Weasner's ETX PE Feedback Page

ETX PREMIER EDITION FEEDBACK

Last updated: 29 June 2006

This page is for user comments and information specific to the ETX PE (Premier Edition). Feedback on the specific PE technologies (Automatic Alignment + SmartFinder, Level North Technology) will be covered here. Feedback on the Autostar Suite AE (Astronomer Edition) will be posted on the regular Autostar Suite feedback page. Items that are applicable to all ETX models (EC, AT, PE) will continue to be posted on the other appropriate feedback pages. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me and I'll post them. Please use an appropriate Subject Line on your message. Thanks.

Subject:	RE: Alignment Problems on the ETX-125PE UHTC
Sent:	Monday, June 26, 2006 08:11:32
From:	Kelly Carroll (soktober@gmail.com)
Thank you such a fast reply.  I had trained the drives and calibrated
the motors, but did not calibrate the sensors.  I went out last night
and barely got Polaris and two alignment stars.  I calibrated on Polaris
and then did an Automatic Alignment.  The alignment was successful, and
when it completed I had the scope GOTO to the first alignment star, and
it centered fine.  I was not able to GOTO any more objects, it was to
cloudy, but I hope that solves the problem.  Thanks again for the
information and your site is doing a great service!

--kc sends.

Subject:	Alignment Problems on the ETX-125PE UHTC
Sent:	Saturday, June 24, 2006 20:53:11
From:	Kelly Carroll (soktober@gmail.com)
I just received a replacement ETX-125, the horizontal lock broke on the
first one, but I have not been able to properly align it.  Sometimes
when leveling it does not become horizontal to the ground but around 15
degrees towards the ground, however, sometimes it does seem to be
parallel to the groundbut I get the same alignment failure.  In
automatic align mode the OTA always seems to be 10-15 degrees low and a
few degrees to the right of the alignment star.  The most puzzling is
that there seems to be fluid leaking from the bottom of the motor, when
I unscrewed the locking screws on the mount the first night out I heard
a "whoosh" of pressure followed by fluid.

I have successfully aligned my ETX-90 and the first ETX-125.  I have
reset the Autostar controller, trained the drives, reversed the cords,
reloaded the latest ROM and patch (42d) but nothing seems to cure my
alignment issues.  Thank you in advance.

--kc sends.

Mike here: Have you done a CALIBRATE SENSOR, CALIBRATE MOTOR, and TRAIN DRIVES? Is the site information correct? Is the Autostar getting the date and time from the LNT? Are you putting it into the proper HOME position for the type of alignment you are doing (Auto Align is one position and Easy Align is a different position)? Sorry for the questions but I need to know more about what you are doing. Also, keep in mind that at the end of the leveling and northing, the tube may not end up level and pointed to the north.

Subject:	Re:ETX 105 PE - LNT modules moves?
Sent:	Thursday, June 15, 2006 11:12:45
From:	mhogansr@comcast.net (mhogansr@comcast.net)
During experimenting with my PE, I came to some slightly different
conclusions about functioning of the LNT than what you offered in your
reply to the referenced message.

What I determined is that the Autostar computes a coarse correction for
magnetic North, based on the lat/lon coordinates entered.  The Cal
Sensors does a fine correction for any physical misalignment of the LNT
to the OTA axis.  Consequently, the LNT does not have to be in perfect
alignment with the OTA.  BUT, if the module is wobbly then the Cal
Sensors correction is invalidated.

I found this by entering several sets of coordinates for widely spaced
geographical points, then measuring the difference in the resulting
direction of the calculated True North.  The differences corresponded to
the published magnetic variation for those locations.  I did not do a
Cal Sensors for each location in order to eliminate the additional
variable.

I don't know if the Autostar uses an algorithm or tabular lookup to
derive the correction for a particular location.  It might be one of the
parameters associated with a particular city or Zip code but that's
beyond my ability to determine.  Maybe Mr. Seymour?

One final note - movement of the LNT cover against the spring tension of
the adjusting screws is  - not - movement of the LNT module itself, only
the position of the Smartfinder lens.

Regards,
Mike

Mike here: I don't dispute any of your conclusions. In fact, I think we have said the same thing; you've just said it more important detail. Hopefully the module doesn't wobble during the north-ing step; if it does then that could create an error. But otherwise, once the Autostar knows where North is, it should work OK. The calculation might change on the next north-ing if the module position changes, but then the Autostar knows where North is again and where the stars are, so it shouldn't matter.

And:

Thanks for replying but I think you might be overlooking something. The
correction for the physical position of the LNT relative the the OTA
determined by Cal Sensors is saved from one session to the next; the
correction for location is recalculated each time.  This allows changing
locations without necessarily recalibrating the sensors.

I measured the length of the LNT PC board at about 8cm.  If it moves in
a way that allows rotation around its center so the end moves 1mm
horizontally, I calculated the shift relative to the OTA axis will be
slightly more than 1.4 degrees.  This is more than twice the FOV of the
Meade supplied 26mm eyepiece in a 125 PE.

The result is the next "north-ing" Autostar calculation will use the
wrong Cal Sensor parameter so it won't know where True North is. This
will have to be compensated during star alignment.  Not a big deal but a
wobbly LNT will result in inconsistent performance from one session to
the next.

This is probably too technical for posting, but I thought you might be
interested.  Hope I'm not wasting your time.

Regards,
Mike

Mike here: Good point. I was assuming that the Cal Sensor was saved but that the North/OTA error would be taken out once the star alignment process was completed.

Subject:	Re: LNT
Sent:	Tuesday, June 13, 2006 21:53:05
From:	io (hoasys.dev@tin.it)
Thanks Mike for your patience, but as I can contact the meade in order
it makes me to send the new module to mount? I have much difficult to
speak in English, I read it, I write it (bad) but I speak it very badly
:(((

you know some contact via email?

Thx
Bruno

Mike here: You can fax your request to Meade. Meade does not have a tech support email address. See the Meade site for fax info.

Subject:	LNT
Sent:	Monday, June 12, 2006 11:30:39
From:	io (hoasys.dev@tin.it)
i'm from Italy and i want to tanks you for your sublime works.

I have a serious problem.

The LNT module wires (red, grey, black and white) on the flex cable are
detached, so I don't know like knitting the just colors on the printed
circuit.

The italian importer-dealer don't want to send me the correct wires
positions, it wants that it sends he my telescope. :(

Can you help me? :,(

Regards.
Bruno
(nickname YenA from Udine Italy)

Mike here: Do you mean the wires have broken off the circuit board in the LNT module? If so, it is best to have Meade repair that. Depending on WHY the wires came loose and the age of the telescope, it could be covered under a warranty. Also, Meade might just send you a replacement LNT module which you can install yourself. I haven't disassembled my LNT to check the wire positions.

Subject:	ETX 105 PE - LNT modules moves?
Sent:	Monday, June 12, 2006 01:30:01
From:	Ken Hyams (ken.hyams@p-seven.com)
Currently, I can't get my scope to get very close to the initial
alignment stars. The targets fall, at least, off the Smartfinder. Once I
manually center the brightest star, and complete the alignment process,
Go-Tos are perfect. I think that means that my motors are trained and
calibrated properly. I've calibrated the sensors (which ain't easy in
the Southern Hemisphere!) several times and can't improve the initial
pointing.

I noticed last night, while aligning the Smartfinder, that the LNT
module has a bit of play in it. It can probably move 2-3mm right/left if
I wiggle the front. I tightened the two screws (under the circuit board
inside the thing) which has secured the module so at least my finder
will stay aligned.

My question is, how much of difference would it make if the module is
not perfectly aligned with the tube? Are any discrepancies compensated
for when calibrating the sensors?

Mike here: If you are using the SmartFinder ONLY for centering the alignment stars then any error in its alignment to the OTA will be evident when you GOTO to objects; they will be under the red dot but not in the eyepiece. So, it does help to have it aligned. CALIBRATE SENSOR compensates for local magnetic interference and your local magnetic variation.

And:

Thanks for the super-speedy response. My initial email was a little
confusing.

What I'm wondering is if the LNT module is misaligned with the OTA due
to play in the mounting, will it be able to accurately point to the
initial alignment stars during the auto-align process?

Mike here: In an ideal world the LNT would be perfectly aligned to the OTA and hence NORTH would be accurately determined and the first alignment star would be perfectly centered without needing a user adjustment to center it. Any pointing error in the LNT would cause an error in where True North is located in reference to where the OTA is pointed. But once you center the first alignment star, the Autostar can take out part of that error when slewing to the second star.

Subject:	ETX-125PE
Sent:	Sunday, June 11, 2006 06:08:08
From:	jasminpindzic@comcast.net (jasminpindzic@comcast.net)
I bought me ETX-125PE.  Last night I took 125PE out for the first time,
I calibrate motor and train drives. I was having trouble with automatic
alignment with my thelescope, the motor slews horizontal until it stops
, I could still hear the motor running but the telescope tube was not
moving. When I did one star aligment I had no problems, do you think
I'am doing something wrong here?

Should I always aling it manually?

I would appreciate your help on this.
JAZ.

Mike here: Did you put the telescope in the proper HOME position for the Automatic alignment? It is different than the non-Automatic alignment HOME position.

And:

Thank you for fast respond to my e-mail.

I read the owners menual today and I think that I didn't put the
telescope in the proper position.

Thank you for your help Mike, I will try to do that tonight again.

And:

I put my 125PE in the proper position just like it was explained in the
menual, I still couldn't get it to work. I put telescope in home
position than I pointed North using compass. First I tried automatic
align, it didn't work than I tried easy align I still couldn't get it to
work, I couldn't even get to work one or two star alignment anymore. I
don't know what I'm doing wrong, looks like I don't know how to align my
telescope.
Any advice would be appreciated.
 
JAZ.

Mike here: You don't point the telescope to Magnetic North when doing an Automatic Alignment. You leave it at the hard stop. You don't point the telescope to Magnetic North when doing an Easy Alignment; you use True North, which can be up to about 20 degrees, when rotating back to the north from the hard stop. For alignment tips see the Helpful Information: Autostar Info page. The tips there apply to Easy Alignment.

And:

I got your last e-mail about how to align my 125PE (Thanks). I will try
to explain how I align my telescope.

This is what I do when I do EASY or TWO STARS or ONE STAR ALIGNMENT.

-I Put the telescope in the home position.

-Turn telescope tube counterclockwise until it stops. (according to
owner manual)

-Than I turn telescope tube 1/4" of a turn clockwise to line up the
computer panel so that telescope is pointing North, now telescope is in
the home position, then I hit (ENTER).

The telescope is looking for two stars, when it slews to first star it
tells me to center the star than hit ENTER, so I do that, than the
telescope moves to the second star I center it and I hit ENTER again,
successful align display.

When I want hit go to Jupiter the tube slews to the wrong direction.

Sometimes if I do AUTOMATIC ALIGNMENT when the telescope is trying to
find the North and find the level, it turns always around and than the
tube just stops but the motor is continually running, I am not sure why.

Aligning the telescope is the only problem that I am having .

Do you think there is something wrong with telescope or maybe I am doing
something wrong.

I hope you wont mind read this thru, but I tried to explain as much as I
could.

Thank you very much Mike.
JAZ

Mike here: The rotation back to North is more like 120 degrees, not 90 degrees, from the hard stop. Regarding slewing in the "wrong direction" to go to Jupiter -- the Autostar does not always take the shortest way around to get to an object. Is that what you mean by "wrong direction"? The Auto Align process does take a few minutes. At the end it slews to the first alignment star. Is that NOT happening?

And an update:

I think I solved the problem aligning my telescope, I was doing
something wrong when I was trying to do automatic alignment. I went to
your website (AUTOSTAR INFO. PAGE) and I found a lot info on how to
align my telescope.

I hit automatic align the telescope leveled it self pointed North and
found two stars, I still had to center the stars my self than I hit
ENTER, it looks like it's working now. I tried so many things to align
my 125PE, but I couldn't get it to work. I think that everyone that's 
having problems with aligning their telescope need to take some time and
go to your website, cause that's the only one place you can find the
answer.

In the future if I have a problem with my telescope, I hope you wont
mind helping me out, because I think you are the only one that can help
here.

Thank you very much

JAZ.

Subject:	no problems setting up the ETX 105 Premier Edition
Sent:	Monday, June 5, 2006 21:03:36
From:	amy stone (amstone1@comcast.net)
I ordered an ETX 105 Premier Edition before I discovered your website. 
After reading some of the posts to you regarding the problems people
have been having with the PE versions of the ETX, I was certain that I
had ordered a telescope that was too complicated and that I'd never be
able to set it up correctly.  (I've never really used a telescope
before.)  I just wanted you to know that I had no trouble inserting the
Smart Finder lens into its slot and the red dot appeared in the middle
of the lens, as it is supposed to.  I also had no difficulty setting up
the AutoStar for the automatic alignment.  The only information that was
not correct was the time -- it was off by an hour.

It's been cloudy or raining since I got it so I have not been able to
use it yet.  I'm just wondering if I should have ordered the ETX 125 PE
with UHTC.  I can try this one out for a month and exchange it if I'd
like.  I'd appreciate your thoughts on that.

Mike here: Did you check the Daylight Saving setting in the Autostar? As to UHTC, it is definitely worth considering. It is like adding another inch of aperture; more light reaches your eye (or imager) than with the standard coating.

And:

I did check the daylight savings setting in the Autostar.  I will
seriously consider exchanging this one for the UHTC.  What about going
up to the ETX 125 -- will I be able to see any deep sky objects that
won't be visible with the ETX 105?  I know this type of scope is not
really the best for viewing DSOs.

Mike here: From a dark site the extra light gathering power of the ETX-125 over the ETX-105 will certainly make a difference. As to the LNT time, did you reset the time in the Autostar to make it correct?

And:

Yes, I did re-set the time to correct it.  Thanks for your prompt
response.  I'm wondering if I lucked out in getting a scope that set up
so easily with no, as of yet, apparent problems.  If most people are
having problems with these scopes, I'd be reluctant to make the exchange
for fear that I'd get one that doesn't work well.  If most people have
no problems, on the other hand, I'd seriously consider trading up to the
ETX 125 with the UHTC coating.
 
Your thoughts?
 
Amy

Mike here: Keep in mind that "most people" write when they have problems, not when they don't. So the perception is highly skewed to the "problem" side of the spectrum.

Subject:	ETX 125 PE - OTA Removal
Sent:	Friday, June 2, 2006 01:25:44
From:	Mal (mkr@ozemail.com.au)
I purchased my scope in November 2005 but have been visiting your site
long before that. The knowledge I gained before and after the purchase
has proved invaluable. Thanks.

I have to return the drive base to the supplier to rectify jerky motion
in the RA drive. As I was concerned about possible damage to the scope
during shipping, it was suggested that I remove the OTA and ship the
drive base only.

The method I was told by the supplier for removing the OTA was to remove
the focusing  knob and the three screws on the rear of the OTA. I assume
that the fouth screw is for the LNT and does not have to be removed.

My problem is, everything I have read on the net regarding removal of
the OTA states to remove the four screws on the side of the fork mounts.

Could you please tell me the difference between these two methods and
also what size allen key I require for both sets of screws, as neither
of the two allen keys supplied with the scope fit.

Thanks for your help Mike. I really appreciate the time and effort
required to answer these types of questions.

Best regards for Australia,
Mal Rose

Mike here: You got bad info. To remove the OTA you do still remove the four bolts, two on either side of the OTA that holds the tube adapters inplace. Once the screws are removed you can carefully pry the adapters away from the tube and slide the tube out. HOWEVER, if you are returning the telescope to Meade I would check with them before removing the OTA. As to the allen key size, unfortunately I don't have an accurate way to measure that.

And:

Thanks for your advice Mike.
To be on the safe side, I think I will return the unit intact so as not
to jeopardise the warranty.

Best regards,
Mal

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