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Old July 8th 04, 05:36 PM
Tuno
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Default Cambridge 302 problems solved

[This post didn't appear on my first attempt, so I'm trying again.]

I had a post a few days ago about having trouble with my brand new 302. I
have it fully working now and thought I'd post what I did to fix the
problems.
a.. The problem with the needle pointing in some odd direction on bootup
was simply a matter of turning it on in the sunlight. Having the canopy
cover on (or hand over the instrument face) on power-up is all it takes to
make it work right. (This was in the manual, shame on me for missing it.)
b.. The speed-to-fly function was broken because I had the wrong number
entered for the V2 parameter on the polar page. (The 302 takes the polar as
a combination of glider weight, wing area, best L/D speed, and V2.) I had
entered the lowest sink rate speed, which is totally different -- V2 is the
speed at 2 meters/sec sink.
c.. The wild vario needle (much disagreement with the B-40, and lots of
wild swinging while cruising) was solved by switching the TE setup from
pneumatic to electronic. This involved removing the tube TE probe tube from
the "TE/Static" port and connecting the latter to the static source (so
static is on the 1st and 3d ports on the back of the 302), then changing the
compensation parameter in the 302 to 100+ (Tom Kelly, 711, suggested I use
111). It works great now. It agrees almost exactly with the B-40, but with a
little better response time. The electronic compensation is impressive.
Hopefully my fixed LX5000 will arrive today and then I'll have what I think
is a really nice setup: the LX5000 as my primary vario, nav/flight computer
and IGC logger; the B40 for mechanical vario; and the 302/WinPilot Pro
combination as the backup nav/flight computer and backup IGC logger.

I like how the 302 and WinPilot Pro work together as a single unit. Not yet
sold on the Thermal Optimizer (or whatever it's called), but the "second
opinion" is useful sometimes.

Region 9 Day 4 today, watch for 711's reports.

ted/2NO