Thanks all for the input on my Stec-50 with altitude hold problems.

 

Well,  the update is - static port connection removed from Stec & magically the unit holds altitude +- nothing !  first time ever since the AC was built in 2002.  So it looks like it was the pitch sensititve algorithm that caused oscillations. Gone when vented to the cabin.

 

Transponder antenna still has problems.  Found where someone had used TV coax from King antenna to transponder.  King coax was still installed - so reconnected King coax and still had problems.

 

Plan is to continue with install of external antenna.

 

Thanks again for  all help with Stec.  Much more usable AC with an operating autopilot.

However,  now I can't justify new BMA EFIS.

 

Regards,

 

 

Wayne