"jls" wrote:

Also instrument needles go crazy.

Aircraft is a Lancair with antenna hidden in the horizontal stab. How
'bout directing us to some reading material about how to stop it.

Our local avionics guy says we may have to live with it, or install
external antennas, which will dirty up a Lancair in a hurry.

Jim Weir?

The easiest thing to try would be to clamp ferrite cores around the
input leads to the AP computer (even better if there's enough slack to
loop the cables through a larger core a couple times).

Next might be to use antenna cable that's more shielded (assuming that
the cable runs quite a bit closer to the autopilot cabling than the
antenna). Might be easier (and certainly cheaper) to just re-route
the antenna cable away from all other cables as much as possible.

And I'm sure Jim's gonna want to know a bit more about that horizontal
dipole (?) antenna you're running.

Mark "RF stands for Random Fluctuations" Hickey