Noise in Dynon HDX intercom when Autopilot engaged

[Newkentboy]

I get a heavy dose of static in my headphones when the autopilot is engaged. Every time the autopilot makes a slight correction, which is often, I get a static sound in my headset. I have the Dynon com. I’m using the Dynon HDX system. Is there any thing that can be done to eliminate this feedback? Turning up the squelch helps a little, but it’s still there and is very annoying.

 

[Rhino]

What autopilot/servos are you using?

Have you looked at this?

Ground Loops and Noise in Aircraft Systems

Quite a few forum threads and articles have at various times addressed ground loops, and their potential to cause noise or other interference in your avionics system. Simply put, a ground loop occurs when different paths to ground are used. The difference in resistance, or impedance, on those...

forum.flydynon.com

 

[Newkentboy]

Whatever came on it as new. It’s a 2019 Flight Design. Could I find that in the system somehow?

 

[Newkentboy]

Just read over the other item. Sounds very difficult to trace out specific issues.

 

[MikeD]

All DC motors produce noise. Some are more egregious than others. I've addressed this problem on two occasions. The problem can be addressed by installing a noise suppression capacitor across the motor terminals, as close to the motor as possible. I have one on my flap motor and one on my AP roll servo. I spliced them into the dsub connector at the motor side.

I had a new roll servo that was very noisy. It was driving me nuts. I called Dynon and they gave me the specs for the capacitor to install. I suggest you do the same.

 

[Newkentboy]

Thanks very much

 

[MikeD]

Good luck. FWIW, this is what worked for me. I would still place a call to Dynon.

Capacitor

 

[Rhino]

Just read over the other item. Sounds very difficult to trace out specific issues.

It can be, yes. Best to start out trying the simplest solutions, like what Mike suggested.