On Friday, July 19, 2019 at 12:48:16 PM UTC-6, John Foster wrote:
On Friday, July 19, 2019 at 10:30:22 AM UTC-6, Steve Leonard wrote:
Is it maybe a CPT50S?

This might help. http://www.bas.uk.net/docs/Mk4_Vario.pdf

This says it will go full scale and stay there up to 3-5 minutes on initial powerup. Have you waited that long to see if it will come back to zero? Worth a try.

More manuals here. http://www.bas.uk.net/manuals.html

Best of luck with the vario!

Steve Leonard

It could very well be a CPT50S. I'll need to look more closely next time.. I have not tried leaving the power on for 3-5 min, and will do that next time. Thanks.

It is indeed a CPT50S variometer. I tolerated on and waited. Immediately the needle deflected downwards for about a minute, then deflected upwards, and then started alternating back and forth from full downward deflection to full upward deflection at varying speeds. He did this for about 15 minutes before I turned the power back off. It did not seem to center itself. There are no other instruments or accessories plugged into the back of this variometer. Not sure what is going on.