Folks,

 

I have a S-TEC 55 autopilot issue that perhaps maybe others have experienced in the past.  Any help would be appreciated. 

 

The problem is this:- 

 

When I have the AP setup in ALTitude hold mode and I key my mic the pitch servo goes nuts and the aircraft climbs for as long as I am transmitting.  I am using the old blue plastic pressure S-TEC transducer which I know to have issues but S-TEC are not officially fessing up to this fact.  Using foil and grounding straps I have tried to isolate the transducer from RF as much as possible but cannot entirely eliminate the pitching.  Has anybody resolved this using problem an alternative sensor, wiring configuration or special replacement deal with S-TEC?

 

Thanks

 

Tom