(PaulaJay1) wrote in
:

I have the original Autocontrol IIIB in my 79 Archer. Lately it has
been flying one dot to the right of course when in GPS/NAV mode. I've
set the CDI scale to 1.0nm full scale on the GPS so the error is only
about 0.2 nm. ... Maybe I should just vent to the newsgroup and leave
good enough alone!

That's all it's off! Heck, you may have one of the best units out there!
G

Seriously... All the IIIB does is sum the voltage from the CDI and the
"created" voltage from the sine wave off of the heading bug (and the AH).
In a cross-wind situation the autopilot WILL track off of the course line
by an amount that is proportional to the cross-wind component. The IIIB
operators manual (which may still be downloadable from Century) mentions
this, and simply suggests to do what you do - move the hdg bug a little off
to compensate.

The only IIIB adjustment for "centering" is probably not relevant. Set the
IIIB in HDG mode (no NAV tracking). Does it track with the DG heading bug
under the lubber line? If so, it's adjusted properly.

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
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