AUTOSTAR INFORMATION Last updated: 30 November 2003

Post Bleep Refinement, Dance and Drift

Sent:	Thursday, November 27, 2003 15:49:10
From:	stephen.bird@bt.com
INTRODUCTION
If you upgraded to version 30Eb, 30Ed or 30Ee software recently, and now
your scope doesn't quite do what it used to, AND,... You can't quite
work out what is going on, or.... Even if it is a small but bearable
niggle you are experiencing, then the following is worth reading, if
only to point you in the right direction. Even if with version 30Eb,
30Ed or 30Ee, you still have the perfect GO TO scope, this still makes
interesting reading. If this helps one other person, then it is worth
the effort I have put in with the invaluable help of the Mighty ETX Site
of course.

26Ec AND 26Ed
With version 26Ec and 26Ed of the Autostar software, most ETX'ers had
easy access to the processor driven GO TO and fine manual adjustable (by
the arrow keys) scope of their dreams.

Select an object from the Autostar database, press GO TO, and the scope
slewed towards the object, and you got that familiar comforting bleep
when Autostar had locked on to and was tracking the chosen object. Press
and hold the MODE button for more than 2 seconds, and the RA and DEC
co-ordinates displayed were in exact agreement with Autostars database
co-ordinates for the object as soon as the bleep sounded. And, so they
should be, no point giving a bleep if the object had not been reached
yet is there?

And, if like I guess, a lot of ETX'ers out there in the world you got
the scope out of the box, followed the Meade manual and picked the
nearest city, calibrated, then trained on a day time terrestrial object,
and set up using Alt/Az mount, put the little bubble level in the
eyepiece and got the tripod legs just about right, followed by flipping
the bubble level over to the tiny little compass that even a boy scout
would laugh at, and used it to get within a few degrees of magnetic
north, applied a bit of local correction to get true north. Then you did
an Easy Alignment or Two Star Alignment, or shame on you a One Star
alignment. Got the alignment stars roughly in the middle of the 26mm SP
eyepiece and pressed ENTER, then don't worry, because at version 26Ec
and 26Ed, even if you never set the Alt Percent or Az Percent above the
factory settings of 1% each, chances are you still got GO TO's that at
the bleep had the object somewhere in the Field of View (FOV) of the
26mm SP eyepiece (52 arcmin) and almost certainly in the FOV of the
viewfinder (7.5 deg). So as soon as the bleep went, you used the 4 arrow
keys with a choice of speed (probably forget 1 and 2 as they take ages
before anything begins to happen and move too slow anyway), to center
the object in the eyepiece. AND,.... when you took your thumb off the
last arrow key, the object stopped dead, right where you put it in the
eyepiece. A glance at the RA and DEC display (press and hold MODE for 2
or more seconds), showed that things were stable. Again why shouldn't
they be? You took your thumb off the arrow keys, this cuts the power
that drives the motors at your choice of speed, they stop. (Except of
course the sidereal movement that keeps the object in the center of the
eyepiece).

Well I have had two ETX105's and exchanged mail with a number of other
ETX users with both 90's, 105's and 125's. They all see the above,
unless they have an unrelated fault to the issues shown below.

Well, both my scopes were set up a little better than above, at times I
used, GPS co-ordinates, Polaris instead of the terrestrial object for
training and so on. Most GO TO's were quite close to center, only on the
horizon or under greater magnification did I need to center things much.

30Eb, 30Ed AND 30Ee
Then along comes 30Eb in September 2003, followed quickly by 30Ed on the
10th October and 30Ee on the 23rd October 2003. Version 30 introduced
the Autostar Suite command functions, essential if you want to run this
new tool. Certainly no reason why you should not upgrade if Autostar
Suite is on your Christmas List like me.

So I upgraded, (doesn't matter which version 30E b, d or e, the effects
are the same). Immediately things were not right, the scope now seemed
to have a mind of its own on GO TO's and went totally screwy sometimes
when I tried to center an object using the arrow keys.

OK fine, this happens sometimes, I reset, double reset, just to make
sure, even reloaded the software, double reset, re-calibrated,
re-trained and carefully aligned all in one continuous action. Still the
scope seemed to have a mind of its own on GO TO's and went screwy
sometimes on centering using the arrow keys.

I tried to contact Meade direct and ask about the problem, I got
stonewalled! They referred me to B,C&F the UK distributor. Well even to
this day, I have not managed to speak to an "engineer", I seem to be
dealt with by the message taker (always nice, always polite, even when I
got excited, he stayed calm, but he ws not an engineer). B,C&F have
phoned me back twice in the almost daily calls since the 3rd November
2003 when I first called them. Thank goodness I don't pay full rate on
the phone bill! I explained the fault to them, their diagnosis was a
dead Autostar or motor board. And credit where it is due, within the
week, a new scope duly turned up, and the supplier who sells these
things all the time, even loaded version 30Ee and set the scope up for
me which took me out of the equation as regards poor set up technique.

Unfortunately, the problems were exactly the same, which is when I
decided to talk to the experts and contact Mike Weasner who put me in
touch with Dick Seymour. With their help and great advice I have been
able to get to grips with the problem, which though not solved (Meade
needs to do that) is now much better understood. Dick has replicated in
part, the problem, and even Meade eventually said they could see what I
could see on 5 scopes in the factory. 

SO WHAT IS THE PROBLEM?
OK, upgrade your scope to one of the version 30 variants, Eb, Ed or Ee,
doesn't matter which.

You can reset if you like, calibrate, train and align. It does not
matter how carefully you do it. All that happens is the problem is
smaller and may be less frequent, but it is still there.

Pick your first object (has to be a star or deep sky object, planets,
etc don't show it up as effectively).
Now check the Autostar database co-ordinates for the object before you
press GO TO (just use the scroll up / down arrow keys until the object
RA and DEC is displayed, then write the figures down.
Now with your stop watch at the ready, press GO TO and wait for the
bleep.
As soon as you hear the bleep, quickly start your stop watch and press
and hold MODE for 2 + seconds to switch to the RA and DEC display. This
will display the current RA and DEC co-ordinates live. Note what you
see.
You will notice that even though you have had the bleep, that you have
not yet reached the database co-ordinates.
What you see is the co-ordinates gradually homing in on the final
database co-ordinates over time.
With a well set up scope or object near the pole or alignment stars, it
can take 30 seconds or less. For a less than perfect scope set up or
objects on the horizon, or well away from the alignment stars the time
can be 2 minutes 30 seconds or more.
In most cases we are only talking about a few tenths of a minute of RA
and a minute or two of DEC.

POST BLEEP REFINEMENT
I call this "POST BLEEP REFINEMENT". Quite why it has been introduced
with version 30, I don't know. Meade won't or can't say. But it is a
fact, it is not there with version 26Ed, it is there with version 30Eb,
30Ed and 30Ee. With a well set up scope you might not even notice it.

CENTERING OBJECTS WITH VERSION 30 VARIANTS Eb, Ed and Ee
Now, WHATEVER YOU DO, DON'T TRY TO CENTER THE OBJECT WITH THE ARROW KEYS
BEFORE THIS "POST BLEEP REFINEMENT" IS COMPLETE. I have waited 5 minutes
after the bleep during tests just to make sure. But as long as you wait
until the displayed RA and DEC co-ordinates equals the Autostar database
co-ordinates you should be safe.

So you got the bleep, you waited until post bleep refinement has run its
course, but looking in the eyepiece, maybe changing for a higher power
eyepiece, the object is not dead center. So quite naturally you use the
arrow keys and speed of your choice to center it. With version 26Ed when
the object was centered you took your thumb off the arrow key and the
object stopped dead. But with version 30Eb, 30Ed or 30Ee, it doesn't
quite work that way.

Again object choice (make it a star for testing), how well your scope is
set up and aligned, do make a difference, but this next "feature" is
always there.

Use the arrow keys to center the object.
Now like last time check the RA and DEC displayed co-ordinates and your
stopwatch.
Write down the exact co-ordinates and time when you take your thumb of
the last arrow key. (You need to be quick and multi-tasking).
Now record the co-ordinate figures as they they change, noting the time
at each change.
Eventually, if you didn't use the arrow keys before "post bleep
refinement" finished, the object will end up back where it started.
It moves away from where it started gets to a certain point, then
reverses course as though on an orchestrated "dance".

DANCE
Originally I called this a merry dance, but as it is not much fun, it is
best to call it just "DANCE".

Again it can be as little as one or two tenths of minutes of RA and one
or two minutes of DEC, or it can be anything up to a minute of RA and 5
minutes of DEC. But it is a "dance" as it retraces its outward steps
ending back where it started.

26Ed does not do this. 30Eb, 30Ed and 30Ee all do to some extent. Meade
told me via B,C&F that this is just poor setup and alignment. Fine I
say, "same setup, same alignment, same object. Doesn't do it on 26Ed,
stops where it stops. 30Eb, 30Ed and 30Ee, test it and see".

DRIFT
Well drift is where you wander aimlessly without a home. In this case,
all you need to do is try to center an object in 30Eb, 30Ed or 30Ee,
before post bleep refinement has finished and you may well see "drift".

What happens is you try to center the object in the eyepiece, but the
Autostar doesn't like being cut off in its prime, so you end up fighting
it with the object wiggling about in the eyepiece. Take your thumb off
the arrow key and the object can rapidly dissapear from view in a random
direction. 

Not only that, unlike with "dance", it never comes back. Further if you
press the GO TO button, the displayed RA and DEC co-ordinates even with
the object stationary after post bleep refinement, no longer match the
database co-ordinates for the object. They can be a long way out.

The only cure for "drift" is to switch off and realign, when all will
return to normal, if you can call "post bleep refinement" and "dance"
normal.

Meade as far as I could glean from B,C&F, made no comment regarding this
"feature".

WHERE NEXT?
Well I promised B,C&F a report on exactly what the issues were, and they
will get the above with 8 hours of figures on actual objects used to
test each of the above. It is entirely possible to reduce the above
effects to negliable levels with a properly tuned, setup and aligned
scope. Polar mount naturally tends to reduce the DEC varaitions, not RA,
but the problem is still present.

Best advice, would seem to be:

1. Don't upgrade your software unless you need to, such as accessing new
features that are essential to you, or be prepared to downgrade if it
goes wrong.
2. If you do upgrade (same advice for any upgrade really) don't do so
just before an essential viewing session, give yourself time to get
aquainted with new features.
3. If you experience any of the above problems, until a newer version of
software emerges, make sure you have a well tuned scope, carefully set
up, calibrated, finely trained ( I recommend Dick Seymour's patch kits
and use of the Edit Training feature with Martyn Edward's training
optomising spreadsheet). Don't rely on magnetic North and rough
centering of alignment stars, or single star alignment. Avoid "synch"
like the plague. Give "post bleep alignment" plenty of time to complete
before centering using the arrow keys. If "dance" changes to "drift"
(which you will see immediately), switch off, switch back on and realign
carefully.

Oh yes, I offered B,C&F the chance to see my scope do its stuff by me
driving 4 hours return to their depot in the UK, they declined.

Good luck, hope the above might help someone somewhere.

Regards

Stephen Bird  

Return to the top of this page.

Go back to the Autostar Information page.

Go back to the ETX Home Page.