Last updated: 30 September 2003
This page is for user comments and information specific to the Meade ETX-90RA (originally known as the "ETX Astro"), the ETX-90EC, and the ETX-90AT. Comments on accessories and feedback items appropriate to other ETX and DS models are posted on other pages. If you have any comments, suggestions, questions or answers to questions posed here, e-mail them to me and I'll post them. Please use an appropriate Subject Line on your message. Thanks.

Subject:	RE:EXT 90 seeing
Sent:	Tuesday, September 30, 2003 18:47:49
From: (June Urich)
Hi can you help me I have  a ext 90 at I have been useing it for about 3
months and I can not see a lot.  by the way I'm very new to the hobby
All see other than the moon is small dots IE stars is this all I can
expect to see using  the 90? I.m getting  turned off the hobbie  real
quick. thank J Urich
Mike here: Check out the User Observations page for some good examples of what you can see. And yes, stars will appear as small dots due to the extreme distance from the Earth. However, planets, like Mars, Jupiter, Saturn, and Venus will shown disks and more.
Subject:	ETX90 Primary Mirror Cleaning
Sent:	Monday, September 29, 2003 10:32:52
From:	ThurberHK@Npt.NUWC.Navy.Mil (Thurber Hiroshi K NPRI)
I need help/advise on how to clean the primary mirror in order to remove
fingerprints smudges and grease. The grease is from the focusing shaft
gear (which is the part related to why I'm in this situation in the
first place). Please see photo.

I've reasearched your site and the MAUG and obtained some excellent info
on optics cleaning. But before I did anything I wanted to send this
message query to makes sure I'm not missing something important.

Here is how I got in this mess: 
First, I inadvertantly disengaged the focus shaft from the focus mirror
block which caused the shaft fall inside the OTA. At the time I was not
sure what had happened except that now there was something metal
sounding rolling in the tube. Fearing the shaft was crashing into the
primary, and in a panic, I unscrewed the lens corrector assembly to
figure out what was going on inside. The primary and focus shaft then
fell out in my hand whiched caused the grease smudges on the mirror

An ETX Tech Tip on the site showed me how to access the rear of the OTA
by unscrewing the mirror block from the tubeI installed the focus shaft
back into the mirror block with the end aligned in the slot of the plate
where the mirror rests on. Turning the shaft secured the mirror assembly
once th shaft gears engaged back into the block. No alignment screws on
the block were touched.

My plan was to clean the primary based on the instructions from your
sight. Some questions I before I start are:

Is this the right thing to do?
Or, should I send it back to Meade to and let them handle it?
(unsuccessful so far in reaching an available support tech)
Do I now also have a collimation issue?
Did I also mess up the primary to secondary mirror/lens rotational
alignment by removing the lens/corretor assembly? (Note that I did not
remove the lens from its housing).
Am I missing any other issues/concerns?

Thanks in advance!

Hiroshi Kevin Thurber
ETX mirror
Mike here: You can follow the cleaning tips on the Buyer/New User Tips page. You may or may not have a collimation problem. Did you make the orientation of the mirror before you removed it? If not, or even if you did, you may still have to work some on the collimation; see the collimation articles on the Telescope Tech Tips page. If you end up with a worse mess you can then call Meade.
Subject:	ETX-90 Collimation
Sent:	Monday, September 29, 2003 09:30:15
From: (Morris Kamelgarn)
I recently bought a used ETX-90?RA and I think the optics need to be
collimated. I noticed that there were three recessed phillips screws at
the back of the optical tube. Can you tell me if these are for
collimating the optics or for some other purpose.

Thanks, Morris<
Mike here: If you mean on the inside, yes. See the collimation articles on the Telescope Tech Tips page. HOWEVER, it is easy to make things worse so make sure you really know it needs collimating.


Thanks for your reply. I had thought that the ETX could be collimated
just by turning the three screws on the outside. I never owned a mak
before so I'm not sure it needs collimation. When I look in the eyepiece
tube (without an eyepiece), it looks like the central obstruction is off
to one side. When put an eyepiece in, and look at the image with a
magnifier, it looks flat, not round (like a squased lime bean), and the
central spot is off to one side. It this the way it's supposed to be?
The actual images are not bad.
Mike here: The ETX is not designed to be user-collimated, hence the screws are not on the outside like on other telescope models. And yes, it sounds like the optics are not properly aligned.
Subject:	ETX 90 EC
Sent:	Saturday, September 20, 2003 02:49:11
Well first I'd like to say that you've got a great website ! I'm new to
star gazing and have bought the ETX 90 EC UHTC to help me navigate the
skies. However I'm a bit un clear about the set proceedure. I unclamp
the scope and turn it as far as it will go counter clockwise, then I
turn it back until the tube is pointing over the control panel where the
on off switch is. I clamp it again at this point then using a compass I
pick up the whole telescope (including mount) and turn it to face North.
Can you tell me if I'm right so far, or direct me to a web page with
more information.

BTW I have been offered a set of eyepieces by Meade for 99, apparently
worth over 700, would you definately take up this offer, even though
the scope was a financial stretch ! ?

Thanks for any feedback,
BTW I intend to buy your book,
Mike Holme
Mike here: You have the concept correct. But just to clarify a couple of points. The left fork arm goes over the control panel and use True North (not Magnetic North) unless they are the same for your location. See the Autostar Information page for more on alignment tips. And yes, the $99 eyepiece is good to have. I got with my LXD55-8"SC.


Thanks for the reply Mike, yes I do like the site you've obviously put a
lot of effort in to it. I suspected magnetic north is not quite correct,
I expect that pointing a correctly aligned finder scope at polaris would
be better at my location. I'm not sure what the left fork arm is though.
I didn't see any reference to it in the manual, though I only bought the
scope on Friday and I must admit, I haven't read the manual from cover
to cover. Could you help me with this information please. I don't want
to assume you're some sort of free ETX advice line, but I think I'll be
ok when I have that piece of information.

Thanks for your help,
Mike Holme
Mike here: READ THE MANUAL, three times. Play with the telescope indoors in the day time. Go through the alignment steps, actually doing alignments (just accept the stars as centered). Get to know your new telescope before going outside in the dark. When standing at the eyepiece end and looking towards to the aperture end of the telescope, the left fork arm is the one on the left side of the tube.


I've figured out what the left fork arm is. I actually read the manual !
doh !

Thanks again,

Subject:	RE: Meade ETX-90EC
Sent:	Friday, September 19, 2003 07:56:38
From: (Ali Maleki)
Thanks for the response Mike.

I called Meade and (after being on hold for more than an hour) the guy
told me that there IS a DSX-90 model (though I have not been able to
find this in any online search). He said that perhaps my ETX-90 had
DSX-90 written on the "front" because the person assembling it had
"grabbed the wrong part during assembly". Not very comforting ! I then
asked why my telescope didn't have an inspection sticker. I was told
that "perhaps the assembler forgot to put one on". I was told the same
thing about the lack of a UHTC sticker.

Based on this, I took the telescope back to the Discovery Channel store
and got them to replace it.

Take care and thanks for the very helpful site,

Subject:	What is a Meade DSX 90 AT?
Sent:	Thursday, September 18, 2003 19:16:45
From: (Tom Lovely)
I was in a Mall tonight and in a Brookstone store saw what a "Meade DSX
90-AT" - it has a silver '90 scope with the 8x21 finder on what sort of
looks like a Celestron NexStar mount plus tripod - but it has the Meade
Autostar 497 controller.  Price was $595.  I found it on their web page:

They also have a DSX-125 AT for $995.

Mike - Maybe someone listened to your NexStar / ETX-90 comparison
comments where you said:

"In the best of all possible combinations, Meade optics and the Autostar
controller on a NexStar mount and tripod would be my choice."

Tom Lovely
ETX 90RA owner - having a good time photographing Mars now

Subject:	882 tripod
Sent:	Tuesday, September 16, 2003 09:45:17
Do not use an 882 tripod with anything other than the ETX70 or you will
find yourself with a scope lying on the ground!

Bob Shutan
Shutan Camera & Video

Subject:	RE: Looking for ETX 90 RA (Astro) Electronic Manual
Sent:	Tuesday, September 16, 2003 00:46:10
From: (Guy Vanmeenen)
Thank you for your quick response; I have found the appropriate page and
reference link to the following website:

Unfortunately, I am not able to open it. I have a Toshiba Pro 2100 which
runs Starry Night very well and also other pdf/Acrobat Reader files but
not this one? What to do?

I bought my ETX 90 RA/Astro, second hand a few days ago. The tube on the
telescope where the eyepiece is fitted does not have a cap thus leaving
the interior of the scope open for dust (as evidenced on the reflecting
mirror). Is this normal or does it have a cap that the former owner
lost? How can I replace it?

Kind regards,

Guy Vanmeenen,
Mike here: It opened fine under Adobe Reader 6.0 (and Acrobat Reader 5.1). Perhaps you need a newer version. As to the eyepiece hole cover, you could contact Meade - they might send you one, or you can use a 35mm film can. If you use a can, use caution if you tighten down the screw that holds the eyepiece; you don't want to drill into the side of the can and create debris that would get on the optics. By the way, the original ETX did not come with a cover; at least mine didn't in 1996.


Thank you so much. I had Acrobat version 5.0 and just updated it to 6.0.
The manual, I downloaded is for the ETX 90 EC while I have the ETX 90
RA/Astro but I guess it is the same in most parts. The only missing part
is the function of the drive with the ETX 90 RA and how to operate it in
the equatorial South setting. Any info on that?

Great tip on the eyepiece hole cover.

For the polar alignment, I will point N on the Deluxe tripod South and
deduct 1 degree 17 minutes (as I am living south of the equator in
Nairobi/Kenya) from the 90 degrees for the alignment. Unfortunately, the
degrees between 70 and 90 degrees on the tripod have no markings so it
will be some kind of guessing. Is this going to work?

Thank you for your support.
Mike here: There is a switch for N-S operation on the bottom side of the base. The "N" leg on the tripod will go on the South side in the Southern Hemisphere.


Thank you for your great website and useful information.

1) My latitude is 1 degree 17 minutes South (Nairobi/Kenya - I am a
Belgian expat). The Deluxe Field Tripod is only made to operate within
20 to 90 degrees latitude. Could the motor drive still be useful if I
would adjust the North tripod leg for another 19 Degrees downward (Full
70 degrees of the tripod head + another 19 degrees by adjusting the N
tripod leg should give me my correct latitude of 1 degree 17 minutes

Kind regards,

Guy Vanmeenen,
Mike here: Sure BUT in that position, the tripod will be very unstable. Use EXTREME caution; otherwise your telescope will likely end up on the ground, in who knows what condition.
Subject:	Meade ETX-90EC
Sent:	Monday, September 15, 2003 03:11:59
From: (Ali Maleki)
First of all, great site !

I have a couple questions that nobody seems to be able to answer:

1) I just bought one of the "new" ETX-90 telescopes with UHTC. I noticed
though that on the front of the lens it says "Meade DSX-90" not "Meade
ETX-90". Everywhere else (product box, battery cover) it says ETX-90.
Any ideas ?

2) How can you tell by looking at a telescope that it has UHTC ?

3) Do you think the Meade 127 2-3 Barlow is a good option ?

4) What is the different between the 124 and 126 2X Barlows ? I assune
the 126 is better. Is there a big difference ?

Mike here: There is no (currently anyway) DSX-90 model. Haven't heard anyone else report this. Could there be some dust or something on the lettering? You might see a UHTC label beneath the tube; at least that is where it is on my LXD55-8"SC. But if the box is labeled UHTC you likely have it. I have no experience with the #127 but keep in mind that for the ETX you need to use a "shorty" type Barlow Lens. And yes, the #126 is higher quality.
Subject:	ETX90RA 
Sent:	Saturday, September 13, 2003 16:11:30
From: (T)
i have a etx90ra that that has a loose time band around the base of this
unit . is it suppose to be loose or is it suppose to be glued down ? 
and  one of the legs that screws into the base of the unit has the
latitude markings on it .   well i cant get the adjustment to set up for
43 deg on the leg . the bevel says its at 43 deg . but the marking seem
to be off . can this be fixed  ?

 thanks t
Mike here: See the FAQ page for information about the RA scale. If your leg has the latitude scale glued on you could move it by carefully removing it and reglueing. HOWEVER, you might be better off just marking it where you latitude would appear after you set it up in the proper position.
Subject:	ETX
Sent:	Wednesday, September 10, 2003 09:37:33
From: (Richard Bentley)
Sorry to trouble you, but, having a bit of a problem across the water.

Bought an LX200 for the little lady, and it came with an ETX 90.  The
previous owner was going to piggyback it as a tracking scope.

One issue, my dad (70 odd) bless him fell in love with the ETX.  we were
told when we bought it that it had an RA drive problem, and boy did it -

1.    Some of the teeth on one of the gears were sheared off

2.    The wires on the battery compartment to pc board were detached.

No RA drive boxes are available (at this time) in the UK.  So I opened
the gearbox - and took a peek, it would seem I wasn't the first to do

I have managed to contact the nice warehouse man at Meade UK who managed
to locate some spare gears - which he is sending me - as he wasn't sure
which one - I get a big bag of them so I can choose one!.

But, and here comes the rub.  I am not sure I know which order they go
into the box (I am a bit of a ham fisted amateur), I have identified the
primary drive gears and the computer sensor, but, the paired cogs are an
issue.  Clearly if I get it wrong it may have disastrous consequences
(for my sanity and the telescope).

I have checked on all the web sites I can't find a schematic of the
internal gearbox arrangement, or wiring information.

It would appear that Meade UK don't have a copy of the data I will need.

May I ask, given your experience and knowledge, if you could point me to
a source of the information I will need to put it back together?

I don't intend using it as a tracking scope, we will be happy to use the
LX200 optically and with a flip mirror for CCD imaging.

Thanking you in anticipation.

Richard Bentley
Mike here: You might look through some of the ETX-90 articles on the Telescope Tech Tips page. But if you are just going to use the ETX-90 OTA on the LX200, there really isn't any need to repair the ETX-90 drive since you will have the OTA detached from the base.
Subject:	ETX-90 With #882 Tripod
Sent:	Wednesday, September 10, 2003 04:43:31
From: (Mark Dunnett)
Do you know if it is possible to use a Meade #882 field tripod (supplied
with and ETX-70) with an ETX-90?

Thanks for any help

Mark Dunnett

P.S Excellent site!
Mike here: Yes, it should work but since I'm currently on travel I can't check mine. But stability will be a concern, especially at higher magnifications.
Subject:	 MEADE ETX-90RA 90mm Telescope 
Sent:	Sunday, September 7, 2003 23:57:14
From: (The SULANTIG Agency)
Just about to buy a telescope and I have been looking at the Meade
ETX-90 AT model with the Autostar Controller and Tripod.  I have seen on
eBay a new ETX-90 RA and I'm wondering what the difference is between
the two models other than the obvious?  Can you add the Autostar to the
90 RA ?  Thank you in advance for your help.


Lance Royce
Cairns, Qld Australia
Mike here: The OTA is the same but no upgrade; see the FAQ page.
Subject:	Updated Info
Sent:	Sunday, September 7, 2003 11:28:51
From: (Tom Price)
It's been a while since I've sent anything (my former address was, no longer active), so I thought I'd give you my new
address and add some comments.

[1] Like several other ETX-90RA users, I, too, bought the very excellent
Bogen 3211 (now sold as the 3011BN) tripod for my ETX. It's very stable
and easily handles the ETX with any combination of add-on stuff. It
originally came equipped with a 3130 video head, but I found something
far better, the Bogen 3275 Mini-geared head, which allows fast and slow
motion angle adjustments in all three axes with no slippage, making it a
terrific mount for accurate and easy polar alignment and leveling. It
has a nice wide quick-release plate which can be attached permanently to
the bottom of the ETX without interfering with battery replacement or
the switches. This allows the ETX to be quickly detached from the tripod
without interfering with the polar alignment if the tripod itself isn't

[2] I'm having reasonable success with Mars observations with the ETX on
some evenings. My 2X Barlow with either the 26mm Plossl or 12.5mm Plossl
seems to give the best results. The image is small, but bright and I can
make out some of the markings with just a slight hint of the polar cap.
A SkyGlow filter from Orion seems to help a bit with that. I'll try a
#11 green-yellow filter whenever it arrives.

[3] I'll be adding the Meade #1244 electric focuser to the ETX shortly,
along with the #825 rightangle finder. I'm still getting great service
with the Orion EZ Finder that I reported to you several years back, but
there are times when a regular finder would be useful without getting
neck cramps.

[4] Finally, I've ordered a SACIVc CCD camera from OPT Corp. and will
experiment with it both at the prime focus and at the eyepiece tube.
Hopefully it'll arrive while Mars is still fairly big (24.57" at -2.8
magnitude tonight), so I can see how well integrated (stacked) images
will work with this difficult object. I'll send along any decent images
that come from this.

Best regards,

Tom Price

Subject:	ETX-90AT Newbie? Questions
Sent:	Saturday, September 6, 2003 21:06:48
From: (Peter J. Wierzba)
Recently, I was waiting in line at the Texas Tech Observatory to get a
look at Mars and other heavenly bodies. Needless to say, with all the
publicity in the media regarding Mars the line was too long to catch a
glimpse. However, there were a number of local stargazers from the South
Plains Astronomy Club there with their own telescopes. In conversations
with them, I told them about my Meade ETX-90AT I purchased in '97 with
the intent to become a hobbyist. Unfortunately, shortly after purchasing
the scope, my mother passed away and it remained in its case virutally

I returned home later that evening and went straight to my closet. I
pulled out my telescope and began looking at the stars...and Mars. The
feelings I had when I purchased the scope all rose to the surface once
more. As I looked at my telescope, it looked like a wind-up toy when
compared to the other telescopes I saw that evening with their high tech
tracking devices and computer hook-ups. All of this has prompted me to
write with a few questions.

1. Is it possible to upgrade/convert my ETX from a "manual" telescope to
a more advanced "auto" variety like the newer ETX scopes with
tracking/touring devices?

2. Is it worthwhile to purchase the Meade #884 tripod versus a standard
video/camera tripod?

3. How do the Celestron 4-element Plossl eyepieces compare to the Meade
Series 4000 Super Plossol eyepices?

4. Is there any diference in barlow lenses?

5. I have the Meade #1 color filter set(#12, #23A, #58 #80A). Are there
any filters I should add to my equipment? And, how do these compare with
the Celestron filters? Others?

6. I like the compact size of the ETX-90, but would my money be better
spent looking for a good LX-90 or LX-200.

7. Should I have my scope "supercharged"?

8. Can anyone recommend a quality introductory reference guide for
amatuer astronomers?

I would like to thank you in advance for indulging me and look forward
to your replies.

Peter J. Wierzba
Mike here: The ETX-90 you purchased in 1997 was the original ETX model, now known as the ETX-90RA. It could not have been the ETX-90AT, which is the current model (and includes a #884 tripod and #497 Autostar). As to upgrading it, see the FAQ page; also see the Telescope Tech Tips page for some "do it yourself" type of upgrades. You need a sturdy tripod for viewing at high magnifications; many consumer photographic tripods are not good enough. If you get a sturdy one though, it can work but for the ETX-90 that only tracks in Polar Mode, you should really get a telescope tripod that can be adjusted to your latitude. I have no experience with those Celestron eyepieces. As to Barlow Lenses, higher price usually means higher optical quality. On the ETX-90 that is not quite as important as with larger telescopes but you would still want a good one. You also need a "shorty" model so that focus can be reached. See the Accessory Reviews - Filters page for some ideas. Which telescope you should use depends upon HOW you will use. Do you need portability or aperture? Serious astrophotography or just occasional visual work? See the Accessory Reviews - Books page for some ideas on guides. Also see the Observation/Reference Guides page for more.
Subject:	Looking for a Telescope for amateur astrophotography
Sent:	Wednesday, September 3, 2003 15:12:24
From: (Nathan T. Tullier)
I am considering a Meade ext-90ec for amateur astrophotography.  I want
to stay under $700.  What are your thoughts?  Any suggestions?

Mike here: If you have specific questions, ask. Otherwise, look through the various pages on my ETX Site; you'll find lots of info there. But do keep in mind that only limited astrophotography can be done with the ETX line. You can see some excellent examples on the ETX Site.
Subject:	ETX-70AT/ETX-90 Conversion
Sent:	Wednesday, September 3, 2003 09:50:39
From: (Ginther, Jason T-Contractor)
I have had the opportunity to scan your very impressive site. I think
you are doing a wonderful job getting information out to folks that use
these scopes.

One bit of information that I have yet to run across is this: I received
an ETX-70AT (70) as a gift a while back and I would like to find an
inexpensive way to upgrade to an ETX-90 (90). The 70 has the Autostar
already and is fine for what I use it for. I just want the focal length
of the 90 for magnification and brightness. Ideally, I could just get a
90 tube and finder scope (from a less expensive 90RA, for instance) and
place it directly on the 70's forks. The overall width of the tube is
the same and I don't see a huge weight difference. In theory, it should

Have you heard of anyone doing this? Do you have an opinion on this sort
of conversion?

Thanks for your time.

Mike here: See the article "Putting ETX-90 on ETX-70 forks" on the Telescope Tech Tips page.
Subject:	ETX90EC
Sent:	Tuesday, September 2, 2003 05:16:54
From: (Chandler Peter)
Many thanks for the Mars comparisons.
I also was definitely expecting too much from the ETX90, but the results
I got compare favourably to yours so maybe my "not so dark" site is
actually better than I imagined. During the winter I got some nice views
of Jupiter and Saturn. I guess I got suckered by all the press coverage
of Mars' approach into expecting to see something substantially bigger.
thanks again
Peter Chandler, London, England

Subject:	Barlow lenses
Sent:	Monday, September 1, 2003 14:06:16
From: (Andrew Collins)
Excellent site - Bookmarked for repeat visits!  Your detailed tips on
setting up the autostar have proven invaluable for good accurate

This page was especially useful.
 The image size I get with my 9.7mm on an ETX-90EC is exactly as shown
(albeit with better conditions).  Having been able to make out the
features of Mars I'm not disappointed.

It is the Barlow 2x converter that I'm disappointed with.  Apart from
being stiff to insert, the scope is also off line and image quality
poor.  Is this to be expected.  I rarely use it as I seem to gain

Best wishes 

Andrew Collins
Aldershot, UK.
Mike here: Which Barlow Lens do you have?
Subject:	ETX 90
Sent:	Monday, September 1, 2003 11:48:07
From: (stephen)
Was getting ready to purchase an ETX 90EC, then read all the messages on
your great site for the first time and wonder if the ETX 90 is what I
want. It seems many "rookies" like me have great expectations but are
falling short, not the fault of the telescope, but perhaps people
wanting to go 200MPH on their bicycle, and it just isnt built for that
type of expectation. I'm a novice at best, and looking for a telescope
where I can see some details. I would rather spend a little more to get
better details, but don't know which model to go with or how far to go
with this. I was considering reflectors, now looking at refractors based
on many recommendations on other websites.

I certainly dont want to spend thousands, and was hoping to find a good
used one on ebay or a similar sight. What can I realistically expect to
see with the ETX 90EC, or should I step up to the next higher model? For
instance, I had aspirations of seeing details on Mars, but apparently
that's not the case based on some of the messages on your site. I think
many scopes are being oversold with their capabilties when many of us
rookies see the incredible photos from the Hubbell telescope, but last
time I checked, most of us dont quite have that kind of budget.

You obviously have a great site and a wealth of information for us
"non-techies" and congatulate you on your help to the many who have
written to you.

Mike here: Yes, many times expectations exceed the capabilities of the telescope. You might check out the photos of Mars on My Astrophotography Gallery - The Planets; while the images don't do justice the size comparisons do. You could also read my article "Mars 2003 - What should you expect to see?" on the Buyer/New User Tips page. Also, check out my LXD55 Site ( for info on the LXD55 line.

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