Andre,

 

Thanks for the info.

 

Yesterday I went for a ride (and what a ride)!

 

I had 800 foot, 3100 fpm dives and steep climbs on alt hold.  If carefully trimmed, hold engagement was fine for about 12 seconds - then another wild ride ensued.

 

A conversation with S-Tec while sitting in the plane at the hangar will result in my performing some ground tests - but, note this -

 

Engaging hold on the ground sometimes resulted the stick moving forward. While talking, I saw the trim lights (randomly) come on and a stick bump would turn them off. 

 

Sucking and blowing on the sensor generally resulted in down elevator movement???????????

 

More tests today.

 

I will mention the "sensitivity" fix to S-Tec tech.  This is probably a good solution to alt hold oscillations, but there is something seriously wrong with my A/P even though the pitch servo motor is new, the sensor is new and my computer was checked by S-Tec within the last 30 days.