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Last updated: 31 May 2013

This page is for comments and user feedback about ETX telescopes. ETX models discussed on this page include the ETX-60/70/80/90/105/125 (EC, AT, BB, Premier Edition). This page also includes comments and feedback of a general nature. Comments on accessories and feedback items appropriate to the ETX-90RA, DSX, 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 for posting. Please use an appropriate Subject Line on your message per the Site Email Etiquette. Thanks. Remember, tips described on this site may invalidate the warranty on your telescope or accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Mike here: One of my images of the International Space Station (ISS) was used in an article by David Dickinson at Universe Today. Thanks David. Also, on Friday, 31 May 2013, I captured the ISS transiting the Last Quarter Moon.

Subject:	Stuck Lens Cap on ETX90
Sent:	Wednesday, May 29, 2013 06:04:23
From:	Chris Chambers (
Is this a common issue?

I have a 15 year old Meade ETX90. I have used it consistently and
heavily since new.  I have all the normal issues with it.. slipping
tripod and mechanical slop in the 'scope.  Well, I didn't get the 'scope
out for about 18 months and now I can not get the lens cap off.  I am
mechanically inclined and fairly strong but I can't budge it.  I am
afraid that I will do permanent damage if I torque it any more.  

Is this common? Is there a trick?

I'd appreciate any help.

Best Regards 

Chris Chambers 
Noblesville Indiana
Mike here: I wouldn't say it is a "commom" problem but the question (and answer) does appear on the ETX FAQ page: "Q. I can not remove the aperture or rear port cover or loosen the Declination/Altitude scale knob. How do I loosen it?"


WOW!  FAST response


Subject:	re: ETX-70
Sent:	Tuesday, May 28, 2013 14:31:36
From:	richard seymour (
As it happens, i have an old (2001?) ETX-70 with a Meade-supplied power

The adapter is rated as 12v 500ma

The worst that's going to happen if you have an "under-rated" adapter is
that the voltage will sag if the ETX requests more current than it can

So a 12v 300ma adapter might drop to (say) 9v if asked to supply 500ma.
A 9v 300ma adapter might drop low enough (perhaps below 6v) to confuse
the Autostar.

The "idling" draw of my ETX-90 (i've never measured the ETX-70 for this)
with a full 497 Autostar is about 120 milliamps ("idling" means ticking
along doing sidereal tracking).
The draw kicks up when a GoTo (or leaning on the slew keys) commences at
full speed of both motors.
As long as the adapter "sag" during that burst doesn't take the
"Calibrate Motors" illumination far enough out of range to confuse the
encoders, the system should operate properly.

have fun

Subject:	ETX 90 Declination failure
Sent:	Tuesday, May 28, 2013 11:03:37
From:	DeMaster (
I bought a used ETX 90 that fails to move in the vertical direction. The
horizontal works fine. There is no sound from the Dec motor when I
attempt to move up or down and I get a motor fault when it does motor
testing. When I check the voltage on the power pins for the Dec motor I
get 12 volts all the time. Is this normal? I presume the yellow and blue
wires go to an encoder. Would I expect to see voltage on them and if so
when and how much. I hope you can help, and thanks for a fantastic site.

Mike here: If there is no motor sound at any slew speed, there are several possible causes. Dead motor, broken/disconnected wire(s), bad circuit board. You might be able to get a replacement motor from a local hobby shop (see the Helpful Information: Telescope Tech Tips page). You might be able to get a replacement board from Telescope Warehouse (link on the Astronomy Links) page.


Problem solved. It appears the the oscillator on the Dec circuit board
was not making contact. I believe I saw someone else on your site with a
similar problem.
Again thanks for the reply and the website. It was very helpful.


Subject:	ETX-70
Sent:	Monday, May 27, 2013 09:07:23
From:	Eleni tell you later! (
Hi! I am the girl who wrote you today on twitter.

I was thinking of connecting my ETX-70 to an external power supply so I
started reading around the web searching for a suitable adaptor. I found
your page and I read about proper voltage -with and without load-,
current requirements, ect but I am still not sure of what to do...

I have AC-DC adaptor and since my telescope uses 6AA batteries, 9V
output seems OK. If I am not mistaken though, I read in one of your
pages that my model uses 250mA when moving horizondally and 450mA max
(when it moves both horizontally and vertically), but this adaptor says
"Current: DC 300mA".

So, if I use it, what could the worst consequences be? I read that
problem would arise for the adaptor itself (overheating) and not so much
for the telescope. But I doupt that this adaptor is regulated since it
is pretty old, and I am concerned of the voltage differentiation when
the ampere is not enough.

Thank you very much and sorry for the whole confusion...!
Mike here: The ETX-70 will be happier with 12 VDC and 1000mA. The old Meade ETX-70 AC adapter supplied that (as seen here: Too low voltage make work (since as you noted the batteries supplied 9V) but too low amperage will cause problems. I would definitely not recommend using an AC adapter that puts out only 300mA. See the Power Supplies section on the Helpful Information: Telescope Tech Tips page for more tips.


Thank veru much for replying,

I came across that during my first research on 'Power Supplies' but I
kept seeing 12V with at least 500mA and I though that it was due to 70
being 70AT or other models -eg ETX90-. Because of the batteries, I was
also wrongly convinced that the #546 meade adaptor would be 9V so I
couldn't make sense of what I was reading..

Seems like I had found the answer all along but just couldn't see it...
Now I can finally buy a proper adaptor!

So thank you very very much for getting me out of this loop I was stuck
in and sorry for all the inconvenience I caused...

Best Regards,
Mike here: No inconvenience. Glad you got the info you needed.

Subject:	ETX 125
Sent:	Monday, May 20, 2013 13:11:03
From:	Geoff and Sue (
Hello Mike once again from the (usually cloudy) UK.
I am somewhat confused over the ETX 125 situation as it does not exist
on the Meade website and your own site says that it was discontinued
several years ago.

I have very recently purchased my second ETX 125 (ETX 125 PE Blue Tube
UHTC) (as a spare to my original one) from Telescope House here in the
UK where it seems to be still available! So what is going on?

Many thanks for a great website.
Best wishes
Geoff Sentinella
Mike here: Ah yes, Meade Europe still sells the ETX-125. With the recent Meade (USA) merger announcement there has been some speculation that the ETX-125 would return for sale outside of Europe. I'm sure the entire product lineup at Meade (all subsidiaries) will come under scrutiny as the merger process proceeds.


Many thanks Mike for the very promt reply concerning ETX 125

I am not aware of the recent Meade USA merger announcent so perhaps you
could possibly post me a link?

I thank you for all your tremendous support for so many budding
astronomers over the recent years. Enjoy Oracle and your clear skies.

My very very best wishes from a cold AND CLOUDY UK.

Geoff Sentinella
Mike here: See the Announcements: Meade page on the ETX Site.

Subject:	ETX 125
Sent:	Sunday, May 19, 2013 12:16:03
From:	Ken (
Haven't been on your site in a while as my ETX 70 stopped working and I
lost interest. Well, I seem to be getting the bug again and have been
looking for a new scope. I cannot seem to find the ETX 125 on Meade's
site, do you know if they discontinued them? Is the ETX 90 a good scope?
Mike here: Welcome back. While you were gone Meade discontinued the ETX-125 several years ago. Its "replacement" are the LT and LS telescopes. The ETX-80 and ETX-90 continue and are good telescopes.

Subject:	Re: EXTERNAL POWER CORD FOR ETX-70 Last updated: 20 December 2007
Sent:	Thursday, May 16, 2013 14:47:14
From:	Stephen Nazigian (
Good news, bad news. I finally got my ETX60 working perfectly on battery
power. Then I connected it to a regulated power supply at 11.44 volts
and destroyed the telescope. The power light comes on, but not the
Autostar handset. I can hardly say how sick I feel right now. 
Mike here: Sorry to hear that. Some external power supplies have been known to damage telescope electronics.


Nothing to worry about. Michael Slevin's jumper wire trick from brought the
scope back to life. I swore an oath never to use anything but batteries
on the scope from now on.

Mike here: I was recently interviewed (once again) by PicStop. Click the link to read the article.

And one other of note: Our friend and associate Dr. Clay Sherrod had surgery recently and is recovering. I know I speak for everyone who has looked to him for assistance in wishing him a speedy recovery.

Sent:	Monday, May 13, 2013 09:46:21
From:	Stephen Nazigian (
I was looking at and the
"electronics engineer" seems to have needlessly melted the plastic
center nut rather than turning the bolt from the top of the base.
Mike here: Some people have had problems getting that nut loose. Heat sometimes seems to be the only method.

Subject:	EXTERNAL POWER CORD FOR ETX-70 Last updated: 20 December 2007
Sent:	Monday, May 13, 2013 04:50:57
From:	Stephen Nazigian (
I have a concern about the page at which gives
instructions for building a $5 power adapter. While your contributor is
concerned about getting the polarity correct, he disregards the
difference between the required 9 volts and the 12 to 14+ volts that a
charged car battery provides. The extra voltage is significant, and I
expect it would destroy the scope's electronics after a while.

Meanwhile I am enjoying your extraordinary site and trying to find out
why my little ETX60 BB continues to slew after it locates a guide star.
Mike here: The old Meade ETX-60 and ETX-70 AC adapter supplied 12VDC. You can see the label on the review on the Accessory Reviews: Miscellaneous page.
As the slew continuing, be certain you have done a CALIBRATE MOTOR and TRAIN DRIVES (both axes).


Thanks for pointing out that 12v label. Calibration and training did not
help yet. Maybe you wouldn't mind listening to this short sound file of
my horizontal motor. You can hear the speed rising and falling as I slew
manually, and the movement is a bit jerky.  I recently greased the gears
with fishing reel lubricant after I started getting a motor fault. 
Maybe the white center bushings/collars needed lube also?
Mike here: Sounds pretty much normal. Be certain you didn't get any grease on the optical encoders.

Subject:	Old vs New ETX-125
Sent:	Saturday, May 11, 2013 11:17:20
From:	Larry Kryske (
First, thank you for the great information on your site about the ETX.

I might be buying an ETX-125 from a private party and am curious if
there is any newer information from what you already have posted
concerning telling the Old from the New. BTW, when did Meade stop making
the ETX-125? My seller told me his purchased his 125 scope two years
ago. I'm suspicious.

I'm buying the scope to use with my astronomy students. 

Thank you, Larry

Larry Kryske, Commander, U.S. Navy (Ret.)
Mike here: ETX-125 was discontinued a few years ago. Do you know if it is AT or PE?


Do not know. Can you tell from the photos shown? 

Many thanks, Larry
Mike here: It is either an ETX-125EC or ETX-125AT. I couldn't tell whether the hand controller in the case was the old EC one or an AutoStar. The description said AutoStar was included so hopefully he got it right.


Mike, I sincerely appreciate your help. Thank you, Larry

Subject:	ETX #881 table top tripod
Sent:	Tuesday, May 7, 2013 07:04:28
From:	Steve Knight (
I have been trying to obtain this for use with an ETX125 when out and

I guess Meade have stopped making it, really struggling to find a source
for one.

Any suggestions?

I am keeping an eye on eBay but yet to find one.

Many thanks

Steve Knight

Mike here: Yep, long discontinued. Try Telescope Warehouse (link on the Astronomy Links page on my ETX Site). Or you could make a set of legs.


Thanks Mike!

Have now managed to find one on ebay!

Next project is to try and capture solar transit by international space
station and need something small and portable that can be polar aligned!

Mike here: I've imaged the ISS and HST transiting the moon with my 8".

Subject:	Horizontal Drive Problem On ETX-60AT
Sent:	Friday, May 3, 2013 16:39:07
From:	gary white (
I just purchased an ETX-60AT from an individual who had it for 3 years
but rarely ever used it and it appeared in new condition.  Even the hand
controller still had the protective tap over it.  I put new batteries in
it and was ready to test it out.  I locked it down into the home
position and followed the prompts on the controller to enter the
date/time.  I chose easy for the auto alignment and the scope moved on
the vertical but would not move horizontally.  I could hear the motor
running when it was attempting horizontal movement however.

I checked the horizontal locking switch and it was a little loose so I
tightened it but no success.  I tried various levels of tightness on the
horizontal lock switch with still no success.  I even tried moving it
with the arrow buttons and it still would not move horizontally.  The
motors are running for both axises so it looks to me like there is some
sort of disconnect between the motor and the horizontal movement.  I
believe I will need to open the base to see what is going on.  However I
am unfamiliar with working on this type of mechanism and would like
advice on what you think is the cause and if I need to open it up.

If I do open it, I would like to have as much reference material as
possible to ensure a successful repair.  Any and all advice is greatly

Gary White
Mike here: I assume the telescope rotates freely by hand with the horizontal axis unlocked. Since the motor is running it sounds like a problem with the clutch. You will have to open up the base. See the articles "ETX-70 Repair Guide" and "ETX-60 Repair" on the Helpful Information: Telescope Tech Tips page.


Thanks for the info. I will let you know how it turns out.


And more:

Thanks for the advice Michael.  I was able to open the base up and saw
that the motor was not in contact with the horizontal gear.  The cause
of the lack of contact was a small piece of plastic that appears to be
like a tension clip.  It had broken.  I set the gear in place and put on
the base and it worked!  However it would not stay in place.  I
improvised a replacement clip with a small piece of rubber that
hopefully was flexible enough to mimic the tension clip.  When I put on
the base it did not work.  When I took off the base again I discovered
the horizontal motor now had failed and the controller also said motor
failure. I'm not sure what happened to it.  It appears to have seized
up.  Unless you know of a way to reset the horizontal motor, vertical
still works, it looks like it would need a new motor.

Mike here: Congrats on the initial troubleshooting. Bummer about the motor. You may be able to get a replacement at a hobby parts store. Just take the failed motor with you when you visit them.


Thanks Michael. You have a great website that provides a great service!

Subject:	ETX-70at slew problem, no answer found in archive
Sent:	Thursday, May 2, 2013 10:37:17
From:	Lee Shann (
I have a problem with the horizontal movement of my ETX-70at.  When it
is upside down so that I can view the clutch and gear teeth, it rotates
freely using the motor, a full 360 degrees.  I can see that all the
teeth and worm drive are complete.  When it is up the right way it
rotates but will stop, as if jammed (the motor still runs but the pitch
is much lower).  It does this in two seperate places in the 360 degree
rotation.  If I disengage the clutch the result is the same.  It turns
freely upside own but gets stuck when moved by hand when the right way
up.  I have attempted to strip the base down, as per your guide. 
However I cannot remove the castle nut, even when using a socket
spanner.  I have not forced the nut but there is zero movement.

I have carried out the RESET, CALIBRATE and TRAIN functions.  I have
also tweaked the locking nut so that the clutch is only just biting when
the locking arm is fully clockwise.  When the scope is upright there
does seem to be a little movement from side to side on the central pin.
ie it 'wobbles' slightly.

Any help would be appreciated.
Many thanks, Lee 
Mike here: It sounds like there is some obstruction that is moving depending on the orientation. I suggest looking for a wire or some other debris. Use caution when rotating the scope as you don't want to cut the wire.


Thanks Mike. That sounds right. Do you have any tips on removing the
castle nut? I can't see any obstructions through the three gaps on the
Mike here: I found this comment in one of the ETX-70 repair articles on the Helpful Information: Telescope Tech Tips page:
"e) Remove the clutch nut from the locking lever shaft. Using a small screwdriver to help make the first turn eases the removal"
Let me know if that helps.


I think this tip may have been referring to the metal clutch nut which I
easily removed.  The white plastic castle nut refuses to move, I even
screwed in a reversed thread bolt to try and get it going but no luck. 
I have managed to get the scope rotating while upright by slightly
releasing the  three screws on the base and then playing with the sweet
spot on the clutch.  I cannot try anything else on removing the white
plastic nut, and so access the horizontal drive, without damaging it

I still find it very odd I cannot shift that nut! It seems so simple on
your repair guide as it should only be hand tight!

Thanks for your help,

Mike here: Might try some heat on the nut to expand it. Use caution though.

Subject:	Re: 125 ETX Wont Slew
Sent:	Monday, April 29, 2013 20:13:12
From:	Toso (
I reset the controller, and dont have the usb cable.  I opened up the
base, and everything looks good.  I unplugged and re-plugged all the
connectors... still no joy.  
Mike here: You can easily make the #505 serial cable; see the Helpful Information: AutoStar Info page. If your computer has only USB, you will need a USB-serial adapter. I recommend Keyspan. But I still suspect a problem in the ETX, not the AutoStar. There is one other thing you can try: reverse the HBX cable end-to-end.


I did check that several times... I remember that it made a difference
once several years ago, so I gave it a shot, but nothing.  I am so
confused since when I was unplugging the handset yesterday the scope
slewed for an instant... 

I reversed the cables and tried a spare too... it runs through the menu
fine, just wont slew.
Mike here: Some AC adapters have been known to cause the ETX circuitry to fail. What adapter were you using? As both motors no longer work, the most likely problem is a problem somewhere in the ETX. You will have to do some troubleshooting to track down the problem and try to repair/replace the failed component(s). Or you could contact Dr. Clay Sherrod for his "Supercharge Tune-Up Service".

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