static from autopilot

[cposer]

I have a dual Garmin G5 and GMC 305 autopilot. For some reason I am getting some static in the radio. I am just wondering if the Roll servo being right above the VHF antenna could be the problem. All of the can buss wires are shielded as per manual.

[Eric Page]

Does the static only occur when the autopilot is engaged and the servo is active? If you remove power from the servos, does the static disappear?

[cposer]

It happens all the time. Just little bits of static here and there whether the autopilot is engaged or not.

[Eric Page]

If that’s the case then it sounds unlikely to be interference from the servo, but... If it’s convenient, try flying with the servo completely de-powered. If the static continues, you’ll have ruled out any possibility of interference from the servo.

A few other things come to mind that you might check/confirm:

Are you sure the squelch on the radio is adjusted properly? Could the static be brief instances of the receiver’s squelch breaking, and not interference? Some modern radios have a digital squelch system that’s adjusted through menus, and no external knob for adjustment.

Do you have a passenger headset plugged in that might be breaking squelch on the intercom periodically?

Are your headphone and microphone jacks isolated from grounded metal structure with fiber or plastic shoulder washers? Are the jacks wired with shielded cables, and are the shields grounded only at the radio/intercom end of the cables?

Is the antenna cable on the comm radio well made, with good shield continuity through the connector at each end? Is the antenna itself well grounded to the airframe?

[cposer]

Thanks, I'll check on those things.