Last updated: 31 August 2009

This page is for comments and user feedback about the "ETX Classic" telescopes. ETX Classic models 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, ETX-LS, 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.

Subject:	ETX 70 AT AZ Drive Problem
Sent:	Monday, August 31, 2009 14:08:44
From:	Paul Lapinski (
I am attempting to repair an ETX70AT. I can see that the AZ drive worm
gear is disengaged from the large nylon driven gear. The motor turns.
How do I remove the AZ housing?

I have attached two images to show how far I was able to go. I believe I
can correct the problem if I can get at it.

Thank you,


Mike here: Remove the rubber feet from the base plate. Screws holding the plate should be there.


Thanks for the rapid response. I removed the three screws. Something
disengaged but the outer housing is still on tight.

Mike here: Hum. I just realized your base is different. The article "ETX-70 Disassembly Instruction" on the Helpful Information: Telescope Tech Tips page shows what I expected. But perhaps, and I'm guessing here, the plate just needs to be pryed away from the base housing.


I had already viewed the ETX -70 Disassembly Instruction. My ETX 70 is
completely different as shown in my photos.

And more:

This is the type of base that is on my ETX 70 AT. I downloaded the image
from the WPO UK website.


Subject:	ETX-90 Premier Edition Mechanical Play in RA axis
Sent:	Sunday, August 30, 2009 14:04:30
From:	Bob Shanks (
I'm hoping you can help me ?.
I have just purchased a second had ETX-90 Premier Edition in the UK from
a local club member. The scope is about 2 and half years old and knowing
the guy I don't think its been abused. With It being the first motorised
scope I have owned I was hoping for some advice if I may ?

The issue is that even with no electrical power on the scope, there
seems to be a large amount of horizontal movement in the RA axis even
with the locking lever effectively locked. i.e. you can stand the scope
on the table, lock the RA axis and still feel some movement if you apply
a slight twisting motion to the scope.

I t does not feel as if  the friction locking mechanism is at fault as
the base will actually lock however when locked their is a measurable
amount of play. According to the graduated band this equated to about 4
degrees !

Using electrical power to manually drive the scopes axis at full speed,
there is a noticeable delay of about 2 seconds after the motor starts
before the drive is taken up and the scope begins to turn. If the scope
is then stopped and re-started in the same direction it will then move
instantly. If however the opposite direction is then applied, there is
again a delay before the movement.

I understand that the drive mechanism can be 'trained' for so called
'backlash' in the gearing but this amount of play seems way too

Without knowing anyone who owns this particular model, I am wondering if
this is normal or if something is wrong in the mechanism and if so what
it is likely to be and where I could get it repaired?
Hope you can help
PS great site by the way.
Mike here: First, see the item "Q. I can not move the Right Ascension (azimuth) lever enough to fully engage the lock. What should I do?" on the ETX FAQ page. That may be all that is required. Second, do a CALIBRATE MOTOR and TRAIN DRIVES. Let me know if either of these solve the problem.


I really appreciate the response and thanks for being so quick.

Although the RA does feel as though it tightens and locks, I take your
point and will give try it a try when I've located an Alan key of the
right size.

Any ideas what the correct size is ? - Im guessing its not metric ? (- I
didn't get one with the scope and my 1.5mm doesn't seem to fit)

Mike here: See the article "ETX Hex Key Sizes" on the Helpful Information: Telescope Tech Tips page.


Thanks mike, I'l let you know in the next couple of days.
Mike here: Keep in mind that the "lock" is just a friction type, similar to car brakes. If you push the OTA or fork arms, there will be slippage. What's important is that there is no slippage when the drive motors are running.


Yes I see what you mean. Although following your car brake analogy, it
feels like the brakes are applied but the brake disc is loose.



Have made the adjustment to the lock lever. 
Its not made any difference in the play I can feel I'm afraid.

Are you saying this amount of free play can be compensated in the
electronic drive mechanism somehow ?

The Train Drives routine does not move the centered object away from its
initial position, such is the play left in the axis.

Mike here: If the TRAIN DRIVES does not slew the telescope then there is indeed a problem. Open the base and check the central large nut. It should not be loose.


Ok - Not sure how to get in the base - Guess I need to remove the 3
rubber mounting pads to reveal some screws heads on the underside ?
Mike here: Probably. Then remove the bottom plate. There are some disassembly photos and interior photos in various articles on the Helpful Information: Telescope Tech Tips page.

And an update:

The good news is I found the source of the play in that the fixing
screws holding the metal worm drive housing to the plastic base plate
were loose.

The bad news is that a lot of plastic fell out when I removed the plate.
It would seem that there are several problems...

1: The tripod mounting post was broken around its threaded brass insert,
hence all the plastic debris. If only this was the extent of the damage
I would be happier, however ...

2: There is a large crack across the base plate from one side to the

3: the plastic posts that surround the worm dive and keep it in position
are broken and the central retaining screw has a stripped thread and
will not tighten.

4: There is a minor crack across the gearbox casing as well.

I suspect that the scope has been over tightened on its tripod at some

Whilst Im tempted to get the super glue out and do the repairs - I think
Im going to take it back to the guy I bought it from and get my money
back as I will always be conscious that the slightest bit of rough
handling on a dark night will wreck the thing.

I really thought I was on a winner with this scope as I saw an ETX-80 a
while ago and liked its portability. This ETX-90 came up and although
slightly bigger I decided from everything I read would be better all

Its a real shame. I don't suppose a man like yourself has a replacement
base plate lerking around or knows where I could acquire one ?

Anyway - Many thanks for your help in this Mike. I really appreciate it.
Ive taken some macro photos and can send them to you if you think it
might help anyone else wondering why there is play in their RA axis ?

Regards & Thanks

Bob Shanks



Subject:	RE: which telescope?
Sent:	Sunday, August 30, 2009 01:56:32
From:	Hempstead, Sue (
Thank you for your very prompt reply!
After doing a little research I came up with the below telescope.  What
do you think?

Orion SkyQuest XT8 Classic Dobsonian Telescope

The telescope would be used in Auckland, New Zealand which is of course
a large city, do you think it is even worth having a telescope due to
city light pollution?
Sue Hempstead
Mike here: Having a large Dobsonian telescope can be both rewarding and challenging. Dobs, by their nature, can provide excellent views, especially of faint nebulae and galaxies. Yes, the Moon and planets will look nice too. On the other hand, they can be somewhat cumbersome to set up on a moment's notice. You can use ANY telescope in a light polluted area but large aperture telescopes will obviously perform best from dark sky sites. So, if you can get away from the city (and the Dob will fit in your transportation), then it should provide years of enjoyment. If you can not get away from the light pollution, then you will be limited to viewing the Moon, brighter planets, and occasionally, brighter Deep Sky Objects (but not too well).
Subject:	ETX 125 RA jittery problem
Sent:	Friday, August 28, 2009 20:15:22
From:	Fred Rains (
I purchased an ETX 125 off of one of the astro-sites a while back and
shortly after the check cleared it began to have problems. I fixed the
random-slew problem by replacing the RJ 45 connectors and adding a
couple of ferrite filters to the Autostar cable. I also added a ferrite
filter to the external power cord.

I am still having a problem with the RA movement. There is an occasional
jitter where the scope lurches forward by a two or three arc minutes.
This occurs every thirty seconds or so. I have tried tightening and
loosening the screws associated with the gear train and nothing seems to
help. One more thing. When I removed the base a small piece of plastic
fell out. Thanks to your site I identified it as one of the plastic
"teeth" associated with the mechanical RA stop.

What could be causing the jittering RA movement?

I'm hoping you or one of your readers can help.


Birmingham, Alabama
Mike here: Did you check the gears for broken or missing teeth? That will obviously cause jumping. It could also be that the lubrication just needs to be redistributed. Sometimes the simplest way to cure that is to unlock the axis and slowly rotate the telescope by hand, hard stop to hard stop, back and forth, several times. Lastly, have you done a CALIBRATE MOTOR and TRAIN DRIVES?


There are no broken teeth in the gears and I have manually moved the
unlocked base a number of times. I honestly could not sense any bind at
all and that made me suspect the gears. One thing I did notice was that
when I loosened the gear assembly screws and tried to move the  entire
assembly, there was a very tight fit between the worm gear and the main
axis gear. Tight to the point that will all the screws loosened the
entire gear assembly was still firmly  in place. Do you know if this is
normal or if the small tension screw adjustments for the worm gear/axis
gear could be too tight?

I have done a calibrate/train sequence each time I make any adjustments
to the gear assembly.

It finally cleared here in Birmingham this evening and I just came in
from trying it out one more time. There were no runaways for a little
over four hours and every object selected was in the field of view of a
26mm Meade SP each time. Tracking was excellent with one object (95 Her,
a really nice double with a slightly greenish secondary) staying in the
field of view of an 18mm SP for an hour and a half while I came in to
watch some TV and send you the email. This makes more than fifteen hours
of observing time without any goto problems. If it doesn't act up by the
Winter Solstice, I will declare that problem resolved. The jitter issue
is more of an annoyance than a real problem. I don't notice it as much
after a while.

If you hear of a solution to a similar problem please let me know.

Thanks again for the suggestions and the timely response. :)

Mike here: I don't know if the tension of the gear mount screws would make any difference as long as the mounts are firmly seated. One other thing to check would be overtightening of the axis lock. I doubt that is a problem since GOTOs seem pretty accurate.
Subject:	How do I identify make and model of Meade telescope
Sent:	Friday, August 28, 2009 18:15:53
From:	RIchard Cummins (
I recently inherited a Meade Telescope along with tripod, ETX autostar
(tracking gizmo) and small handheld "autofocus" remote.  Unfortunately,
I did not get any of the operating manuals for this equipment.  Are
there specific identifiers that I can look for that might narrow my
choices down to a mere handful?  Any help would be greatly appreciated.

RIchard Cummins (

Lansdale, PA
Mike here: Well, since it has an AutoStar and a remote focus controller (assuming it also has the electric focuser as well), it could be an ETX model. But it might be a different model as well. You can check Meade's web site and look at the manuals listed there. If the telescope is not too old, you'll probably find the right manual. Alternatively, send me a picture of the telescope and I'll try to ID it for you.


Thanks Mike,

I off for a two week trip but will try to get the information to you (if
unsuccessful on the Meade site).  Many thanks for your very prompt

Subject:	New ETX-90 owner with a few questions
Sent:	Friday, August 28, 2009 11:59:46
From:	Anonymous
I stumbled upon your site when searching for some ETX-90 tips via
google. I just purchased a used Meade ETX-90 and had a few questions.

It came with 4 eye pieces: 4000 series super plossl; 9, 15, 26, and 40mm
I also purchased a t mount and t mount adapter as I plan on taking some
digital photos.

Will these different lenses provide different magnification power ? If
so, what magnification does each lens provide. I plan on using the scope
for bird watching as well as some astro viewing.

Am I able to zoom in and out with this scope, or would that require a
certain eyepiece ?

Finally, is there anything else you recommend for the scope (eyepiece,
dew shield, etc)

Thanks a bunch and great job on the web site...its got a ton of useful

Mike here: Info on how to calculate magnification with eyepieces is on the ETX FAQ page. To "zoom" you need a zoom eyepiece; see the Accessory Reviews: Eyepieces page. As to what else to purchase, first get used to what you have and learn how to effectively use the telescope. As you use it more you will will learn what you might need to enhance your experience and what you might like to concentrate on. Of course, there are lots of tips and suggestions on the ETX Site! Enjoy!


Sounds good...thanks and keep up the great work !

Subject:	ETX-125AT with red dot viewfinder.
Sent:	Friday, August 28, 2009 04:42:43
From:	Iotour Iotour (
Finally i bought the classic etx-125at -- the  classic one , and i am
very happy with it.
I noticed that it has the smartfinder , is it the  new re-engineered
John Greece.  
Mike here: Is the Smartfinder lens on the side or top? If on the top, it is a newer model than the one with the lens on the side.
Subject:	ETX 125
Sent:	Thursday, August 27, 2009 17:58:55
From:	Gerald Jenny (
Well I'am back at it  I have tried everything I know and no luck I think
maybe I have a bad board  not quite sure how to check that. Any how to
get you up to my problem .I have 4 HBX cables three do not  work these
are brand new. I have one that works on one end when I swap ends only
one end works. I have up and down movement but no left to right movement. 
I turn on the Autostar and it searches for my GPS and get that and the
alignment one star or easy after that I cannot move left or right but up
and down is OK any ideas I look for a wiring diagram and no luck.Any
help from anybody wouls be great can a new board be purchased.
Mike here: If you want to try for a replacement board, try Telescope Warehouse (link on the Astronomy Links page).
Subject:	Eyepieces for an ETX-70
Sent:	Thursday, August 27, 2009 13:11:49
From:	Miramonti, John (
I own an ETX-70 I bought new several years ago, when the kids and the
world were young.  Well, they're older and I've still got the 'scope.

I've got the stock eyepieces (9 & 25 mm MA) and another "Super" Ploessl
(can't remember the size right now, but it's somewhere between 9 & 25).

I'm trying to get a bit magnification when the wife and I look at
planets, etc.

Way back when I had my eye on the Meade "Value Pack", a combination of a
Barlow and 2 eyepieces, the 4 & 6 mm Ploessl's.

Appears they don't sell it anymore, so I've been looking at eyepieces

I've got my eye on a couple of candidates: the GSO's and the in house
brand at OPT.  I'm also wondering about the Vixen eyepieces.

Do you have any recommendations?

On a slightly different subject...I've got the Meade tripod and I'm
thinking about setting up for a polar mount (might try that photography
thing).  Any ideas about the best way to make/buy a wedge for the
tripod/ETX combination?

Many thanks for your site!
John L. Miramonti 
Hanover, NH 
Mike here: Keep in mind the theoretical magnification limit for any telescope; see the ETX FAQ page if you're uncertain how to calculate that. With that said, you can easily "double" your eyepiece collection by getting a 2X Barlow Lens ("shortly" style for the ETX). There are many eyepieces reviewed on the Accessory Reviews: Eyepieces page. Also, there are some eyepiece tips on the Helpful Information: Buyer/New User Tips page. I have some OPT brand eyepieces that I used on my ETX and LX200 telescopes. Good eyepieces at good prices. As to a wedge, there are many articles on wedges on the Helpful Information: Telescope Tech Tips page. Alternatively, you can get a Meade #884 tripod, which works in both Alt/Az and Equatorial with the ETX.


Well if memory serves, the ETX 70 has a 350 mm FC, so I'm thinking
100x-125x or so ought to be about the upper limit.  So I'm figuring a 4
mm (w/o Barlow) ought to be about 87.5x and a 6mm ought to give me about
58x (w/o Barlow) and about 116x with 2x Barlow.  This sound about right?

So any feeling on OPT house brand vs. Vixen?  Maybe I should talk to
someone at OPT?

Thanks again!
Mike here: That's a conservative estimate vs what's noted on the ETX FAQ page. But that's OK. Your eyepiece magnification calcs are right on. I have no experience with Vixen eyepieces. Contacting OPT is certainly worthwhile.
Subject:	Re: LNT Alignment with ETX125PE
Sent:	Wednesday, August 26, 2009 20:45:23
From:	dan colesworthy (
Contacted Meade customer support again.  Now they want me to remove the
LNT module, mounting bracket, and piece of shrouding to which all is
mounted.  I'm supposed to send it back for replacement.  I still wonder
if it is possible that the scope tube is "not quite rightly placed" in
the mount?

Dan Colesworthy
Mike here: The LNT Smartfinder alignment would have nothing to do with the OTA mounting in the fork arms. There are four screws holding the OTA to the tube adapters. Hard to have a problem there.
Subject:	which telescope?
Sent:	Wednesday, August 26, 2009 03:29:05
From:	Hempstead, Sue (
I have been looking for telescopes on the internet and came across your

I am looking to buy a first telescope for my  adult son's birthday.  He
is a complete beginner but shows interest in the 'skies'.

What would you recommend without breaking the bank!
Thank you
Sue Hempstead
Mike here: Which telescope to get will depend on a couple of factors. Budget is of course one. But so is the capability of the telescope. A telescope that doesn't meet expectations of what can been seen ends up unused and can even dampen enthusiasm. A telescope that is too large or too cumbersome to easily set up also ends up unused. The best telescope for anyone is the one that gets used. All that said, there are many excellent choices out there. I recommend visiting a local telescope dealer (not a camera or department store). If there are none close to you, check out dealer web sites, such as OPT (; note that I have a relationship with them but they are good). There are other excellent dealers online as well. Search their sites for offerings that match your budget. Once you narrow down your choice, drop me a note and we can discuss it more.
Subject:	Dew Control
Sent:	Wednesday, August 26, 2009 05:24:04
From:	Rori Baldari (
Congrats on your new observatory. I'm attending my first star party in
September and am concerned about dew control on my ETX-125. I have the
Meade dew shield, but for extended observation do I need a heater? I
have a Black & Decker 12v auto battery, with only one input for the
scope, but no RCA connector for a dew band. Any suggestions?
Mike here: There are several articles on dew shields and dew heaters on the Helpful Information: Telescope Tech Tips page. Whether or not you need a dew heater depends on the local conditions and your observing habits. Keep in mind that in heavy dew-ing conditions, EVERYTHING is going to get wet. The aperture, the finderscope, the eyepiece, the handcontroller, star charts, you, etc. Having just a dew heater won't prevent all that.
Subject:	Remote Telescope
Sent:	Tuesday, August 25, 2009 09:21:11
From:	Bill Cherry (
I want to do basically the same as you are doing, have a remote control
telescope and also add high resolution video camera at eyepiece. But I'm
a novice on astronomy.
What you recommend as a starting telescope, controls, etc.
CDR USN Retired
Bill Cherry
Fort Collins, CO
Mike here: First, I don't have a remote controlled telescope, nor do I plan to do one. So I'm probably the wrong person to ask. But first you need to ask yourself "what's the available budget?". So, I'll ask that. How much do have you have spend on the setup? Next question, what do you plan to do with the remote telescope? Visual work on a monitor or astrophotography?


Aha, I misread your web site or one of the documents; stating that you
had planned to do that.

I'd like to do both, personal direct use & then when I'm not there,
provide web access with the best video I can come up with.

Budget is <=$10K.


It was on a tech tips page you had in 2002. I just got the address
Mike here: Probably someone else mentioned doing it. Depending on the observatory building, you can plan to spend from a few hundreds to a few thousands of dollars. Check out the SkyShed POD web site ( for pricing on that style of pre-fab observatory (which is what I now have). Of course, there are many other alternative designs of observatories. You'll want to pick the one that fits the budget, your specific needs, and your location. As to a remote controllable telescope, almost any of the GOTO telescopes can be remote controlled using a computer. You can either leave a computer connected to the telescope AT the observatory and then remotely control the computer using a second computer at a different location. Either way you need to run Ethernet or serial cables. You might be able to use Wi-Fi. Carina Software is about to release their SkyFi ( So you need to factor in potential costs for a computer (if leaving one at the telescope). Next comes imagers; you can spend hundreds to several thousands of dollars on imagers. It just depends on how serious you want to get with astrophotography. Now that we've spent all your budget, you get to decide on a telescope! Of course, the higher-end the better; you get better optics, better mount, better drives, better electronics, etc. And of course, you will probably want the largest aperture telescope that the remaining budget will tolerate. Have I scared you off yet? Alternatively, you can approach the problem from the opposite end. Start with the telescope and add items over time (months or years).


My business is computers and I have cat 5 run everywhere. So the
computers, computer control and networking is no Problem. And I would
choose to do the observatory and telescope first, leaving the imager
last as I also do a lot of things with those.

As for computer in the observatory I would probable use an embedded
processor which could control the computer, generate a simple web page
for remote access and then some extra electronics to serve out the image
either as high resolution stills or lower resolution video.

As I mentioned I was thinking it would be dual purpose:
- Personal for use as a regular observatory permitting still film camera
- Then as a web observatory for use in the house & for other family
Controls to open/close the door, the GO TO function, etc. This of course
would be password protected. I would give you the pawword.

Where is a good source to shop for a telescope and the associated

Mike here: Sounds nice! Good luck! Looking forward to hearing more about it as you start marking progress! As to a dealer, if there is a dealer near you (not a camera store or department store), then I recommend starting with them. If no dealers near you, give OPT a look (; note that I have a relationship with OPT). They have very knowledgeable people and sell a LOT of telescopes and accessories.
Subject:	collimate etx 125
Sent:	Monday, August 24, 2009 14:31:42
From:	jon (
Jon from England here, got a good etx 125 from the states, just started
to use it from last year per  work problems and its miles out.

Im ok with removing the tube ect, but be dammed if i can move the
doughnut towards ten past as per clock,i also notice that the results
are not the same in focus as against out focus, please help, im a bit of
a perfectionist and wandering if I'll ever see a perfect star image.
Best regards
Mike here: Have you read the collimation articles on the Helpful Information: Telescope Tech Tips page? If not, do so and see if they help.


Yes mike. Im reading them as we speek, im just needing more specific
quidance, ie if the rings are sqewed to 20 to per clock, which screws
move it back central. Also im reading the forbidden to touch flat head
screws can in fact be used
Mike here: I think something is being lost in translation. I must be misunderstanding what you are asking ("...sqewed to 20 to per clock..."). Anyway, are you certain you need to collimate it? Have you done a "star test" after letting the telescope reach thermal equilibrium?


I translate the doughnut to a clock face, ie if the pattern is all
leaning towards the bottom left if the centre im calling this twenty to,
ie twenty minutes to 12
Mike here: See if the article "Doc G's ETX OTA Guidescope & Disassembly Photos" on the Telescope Tech Tips page helps.


Thanks anyway, I thought you would have some info rather than refer me to
write ups.
Ill struggle on.
Thank you for your help anyway.
Best regards
Mike here: One of the purposes of my ETX Site is to share information and make available tips from many users. If there is something that I've not done myself (like disassembling an ETX to collimate it), I refer to articles on the web site, if they might be pertinent. If that's not helpful, then you can always visit the ETXastro Yahoo Group; it is pretty active with knowledge ETX people.
If you want to document what you doing with your ETX collimation, with photos if possible, I'll be happy to add it to the ETX Site for the benefit of others who might be in the same situation as you. Thanks.


Ok thanks mike.
There is not really anyway I can take images in what im doing, and im
not sure how to post info, I did find one interesting thing that knowone
has pointed out,when adjusting the hex screws for the collimation, this
can stiffen the focusing spindle to the point it cannot be turned with
the fingers,(without the focus knob on ) so I very slightly adjusted the
flat head screws which released the tension
Im all but there with the adjustments,
Mike here: Regarding having articles posted, you just email them to me.
Subject:	Crosshair repair
Sent:	Monday, August 24, 2009 02:12:33
From:	Doug Enns (
I just did this on a piece of optical equipment, and I used dental
floss. I looked at all the choices you had made under a scope and was
brushing my teeth when I got the idea. The floss can be separated into
threads so fine I had to use a microscope to separate the last two. They
are long and fairly strong. They look good in the scope. Sorry no


Subject:	LNT Alignment with ETX125PE
Sent:	Sunday, August 23, 2009 16:34:26
From:	dan colesworthy (
Its been 8-9 months since I last whined about my ETX125PE.  In the mean
time it has had 3 round trips to Meade's service department.  Just got
it back for the third time.  They replaced the LNT module, mounting
bracket, and I think the shroud to which the LNT mounting  bracket
attaches with two screws or bolts.  They have also sent a different hand
controller back each time.

Now I find that I cannot adjust the red dot finder so that it aligns
with the optics.  Even when adjusted to its maximum elevation, it still
points low  Tried to auto align just accepting the initial point to the
alignment stars followed by a goto Polaris,   The optical tube pointed
about 4 degrees high, the LNT module seemed as best I could tell to be
elevated to about 40 degrees.  Correct for my location just a mile from
the 40th parallel.

Although I'll likely call Meade again tomorrow morning, I am wondering
if there is a simple adjustment I can try myself?  The replacement LNT
module has the rubber plug on the  bottom side presumably to allow
replacing the battery without disassembling the LNT module as my
original module required.  Haven't  had a scope to use since early
January, so would like to avoid another 1-2 months of "service" turn
around time.

Thanks for a very informative site.  Hope you the moonsoon ends soon!

Dan Colesworthy
Mike here: Which version of the LNT do you have? Is the lens on the side or top?


On the top.  I have run the vertical adjustment screw all the in and out
a couple of times.  When the screw is all the way in - maximum elevation
- the red dot still points low!

Just got off the phone with Meade.  They are suggesting I disassemble
the LNT module and cut a couple of turns off the vertical spring and see
if that helps?

Thanks for the prompt reply.

Mike here: Interesting tip from Meade! Let me know how it goes.
Subject:	ETX tripod azimuth knob thread
Sent:	Friday, August 21, 2009 13:04:56
From:	V.A. van Wulfen (
Do you happen to know what the thread is of the Meade #883 tripod's
Azimuth Adjustment Knobs? This is the tripod that was originally shipped
with the RA and EC series.
Victor van Wulfen
Mike here: Mine looks to be 3/8" diameter and maybe 24-25 threads per inch.
Subject:	ETX 105 Broken RA Drive
Sent:	Friday, August 21, 2009 02:16:17
From:	Frank Bonner (
I have had an ETX105 for about 5 years now and have been generally
pleased with it. A couple of years ago the RA drive started to split but
I was able to repair it with the help of instructions from your site.
The drive has now sheered completely and needs to be replaced.

I have spoken to Meade but they will not sell me a new drive saying that
I must take the telescope to one of their repair agents to have the
drive replaced. However I live in Spain and their nearest listed agents
are in Northern Germany or the UK. It would cost less to replace the
scope than make these journeys. Do you know of anybody who makes a
compatible drive that I can install myself?

Many thanks

Frank Bonner
Mike here: There are some possible options. Check the article "Replacement Gears Source" on the Helpful Information: Telescope Tech Tips page. Or try Telescope Warehouse or BinTel (links on the Astronomy Links page). Or if you want to send it off to the USA, you could contact Dr. Clay Sherrod (of "Supercharge" fame; link on the ETX Site Home Page) and see if he might be able to repair.
Subject:	I need sme help
Sent:	Thursday, August 20, 2009 16:10:59
From:	yunus munus (
Hi i wanted to ask a question about telescope eyepieces. I have a Meade
ETX-80 telescope and i want to enhance my view of the night sky, what do
i need to see stars and other objects better and closer? Also how would
i know the qualitys of a particular eyepiece/lens(mm?)?.
Awaiting your reply, thanks
Mike here: I see that your email was returned to you as "undeliverable" and it had been deleted UNREAD as SPAM. This was due to the ambiguous subject line. PLEASE read the Email Etiquette item on my ETX Site. Thanks for understanding.
You need more magnification, so need one or more shorter focal length eyepieces. However, keep in mind that the ETX-80 is a short focal length telescope with a small aperture, so how much magnification you can actually get is limited. If you are unsure how to calculate magnification and the maximum magnification that is usable for any telescope, see the ETX FAQ page. As to eyepiece quality, if you stick to name brands you will be OK. See the Accessory Reviews: Eyepieces page for more on some eyepieces.
Subject:	Meade EXT 125 EC
Sent:	Thursday, August 20, 2009 16:05:28
From:	Ed Moore (
I own a Meade EXT 125 EC for over one year. I have not got to see
through it. I had a stroke in 2000. I live with my daughter's family
where we see Mt St Helen's, Mt Adams & Mt Rainer from my living room
window and as we go into town see Mt Hood. Being in a wheel chair makes
getting in the correct position very difficult for good viewing. I
bought a Meade Electric eyepiece that I thought would help me viewing
etc. Do you have a book that covers this telescope?
Thank you
Mike here: My "Using the Meade ETX" book is applicable to that model ETX. Of course, a lot of the information on my ETX Site is applicable to it as well. You can read some articles about the Meade Electronic Eyepiece on the Helpful Information: Astrophotography page on the ETX Site.
Subject:	Re: LNT not keeping proper time
Sent:	Thursday, August 20, 2009 09:09:48
From: (
If the LNT is keeping time but has excessive drift, it is almost always
a problem with the battery. The only thing the battery does is power the
clock while the rest of the LNT functions use the main scope power
source. It's not unheard of for even a new scope to have an old battery
since they are installed during assembly and may have been sitting on a
shelf for years.

As for the red dot, it turns off after the alignment process is complete
but can be turned on and off any time with the '0' (light) key on the
Hope this helps.
Mike Hogan

Mike here: If you have a Geocities web site that is referenced on the ETX Site, or if you know of one that is (or has) changed, please email me the old and new URLs. Thanks for your help!
Subject:	ETX90 Problem
Sent:	Tuesday, August 18, 2009 08:50:16
From:	Edd (
Hi all, great site with lots of decent info so keep up the good work.

I have a problem with my ETX90 scope, one evening i was setting up a new
LPI camera and during this my autostar 497 stopped responding. I tried
all the normal reset and have now tried it in another scope (it worked
in the other one). I have also tried a new controller in my scope and
get nothing. The LED comes on, on the scope but nothing on the
controller. This is with batteries and external power.

Has anyone got any ideas as to what may have caused this and how to
remedy it. Are there any internal fuses that may have blown etc.

Any help gratefully recieved
Mike here: Does the power LED on the ETX base illuminate?


Thanks for the prompt reply, yes the led does illuminate.
Mike here: There is no inline fuse but sometimes the battery cut-out switch can get stuck. See the article "Repairing Battery Cutoff Switch" on the Helpful Information: Telescope Tech Tips page. Also, did you try the AutoStar cable on the other telescope? If so, check the HBX jack on the ETX base; look for bent, dirty, or too depressed pins.


Tried all these things but to no avail, where can i get a copy of the
board schematics so i can test these at some point. I have taken it to
telescope house and have to wait for a week for their man to come back
:(. Typical we have clear skies at the mo. You can bet it clouds over
when i get it back

Mike here: There is no schematic but some of the "wiring" articles on the Telescope Tech Tips page might help you. I'd first recommend checking the connections to the HBX jack; that sounds like it could be the culprit.


Thank you i will look into that, Hope your righ otherwise new boards
could be expensive. Enjoy your new observatory

Mike here: Replacement circuit boards are hard to locate. And thanks. I'm looking forward to getting "first light" in my new observatory!
Subject:	LNT not keeping proper time
Sent:	Sunday, August 16, 2009 18:03:33
From:	Brian King (
How far off on the time should the LNT be? Mine seems to be off every
time I go back to the telescope after one day or a few weeks. Its off by
at least a half hour. I do have it in daylight savings time. It seems to
be messing with the star alignment at the first startup. I use a atomic
time set clock to set the time before I start after I make sure the time
is incorrect.   Thanks Brian
Mike here: It should maintain good time. Have you checked the LNT clock battery?


Hi Mike   The battery is fine. Any other ideas?  Thanks Brian
Mike here: When I first got a PE model I had some intial problems getting the time set from the AutoStar to be saved to the LNT. Eventually it took. There are some LNT troubleshooting tips on the Helpful Information: Telescope Tech Tips page. You can also search the site for "LNT time" and see if anything useful comes up.


After reading some other problems with the LNT I have another question.
Is the red dot on at all times? Mine is not only when it is aligning on
initional setup.  Thanks Brian
Mike here: You can set the red-dot display mode in the MODE menu under Finder Options.
Subject:	EXT 125 EC tracking issue
Sent:	Friday, August 14, 2009 19:30:24
From:	Blue Moon Woodcrafts - Peter J. Perrone (
I picked up this scope used last year to use as my travel scope and
honestly don't get to use it much but it appears to not want to track at
all.  It's probably something stupid I'm doing but I just can't figure
out what.  To make things as simple as possible I enter the correct time
and date, do a one star alignment routine, then after I center the
object the scope is either not tracking at all or tracking in a
different direction in both alt and dec.  This is all being done in
alt/az mode.  Any object centered in the FOV never stays put.  I've
tried training the drives, downloading the latest Autostar software and
calibrating the motors but nothing changes.  It's been frustrating to
say the least.  If nothing else if you could just point me in the right
direction I'd greatly appreciate it.
Blue Moon Woodcrafts - Peter J. Perrone
Mike here: Have you tried the Easy Align (2 stars)? Also, have you checked your location and HOME position set up? For more on alignments, see the Helpful Information: AutoStar Info page.


Yes and yes but I'll certainly try it again just to make sure.  Will
check the site info too.  Thanks for the help.

Subject:	ETX-90-EC base gearbox in pieces - Meade can't repair-no parts
Sent:	Wednesday, August 12, 2009 14:37:49
From:	Haggerty, Robert LCDR (
My ETX was boxed up the past 3 years while I was working in Europe.

The other night I tried to put it to use and had problems with the base

I opened it up and found the black cage surrounding the gears to be
loose and cracked in several places (greasy black pieces all over the

This is well beyond warrantee but I called Meade Support to see about
parts or getting it repaired.  I was told they don't carry the parts for
the ETX-90-EC anymore and couldn't help.

I am coming up with a belief that the lack of continued support makes
the Meade telescopes a disposable item!

Do you know of any repair shop or ETX enthusiast that may have the gear
cage available or other option to get this back in working order?

I can do the work - just need the parts!

Please respond to my home e-mail account at:

Thank You!

Mike here: Please see the Email Etiquette page on the ETX Site home page regarding email addresses. Thanks for understanding. As to replacement parts, you can try Telescope Warehouse (link on the Astronomy Links page) or see the article "Replacement Gears source" on the Helpful Information: Telescopes Tech Tips page. Alternatively, you can contact Dr Clay Sherrod for his Telescope "Supercharge" Service (info linked from the ETX Site home page.
Subject:	question
Sent:	Saturday, August 8, 2009 10:04:41
From:	Amy Woodward (
Are spare parts available for Meade? Such as, the lens holder tray which
also allows you to fold the tripod legs.
Thank you!
Amy W.
Mike here: Just noticed that your message was rejected as undeliverable due to the ambiguous subject line. PLEASE read the Email Etiquette item on the ETX Site Home Page; thanks for understanding. As to replacement parts, Meade can provide some parts for some telescope models. Give their Customer Support a call.
Subject:	Re: The hard stop problem
Sent:	Saturday, August 8, 2009 00:46:30
From:	Philip Mann (
Having sorted the Tour problem I am still plagued by the hard stop one. 
Last night using Easy allign it first went to Arcturus then came up
against the hard stop on its way to the second star Altair. I tried Easy
alignment but had the same problem.  For both I started in home position
CCW to level/find north then set the telescope north for the alignment
procedure.  Do I have a duff ETX125 PE?!  Many thanks for your help
Bye for now
Mike here: If I follow the steps you did, you were in the wrong HOME position for the PE Auto Align. You indicated you rotated CCW to the hard stop and then you rotated it back to North. That is the HOME position for the non-Auto Align mode. For Auto Align, leave it at the CCW hard stop. The OTA should be pointing approximately Southwest.
Subject:	Meade AC power supply
Sent:	Friday, August 7, 2009 15:07:56
From:	Louis Welke (
My ETX-LS telescope lists a AC power adapter #07584 

Awhile ago I wrote in about using a Meade AC adapter with one of my
other 'scopes, I couldn't remember if it was this one anyway when I used
that adapter on one of my other 'scopes I had a problem where the 'scope
would go up/down but couldn't go right/left and it was determined that
the problem was electrical and caused by a spike in the operating
current. Another user wrote in about having the same problem after using
a Meade adapter, I would feel more comfortable by using a 12 volt
storage battery that can be recharged very much like Celestron's Power

My telescope was repaired by Meade but this should never have happened.

Having portable power is a step better anyway I would like to see if
these adapters were checked for spikes

Lou Welke


I found that the AC adapter having problems was a # 541 maybe Meade
fixed this problem and  it is now # 07584

Lou Welke
Mike here: They now have a "universal" power adapter to control current shipping telescopes. Previously, they had adapters that would specific to the power requirements of specific telescopes.
Subject:	How can I bolt a red-dot finder to the ETX-90EC?
Sent:	Thursday, August 6, 2009 22:06:47
From:	Tom Loftus (
Thanks for your wonderful web site; it's extremely helpful.

I have an ETX90 EC and would like to replace the standard 8 x 21mm
viewfinder with a red-dot finder. I'm hoping to avoid using double-sided
tape, wire ties, glue, etc and would instead like to bolt the finder (or
a suitable dove-tail mount, etc) directly to the optical tube via the
mounting bracket that's currently used for the 8 x 21 finder --
basically I'd like to mimic the ETX-90PE setup.

I've tried to find the finder provided with the ETX-90PE, but it appears
that it's not sold separately from the scope.

I don't have easy access to a shop, so if possible I'd like to buy a
"ready made" component. The Orion EZ Finder Deluxe is appealing, but it
looks like attaching the dovetail to an ETX-90 requires the double-sided
tape I'm trying to avoid.

Do you know of any mounting brackets, etc that would allow me to mount
the Orion dovetail (or something comparable) in place of the 8 x 21
finder bracket? Alternatively, do you know of any red-dot finders that I
could simply insert into the 8 x 21 finder bracket (and perhaps hold in
place with longer screws)?

Thanks for your help,

Tom Loftus

Thomas H Loftus
Department of Physics
University of Washington
Seattle, WA 98195
Mike here: You can probably get some ideas from the Accessory Reviews: Finderscopes page. There are also many articles on attaching finderscopes on the Helpful Information: Telescope Tech Tips page. Some people have used the existing finderscope bracket mounting points, others have mounted a second finderscope to the right of the eyepiece, and others have used rings or other means of attaching accessories more towards the front of the OTA. As to the LNT module (for the PE models), Meade used to sell it separately; try contacting them directly.


Thanks for your quick reply and helpful suggestions. I've already found
some possibilities on the web pages you listed and will try to get in
touch with Meade soon -- probably I just wasn't careful enough when
searching their web site, etc.


Tom Loftus
Mike here: I don't think you will find the "replacement" LNT part listed anywhere on the Meade site. But you can call them. Or try a Meade dealer. By the way, there are a couple of LNT articles on the Telescope Tech Tips page you might want to read: "Adding a LNT Module" and "Adding a LNT to a non-LNT Telescope".
Subject:	RSS Feedback
Sent:	Thursday, August 6, 2009 05:17:36
From:	Arran Marshall (
I've just ordered my ETX 125 inc special observatory kit - looking
forward to it immensely - just dropping you a note to say that I've
bookmarked your page and I'm linked up to your RSS feed as you requested
Arran Marshall
East Yorkshire
United Kingdom

Subject:	ETX 125EC:Where to find a vertical (dec) drive gearbox ?
Sent:	Wednesday, August 5, 2009 14:58:51
From:	Coskun Toprak (
I need a new vertical drive gearbox for my ETX 125EC I bought in Turkey
in 2000 and used only a few times.Mine's plastic body is broken on
several sections.

Disassembling only now,I was surprised to discover the weakness of the
design and of the internal components of the drive.

Local dealer said that the model being obsolete,replacement parts were

Could you help me to find either a spare gearbox or a drawing of
it,giving the functional dimensions.
Best regards,
Coskun Toprak
Mike here: You can try Telescope Warehouse and Bintel (links on the Astronomy Links page). If they can't help, check the article "Replacement Gears source" on the Helpful Information: Telescope Tech Tips page.


Thank you for your extremely quick reply.Having learned that the newer
PE's gearbox was compatible with EC from your indications,I recontacted
the local dealer and I am waiting.

Your site is an outstanding asset:it gave me the courage to open my
telescope and look inwards. Pity that I did not came across in the
guarantee period.
Best regards
Coskun Toprak

Subject:	Re: Broken drive mount and retaining ring on ETX125EC
Sent:	Tuesday, August 4, 2009 07:25:13
From:	Damon Leverett (
Here is a follow up after reading the tech tips. There is enough
information to replace the gearbox however, finding the source for a
gearbox will take some time. I am headed out to Santa Fe this weekend
stopping by the VLA on the way and looking forward to some dark sky and
a test run of my Starry Night computer interface. So I devised a band
aid for now until I can find the parts.

Certainly  this would not be recommended unless the parts in question
are considered a throwaway and will never function properly again. The
gear box problem I have is one broken plastic fastening point that
attaches the gearbox to the bottom plate. Since  there are three
fasteners , missing one is like removing one leg from a three legged
chair. Lots of rocking and rolling but no engagement of the gearbox
sprocket to the worm axle sprocket.

After studying the forces that act on the gearbox in both motor
directions, I attempted to create restraints to resist uncontrolled
movement. To keep the gearbox stable, I tied down the gear box to the
frame with ridged wire . The horizontal wire to resist forces of the
worm gear rotating clockwise and the vertical one for the opposite

I tested it out for 30 minutes and all works fine for now. There are
plenty of unknowns here. For one the pressure between the two sprockets
are now definitely out of spec and will probably begin to wear. I will
only use the scope at mid to low speed until a full repair can be done.
damon k leverett



Subject:	Broken drive mount and retaining ring on ETX125EC
Sent:	Sunday, August 2, 2009 16:25:44
From:	Damon Leverett (
I have a broken drive mount and retaining ring on my ETX 125EC with #497
Auto Star and #884 Delux Tripod, purchase in Feb 2004. The gears look
fines  but because one screws that mount the clutch and drive gear to
the plate is broken the gear cannot engage the worm gear sprocket. It
just pops up and down going nowhere.

Due to the economy I cannot afford a supercharge at this time. I do feel
confident that I can change the broken assembly if I could only obtain
it. Please advise on the feasability of obtaining this part. Additional
advice is also welcome.
Thank you
Damon Leverett
Scottsdale, Arizona



Mike here: See the articles "ETX-125 gearbox repair". "Replacement Gears source", "Gear Grease Information", "Fix for Worm Gear", and "Gearbox Replacement" on the Helpful Information: Telescope Tech Tips page for replacement parts. Perhaps they will help.
Subject:	ETX tripod mouting screws
Sent:	Sunday, August 2, 2009 12:41:08
From:	V.A. van Wulfen (
I'm looking for a set (4) of screws to mount my ETX-105 % -125's to
Meade #883 tripods. Can't find them in Europe. I really hope you or
other ETX users visiting your site can help me out. Will pay for them
and for shipping & handling of course, through PayPal (verified
Mike here: They are standard camera tripod mounting screws, 1/4"-20 (I believe), just longer. You can probably get them from Meade Europe (


Thanks, I'll try. Might be lucky, as far as I know the #883 tripod is no
longer in production.

Victor van Wulfen
Mike here: Yes, no longer in production but the bolts still might be available.
Subject:	ETX 125 Issues?
Sent:	Friday, July 31, 2009 22:31:58
From:	Warp (
If I may, I have a couple of questions regarding my first light tonight
with my newly acquired ETX125AT.  I did some dry runs inside tonight
using the LNT module installed and it seemed to behave as it should, but
here is the issue.

In the directions for set up for the ETX125PE with LNT module it says
that I need to loosen the RA lock and rotate the scope to the left
(counter clockwise) till it hits a hard stop.  There doesn't seem to be
a hard stop on the AT model.  It just turns very smoothly all of the way
around - so I stopped for fear of twisting off the contacts internally? 
Is this normal?  This is a brand new out of the box unit.

So right now, to set it up to "calibrate sensors" I start with it
leveled and pointing North and then manually loosen the lock and rotate
it till it is pointing west - and then start the "calibrate sensors"

Also, I am assuming that the correct orientation is for the control
panel to be pointing due west?

Does any of this make sense?  Any ideas?
Thanks in advance for any help you can offer.
Mike here: Keep in mind that there is a rotation of almost twice around from hard stop to hard stop. If there is no hard stop(s), then it could be broken. Since the telescope is new you should contact the dealer for an exchange. When doing the CALIBRATE SENSORS, you will be prompted to center Polaris. The starting point won't have much affect on that. And yes, the control panel should be on the west side.


Thanks for the quick reply - you must be a night owl also.  The
instructions seem to indicate that by turning it just 90 degrees from
north to the west (counter clockwise) it should hit a hard stop.  So
what you are saying is that it will turn a complete 360 degrees and
possible twice that before a hard stop is hit?  I didn't allow it to do
that - being afraid that the internal connections may twist off???
So.. I should let it keep turning?
Thanks again.
Mike here: The hard stops are nearly twice around apart. So, depending on the initial orientation, if you only rotate the telescope 90 degrees, you can easily not go far enough.


Once again... thanks for your help and insight.  It is much appreciated.

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