hand held AM medium wave radio - the old types that had the very directonal internal ferrite rod antenna. These radios are extremely sensitive to static discharges (they detect lightning also very well) and will crackle when there is any issue.
As they are directional you can locate the source by turning the radio for lowest clackling sound while standing a dozen feet or so away from the aircraft - the source is then located to the side of the radio (the ferrites are mounted along the length of the body as they are fairly long).

Have used this in the past with good success.

Rainier
CEO MGL Avionics
 
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