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Re: [APML] ST-4 HELP (!!!!) needed... (thanks!!!)
Bill, et al,
Many thanks, you guys are brilliant! It did turn out being one of the
relays, I opened up the st-4 and moved each of the relays over one, and the
problem 'moved' to the -y step of the calibration (the fourth motion). Now
I just have to figure out which is the alarm relay and which is the bad
one... does anyone have a wiring diagram for the st-4?
And yes, it turns out that one of the motion controls on the st-4 doesn't
work.
Unfortunately, I'm clouded out tonight (just as well... go pats!) so I'll
have a few days to fix this problem.
-john
John Lanoue
Principal Software Engineer
Bedford, NH
http://www.geocities.com/johnlanoue/
>From: "William R. Mattil" <wrmattil@ix.netcom.com>
>Reply-To: Discussion of Film Astrophotography <astro-photo@seds.org>
>To: Discussion of Film Astrophotography <astro-photo@seds.org>
>Subject: Re: [APML] ST-4 HELP (!!!!) needed...
>Date: Sun, 16 Nov 2003 09:54:43 -0600
>
>John Lanoue wrote:
> >
> > Greetings,
> >
> > I missed out on 5 good hours of imaging last night because my st-4
>wouldn't
> > calibrate and I'm wondering if anyone else has seen this problem. This
>may
> > be a continuation of my 'aurora' problems from two weeks back, I don't
>know.
> >
> > Problem:
> > The ST-4, when calibrating (depending on the orientation of the CCD
>head)
> > will do the following four movements, increase x by C0 seconds, decrease
>x
> > by C0 seconds, increase y by C1 seconds and decrease y by C1 seconds,
>for
> > shorthand sake, I'll call these four steps +x, -x, +y and -y. I have
>the
> > head oriented such that x corresponds to RA and y corresponds to Dec.
>What
> > I'm seeing is the +y step results in no change in y (on the ST-4
>readout)
> > and the -y step results in y incrementing (like you would expect it to
>do in
> > the +y step).
>
>To summarise then, during the calibrate mode there is no movement in a
>single direction (depending on orientation of the CCD head) but the
>reverse seems to work. This imediate points a fickle finger at one of
>the following:
>
>1) Cable
>
>2) Internal relay in the ST-4 (most likely I would think)
>
> >
> > That's the jist of the problem, but here's more...
> >
> > Using the lx200 hand controller, in guide mode, I can move the scope in
>x
> > and y (such that the display increments and decrements on the st-4).
>
>Just proves the mount is working ....
>
> > So I
> > believe that eliminates the lx200 drive as the source of the problem.
>Also,
> > it doesn't matter what I increase C1 to, on my scope, a value of C0=C1=3
>has
> > worked fine in the past (I'm guiding at prime focus of a 12" lx200), I
>upped
> > C1 to 10 seconds and it made no difference in the third step, the +y
>step
> > still resulted in zero movement. Also, during the failed third step,
>the
> > scope is making no noise, and I've always been able to tell when it's
>moving
> > in declination. I can clearly hear it moving when it's doing the -y
>step
> > (which turns out moving the scope in the +y direction). And finally,
>not
> > that it matters for calibration, but I set SA to 10 to turn it off.
>Also,
> > my drive has a bit of backlash, what lx200 doesn't? However, it's never
> > been a problem, but regardless, I messed around with H1 (hysterisis-y)
>and
> > it made no difference.
>
>So what happens if you try to manually move the scope using the
>appropriate buttons on the ST-4 ? Particularly the +y movement
>???????????????????????????????????????????????????????
>
>My guess is that is won't move ?
>
> > Oh, one last thing... (I know, I sound like columbo), if I disconnect
>the
> > ST-4 from the lx200 control panel during calibration and using the
>audible
> > clues of the st-4, manually press the N/S/E/W keys to emulate the
> > calibration sequence, then believe it or not, the calibration succeeds
>and I
> > can track. What this points out is that in track mode, it appears that
>the
> > st-4 can issue declination corrections (declination=y). I say appears
> > because I have a pretty good polar alignment, so its possible that no
> > corrections were needed.
>
>I think this doesn't help much .....
>
> > I can't help but think this is a cabling issue... anyone out there seen
>this
> > or want to take a guess? If you want to contact me off list and/or
>speak
> > over the phone, that would be great. I would love to get out tonight if
> > possible.
>
>John, its trivial to open up the ST-4 and locate the relays inside.
>There should be 5 IIRC. The *extra* relay is for the alarm. So you could
>easily swap relay's around and see if that rectifies the problem or
>"moves" it to another axis. if it does then the relay is the culprit and
>it can be replaced with the alarm relay. I am not familar with the LX
>wiring so cannot comment on it. Someone else can probably provide some
>help there.
>
>Hoe this helps ?
>
>Regards
>
>Bill
>
>--
>William R. Mattil |
>wrmattil@ix.netcom.com | http://celestial-images.com
>(972) 399-4106 |
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