Well, the verdict is in. Turns out that
the simple act of 1) removing the plastic
back and 2) unscrewing the mirror mount from
the tube and then reassembling the whole mess
lead to a situation where the collimation was
pretty close to dead-on. Needless to say, it
didn't break my heart not to have had to touch
the collimation screws. My only guess is that
maybe the plastic back the holds the eyepiece
might not have been fully mounted with respect
to the tube/mirror assembly and that reseating
it did the trick. In any case, it works quite
well now. With that potential train wreck out
of the way and some delightfully clear skies
(well not quite, the moon was up), I was finally
able to give the ETX/autoguider setup a good
shakedown. Mounted everything up to the 8" LX200,
slung a chunky Minolta body/telephoto lens setup
as a counterweight (the Losmandy set's on backorder),
sighted up the ETX on 87 Leonis (a roughly 5th
magnitude star), aligned the crosshairs of the
illuminated eyepiece on the radial guider on
the 8" and let'er rip. Using a 0.5 second update,
the reference star stayed aligned on the inter-
section of the crosshairs for about 45 minutes
(this is about a 1 arcsecond precision). As the
scope got near the meridian, the system shifted
a bit and the reference star moved about 7-8
arcseconds and held there through the end of
the one hour and fifteen minute test period.
All in all, I'm pretty happy with it. Here's
hoping for clear skies when we hit the last
quarter moon...

M.

----------
From: JDDGA
Sent: 4/4/98 3:22:17 PM
Subject: Re: [M]: Collimation of Meade ETX

Mike,

Thanks for the feedback. You certainly seem to know the interior of
your
ETX pretty well, and you sound like you have enough experience to take
on the
project. I wish you all the best with it. By the way, your posting was
so
interesting to me, that I'm going to print it out and put it in my
telescope
information loose-leaf book. It might come in REAL handy in the future.

I wonder how many Meade ETX's come to the customer miscollimated.
Right
now I'm still interested in the ETX, but I am concerned about Meade's
quality
control.

Please let me know how the collimation effort turns out.

John

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