To answer some of the questions posed regarding my setup:
- I replaced the non-permanent lines last year because they were quite
old and looking dry. I was also having TE troubles. The replacement
lines tested leak-free (I hooked up a hyperdermic and an ASI, the
speed held when I pushed the plunger). I left the hard plastic
original lines in place, figuring they weren't part of the problem.
- I split the TE line under the seat when I replaced the other
tubing. It was originally split with a "T" at the panel and I read
that this was a no-no (article by Mike Borgelt)
- I tested all the hard plastic lines with the hyperdermic an ASI,
they all held the pressure.
- then traced my original TE troubles to a leak in the 4-way connector
at the panel. Replaced the connector this year.
- I don't recall the varios doing a quick jump when I accelerate.
It's rather reminscent of a "stick thermal" on non-TE varios, lasts
only a couple of seconds
- I'm not doing hard accelerations, at least to my mind. Not feeling
much force on my body
- Winter mechanical has a capacity flask mounted under the instrument
hood. VariCalc has no flask.
- I'm not sure if there were vario changes when I opened or closed the
vents as I wasn't paying attention to that aspect.
- the VariCalc has connections for all three lines; the Winter
mechanical connects to TE and capacity. A problem in static shouldn't
affect both instruments.
- the TE probe is a simple straight out and then bend down, with 2
slots. No idea who made it, but I suspect it came standard from the
Slingsby factory in 1972.

According to Mike Borgelt's article, it's okay (but not best) to
connect two varios to TE, but they should be split as far away from
the instruments as possible. The farthest back I could get was under
the seat, since I'm too big to fit into the boom and all those pesky
control connections were in the way.

I'll try blocking off one vario at a time to see if that changes
things.

The VariCalc has an option for electronic compensation, but I read
somewhere that it's not as good as using a TE line.