Re: [APML] Refractor Guidescope Suggestions???

["bert katzung" <katzung1@home.com>]

Hi Kent:
I've been using the A-P guidescope (80 mm, f11) with very little flexure on
the Losmandy side-by-side plate with my 130 EDF. I crank all the knobs on
the Losmandy really tight (and repeat during the night as things cool down
and shrink). I have no experience with the other brands you mentioned. The
focuser on the A-P scope is smooth with lots of back-focus and it locks down
as tightly as you want. There is a *very* slight image shift as you tighten.
Not enough to shift the guide star off an ST-4 if it's anywhere near the
center of the chip. The scope has one thing that I think is mandatory for a
guidescope in rings: the grooved bands on the OTA. Because the 3 adjusting
screws are in the groove, you can loosen one (in preparation for tightening
the others) without the whole OTA slipping out on your eye (or the ground).
If these aren't available on the other brands that would rule them out for
me. The guidescope I used before did not have them and it landed in my face
several times before I gave up on it.
Hope this helps....
Bert

Bert Katzung
katzung1@home.com
www.astronomy-images.com

----- Original Message -----
From: <KGKIRKLEY@aol.com>
To: <astro-photo@seds.org>
Sent: Saturday, 04 August, 2001 7:30 PM
Subject: [APML] Refractor Guidescope Suggestions???


> OK APML list subscribers:
>
> I've been fighting a flexure situation with my AP155 on AP1200GTO mount,
> mounted in AP rings with Losmandy plates top and bottom. For a guidescope
> I've attempted to use an AP Traveler or TV101 mounted in Losmandy DR125
rings
> atop the 155.
> I keep gettting flexure in the amount of 7-15 arc seconds, depending on
where
> in the sky the system is pointed. The Traveler shows more movement than
the
> TV101 (its heavier)
>
> I've decided to use a lighter weight guidescope such as one of the 80mm
f11's.
> Roland at AP suggested this.
>
> My question is which such 80-90mm f11 or guidescope is acceptable.
> AP offers what appears to be a nice 80mm f11 import, painted white,
lockable
> focuser, with aluminum bands around the tube where the mounting rings go,
for
> $495. Apogee offers a couple of imports, 80mm f9 $100 and a 90mm f11 $150,
> black tubes with lockable focuser. Celestron and Meade offer simple
imported
> refractors but the ones I've looked at have very sloppy focusers. I don't
> want to add to my problems.
>
> Any ideas or suggestions??
> Kent Kirkley



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