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Thanks everyone who responded. I especially
find this and Bobby's responses to be interesting. I appreciate the
links. I have read through Phillip Perkins' articles (loved the GEG
article!), but not Jim Janusz's. I will read through it carefully.
I am embarrased to admit, I don't know what the
settings (C1 and C2) were/are. I also don't know what the agressiveness
settings and calibration times were. I use the default setting unless I
read somewhere in an article that something would help. (yea, I know-
RTFM). As I said, I am new to actually digging into the ST-4. I
started with a 201XT, which had one button and not a lot of settings. I
messed with the B setting, but that's about it. I have done nothing with
the SA or any other setting.
Here's a little better description of what I have
going on...
10" LX-200, Lumicon GEG (tried in f/10 and f/6.5
modes, which neither affect the ST4), using the ST4 in off-axis. Not that
it matters much, but on the back of the GEG hangs a Nikon F2. I know the
docs say to try straight through, but I assumed I wouldn't have a problem if I
was seing a somewhat crisp dot for a guide star on the laptop monitor.
When I do a find/focus, I get what I believe to be a decent focus (confirmed
with the laptop/CCD Track util). (While I'm thinking of it, the CCD
program asks for these settings: Focal length (got that one figured out),
aperture (in in^2), and response factor. Anyone know what the aperture and
response factor should be set to? Yes, I'm an idiot with math. When
I try to do the drive calibration, it appears like it's working- goes off into
different directions, but normally comes back to the center, or closet to
it. It's mostly when I hit track that things just go nuts. And it's
not like it takes awhile. If I hit track, the relays start clicking
away immediately. If I stop it 5 seconds after that, and bring up the
focus screen (larger than the tracking screen), I'm lucky if the guide star is
still in the view.
I am strongly considering replacing the relays just
in case. I bought the ST-4 used, but it appears in pristine shape, and
responds like it should except for that little problem of not tracking. I
am assuming there may be a short between the buttons and my chair (also known as
the ID-ten-T error) more than a problem with the ST-4.
Thanks for the advice so far. I will read
through those articles you suggested, and will look into the relays.
Frank
----- Original Message -----
Sent: Saturday, July 13, 2002 12:48
PM
Subject: Re: [APML] Trouble with ST-4
& LX-200
Hi Frank,
You didn't mention your calibration settings (C1 and
C2) or the results of running the calibration. And on a long FL scope it's
usually a good idea to set the scintillation adjust (SA) to 8 or more to
essentially shut that feature off. Have you read APML member Jim Janusz's ST4
article? It's at: http://www.astrocruise.com/st4tips.htm
Jim's article is located at several websites, but I
refer you to Philip Perkins site because he has an additional article about
using the ST4 with a 10" LX200: http://www.astrocruise.com/guide.htm
----- 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
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