Wild Vario Needle Swings

First flight today in glider with LX 7007 and Winter varios. Needles on both the LED vario and the Winter
mechanical would swing wildly from 10 kts up to 10 kts down all thru the flight- mostly in cruise,
but also in the early phase of thermalling. Needle and LED display seemed synchronous. Both would settle down to give reasonable readings once established in a thermal.


I believe both are plumbed to the same TE probe (an unusually long probe with tee at the end-- not the
usual bent up variety).

Can't be a computer or electrical problem as the Winter would not be affected.

Any suggestions as to cause and fix?

Bill