----- Original Message -----
Sent: Saturday, July 13, 2002 12:16
PM
Subject: [APML] Trouble with ST-4 &
LX-200
I've had this ST-4 for a few years, tried to get
it to work with my LX-50. No such luck, and I didn't have the patience
then to do much about it. About a year ago, I got rid of the LX-50 in
favor of a 10" LX-200. Same thing, didn't have much time to play, so I
just set it aside. Now, I finally have the time to try to get to know
the thing better, and I'm having a real hard time getting it to
work.
I hook the ST-4 to my laptop to try to focus it
better. I have it focused in what I believe to be the best focus I can
possibly have it in. On the screen, I see a nice round dot in the
x-hairs. If I move the head outward or inward, it get distorted, so I am
fairly confident it's in focus. I have even verified this with a ronchi
focuser.
Now, if I don't do anything, the acuracy of the
scope is pretty good. In fact, the other night, I forgot to hook the CCD
cable into the LX-200, and it worked like a champ, thinking I had it working,
the guide star barely moved except for some basic turbulence, which corrected
by the next cycle. This got me through a 1-hour exposure of M8. I
then realized what was going on, and connected the ST4 to the LX200, and as
soon as I set it to guide, it just goes out of control. What I mean by
that is, on the photo, it looks like a zig-zag line. If I use the
CCDTrack software, I get similar results, only I can actually watch it lose
the guide star. How is it that I can see the thing clear as a bell, yet
the guide software and/or the ST4 in standalone mode just act like it has no
idea where the star is, and goes off in some random direction?
Again, keep in mind that I am new to the ST-4,
and have never really had it work completely. I know I have good polar
alignment, and I am almost positive it's focused as best as possible. I
have tried re-doing the dark frame several times, and I have made sure that
the guide star was around 50,50, and the star brightness was between 30 and
60. I have not really done much with the settings on the ST-4 other than
the brightness (b=3), and FL=L (long focal length).
I apologize for those who are members of both
MAPUG and APML, as I have posted this message to both lists. I am
just getting frustrated with this thing after two telescopes and several
unsuccessful nights of even getting a decent track. Any help would be
greatly appreciated.
Frank Schwartz