Robert Preston wrote:
>
> Also, it's possible that few people actually use Meade's iterative
> polar alignment method, so they might not encounter the problem you have
> seen. I have the impression that most serious polar people go for drift-
> aligning as far better than, and, once learned, almost as fast as, the Meade
> method (with or without iterations). It might be the case that drifting
> (plus one sync to set the sidereal clock) avoids the problem you're seeing.
> I mean, most people probably wouldn't mess with a polar method at all unless
> they were doing photography, and if they're going to all that trouble anyway,
> they might just opt for a precision drift method rather than mess with the
> Meade method. But I'm just shooting from the hip on this - if any of this
> is true, it'd be pretty damn good guessing.
>
> RP
> Pgh PA

I reckon anyone with noticeable and consistent alignment and/or finding
problems should check that their DEC and POLAR axes are set orthagonal,
and that the DEC circle indicates truely. Both of these can be tweaked
if found to be in error.

When polar aligning, if the DEC is not reading correctly (for example)
when you point it at polaris you already have an error in the pointing
system. You move to the second star, synch on it, do a GOTO back to
Polaris - and hardly surprising that it's not where it should be. Hence
the iteration to remove this error. Best do your best to accuratly drift
align once, then GOTO 90.0 degrees and reset the DEC circle to read 90
degrees as accurately as you can (you will need to loosen the circle
beforehand). This will greatly reduce the error for future setups.

On Doc's web page, the article by Michael Hart on replacing the DEC
bearings gives details for setting the OTA orthagonal if you suspect
it's in error.

Chris
--
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