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Last updated: 29 April 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: Sky & Telescope has published an "ETX-90 Test Report" in its June 2013 issue.

Subject:	125 ETX Wont Slew
Sent:	Monday, April 29, 2013 07:07:29
From:	Toso (
Thanks for all the great information on your site!!  I put in many hours
searching the posts yesterday, but couldn't find my problem.... I took
out the scope for the first time in a couple years (I keep in in a hard
case, well protected), and setup went as normal (though I recall that it
used to ask for my location as part of the setup, but it isnt doing that
now) until I got to the ALTAZ alignment... Once the controller selected
the first star and displayed that it was "slewing" nothing happened.  I
waited a good long time and selected the second star, still no movement.
As part of my troubleshooting I tried every combination of turning it
on and off, plugging and unplugging the controller that I could think of
(while doing so the motors did occasionally move the scope short
distances, so I feel confident that the motors and gears are fine).  I
even reset the controller, still nothing.  What am I missing?  Any ideas?

Thanks for your help!

Mike here: First, the AutoStar should not have asked for your location once it was input. It stores that information. It will ask for the date/time/DST. As to not slewing, have you checked the batteries? Be certain you are not overtightening the axis locks. Have you done a CALIBRATE MOTOR? (Remember to do that when swapping batteries.) Can you slew with the arrow keys? All directions? If so, nothing is wrong with the motors/gears. If slewing is OK, which star alignment mode are you using?


Thanks so much for your prompt and insightful response!  
I am using an AC adapter not batteries... I tried loosening and
tightening the locks in various combinations with no luck.  I tried to
calibrate the motor, but nothing seems to happen (it completes without
doing anything).  The arrow keys will not slew either (but it does slew
every now and again when I unplug the handbox (it will run just for a
second, but enough to get me excited)... 
Thanks again!
Mike here: Try using internal batteries. The AC adapter may be bad (and could have damaged the circuitry).


Thanks... just tried batteries- same result :(
Mike here: It might be corrupted AutoStar software (but I doubt it); reloading 4.3Eg may (or may not) help. If updating doesn't cure it, and since there is no slewing using the arrow keys in either axis in either direction, time to open up the base. It sounds like it might be a circuitry problem. Look for burnt components or traces.

Subject:	Motor Meade ETX-70 not working
Sent:	Friday, April 26, 2013 00:27:06
From:	Raf van de Vreugde (
For a quite long time, I own a Meade ETX-70 telescope but the last year
I did not use it very much anymore. :-)
Recently, I wanted to search for the PanSTARRS comet, but when I
"constructed" my Meade, it did not work anymore.

In fact, I use a 9V AC adapter instead of 6 1,5V batteries, but when I
switch on my telescope, the AutoStar remote made a noise and started up,
asking for the date and time and afterwards for aligning my scope.
But, I noticed I did not hear the nice sounds of the motor(s) anymore.
So aligning was of course not possible.

Is there a "quick" way to check what possibly could be wrong with my
Could it be "unrepairable" of "expensive" damage?

Thanks in advance for reading (and hopefully answering) this mail,

    Raf van de Vreugde
Mike here: First, I suggest using the internal batteries instead of the AC adapter to ensure that the external power source is not the problem. Second, after powering on the telescope, do any of the slew arrow keys move the telescope?

Subject:	Meade #825 8x25 Right-Angle Viewfinder exploded view
Sent:	Saturday, April 20, 2013 08:02:04
From:	David Henderson (
I know its a bit of a longshot but whilst fixing the crosshairs back
onto the 8x25 right angle finder the eyepiece assembly landed on the
carpet spilling out the 3 lenses and two spacers.

I have tried to identify which eyepiece it might be, but none of the
common ones (Ramsden, Huygens) look at all familiar.

All three lenses are plano convex of the same diameter, one of which is
twice as thick with a more pronounced convex face, the other two appear
to be  the same (as each other) .

there are two spacers, one thin and one a lot thicker.

Any ideas how to narrow down how to put it all back together?

Many thanks in anticipation,
David Henderson
Mike here: Ouch. I took a look at my Meade 8x25 right-angle finderscope (with the eyepiece still attached). All I can tell is that the lens surface nearest your eye is flat.


Many thanks Mike,
well, thats at least one known factor,
I will report back with , hopefully some results.

Subject:	ETX 90EC question (again)
Sent:	Thursday, April 18, 2013 15:06:19
From:	A. Lancour (
I was asking you from work today about a damaged ETX 90 available on
craigslist, but it appears to have been bid on. With it being damaged I
think it is too pricey.

I continued my search and found an ETX 90EC for sale that has the
controller style without the digital readout. The owner knows nothing
about it, and ended up with it via a home foreclosure. The scope is
still wrapped in plastic in the original shipping box.

1) will the current hand controller it has track objects, or do the
arrows only allow finding targets? (ie they will drift from view)

2) if so, can the hand controller be upgraded to either a 494 or 497?

3) roughly what is the last year that Meade offered these? I am trying
to get a rough idea on its age, and potentially how long it has been
boxed up

Thanks again Mike!!
Andy Lancour
Mike here: The ETX-90EC first shipped in early 1999, with the AutoStar #497 available at extra cost. At some point (2000, 2001?) the EC handcontroller was dropped and the AutoStar included as standard. If the EC model is mounted in polar mode, it will track at Sidereal rate.


Thanks  so I should be able to unplug and replace the current handbox
with a 494 or 497 and essentially have a scope comparable to a current
model? Thanks  sorry to be a pest
Mike here: You need a #497 (or a #495, if you can find one, which you can upgrade to a #497 with software).

And this:

Thanks - one last question please - it looks like some of the early
models came with that funky #883 tripod. Will it fit onto a more recent
one - I think the newer ones use the #884 for a strictly alt/az setup?
Thanks so much!!
Mike here: The #883 tripod was an extra cost option. The #884 will work.

Subject:	ETX 125 UHTC Lens assy swap
Sent:	Thursday, April 18, 2013 12:04:31
From:	John Pizzulo (
I have two ETX 125 scopes but have a problem with the motor control PCB
that drives the azimuth motor (runs in right to left direction only) in
one of them.  It unfortunately is the one that has the UHTC optics.

Is the only difference between a UHTC scope and a non UHTC the front
lens assembly or is the mirror different also? I am hoping that I can
just exchange the front lens assemblies.

Any thoughts or suggestions would be appreciated.

Thanks in advance.

John Pizzulo
Mike here: You could just swap out the entire OTA rather than just swapping the corrector lens. Swapping just the lens would likely require a re-collimation of the optics. But other than that, either swap will work. To swap the OTAs, remove the four screws (two each side) that hold the tube adapters onto the OTA. Carefully pry the tube adapters away from the tube and slide the OTA out from between the fork arms. Reverse the problem to install the replacement OTA.

Subject:	ETX 90 EC Right tube adapter fix
Sent:	Thursday, April 18, 2013 07:10:10
From:	Andy Lancour (
at the bottom of the page of the attached link you mention a "right tube
adapter fix" for issues with the ETX 90EC. I know it's a pretty old
post, but do you know if this is something they still offer? I ask
because I am considering purchasing an ETX 90 that will not lock in
declination. I am unable to view/test the scope, but wonder if I can get
it cheap what the fix options might be. Not even sure what the problem
even is.
 Thanks again Mike!
Andy Lancour
Mike here: Meade no longer offers that. No one else does either that I know of. However, you may be able to repair it yourself. See the article "ETX-90EC DEC fix (Right Tube Adapter repair)" on the Helpful Information: Telescope Tech Tips page.


Thanks Mike. I love the ingenuity!


Here is the victim. I may try to low ball the price if it doesn't sell.
Funny how she says it is still operational. Please asplain dis to me -
Mike here: Well, the telescope is still "operational": light goes through it. The seller obviously doesn't use telescopes. Description says "scrolls" when meaning "slews". Buyer beware.


I was considering a $50 offer, and hope I can do a fix.
Kinda scary though. : )
Mike here: If not, and the optics are ok, you can always remove the OTA and use it on another mount.


good point - thanks Mike

Subject:	re: ETX-90
Sent:	Wednesday, April 17, 2013 17:02:05
From:	richard seymour (
When you say it doesn't go "up", does the motor run (without telescope motion)
or does the motor just sit there silently doing nothing?

If the latter (i.e. silence), you probably have a blown ("open") power
MOS FET driving transistor on the motor control board.

I've attached the schematic of the DS family motor card and a "generic"
(taken from Meade's patents) which should be very close to the ETX-90's
(if it's an older model).

If you were to replace the International Rectifier F9936 and F9933 , you
may restore function.
(you can also use the F9953 and F9956,  or  SI4936  and SI4947)

The Alt (up/down) motor card is up in the fork of the old ETX-90, behind
the "clamp" knob.
You should also visually *inspect* that card very carefully...
What sometimes (usually) happens is that one of the MOS FET sections
fails by short-circuiting.  That causes excessive currents through the
copper-foil traces on the circuit card, and blows a trace or two right
off the board.  That damage can be repaired by jumping over the missing
trace with some wire, but you still have to replace the FETs, or they'd
simply cause some other part of the copper to vaporize.

good luck




From:	Mike Kropf (
Sounds like my weekend may be taken up by telescope repair!!

Thanks all, will let ya know!

Subject:	Adjusting RA drive worm on "NEW" ETX-90
Sent:	Tuesday, April 16, 2013 14:37:54
From:	Mike Pepper (MikeP@ACMA-INC.COM)
I have several telescopes but wanted a quick, back patio telescope so
bought an ETX-90 from Ebay  purportedly new, unused.  It is apparently
the newest ETX incarnation with the logo cast into the fork arms and the
battery compartment access on the top side of the base  comes with red
dot finder.

When first out of the box, the RA axis was basically immovable.  With a
little head scratching, found three base screws (under the rubber feet
that have dots by them), popped the center cover and puzzled out how
back out the RA lock shaft and remove the clutch stack.  After that the
base comes off, it has the worm gear around the center post.  Finally
the worm and drive motor came into view.

The worm seems to be on some sort of flexible mount.  Pushed this back a
little.  Reassembled and the RA turns now, but is very noisy and jumpy.

Is there any procedure for adjusting the worm position?  Yes, it is
really cheaply built!

Thanks.  I enjoy and use your site's info a lot.  Glad that someone is
able to retire to clear skies.

Oh, you may need to encourage the mud dabber wasps to patrol your
Mike Pepper
Mike here: No way that I know of to adjust the worm on the ETX. Have you tried adjusting the position of the RA lock lever to ensure you are not overtightening the axis lock?

Subject:	ETX-90
Sent:	Tuesday, April 16, 2013 13:30:10
From:	Mike Kropf (
I purchased an ETX-90 off Ebay and it arrived this past week.
When I set it up, I get a general Motor Unit Fail, when the scope tries
to go "up".
Do you know what this could be and or if parts are even available for it?
Thanks so much!
Mike Kropf
Mike here: Some possibilities: lock too tight, batteries too weak, you didn't do a CALIBRATE MOTOR, AutoStar software corrupted. Start with the easy fixes first.



How, perhaps, do I calibrate the motor?

(Sorry for being a bother)

-sent from my Blackberry. 
Mike here: No bother.
See the AutoStar menu tree in the ETX manual. Once selected, it is run. If that solves the problem, do a TRAIN DRIVES on both axes. Just follow the onscreen prompts.


Ok, did both. 
"Training" did not go "up". 

Calibration, again yielded Motor Unit Fail. 

(Loosened the locking wheels as well)
The motor does work in the other 3 axis. (Left, right, and down). 

Mike here: When you lock the altitude (DEC) axis with the telescope pointed upwards, does the tube stay pointed up or does it want to fall back down towards the base?


Stays pointed up. 
Mike here: Try reversing UP/DOWN in the Setup: Telescope menu. Then see if you can slew up and down, or just in one direction.


No change. 

(Will go down now using the other key, but not up). 
Mike here: Time to open up the base and right fork arm and look for disconnected wires or a loose gear. Lots of articles on the Helpful Information: Telescope Tech Tips page. I suggest reading & following the advice in the "Disassembly Procedure" article first.



Already have that page open and will proceed a bit later. 

Thanks for your help!!!
(If you don't mind, I will keep you up to date)

Subject:	GC Wi-Fi Adapter and ETX-80
Sent:	Saturday, April 13, 2013 07:03:39
From:	S-O&M Auno (
I have read your review of the GC Wi-Fi Adapter and got very interested
in this device. I wonder if you know if it is possible to control my
ETX-80 (Autostar 494) with the GC Wi-Fi Adapter, a Meade 506 cable and
the SkySafari (release 2.1.2) app running on iPad?

Best regards,
Sven-Ove Auno
Mike here: It may or may not work. I didn't test that.


Forgot to tell you that the only ETX options in my SkySafari are ETX 90-125.

Mike here: I'm hoping to test the Wi-Fi adapter with my ETX-70 with #494 AutoStar at some point.
Thanks for the response. I will wait to see the results of your test.


Sven-Ove Auno
Mike here: Don't know how soon I'll be able to make that test.

Subject:	Using the Meade ETX
Sent:	Wednesday, April 10, 2013 07:13:48
From:	John Pizzulo (
First, thank you for the time and effort you put into your websites.  I
enjoy reading about others experiences.

Second, I have your book, "Using the Meade ETX" but unfortunately it got
exposed to a water spill and I have several pages that have stuck so
badly together that when I tried to carefully separate them they are now
unreadable. Is it possible to get a reprint or copy of the text for just
the following pages? (Pages 182, 183, 186, 187, 189, 194, 195 and 199).

Pages 205 to the end are so badly stuck I haven't even tried to separate
them, but they are non crucial so not really a problem.

As for the book version and printing, it seems to be a first edition as
no other printings are listed.  Library of Congress ISBN 1-85233-351-0
is the only information that I can find on it.

I am very new with my ETX-125 and need all the help I can get.  Of
course as luck would have it, the pages that would be most helpful are
now unreadable.

Thank you in advance if you can help me with my damaged pages.


John Pizzulo
Mike here: Thanks for getting my ETX book. I don't have a PDF version of the book. OPT or Amazon may still have copies of the book. You could also contact Springer; perhaps they can help.

Subject:	ETX 80 stiffness
Sent:	Wednesday, April 10, 2013 07:07:24
From:	Andy Lancour (
perhaps you could help me assess an ETX 80?
I received the telescope yesterday and assembled it. It seems that the
telescope is very stiff in both horizontal and vertical movement. So
stiff that I could do an alignment and track objects without even
locking the scope in RA. I have owned other ETX scopes in the past, and
have a larger LX90 as well. The other ETX scopes were the 90 and 125, so
I don't know if it is a fair comparison, but they would turn very freely
on both axes. Is this normal for this scope not to? I know this isn't a
high end scope, and that Meade has cheapened their low end scopes up
even more, but I am not sure what is normal to expect from an ETX 80?

I opened it up and loosened the white castle nut on the clutch assembly,
and it improves movement, but when I re assemble the clutch and tighten
it to the point where the RA lock will grab, it's all really tight
again. I have tried 20 times with different castle nut tensions with the
same results.

I am concerned the motors and plastic gears will not last long if they
have to labor so hard to overcome all the friction? Let me know if I am

I am afraid a return to Meade will yield another scope with the same
issues? I appreciate your expertise and time.

Andy Lancour
Mike here: Does adjusting the RA lock lever position change where the locking occurs?


I've adjusted the RA lever and loosened it enough to get the scope to
turn freely, but at that point it is nowhere near to being able to lock
the RA movement. The stiffness is across the board in RA rather than at
one spot.

Mike here: It might loosen up with use. Unlock the axis. Rotate the telescope in RA slowly by hand. Go several times around in each direction.


Thanks Mike - that is what I have been doing. In your opinion can I
expect similar issues even if I would get the scope replaced?

Mike here: I don't have one of the current ETX-80 model so can't say whether this is normal or not. But if there is no free movement when the axes are unlocked, then I would have the same concern as you. I suggest contacting the dealer where you purchased it and see what they advise.

Subject:	Meade ETX-60AT display scrolls too fast to read.
Sent:	Saturday, April 6, 2013 07:31:59
I just got a used Meade ETX-60AT and love it.  The only problem is the
bottom line of the display scrolls too fast to read.   There is lots of
interesting information about the object that I am looking at, but I
can't read it because it is moving right to left so fast.  The
alphanumeric characters all blur together.  Is there any way to slow
down the scrolling speed?
In theory, practice and theory are the same.
In practice they aren't.
Mike here: See "Q. My AutoStar scrolls text too fast to read. How do I change it?" on the ETX FAQ page on the ETX Site.


Oops, never mind -----------
Mike here: Glad you found it. Sometimes I guess I respond too fast!

Subject:	Damaged etx 125
Sent:	Thursday, April 4, 2013 11:53:10
From:	Clinton Miles (
My etx 125 has been damaged at the main gear drive shaft. Plastic ring
that go's around the main drive shaft has broken as per the attached pic
any advice on how to fix it or where i can get a replacement part???


Mike here: There are several gearbox repair tip articles on the Helpful Information: Telescope Tech Tips page. There is also a "Replacement Gears source" article which may help.

Mike here: I was interviewed by PicStop in the UK. You can read the interview here.

Subject:	ETX 60 Drive Malfunction response
Sent:	Monday, April 1, 2013 12:53:39
with regards to 's drive failure; I know exactly what
he's talking about. I bought an ETX 60 with this exact problem, listed
for cheap on fleabay, the little fish hook tension thing was broken. I
wedged a thin slice of dense, closed-cell foam between the "fish hook"
's support and the flat spot on the motor mount that it was supposed to
press against; just enough foam to keep the hinged motor mount against
it's stop without a lot of tension. I used closed cell because it
doesn't easily take a permanent set. Works fine. Only caveat, be careful
re-assembling the plastic castellated piece, it was originally assembled
with loc-tite and probably will need that again else it'll unscrew
itself when the mount pivots on RA.

There are a bunch of other fixes on the website, including a creative
one using fishing line and a very rigorous one with a spring-loaded set
screw that I particularly like. The important thing is to get something,
anything, to lightly press the hinged motor mount with the worm gear
inward to it's stop; a light spring epoxied on would probably work
(note; I first tried a folded piece of stiff plastic to replicate the
fish hook, didn't work because it took a permanent set after a while),
but there's not a lot of room for anything large.

I'm cc'ing the OP on this, hopefully he won't give up, it's really an
almost trivial fix. Or if he does give up, I'll take it, fix it up, and
give it to my granddaughter  :-) Like the rest of the mount, it appears
to have been designed without regard to strength of materials,
serviceability, or general practicality, but most of the shortcomings
are easily fixed. I think in the future they should consider hiring
engineers who actually graduated, though. Just an idea....



Subject:	RE: ETX-80 slews down but not up
Sent:	Sunday, March 31, 2013 23:54:41
From:	D Webb (
Thanks very much. I checked the internet on this problem and there was 
a spectrum of answers, including returning to factory. I now see the 
problem (in my case) relates to personal subjective interpretation of 
"fasten to a firm feel only" in the manual. Tightening vertical lock a 
bit more solved this problem.

Above prob happened with fresh batteries or battery eliminator.
I do not think it is possible to get this problem because of lack of 
training/calibrating, but weak batteries might be causing other strange 
behaviours. Last night, after solving above prob, I used the autostar 
to goto Jupiter with batteries. It was off axis, so I used the handbox to 
move it on axis. Within seconds, the motors turned scope right back 
to the earlier position that was off axis. It tracked for a couple 
minutes and then finally started slewing towards the horizon, as if 
compensating for a much fast earth rotation. At that point, I noticed 
the handbox was much fainter, so batteries were weak. Have not gotten 
this behaviour yet with battery eliminator.

Finally, I got razor sharp view of moon with 2x barlow and 26 mm lens. 
The ETX-80 can produce much better images than many I seen 
on youtube, etc. There is some off axis color separation. I suspect best 
views of planets can be had with an off-centered 25-35 mm aperture 
stop. Sweet spot on mine is slightly off axis.

Mike here: Yes, proper axis tightening (and not over or under tightening) is important for reliably operation. Remember to CALIBRATE MOTOR whenever swapping power sources or changing batteries. "Rubberbanding" can usually be cured by doing a TRAIN DRIVES (on both axes).


Thanks bunches! Truly appreciated.

Dominic-Luc Webb
Marsta (near Uppsala) Sweden

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