Noise

[lalnaes]

My 10' SkyView displays create quite a bit of noise in the headsets. The noise is particularly strong on boot-up. I am not talking about popping or clicking noises, but a fairly constant hum. I have a pair of Lightspeed Zulus connected to a PM3000 intercom. I have installed the filters to the D-sub connectors Do you have any suggestions as to this noise can be reduced or eliminated?

 

[Brantel]

Make sure your PM3000's music input is isolated from the panel or it will pickup all sorts of noise.

 

[preid]

lalnaes;
Did it start after the 3.3 upgrade? I have the Zulus and I noticed the noise you mention after the upgrade. I turned the audio alerts off (0%) hum remained. Do not recall the noise with 3.2. Interesting that the filters did not resolve/diminish the issue.

 

[lalnaes]

The noise has been there all along and 3.3 has not made any difference either way.

 

[dynonsupport]

Is the noise there when your radio is off?

 

[mmarien]

Make sure your PM3000's music input is isolated from the panel or it will pickup all sorts of noise.

That's interesting as PS Engineering takes great pains to isolate the headset plugs from everyting with rubber washers but they didn't say anything about the music jack. I had them supply the harness with my PM1200 (no warranty if they don't) with the plugs but I don't remember the music plug having a insulating washer like the headset plugs. So you're saying the music jack should also have a rubber washer to isolate it from the panel or where ever it's mounted? :-?

 

[lalnaes]

Is the noise there when your radio is off?

Yes, the SkyView noise is present in the headsets with the Comms radio turned off.

 

[jc2da]

The first thing I noticed was extra static as well.

I have my SV audio, left and right channels shorted together as per manual, connected to an Aux switchable channel on a GMA-240.

With engine off. With Aux off, no static. With Aux on, i can hear static that is mildly annoying with engine off.

With the engine on or flying, it's not noticeable.

Just another data point.

Jae

 

[dynonsupport]

What volume in SkyView are you using to make the volume right in the headset? Every audio source has some noise, and if your intercom has a lot of gain, it will amplify the noise. The easiest way to tell this is by the volume you run on SkyView. Most of the time we seem to be able to run 50-80%. If you're running below 40%, your intercom has a lot of gain, and you can knock down the noise with a resistor if you want.

If you hook a 50 ohm resistor between the audio output of the SkyView and ground, this will halve the volume of SkyView but will also halve the noise. You can then turn SkyView's volume back up to compensate.

Use two 50 ohms in parallel or one 25 ohm if you are using the system in mono mode with the Left and Right tied together.

Again, this will only help if you are using SkyView with a volume setting below 50%.

 

[johnsteichen]

Adjust your screen brightness to full. That totally solved my hum problem. The hum was coming from the Dynon.
What filters?

 

[lalnaes]

Following johnS' advice, and in the setup menu, I set the dimming to manual and adjusted the brightness to 100 %. The noise went away. Problem solved.

The intermittent clicking/popping noise is still persisting though. The serial numbers for both screens are in the range that Dynon has identified as possibly having a problem, so I'm considering to return them for repair.

 

[vlittle]

SkyView audio noise eliminated!

I have found the solution for elimination of the SkyView system audio noise.  It includes Dynon's recommendations on adjusting audio levels, plus grounding issues.  Rather than replicate the discussion, please go to: http://makerplane.org/forum/viewtopic.php?f=23&t=137&p=642#p642.

This has virtually eliminated all hum, dimmer noise, cpu noise and serial port noise.

Thanks, Vern Little

 

[dschubi01]

Same problem here. The noise is constantly opening the squelch of the external-in of my radio. Volume of ext-in is on lowest level and Dynon out on 35. Sound like the resistor can sort my problem. What I don't get still from your description:
If you hook a 50 ohm resistor between the audio output of the SkyView and ground
is how exactly this needs to be done.
I would simply connect like drawn in the attached, would this work?

 

[dynonsupport]

The resistor hooks between SkyView's audio out and ground, not in series with the intercom:

SkyView L------|
               |----------------------|Intercom
SkyView R------|             |
                             |
                          resistor
                             |
                             |
                          GROUND