Last updated: 31 October 2007

This page is for user comments and information of a general nature or items applicable to all ETX, DSX, and DS models. Comments on accessories and feedback items appropriate to other ETX and DS models are posted on other 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:	On the subject of ETX Collimation
Sent:	Wednesday, October 31, 2007 14:17:10
My hope is that this message will result in some "lively responses" from
the more learned ETX experts, regards "collimation".

I have both an ETX90 OTA and a first-generation ETX125. Both have
traveled the world with me. The 90 looks rough, but optically, it is
excellent. I've completely rebuilt it and collimated it myself on real
stars (only during excellent seeing), thanks to "access holes" I drilled
in the back of the plastic housing behind the primary (ugly but
functional for this road warrior). Out of focus stars form nice
concentric bullseyes, and in-focus stars form perfect Airy disks with
perfect tiny bullseyes. If you look into the front of the OTA at various
distances from a few feet out to 10 feet or so, the alternating
black&white rings are nicely concentric.

I bought the ETX125 about a month after Meade started selling them, so
it's about 10 years old. It has also traveled quite a bit. Because of
dust inside the OTA, and a slight clunking noise inside when I moved the
tube, and because it was so out of collimation, I decided to clean (the
primary only) and collimate it. The "clunking" was eliminated by a
single wrap of Teflon tape over the paper sleeve on the baffle tube
which passes thru the primary mirror. Note that the mirror still
"floats" on the baffle tube - but it no longer "shifts", i.e. "clunks".
I carefully reassembled the OTA (with all the components carefully

Results of rough collimation by aligning the black & white rings,
visible when looking into the front of the OTA were awful: "stars"
looked like comets.  No amount of tinkering yielded improvement. So, not
wanting to drill access holes into my ETX125, I machined an adjustable
aluminum assembly ("disk") for the back of the OTA which provides access
to the push-pull adjustments. This disk also has a 1.25 inch eyepiece
adapter in the center. I machined everything with precise tolerances,
then Laser-aligned it making it coaxial with the OTA optical axis.

I mounted the OTA on a heavy duty GEM, lined up on Polaris with seeing
about 9 out of 10, let it equalize for about 5 hours, then went to work
on the push-pull screws until I had a perfect little Airy disk while
using a Televue 3X Barlow and a 4.8mm Nagler (over 1100 power). Polaris
B (19 arc-seconds from Polaris A) was easy. (And no, I won't even
pretend I could see any sign of Polaris AB: 0.2 arc-seconds from the A
star - but I sure hoped I could !). Over the next few nights, I setup
again, and verified the collimation on Polaris and other stars.

Now here is the puzzling part - when I look into the front of the OTA,
instead of perfect alternating black & white rings, they aren't
concentric. The pattern isn't terribly off, but it just doesn't appear
as perfectly concentric as it does in the ETX 90. So the point of this
treatise is this: if anyone else out there in the ETX world has
undertaken such an endeavor, I would be very interested in any ideas,
advice, comments, experiences suggestions, etc...

Note that this process is not for the faint of heart - it is very time
consuming, VERY risky, and can cause great frustration, anxiety, stress,
and sleep depravation. I don't recommend the average telescope tinkerer
attempt to collimate an ETX without access to a machine shop, optical
test apparatus, excellent skies, some good references, and lots of time.
But in my case the results have been very rewarding !

Oh, and thanks to Richard Suiter's book "Star Testing Astronomical
Telescopes", which was invaluable to me in this enterprise.

And of course, to Mike Weasner's website for providing this excellent
forum !

Best Regards,

Michael Lang
Aldie, Virginia

Subject:	ETX-125 setting circle problem
Sent:	Wednesday, October 31, 2007 10:37:07
From: (
Last night when I uncovered my polar-aligned ETX-125 (stored in a
SkyShed POD within a Reflectix cocoon) to take a look at Comet Holmes,
the RA setting circle had expanded and fallen down around the base and
over the 884 mounting plate. I was able to ease it back up into its
groove, but every time the scope slewed, the thing dropped off again.

I cannot think of a way to shrink it the few millimeters to make it stay
put.  If I cut and resize it, even that small amount, the accuracy might
suffer.  Have you ever heard of this problem before?  Is there a cure
that you know of?

Dr. Clay Sherrod supercharged this scope last June and I have never had
any problem at all since then.  Now, all of a sudden, this mystery. I
need some help with this one.


Kris Torrey 
San Bernardino, California
Mike here: Mine came off years ago and I've never bothered with trying to put it back on. Someone else reported a similar problem. Do you EVEN use the RA setting circle? If not, don't worry about it.


It is true, I didn't really use it.  I've noodled around with it
occasionally, but nothing serious. I'll probably take your advice and
leave it off.

Thanks again for the -as always- great advice, 


Subject:	ETX-90 EC Gears
Sent:	Monday, October 29, 2007 15:05:08
From:	roger farhat (
I have bought my first ever telescope, a used ETX 90 EC. I was so
excited about it and about how it is going to show me the universe. Once
I turned it on, I found out that there is a problem with the Azimuth
rotation. I contacted Meade customer support to find out they no longer
service this kind of telescope. I went ahead and opened the telescope to
find out that one of the gears teeth are missing on one of its gears
(which I have attached a picture I found on the web from someone who had
the same problem, with the arrow pointing to the bad gear).

I tried so hard to find out a similar gear or a place that sells them
but no luck so far. I was hopping to hear your suggestion on where to
find this gear or a way to fix this problem.

Your responce would be greatly appreciated.



Mike here: Try Telescope Warehouse or Scopestuff (links on the Astronomy Links page).
Subject:	ETX125PE will lose appox. 2'30" for evey 6hr of rotation 
Sent:	Monday, October 29, 2007 05:39:05
From:	wilcoxg (
First let me thank you for such a outstanding site, the in-depth
information that I have obtain from your site has been priceless, hands
down to your sir.

The problem that I am having with my ETX125PE is no matter what I do the
goto accuracy will continue to lose approx. 2min 30 sec for every 6hr of
rotation. In other words if I rotate the scope 12 hr using the goto on
the 497 or using the Autostar Suite (scope connected to my laptop) the
goto accuracy is now off by approx. 5min. I must manually rotate the
scope to the east using the 497 hand controller to bring the object into
the FOV. This happens in both the east and west rotation. From my
observations this is only happening in the R.A., declination seems to be
very close, using a 26 mm eyepiece.

The action I have taken to fix, troubleshoot this problem has been to go
through the step by step "creating the perfect goto" as outlined on your
web page. The problem to me seems that I am getting clutch slippage in
the R.A., but this axis will lock with little pressure and requires
effort to cause this axis to slip by manually turning. Also I have
checked that I do not have any missing teeth in the R.A. drive train.
Repeated "train drives" as outlined on your site has not corrected the
problem with and without 497 resets. This scope is new and the only
mechanical issue that I found was slippage in the declination clutch
that was corrected as outlined.

Thanks in advance for any suggestion in correcting this issue.

Gil Wilcox
Mike here: Have you done a CALIBRATE MOTOR? Also, when doing a TRAIN DRIVES on the RA axis, what eyepiece are you doing and how distant is the object? The accuracy of the training will effect the size of the error. Also, do you see the error regardless of the type of alignment you do? Does the error occur no matter which direction you slew, CW or CCW?


Thanks for the fast reply,Yes the motors were calibrated after a reset
of the 497 (it did this auto after reset) also tried it after manually
doing a motor calibration. The eyepiece i was using to train the drives
was a 9.7 mm with a object approx 1 mile away. This error occurs both in
CW and CCW , also i see this error in auto and easy 2 star alignment
setup using alt/az mount. Here are the steps in order that i took .

1) sets scope up
2)released RA lock, rotated CCW to stop, Rotated CW till yoke with dec
centered over control pannel, locked RA
3) picked scope pointed ota to north (c/p pointed west)
4) leveled scope tripod
5)unlock ota clutch, leveled, relocked
6)power up autostar (using meade a/c power surpply)
7)reset 497 (auto calb. motors), entered zipcode/daylight savings/ETX
model number, checked date and time all ok .
8)Train Drives using 9.7mm eyepeice
9)set RA setting circle to 0 (manually turned ring to 0)
10)setup training object as landmark
11)moved ota using 497 west and down approx 6 hr west 20 dec down
12)selected the training object from landmarks and pressed goto
13) scoped moved to training object but was 2min 30 sec to the left of object (per scale set in step 9)
14)repeated step 11 but movied to east and down same amount as step 11
15) repeated step 12
16) same results as step 13
17) repeated step 11,12, 2 more times but moving west and up/east and
up, each time same results as 13.
18) i than repeated the whole process over but this time moved the scope
12hr and the error was now appox 5mins. 2 x the error of 6hr rotation

I tried this method again after doing a manul motor calb. with approx
the same results. Reset the 497 again entered all information, trained
drives. All this was done during the daytime. Later that night i did the
easy 2 star alignment and noted approx the same error as i had using the
landmark target, than i tried the auto alignment with the same results
both using 26mm eyepiece to center alignment stars. Sure hope i did not
miss anything as i was taken notes during all the testing. Oh after i
did the auto alignment is when i tried the Autostar Suite slewing the
scope using the software with the same results.

Gil Wilcox
Mike here: First, I wouldn't rely on the setting circle tape to be accurate as it can slip. If you want accurate readings use the MODE display to display azimuth or RA. That said, there have been occasional reports of not being able to slew accurately to landmarks. You might search the Site for "landmark" and look through those articles. By the way, how are the GOTOs to astronomical objects?


Mile, this same error happens using the goto astronomical objects also,
using the 497 or autostar suite..
Mike here: Well, all things considered that is a pretty small error for a 180 degree rotation. Some error is possible in the AutoStar/ETX movement due to the design (even the 3.5 meter WIYN telescope at Kitt Peak had GOTO errors when we have visited it). Using High Precision or SYNCing on another object will improve GOTOs in that area of the sky.
Subject:	ETX-125EC Dec/Alt design fault
Sent:	Sunday, October 28, 2007 12:03:56
From:	Glenn Craig (
To begin with there is just too much weight hanging out there in front
to make for a very happy scope.  This ends up as looseness in the
vertical axis.

The right trunion, the one that has the clamp on it, has a groove for
the key on the "limiter-ring".  (This is the one on the right side, with
the drive-ring and the star compression-ring to the left of it.)

This ETX-125EC was very much abused by its previous owner.  The optics
are still very good, but when I got it would not hold in the vertical
axis at all.

Cleaning and trying the tips on your site helped a lot, but the tube
will still move almost an inch at the front because the key of the
limiter-ring is loose enough to rotate on the black plastic trunion. 
This entire part should have been metal, or at least had a metal sleeve
to prevent this from happening.

Close examination of the parts shows some wear, but nothing that would
indicate how much slop comes from this one location on the vertical

The excess motion can be stopped by clamping tightly, but only a small
amount of force is required to move the OTA out of its clamped position.
Unless there is a replacement part, or better still, a redesigned part
made of metal, there is no fix for this.

(If anyone knows where to obtain a new right trunion for this model,
please advise !)

As it is, I am thinking of externally augmenting this scope, so that it
operates as it should.

Those 1/4" holes in the bottom of the tube assembly are a good place to
attach a counter-weight to restore balance to the instrument.
Mike here: Yep, those photographic tripod mounting holes work fine for that. In fact, one particular camera piggyback adapter that I'm aware of supplied a counterweight that attached there.
Subject:	etx-125 excessive slewing
Sent:	Sunday, October 28, 2007 11:52:38
From:	Alexandre Koukarine (
I'm having problem with my telescope and Autostar 497 (ROM 4.3eg
flashed). I've searched your site for "random slewing" but most
occurrences are not exactly refer to my situation. Though, I've tried
most of the suggestions (reflashed ROM, reset Autostar, safe mode,
recalibrated motors, retrained drives, and checked cables) nothing

Here is the problem.
It works perfectly without the alignment. With either batteries (100%
fresh) or AC adapter power.
But after the star alignment process, if I slew the scope manually in
any direction (vertical or horizontal) it's slewing  upwards for a
degree or so by it's own right after that every time! Sometimes it's
self-slewing in horizontal direction too (but less or less frequently).
After that it stays put. Sometimes I can't align the scope because when
I'm centering the alignment star manually it's slewing in response like
described above so, there is no way to center the star at all.

One time, after exiting the safe mode, I was in retraining the drives
mode, but no matter which slewing speed I select on the Autostar the
horizontal speed was always the highest.

Any suggestions?

Mike here: The first problem might be due to dirty encoders. You might be able to just redistribute the lubrication to clear the problem. To do this unlock both axes and slowly move the telescope from hard stop to hard stop, back and forth several times. If that doesn't help and the encoders are indeed dirty then you will have to open up the mount and check them and perhaps clean them. See the article "Cleaning the Encoders" on the Helpful Information: Telescope Tech Tips page for more info. Another possible cause of the first problem that could be related to the second is a dirty contact (or more than one) inside the AutoStar handset. See the article "Keypad Cleaning" on the Helpful Information: AutoStar Info page.
Subject:	RE: Poor/no power
Sent:	Sunday, October 28, 2007 08:20:52
From:	richard seymour (
For diagnosing COM problems, there's always:

good luck

Subject:	Comet 17P Holmes
Sent:	Thursday, October 25, 2007 20:22:17
From:	richard seymour (
Mike Weasner wrote:
... my ETX PE is packed away for a move)

Unpack it and go out and look at comet 17P/Holmes.
(or at least binoculars)
It's on the straight line between Capella and Mirphak (Mirfak),
about 80% of the way towards Mirphak.

It's naked eye here in Seattle, and the only other stars
i can see in that octant of the sky -are- Capella and
Mirphak (who needs flashlights in-city?)

have fun
Mike here: Just went out (2110 Thursday) and found it in 7x50 binoculars. It was very bright, even through our smoke filled skies (from all the Southern California fires) and a Full Moon. Looked like a bright out-of-focus star! Impressive!
Subject:	possible declination clutch slippage...
Sent:	Thursday, October 25, 2007 16:03:36
From:	Steve Seman (
As always great site. I was reading the recent update and saw that a
fellow 125 owner is having a problem similar to one I had about a year
ago. I would suggest that you advise Bryn Davis from the Isle of Wight
to look into Jordan Blessing's method of degreasing the friction
surfaces of the declinaton clutch. I followed it to the t, and bang,
problem gone! Just a possibility, but I'd give it a try.
Jim Seman

Subject:	RE: Poor/no power
Sent:	Thursday, October 25, 2007 14:47:49
From:	kath (
A replacement Autostar arrived yesterday!

No documentation as to the fault, but a very fast and efficient service
form Meade Europe.

I haven't had a chance to put it through its paces yet (too cloudy).
However, I was hoping to upload a few of the Tours, but don't seem to be
able to get it to connect to the computer.

I keep getting the "Could not connect to Autostar" and "could not find
com port" messages.

I'm trawling through the Autostar help pages at the moment to try and
find a solution.

Mike here: If you have a USB-serial adapter, see the article "AutoStar and USB" on the Helpful Information: AutoStar Info page. Not all USB adapters work reliably with the AutoStar.


It's the bog standard type not the USB.
I've checked all the port settings, but they're fine.
I wondered if it was some other WinXP problem.
Still looking....
Mike here: Check for a serial port conflict (typically fax software). Also, be certain you are trying to use a serial com port between 1 and 4.
Subject:	Autostar 497
Sent:	Tuesday, October 23, 2007 09:49:44
From: (
Hi, I have just purchased a mint condition, used ETX 90. All the
components were included. The Autostar unit was DOA. No read out, Light,
Led, nothing.Is there a trick to reset the unit ? I am in Hawaii and the
unit was bought from PA. Any suggestions would be greatly appreciated.

Thanks for the great info, I've been reading your pages,good job.

Mike here: It sounds like power may not be getting to the AutoStar. Have you tried reversing the cable? Also, check the condition of the pins on the connectors and inside the ETX base jack and AutoStar jack. They should be clean and not bent to one side or too depressed. You could also try a reset from a terminal program; see the article "AutoStar RESET from Software" on the Helpful Information: AutoStar Info page. If nothing helps, you could check for a truly dead AutoStar by making an external power supply for it; there are several articles about this on the Helpful Information: AutoStar Info. But I suspect you will end up contacting the dealer for a replacement.
Subject:	on clarity and good seeing for detail
Sent:	Monday, October 22, 2007 23:24:43
From:	Benjamin Waranowitz (
First to congratulate you on your fine site as a resource I have saved
in my Favorites.

I found your link

- and it is durned good. I didn't notice mention of my 'discovery'.

I have found that in the hour before sunrise there are opportunities of
the best seeing I have had. Caveat: The air must be fairly clear and
cloudless. This is in locations near Nashville, TN and Prince Frederick,

AND I expect these conditions may be universal to most amateurs
observing sites. I remember at dawn from Breezy Hill when camping at
Stellafane the fog lay in the valleys below like pea soup in a bowl!


Subject:	classification of M71
Sent:	Monday, October 22, 2007 22:56:54
From:	Benjamin Waranowitz (
I came across the writeup you have for M71 so thought you would like to
know of this reference as you could not tell if it is a globular or a
tight open cluster. Don't feel bad, the experts are not certain which it

Mike here: Thanks for the feedback. Which page did you see that report? As to the SEDS Site, it is a great Site and I've had it listed on the Astronomy Links page for a few years.


I found your ref to M71 here:
Mike here: Those articles are written by Dr. Clay Sherrod, retired Astronomy Professor and noted researcher. I have passed the comment to him.
Subject:	Update: my saga with Meade customer support and ETX 90 PE UHTC ... continues and continues
Sent:	Monday, October 22, 2007 16:37:55
From:	Tom Farrell (
Wanted to give a short update on what you posted on my behalf in early
September.  No response of any kind from Meade.  Today I telephoned, got
through amazingly quickly, considering it took a month of tries last
time, and got a rather helpful customer support engineer, who was
willing to personally expedite to the appropriate person emailed copy of
what I US Mailed to Meade on same date as my post on your website 
containing my collected correspondence to Meade regarding RGA0098. 
(Wow, "collected correspondence"  sounds like I'm a dead author or
something  and it does feel as though I have written a book on this.)  I
really hope this document gets some attention at last, even if my
request will not be granted, because of the wealth of meticulous
feedback I provided which should be of some use.  We'll see how it goes.

It turns out there is a probable reason why my multiple inquiries have
gone ignored and perhaps also why I have encountered manufacturing
issues in the three ETX 90 PE UHTC models I have had to swap out with
Meade after my original purchase in February 2007.  I did not know till
today that Meade had a pretty big layoff earlier this year.  The
customer service manager, Ty Robertson, whom I had originally attempted
to email, has been "doing the jobs of three people" so I am told. 
Sounds like this may now be the case throughout Meade.  A shame they had
to do the layoffs.  At least this begins to offer some kind of
explanation for what I have encountered.

Will let you know what I may hear next.

Incidentally, I reviewed my MP3 recording of drive sounds before
emailing that as well.  I found the aberrant counterclockwise RA drive
sounds as recorded do not really represent how loud and rickety they are
in person.  I think I had the microphone up too close to the base where
the drive motor and regular gear train sounds seem to almost overwhelm
the different-timbred and pictched this whole thing is all about.  It
really is a nasty sound in person.

Tell you what, if Meade does not cooperate, I've pretty much already
decided, once my one-year warranty expires, to make use of instructions
and photos on your web site to go in and do some quick "exploratory
surgery."  While my major concern her is averting a later major failure,
I suspect the problem is quite small and isolated  and as easy to remedy
as perhaps just scraping a bit of errant cement of a gear cog.

But if Meade does cooperate then I will be sending my scope back to
Irvine for repair just as the skies are finally clearing of the summer
haze which obscured nearly every star in the sky.
 Tom Farrell

Subject:	Problem with declination motor using autostar - ETX125
Sent:	Monday, October 22, 2007 05:22:48
From: (
I have just found your site and it looks very useful.
I have a problem with my ETX125. I have been using it for several years
with great success. However recently, when used manually or under GOTO,
the declination motor fails to raise the tube, the motor just seems to
grind away. The motor operates as normal when lowering the tube. I have
stripped the unit down, by removing the tube and the inner facing to the
arm and found nothing seeming wrong. The gearing seems to be firmly
connected. However I found that when operating the motor without the
tube in place the holder moves properly up and down.

On refitting the tube and trying the motor again, I found that with a
little help from a finger under the front of the tube, the motor was
able to cope in raising the tube. Similarly with a little help from a
finger or a little extra weight at the rear of the tube it works well.

Why should this have happened do you think? Is it OK to continue to use
the telescope with the extra weight on the rear? Has anyone else
experienced this problem?
Any help or comments welcome.
Bryn Davis
Isle of Wight
Mike here: It sounds like the friction lock is not engaging sufficient to overcome the weight of the OTA. You could add a counterweight or you could see if something in the article "DEC lock mod" on the Helpful Information: Telescope Tech Tips page might help.
Subject:	ETX 90 - 125 - LX 90 8" GPS Short report
Sent:	Saturday, October 20, 2007 15:16:18
From:	Jan H Kolst (
I started out with a ETX 90 AT and after some years I bought an ETX125
AT. To me it seems as if the ETX 90 AT is more stable concerning
accuracy than the ETX 125 AT. On the other hand ETX 125 is of course
better concerning viewing the sky due to having a larger aperture. But
I'm very comfortable with both scopes. After investing in an LX 90 8"
GPS the stargazing had a new dimension because of the aperture and the
accuracy which was tremendously improved. When taking images with the LX
90 , the objects are always inside the eyepiece ( 18mm UWA) and this
makes imaging much easier.( I'll give the  ETX 90 AT to my grand
children, hoping they'll take an interest in astronomy) My 4 children
have no interest so far. Politics and money are their interests. Like
their father(I) at their age. But life moves on

When training drives I use the Polar star and speed 2 with the scopes.
In spite of that the LX 90 is always much more accurate than the ETX
scopes. Does this make sense? Perhaps the price of the scopes is the
answer? Anyway I had a lot of success with the LX 90 which I use as
often as possible , but living in Western Norway I do have a problem
with clear skies. Anyway I think this is the largest scope that is
easily portable. But finally I'd like to mention the brilliant service
I've received from OPT throughout the years, and especially Rayna. She
is just marvellous and clever, giving an excellent service even if I
live in Norway. Clear skies!!!
Jan H Kolstoe

Subject:	eyepieces
Sent:	Saturday, October 20, 2007 13:19:42
From: (
hi mate, i have an etx 90 spotting scope,  which eyepieces do i use for
looking at the moon, and whi ch eyepieces are good for planets?  i have
26mm eyepiece, 2x barlow lens and a  9.5mm eyepiece  which eyepice is
good for both  lunar and planetary observing?
thank you
Mike here: What you have is fine for looking at the Moon and planets. For more on eyepieces see the Helpful Information: Buyer/New User Tips page as well as the Accessory Reviews: Eyepieces page.


i tried using 26mm eyepiece in 2x barlow to look at the moon but the
image was shaking,  so i was wondering would just the 26mm be ok for
looking at the moon and the planets or would have to use the 9.7mm
eyepice for planets?  what would i use the barlow for?
Mike here: Using the 2X Barlow Lens doubles the magnification of each eyepiece it is used with. How much magnification you can use depends on many factors including the diameter of the telescope's objective, the current atmospheric conditions, whether or not the telescope has reached "thermal equilibrium", the sturdiness of the mount, and the object being viewed. As I said, those eyepieces are fine, with or without the Barlow Lens. Use what the conditions and your experience allow.


hi mate i just tried looking at the moon with 2x barlow with 26mm,  it
was very near to the moon but the scope was so shakey.  how do i keep it
still, would i get the same mag with just the 26mm?   months ago i
looked at venus with the 26mm eyepiece but the planet was a bright dot, 
with which eyepiece can i see a little detail of how planets look, but
not too strong and shakey? do i need the 2x barlow or can i get close up
images of the moon and a little detail of planets without the barlow?
thanks mate
Mike here: It sounds like you need a better tripod for use with the telescope. What are using for a tripod? Also, if the tripod doesn't have a motor and mount that will correct for the Earth's rotation you will have to keep moving the telescope yourself to keep the object in the eyepiece, leading to even more shaking.
Subject:	ETX 90 Focusing and LNT
Sent:	Friday, October 19, 2007 14:53:24
From:	david ll (
I was one of the lucky ones to purchase the etx90AT during meade's close
out last week.  It arrived Friday, and took it out for First Light sat
evening.  Quick images of the moon and jupiter were crisp and sharp, so
overall I am happy with the scope.

Few questions, comments, complaints:  Like manyI have read about, the
whole corrector plate came off rather than the cover plate.  was a bitch
to finally get it loose, but I finally did, and it did not seem to
affect the colmination. (I'll check it out with others at the next star

The focusing knob/shaft seems to be rather rough and has quite a bit of
play as you try to fine focus... almost seems to "jump"... is this
normal or should the focusing be smooth like on my lx90 8"??

I have an extra LNT unit (don't ask!! :)  Is there a way to attach/use
this with the etx90AT? (this is not the new PE model, but it is complete
with autostar 497).
Mike here: The focusing shaft rotation should not be rough and may just need to be loosen up by using it. There have been such reports in the past. If it doesn't loosen up or you see a lot of image shift then something in the primary mirror movement may be catching. As to the LNT, see the article "Adding a LNT to a non-LNT Telescope" on the Helpful Information: Telescope Tech Tips page.


One more... on the base of my new etx90at, one of the screws is
springloaded, the other is not.  Is this normal, or should both be
Mike here: The only spring-loaded screws that I know of are the two on the tripod mounting plate that hold the ETX to the tripod. I don't know of any on the ETX base.


that's what I meant... on the mounting plate of the 884 tripod... are
both supposed to be springloaded? (or just one?)
Mike here: Both.
Subject:	ETX-125: to train or not to train?
Sent:	Friday, October 19, 2007 05:15:04
From:	Ihab Mohsen (
I tested my telescope as you recommended and the picture looks
perfect(well exactly the same as it did before, maybe a little clearer),
so I guess everything is ok with the optics. Know I'm having another
problem. I only started noticing it since I recently bought the LPI and
#64 adapter for my DSLR: The telescope doesn't track objects at all!!
Since I also had a problem with AZ/RA backlash I thought maybe the
problem is with the RA/AZ or Alt/Dec % setting. I adjusted the RA/AZ
from 1% to 99% and I noticed no difference, and the telescope still
doesn't track! After reading some posts on your website I concluded that
I would probably need to train the drives(in Alt/Az mode which I always
use). Sounds easy except that from my location(Dubai, UAE) Polaris is
hardly visible(due to too much ambient light everywhere, even on the
beach!!). My questions are:1)Is my conclusion about training the drives
correct? 2)Can I achieve enough accuracy using a terrestrial object for
Alt/Az training to be able to get the telescope to track properly?

Appreciate your advice.

Ihab Ali
Mike here: Ideally TRAIN DRIVES should be done using a terrestrial object. Since you have already adjusted percentages (which you may or may not needed to do) I recommend doing a RESET, CALIBRATE MOTOR, and then TRAIN DRIVES. Do the training on BOTH axes. When you do the RESET you will restore the AutoStar back to its "factory default" settings and will have to re-enter your Site location and any other changes you made. When doing the training be certain to use a distant object.
Subject:	ETX90
Sent:	Wednesday, October 17, 2007 14:09:25
From:	Paul Quenneville (
I recently fixed my ETX 90 Meade telescope where the focus knob came
undone. I unscrewed the front lens and was able to adjust the mirror
back down into the tube, (after connecting the focus shaft back) and
re-tightening the shaft through the opening. The focus works great now.

Now when I look at the night sky, ONLY bright objects can be seen. I was
VERY careful NOT to tough the mirror when putting it back in.

It seams that there is a dirty lens or something, but everything looks

Could it be that I need to collimate the scope? How do I do that?
..........or what other things can I try?

Paul Quenneville
Mike here: Have you done a "star test"? Let the telescope reach "thermal equilibrium" (about 90 minutes for the ETX-90). Aim the telescope at a star like Vega and turn the focus knob back and forth in and out of focus on either side of in-focus. You should see the out-of-focus star as concentric rings of light on both sides of in-focus. If the rings are not concentric then you have a collimation problem. Re-collimating the ETX optics is not for everyone and if you don't feel comfortable doing it (as you can make things even worse) you will want to send it to Meade. But if you want to try it yourself there are collimation articles on the Helpful Information: Telescope Tech Tips page.
Subject:	re: Using Meade's "My Sky"
Sent:	Tuesday, October 16, 2007 21:06:40
From:	richard seymour (
Do NOT plug the MySky's cable into the AUX port.

It is intended to go into the Autostar's serial port.
That's the small hole on the Autostar itself, near the [scroll up] key.

The cable is NOT the same as any previously-supplied cable
which Meade may have supplied with other devices.

The pinout on the MySky cable was explored by Charles Jagow
of the Meade_MySky Yahoo group.

It is a one-to-one cable, with the pinout being
using a 4-pin 4-wide RJ10 plug at each end.

You wrote:
> I tried this out with a friends Meade 10" LX200 gps that is about 7
> years old and it wouldn't work is it because of too old of computer
> circuitry?

The DSI cable (9 to *11* pins?) (i think you meant to type 9 to RJ11?)
-should- work on the LX200gps (which has only been produced for 5.5 years).
I use it on mine.  You connect to the RS232 Serial socket next to the
Handbox socket on the LX200gps power panel.

If you build a MySky cable as described above, it would also work
with the LX200gps (it would be a very loose "fit" in the wider RJ11
socket used by the LX200gps... you could build a 4-to-6 pin cable
that would -look- like the "comes with DSI" cable, but the pinning
is quite different.  The comes-with-DSI cable is 1->5, 2->4, 3->3, 4->2
with pins 1 and 6 not connected on the 6-pin end.
The MySky cable for an LX200gps would be 1->2, 2->3, 3->4, 4->5
(with pins 1 and 6 not used on the 6-pin end)

All pin numbers are based with you looking at the pins,
with the locking clip towards the floor, and the wire going
out the "back" of the connector.  Pin 1 is on the left.
+-1 2 3 4-+
|___   ___|

have fun


Lou Welke wrote:
> Richard:
> Thanks for the info.on the My Sky cables, I found that the inlet to the 
> My Sky is a type of narrow phone type plug probably the 9 pin type and 
> if it goes to the inlet of the Autostar itself it also is a 9 pin type.

Both MySky and 497 Autostar use 4-pin RJ10 connectors.
Just like your sitting-on-the-desk telephone handset.
However the pin-to-=pin is -not- the same as the telephone handset.
(you could chop a telephone handset cord in half,
and rejoin the wires in the proper order for MySky purposes.)

have fun

> The cable I have is a 12 pin phone type plug on one end and a 9 pin 
> phone type plug on the other end(which of course will not work)
> This cable came with my Meade DSI Pro,so I suppose I will have to get 
> that cable from Meade.
> Lou Welke

Subject:	ETX-125  Help with all
Sent:	Monday, October 15, 2007 19:02:39
From:	Tom Perrone (
I just received a New ETX 125 and I took it out quick tonight.  A few
things I noticed is the DEC lock needs a tight turn.  I have the AT ver
not PE.  Also the focus at high mag is difficult.  It's not just the
mirror flop but when I wiggle the focus knob the image jumps everywhere.
I own an ETX90 and an LX200 SCT and I'm use to image shift not shaking
everywhere.  Also, star testing the scope proved the collimation is off.
My in focus image of Vega with a 6.4mm plossel was not a perfect point.
Flared to one side.  I'll confirm all my findings hopefully tomorrow. 
I guess it's back to Meade for some repairs.  I don't think it's right
for me to pay shipping on an in warranty item especially with
collimation that has no user adjustments.  I'll have to bring that up
with them.  Thanks for your ear!

Mike here: The image movement during focusing and the poor collimation may be related and due to damage during shipment. Did you pick it up at a local dealer or was it shipped to you? You might want to check for shipping damage on the carton and contact the dealer and/or shipper if you see any evidence of damage.
Subject:	ETX-125 Corrector Lens cleaning
Sent:	Monday, October 15, 2007 09:28:52
From:	Ihab Mohsen (
I have owned an ETX-125 EC with UHTC for about 2 years and today(for
some reason!) I decided to clean the outer lens(the outside surface
only). I have a camera optics cleaning kit with a cleaning fluid, lens
paper, and a dust blower. Not having read the recommended cleaning
methods in the posts on your website and on the meade website, I
proceeded to blow the dust from the outer lense(because I figured that I
had to touch the lense it would be better to remove any particles that
can scratch the lense) then applied a couple of drops of the cleaning
fluid and started to lightly rub the lens with the lens paper. This is
when I relalized that I might have made a mistake: as I dried out the
cleaning fuild with the lens paper(which is very soft) the cleaning
fuild left markings on the lens that wouldn't evaporate. I started
freaking out and got out my laptop screen cleaner and put a couple of
drops and rubbed the lens with a very soft cotton towel(made for
clearing sensative shiny surfaces). The markings disappeared and the
lens is now spotless. After reading the posts on your site I realized
that I have done something very very bad! Do you think I damaged the
corrector lens and the coatings?(I carefully inspected the surface of
the lens in bright sunlight, there is not a single scratch, it actually
looks better now)

Mike here: Using the dust blower (assuming it was the "squeeze-blub type and not the compressed-air can) was good. But using a cleaner not recommended for telescope lens coatings was a bad idea (as you have discovered). You probably didn't damage the lens glass but may or may not have damaged the UHTC coating. Since you don't see any evidence of streaking it could mean that you are OK (unless you completely removed the coating). Checks the views through the telescope using the Moon, brighter planets, and bright stars. If you don't see any glaring or flaring you should be OK. For the proper method of cleaning the corrector lens see the article "Cleaning Optics" on the Helpful Information: Buyer/New User Tips page.
Subject:	ETX90 Focuser help!
Sent:	Monday, October 15, 2007 06:23:11
From:	Paul Quenneville (
I was recently adjusting the focus shaft (I had taken the knob off at
the time) of my ETX90 Telescope and, by mistake) had turned it too far
and the whole shaft got sucked up into the scope. I can see the end, but
was not able to wiggle it out. I'm sure I need to take something off to
get to it.  Is there a way of getting it back out without too much
trouble? Do I need to re-calibrate the scope again?

I was planning on re- collimating my scope also.

Thanks for the (much needed) assistance.

Paul Quenneville
Mike here: There are articles on the focus shaft and on collimation on the Helpful Information: Telescope Tech Tips page.
Subject:	RE: ETX-90EC RA slop not due to slipping clutch
Sent:	Friday, October 12, 2007 07:58:22
From:	Chris Mahar (
I did the math, and my eight thousandths slop at 0.5 inches diameter
(approximately the diameter where the key engages the slot) works out to
1.8 degrees of slop.  That's just about what I estimated originally,
about 2 degrees of slop in the RA.  Add the normal gear backlash into
this and it adds up to our culprit.  This is just like C.S.I. only

Discussed the problem with several machinists at work, and they suggest
I bring the aluminum clutch plate in and let them reproduce it with
correct slot width.  Problem is those four thin wires that run through
the middle.  I'm considering their offer, but would have to cut and
re-solder the wires after.

On another note, I was reading through your wonderful website and came
across another occurrence of a phenomenon I'm seeing when I slew left
and right at speed 9; the whole RA plastic gear train and motor moving
up and down a slight amount.  It doesn't seem to be a problem, so I'm
ignoring it for now.

Part of the package when I bought this scope was your book.  Nice job on


Subject:	Using Meade's "My Sky"
Sent:	Thursday, October 11, 2007 20:16:40
From:	Lou Welke (
I am a new user of Meade telescopes and now have a new  LX90 8" and a
Meade My Sky, what I would like to know is how to use the My sky to
control my LX90 and is the cable that I got from a Meade DSI camera that
has a 9 pin plug on one end and a 11 pin plug on the other that goes
into a RS232 adapter be the cable I can use  between the My Sky and my

they seem to plug into each other ok.

Does the cable plug into the aux. port of the LX90?

I tried this out with a friends Meade 10" LX200 gps that is about 7
years old and it wouldn't work is it because of too old of computer

I just received the 8" scope today.

Thanks for any help you can give me.

Lou Welke
Mike here: I have not yet received my evaluation unit so I have no information that I can supply. I would think that the mySKY connects to the AutoStar #497 serial port but don't know for sure about that yet.


Thanks for the reply and I guess there are really not that many users of
My Sky yet seeing that it so new and being backordered in many cases.

When more people have this device there will be more info. on it's
ability to control many of Meade's 'scopes.
Lou Welke
Mike here: Meade4M members can get a free cable ( I can't tell from the photograph on that page if it wired differently from the standard #505 serial cable that connects the AutoStar #497 to a computer.
Subject:	Broken Link
Sent:	Thursday, October 11, 2007 10:22:07
From:	Jimbo's Place (
In your tech tips section I noticed the "Inside the ETX-125EC (11/13/01)" 
link is no longer active.  I was wondering if the data could be
recovered as I'd like to get to know the innards :) of my 125EC. 
Especially since my RA gearbox is on the blink at present (I speared it
with a Qtip while cleaning the grease off) and I need to find a way to
tighten my OTA to reduce wobble.



P.S. - As always, Thank You Thank You Thank You for keeping this site
up.  There is such a wealth of information available.
Mike here: Thanks for the report. I have removed the link. I used the "Wayback Machine" ( and while that gets the text, the images are missing and without them the article is meaningless. However, there are still other "inside" articles on the Helpful Information: Telescope Tech Tips page that might be useful to you.
Subject:	ETX125 Baffle Question
Sent:	Thursday, October 11, 2007 06:59:35
From:	Tom Perrone (
I recently purchased a ETX125 which hasn't arrived yet but I was
wondering.  Since there has been complaints about the size of the
baffle, is it possible to remove or shorten the baffle for less
obstruction, and use a dew shield to extend the tube to block any
off-axis light?  Just a thought.

Mike here: There are a couple of "baffle" modification articles on the Helpful Information: Telescope Tech Tips page. However, I don't recommend shortening or removing the baffle; it is there to reduce light glare and enhance the image contrast. Plus making such a modification will definitely destroy the warranty on a new telescope and may also result in putting the optics out of collimation, further deteriorating the image.
Subject:	ETX-90EC RA slop not due to slipping clutch
Sent:	Thursday, October 11, 2007 01:55:32
From:	Chris Mahar (
After following the directions for degreasing my RA clutch I still have
significant slop in my RA.  Going left and right at full speed I notice
that the clutch plate and drive gear are moving together without slip,
but the scope isn't turning with them.  I see that the clutch plate has
a slot that lines up with a key, so I use a digital micrometer to
measure each.  The slot is 0.198 to 0.200 inches.  The key is only 0.192
inches.  It's enough to cause significant delay in response on the RA
axis on anything but the highest speeds.

How might I go about getting rid of this slop?  My DEC axis is great,
but it's painfully slow going on the RA axis, and it's certainly
affecting goto accuracy.
Photo enclosed.


Chris Mahar
Mike here: Have you done a CALIBRATE MOTOR and TRAIN DRIVES? If so, you can try adjusting the "percentages" for the RA axis; see the Helpful Information: AutoStar Info page for more on percentages.


I'm all over that.  I downloaded the latest autostar upgrade (4.3 as of
this telling), did a Reset, calibrated motors then trained the drives,
then set my RA percentage to 15% as suggested.  Still very long delays
in reversing RA direction, on the order of 20 seconds on speed 5 for
detectable motion.  ON a lark I tried upping the RA percentage to 50%,
and then even to 99%.  Totally unstable.  Funny really, it's like the
autostar went schizophrenic and I'm fighting with it.  The slightest
touch of either left or right button causes the scope to take off.

Goto accuracy was 1 in 10 last night.

So you don't suggest doing anything with the slop in that key/slot?  I'm
thinking that's where the bulk of my slop is coming from.

Mike here: I suspect something with the AutoStar rather than the mount itself based on your comments. If you just touch the slew arrows and the scope "takes off" then perhaps it is a mechanical/electrical problem with the arrow keys. Have you tried reversing the arrow keys to see if the problem is with the keys?


It only did that (taking off) when I had the RA percentage set at 50% or
higher.  When I set it back down to 15% it behaved much better, more
like normal.  Of course, the slop is still there.  I'm convinced it's

It's a bit disappointing, the performance of this scope.  I had an
ETX-70 and after tuning it up per your website it was a marvel, with
wonderful goto accuracy.  I had the opportunity to upgrade to this
ETX-90, and now I'm going through the learning pains.  Still, you gotta
love the whole idea of goto.  It's what keeps me going.

I'll persevere and let you know what worked.

Subject:	125 ext
Sent:	Wednesday, October 10, 2007 18:30:42
From:	Ed Moore (
you ever find information how to use it? I have owned it over a year and
haven't seen a single star or the moon. Any websites you would
Mike here: Lots of information on my ETX Site. Look it over. Also, I recommend reading the manual, three times. If you have the AutoStar, play with it indoors until you understand how to use it and what the telescope does in response to your AutoStar selections. That way you will avoid some frustrations of trying to learn how to use the telescope in the dark.


Thank you

Subject:	ETX 125EC at Meade's 4M Community
Sent:	Wednesday, October 10, 2007 04:44:16
From:	Robert Haugen (
My name is Robert Haugen and today, I'm excited to say, I will purchase
my first telescope, an ETX 125EC.  I am getting it online from Meade's
4M Community. Do you think it's a good choice for a novice?  I'm not
worried about aligning or finding stars for I have been working with
navigational astronomy for many years, first in the US Navy, then the US
Merchant Marine. (I've reduced many a sun and star sight over the years
and I still use my Star Finder when practicing with my sextant. Which
has a bubble level to simulate sea level.) What I am worried about is an
article I read online concerning the telescope's altitude/azimuth
tracking motors. The author said motor vibration while tracking an
object was problematic, causing blurring. I've called Meade to ask about
the problem, so far, no reply. Also, can the telescope slave to a
handheld GPS?

For your information, I've found an awesome dark sky location in Queen,
New Mexico, where my wife and I go camping. Google Earth's light
pollution overlay showed no pollution. I've camped there quite a few
times and noticed one can see color in the night sky. So, if you're ever
in SE New Mexico and have time to gaze upwards, then I'd recommend going
to N32 09' 24.4"  W104 45' 17.1" in Queen, NM. It's 6009' above sea
level with a clear, 360 view of the sky. The only drawback is the
mountains. But anything above 30 is clearly visible.
God bless you and have a great day.
Sincerely yours,
Robert Haugen
Carlsbad, NM
Mike here: You can read my report on the ETX-125 on the Helpful Information: Buyer/New User Tips page. You can read reports from others on the Helpful Information: User Observations page. As to vibration from the motors, that should not occur to any extent that would affect visual observations. As to attaching a GPS to the AutoStar, yes, it can be done with some models. There are some GPS articles on the Helpful Information: AutoStar Info page.
Subject:	Meade 125 PE UHTC Base Misalignment
Sent:	Tuesday, October 9, 2007 20:04:02
From:	David Wilson (
Meade 125 PE UHTC base misalignment. The scope is not under warranty.
Bottom half underhang.


AZ/RA ring at top of travel, Note: gap.


Top half overhang equal, 180 out.


I am a Aircraft Mechanic A/P (airframe/powerplant) with Avionics
training and Armature Radio background is this a adjustment I can do.
And what is involved.

Scope works well.
Noblesville IN
Mike here: Hard to tell if anything is actually wrong. Is the RA Setting Circle track of different width around the circumference? Are you experiencing any problems, such as a wobble in the base? If you have no problems I suggest not attempting to make any repairs at this time.


> Is the RA Setting Circle track of different width around the circumference? 

> Are you experiencing any problems, such as a wobble in the base? 
no ,the only thing is the RA circle can slip down past the ? bottom stop?
It's like Meade put it back together after the RGA  2005 (motor fault
RA) but did not seat it centered and down. Looked at Neptune last night.
Mike here: Well, the RA Setting Circle tape on my original model ETX-125 fell off a couple of years ago (after 6+ years of use) and I left it off. So perhaps there is no real problem.


Thanks Mike.

Good job with the site.


Subject:	Did You Get Your mySky Yet?
Sent:	Tuesday, October 9, 2007 12:02:51
From:	Art Thomas (
My mySky is scheduled for FedEx delivery tomorrow.  When I searched your
website for your evaluation of mySky, the latest entry says you were
still awaiting yours so you can evaluate it.

So, have you received your mySky yet?


art thomas
Mike here: Eval unit hasn't arrived.


Would you like to borrow my unit?  Seriously.  I'm sure a lot of people
will be interested in your evaluation, and I won't be able to do it
Mike here: I am supposed to get one. I suppose it will come once all the paying customers get theirs. But I'll will gladly post a review from you!
Subject:	Putting ETX on German Equatorial Mount
Sent:	Saturday, October 6, 2007 15:40:49
From:	Randy Culp (
First thank you for a great site and a great book. 
Second, my question:  is it fairly common for people to remove their ETX
from the original fork mount and mount it on a German Equatorial mount
like the Orion EQ-2?  As much as I love my ETX, I would really like to
get it onto a respectable set of mechanics.  The EQ-2 looks tempting,
and if it is not too risky to take the scope off the fork I would really
like to do that.

The (obvious) follow-on to this question is, "where could I find
instructions to do this?"
Best regards,
Randy Culp
Mike here: It simple to remove the ETX-90/105/125 from the fork arms. See step #1 on the bottom of my ETX-90EC comments page ( As to mounting on the GEM, see the article "ETX-125 on a LXD75 Mount" on the Helpful Information: Telescope Tech Tips page.


Wow.  I'm blown away by both the simplicity of the answer and the speed
of your response.  Thanks so much, Mike!


Subject:	Meade Repair Time
Sent:	Saturday, October 6, 2007 07:11:54
From:	Steven S. Greene (
Just wanted to find out if you or anyone you know has a handle on how
long Meade's "lube, oil, and filter" maintenance program usually take
and/or is there a way to check on the progress using the RGA number
provided by Meade?

I spent the $90 for the general repair and return shipping. The 'scope
arrived at Meade on September 17th, per the FedEx tracking. I'm stuck at
home recovering from knee surgery on 9/27 and thought I'd see how the
repair was coming along. First, I poured over both the Meade and the
Meade4 web sites and found nothing. Then I tried call Customer Service
on both the 800 and the toll line. As usual, I was placed on hold and
after two calls and nearly 45 minutes on hold, I quit.
That's my story!
Clear, dark skies!
Steve Greene 
Mike here: A typical repair time would be 3 weeks, not including shipping time. But I've heard of longer and shorter times as well.
Subject:	Western Massachusetts Non Profit Public Observation
Sent:	Friday, October 5, 2007 08:19:35
From:	Mike (
I "Searched" your Site for a Link to a Non Profit orgainzation located
in the Berkshires of Massachusetts. (Cummington)
I would like to provide you with a Link to this great location.
These folks are very helpful and Friendly.
Thank You.
Mike F

Subject:	EXT125AT Supercharge
Sent:	Thursday, October 4, 2007 01:06:24
From:	Sergio Rivero (
I am presently on a job at the north slope of Alaska and thinking of
purchasing a Meade ETX125AT. I have two boys one seven and the other one
is five and I would very much like to get them involved in Astronomy.
They belong to the cub-scouts and the telescope would be a fun addition
to our camping trips.  I have done quite a bit of research and for the
money it's hard to beat the unit. The unit is brand new never been used
in the box. It is from a Meade dealer.

My questions for you sir are these; Are the prices listed on your site
current?  What sort of lead time would you need? What level of service
would you recommend?  How would I arrange shipment/payment to you? How
do you find the time?

I don't expect to have the telescope in my possession till about 10 to
15 days from now. I am having it shipped to my wife at home and I will
not arrive there for another two weeks.

I have read quite a bit on the Meade units and the plastic gears seem to
be their biggest weakness. Lots of people complain about their workings
but they all seem to praise their optics.  Would you agree with that
statement? Also I know of a Meade 90 that will no longer rotate. The
unit powers up but just will not rotate.  Do you do repairs?

After reading through the information on your site, I can't wait to get
all that information from you, what a value. It will be lots of fun
teaching/learning with my boys. I am from Cuba originally and always
dreamed of having a real telescope to use.

Awaiting your reply
Sergio Rivero
Mike here: First, are you sure that your unit needs a "Supercharge". I would recommend using it before making that decision. Second, as noted in the ETX Supercharge page, I don't do these; Dr. Clay Sherrod does and you need to contact him directly if you decide to have one done.


Mike thanks for the quick reply.  I don't know that it needs it as I
don't have it yet but replacing the plastic gears with metal ones sounds
right to me. Also getting it all tuned up professionally can't hurt.

I am just starting on this adventure but it's a dream I've had all my
life. Any advice would be greatly appreciated.

Could you please forward the good doctors email to me.

The nights here are truly spectacular. To bad I live in Houston, TX.
West Texas has some good dark skies as well though.

Thanks for you help.

Mike here: All the info on the "Supercharge", including Dr. Clay's contact info, is on the Supercharge page (
Subject:	Suggestion on ETX 90 - EC
Sent:	Wednesday, October 3, 2007 16:36:57
From:	William Penrod (
After doing a lot of homework, asking questions and some soul-searching,
I believe I want to buy an ETX -90 telescope.  The $700 plus tax won't
kill me, but it is a lot of money.  Before making my purchase, I went to
Craig's list online and found two ETX-90 EC's .  In trying to determine
the difference between the EC and the current model "premier" I
contacted Meade directly.  The person I spoke to said he would not buy
the older "obsolete" EC as it is not supported any longer and parts most
likely will not be available.  Something has me questioning the accuracy
of his comments.  So my question is would you buy the EC (one even has
extra eye pieces, sturdier tri-pod and carrying case) for $400 or stay
with the new model at $700, and why?
Thanks in advance for your help,
Bill Penrod
Mike here: There is nothing bad about buying a used EC model (as long as it is in good condition). But you do run the risk of getting a bad one. At some point Meade will likely stop repairing it but I don't think we have got to that point yet. However, the used model doesn't have any Meade warranty; which may or may not be important to you. This can be a consideration whether you are buying a telescope, a computer, or a car. As to the tripod, are you sure it is sturdier? The #884 that comes with the current models is better than the #883 that Meade had for the older ETX models. Lastly, if you plan to get an AutoStar (which you didn't say was included, which would make it an ETX "AT" model), that will cost you $100 (or more) to add. So if you really add everything up (or subtract what you don't get), which price is really "right" for you?


WOW!  That's what I call a fast and in-depth reply! Thanks.  Based on
your reply, I would like to send you the two links to the used ETX 90's
for sale, in that way you can see exactly what is being compared:

It appears to me that they both have the "Auto Star" feature, although
the one has what appears to be two controllers??
Mike here: The $390 one includes the #884 tripod. As to the controllers (which seem to have according to the photos), the EC model shipped with just the standard handcontroller; the AutoStar was an optional extra cost item. The AT model dropped the standard handcontroller and included the AutoStar as standard.


So bottom-line, the $390 one with Auto Star 497 and the 884 tri-pod,
knowing what you know, would you buy it or go with a new one?
Mike here: The best telescope is the one that gets used. Of course, a corollary to that is the one you can afford. Personally I prefer purchasing new products as their life cycle costs are typically less and they take advantage of the latest designs. I apply that to computers (my Macs), cameras (my Nikon D70 DSLR), my car (a Prius), and my telescopes. Get the best you can afford and that you will use.


Thanks so very much for your help with this decision.


Bill Penrod
Mike here: By the way, have you checked into the current rebates on new ETX telescopes? See the Dealer Specials page on my ETX Site.


Thanks once again!! I sure can use the rebate form.


Subject:	Guiding with an ETX 125 in polar mode
Sent:	Tuesday, October 2, 2007 12:54:32
From:	O'Keefe, Tony (
If properly balanced, does the tracking mechanism on my ETX125 have
sufficient precision to guide a 5 minute exposure sequence if the scope
has a light weight guide scope and DSI camera for guiding paired with a
DSI pro camera for imaging thought the main scope? I do this on an LX90
8" is it too much to ask of an ETX125?
Mike here: The ETX can track for hours if properly set up and aligned. However, you may experience Periodic Error over long periods so applying the PEC in the AutoStar may be appropriate.


Super! I have worked this well with my LX90... I'll give I a try, thanks
for the prompt reply!!

Tony O'Keefe, AIA

Subject:	ETX issues
Sent:	Monday, October 1, 2007 13:41:00
From: (
Hello again,

Wanted to get back with our continuing ETX issues.  You may recall we
were having several issues including the rubber banding effect and the
scope slewing the wrong way in the first (and only the first)training
mode.  After the software upgrade and careful calibration and retraining
we suddenly experienced a total cessation of RA movement.  Motors would
run but it would not slew in either direction.  OTA wasn't near either
hard stop.

We have since spent a fair amount of time talking about the issues and
thinking through everything we could consider.  We did open up the unit
and check all the possible potential problems and fixes as referenced in
both the Jordan Blessing and R.B. Ingersoll's Tune up tips.  The only
issue we could see was excessive grease.  We cleaned all the recommended
areas with mineral spirits, sanded and lightly brushed the clutch plate
with steel wool, lightly re-greased the gear teeth with Lithium grease
and re-installed everything.  Before re-attaching the bottom plate and
the OTA, we inserted batteries and using the non-AutoStar paddles tried
the RA motors.  All the gears turned as they should, there was no
looseness or slippage noted in any of the gearing BUT the clutch plate
did not turn.  We were puzzled of course but a few thoughts came to

1. Might the clutch plate's failure to turn be related to the OTA not
being attached to the fork arms?  We were thinking the weight of the OTA
might affect how tight the RA clamp needs to be in order for the clutch
to function.

2. Doug Loukota posted a tip  (Dec 2000) where he discussed the clutch
plate issue and his "fix" by adding an intermediate friction plate from
.032 fiber clutch material.  I wrote to him asking him some details on
the material but apparently his email is no longer valid.  Anyone know
how to reach him or have some experience with his fix?

Possible Weak Battery Cause?

As to the other issues (specifically the rubber banding and odd training
motion), neither of them had ever occurred before but rather they
"appeared" on subsequent nights (which led us to not consider the
reversed wire theory).  Could these problems be associated with
weakening batteries?  The training motion issue occurred on one night
while the rubberbanding issue manifested itself the next night we were
out (as well as the training motion).  At the time I didn't think the
batteries were that old, but when we removed them to do the internal
work they each tested at something like 1.4V.  I have a small radio that
will power up but perform no other function if the battery level drops
to a certain point.  Might our ETX have the same issue?

While we on the subject of voltage, I was wondering if anyone uses NiMh
rechargeable AA's?  I haven't tried them yet but I have some that are
rated at 2500 mah but on a full charge, they only measure 1.36V (as
opposed to nearly 1.6 with a fresh alkaline).  That's a full 1V + below
the 12V listing.

Thanks again for any help!  

Steve Arnold - Athens, GA
Mike here: Certainly weak batteries can cause some problems. You didn't indicate if you have tried a different set of batteries or external power. As to rechargeable batteries, there is an older article on them on the Helpful Information: Telescope Tech Tips page. If you do swap batteries or try external power, remember to CALIBRATE MOTOR.


We did not try new batteries or external power at the time of the
slewing issues.  Once we had the base opened up and checked the gears,
sanded the clutch plate and cleaned the excess grease we did substitute
newer batteries.  We did not calibrate at that time since we had not
reattached the OTA or AutoStar.  Our test movement was made with the
basic controller.

I will check out the article on rechargeable batteries.  Since writing
to you I found an article by Dr. Clay where he, among other things,
discusses power options.  He suggests AC power whenever possible or a
reliable non-battery DC source.

Steve Arnold
Mike here: I tend to use AC when available and my Celestron Power Tank (discussed on the Accessory Reviews: Miscellaneous page) when no AC is available.


From:	P. Clay Sherrod (
The clutch plate does NOT turn when motion is activated in RA; note that
you should not keep interchanging between the Autostar and the button
box; once you have trained on the Autostar you should never use the
simple electronic controller for batteries, I do not
recommend it unless you are way out in the woods with no other source of
power.  The ETX thrives on about 13.8 volts; anything less and you will
have questionable performance.

Best of luck on this...

Dr. Clay
Arkansas Sky Observatories
Harvard MPC/ H43 (Conway)
Harvard MPC/ H41 (Petit Jean Mountain)
Harvard MPC/ H45 (Petit Jean Mtn. South)

Subject:	RE: Question about remote control of telescope
Sent:	Monday, October 1, 2007 09:14:10
From:	richard seymour (
There are many free programs capable of controlling Autostarred scopes.
Cartes du Ciel  is perhaps the "best", and there are others
("Home Planet" comes to mind, but i haven't looked at it for years)

have fun
Mike here: As Dick says, there are many free as well as shareware and commercial applications that can control the AutoStar. Several are discussed on the Accessory Reviews: Software page.


From:	Chris Reich, Observer (
Richard & Mike---Thank you!

For now I'm leaning toward the Stellacam III camera as it might give me
the best view for sharing without cobbling together USB cables.

Here's what I plan:

I want to use a type of Netmeeting to show my screen to several people
(I have a go to webinar account)

Stellacam III W/Frame Grabber to PC
Control of LX-90 with Cartes du Ciel or (?)

I am a little nervous about the stellacam III as it is very expensive
(for my application) and may not deliver a very good image after
converting from composite to PC via frame grabber.

Advice is greatly appreciated.

Visit our website for updates and new offerings!
Mike here: My experience with NetMeeting (at work on Windows) is that it provided less than ideal color display (appeared to be about 16 colors with lots of banding). A VNC solution (that I mentioned previously) would provide full color.


No, netmeeting isn't good. I am going to run cable from the equipment to
the PC inside. Then broadcast using gotomeeting that works nicely with
no degrade.

I think that's where I'm headed. My decision now is whether to get a
stellcam III ($1250) and a frame grabber, or go with a USB camera and
powered extensions---a little cheaper. I only want a B/W image that
would be better than one see at the eyepiece. I'm thinking 30 second
exposures would be OK.

Mike here: Keep me posted on your efforts and the results.
Thank you for your interest. I'm wading through a maze right now.  This
whole thing is a public outreach and I'm bearing all the cost so I'm
trying for simple (elegant) and not too expensive. If I had an
observatory it would be a different setup but as it is, I need to take
things out.

Here's the base site:


Subject:	RE: Poor/no power
Sent:	Monday, October 1, 2007 02:05:51
From:	ben (
No luck with the widget.
I'm going to contact Meade.

Subject:	Hi there
Sent:	Monday, October 1, 2007 01:00:43
From:	Frederick Littler (
Hi there Mike. I was having a look at your publication " Using the Mead
ETX " and it looks an excellent publication however I have an ETX125PE
and looking at your book there is no mention of the PE model. Some time
ago I purchased a book in the UK titled.."The ETX Telescope guide" third
edition by Dr.Lilian Hobbs but I am afraid that to me it was a waste of
money as it is almost a reprint of the ETX Instruction book.

Your publication does look more informative but I do not see any
reference to the PE Model.. does this matter ?? I am a very basic
learner and took up this hobby only about 6 months ago and therefore I
am looking for any book with particular reference to the 125PE.

Do you think this book would suffice my needs and be helpful to me or
should I wait for a publication that deals specifically with the PE

Your help and advice would be most appreciated and by the way I think
your website is fantastic and most helpful.
Yours truly. Fred Littler
Mike here: Just noticed that your message was DELETED UNREAD as SPAM and bounced back to you due to the non-specific subject line. PLEASE read the Email Etiquette item on the ETX Site to avoid this happening in the future. Thanks for understanding.
The current edition of my book does not cover the ETX PE models. However, since the only change on the PE models is the LNT/SmartFinder, you may find the book + manual + ETX Site a viable combination.

Feedback Archives

Check the Feedback Archives for previous editions of the Feedback page.

Go to the ETX Home Page.

Copyright © 2007 Michael L. Weasner /
Submittals Copyright © 2007 by the Submitter