ADI Pilot II and pitch control runaways when mic is keyed.

[Wicked Stick]

For those of you flying with a TT ADI Pilot II autopilot.
Do you have issues with altitude hold when you key your mic ??

Pat, I think you have this setup and are flying... Any issues ?

I recently had TT upgrade my ADI Pilot II to the new aluminum box but it still makes the pitch servo go crazy when I transmit.

WHY just the pitch and not the roll ? Any ideas ?

[rob]

Mine works great -- no issues at all whatsoever when the AP is engaged. I have a TT ADI Pilot II that is coupled to a Garmin 420W.

Are you using local grounds or all home runs in your wiring? Have you tried to switch out the elevator servo for another one? Or, even switching the elevator and aileron servos? It may help you isolate the problem....

[Wicked Stick]

I have 99% of my grounds at a common ground point on the fuselage. Just the pitot heat and nav lights will have a ground out at the wing tip area.

The RG400 coax is run down the left side of the fuselage to the belly antenna, and the servos and harness run down the right side of the fuselage. The radios are on the left and the autopilot is on the right so nothing crosses paths either.

I'll look further into it, but everyone who has had the issue has had the problem in pitch only. NEVER heard anyone have a problem with roll or why not a problem with both at the same time. In fact, the roll servo is closer to the antenna than the pitch is so go figure.

I'd be willing to blame it on something I did wrong if I was the only one.
But there seems to be a growing number of them who have the exact same issue. Well see, I havn't given up yet.

[4kilo]

Dave,

You are correct, I have this set-up and have not had the pitch problems. Although I can't recall the context exactly, I do believe I remember something about grounds being suspect.

I have all electronics (avionics, radios, autopilot etc.) grounded to a single point in the instrument panel, but use local grounds for lights, pitot heat and similar loads.

Pat

[Wicked Stick]

Dave,

You are correct, I have this set-up and have not had the pitch problems. Although I can't recall the context exactly, I do believe I remember something about grounds being suspect.

I have all electronics (avionics, radios, autopilot etc.) grounded to a single point in the instrument panel, but use local grounds for lights, pitot heat and similar loads.

Pat

I have one ground wire I could re-route to see if that is the problem.
Other than that, I too have all devices with ground wires going to a single point behind the panel like yours.