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Subject: Re: [M]: RA trouble LX200 12"
From: Bill Arnett
Reply To: mapug@shore.net
Date: Fri Mar 27 00:08:48 1998

At 10:06 PM -0800 3/26/98, Douglas Schmutz wrote:
>Thanks to everyone that has responded to this problem. John Piper told me
>today ( from Meade's Engineers ) that when the east key is pressed that
>this slows the RA motor speed in 1/2 not stopping it so that loading is
>maintained on the worm gear....

I'm pretty sure that is not correct, at least in altaz mode. I believe
that pressing the E key stops the RA drive and pressing the W key runs it
at twice sidereal rate. First of all, when you press the E key you can
usually hear the motor stop. But more definitely when you press the E key
the stars drift thru the eyepiece at exactly the sidereal rate and the W
key makes them drift exactly the same rate in the opposite direction. This
is easy to measure if you have a calibrated reticle (like the Celestron
Microguide) or if you know the actual FOV of your eyepiece (and it's
simpler if you pick a star near the equator so you don't have to worry
about correcting for the star's declination).

Perhaps it's different in polar mode? Otherwise, I'm not sure why John
Piper would make such a basic mistake.

---
Bill Arnett "Science is a way of trying
San Jose, CA USA not to fool yourself." -- Feynman
billa@zNet.com <URL:http://www.seds.org/billa/>