Radio Static From Trim

[Bartman1959]

Almost every time I adjust the trim on my Kitfox 5, I hear static in my headset. I doesn't happen every time, but most times. Any ideas what could cause this?

[PaulSS]

Assuming you have electric trim it sounds like a ground loop. Are you using the airframe as a ground return for all your services? Try running a separate ground from the trim motor to the battery and see if you still get the same. The only other thing that I can think of would be the trim motor being close to the wires in your headset circuit (not the headset itself but the wires running to the headset plugs) and inducing the static. Does it happen to both headsets at the same time? If it's only one side then it would be a simple matter of routing that headset's wires away from the motor.

[dcsfoto]

tip I got from Garmin ground trim motors as close to the trim motor as you can

D Kelm 7SS
Garmin G3X
912iS Big Bore

[Bartman1959]

Assuming you have electric trim it sounds like a ground loop. Are you using the airframe as a ground return for all your services? Try running a separate ground from the trim motor to the battery and see if you still get the same. The only other thing that I can think of would be the trim motor being close to the wires in your headset circuit (not the headset itself but the wires running to the headset plugs) and inducing the static. Does it happen to both headsets at the same time? If it's only one side then it would be a simple matter of routing that headset's wires away from the motor.

I am not the builder, so I'm not sure how everything is grounded. It does happen to both headsets at the same time.

[Esser]

tip I got from Garmin ground trim motors as close to the trim motor as you can

D Kelm 7SS
Garmin G3X
912iS Big Bore


This pretty much goes against all the theory in AeroElectric connection. Everything should go to a common ground to prevent ground loop. My Kit was supplied with 2 wire cable that would reach from the firewall to the tail.

[efwd]

Yeh, that's opposite of what I have read and therefore did in my build. Haven't really tested the audio yet. Crossing my fingers.

[mr bill]

At his seminar, Bob Nuckols said to have an avionics ground and an electrical system ground and at some point, connect the two grounds.