Last updated: 28 May 2003
This page is for user comments and information specific to the Meade ETX-90RA (originally known as the "ETX Astro") and the ETX-90EC. 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:	ETC90 broken
Sent:	Wednesday, May 28, 2003 06:05:05
From: (Ken Hinderer)
My vertical lock is broken. It appears that someone has forced the
telescope. The motor runs but the telescope does not lock or move.

What should I do? I am wondering if I could get the parts to repair it.
Should it be returned to the factory or could you suggest a good repair

Mike here: Contact Meade for a Right Tube Adapter replacement. They will likely send it for free. The fix is easy; see my comments on this at the bottom of this page (below the light blue colored box):


Thanks a lot. I guess I shouldn't blame my boys for the problem. My
scope was broken just like yours. Meade wants $15 for the kit. I paid

Thank you very much for your help and for pointing me at the pictures
and  description of the problem AND the fix.


Subject:	RE:  questions about ETX-90RA
Sent:	Sunday, May 25, 2003 07:40:44
I read Kyle's questions concerning the etx-90 scope and would like to
say that I was in almost the same spot as he is.  A friend of mine
passed away and his widow gave me his etx-60, after using it for a
couple of months and getting very frustrated with the goto feature, I
found your site.  I purchased your book, lots of great information, and
I started to get curious about the etx-90ra.  If you don't need or want
the goto feature the etx-90 is a great scope, I have only had mine a
couple of months but in that time I have not touched my 4" reflector. 
The ease in getting the scope outside and set up makes for many more
nights of observation even if only for 30 min. a night.  I love watching
Jupiter, and its moons changing position constantly,  Saturn is a
constant amazement.  If you decide on the etx-90, do yourself one favor
and order the right angle  viewfinder also.  I have had no mechanical
problems but I am careful with my equipment and do not abuse things
intentionally.  I have not even used the motor drive other that checking
it out when I received my scope.  Quality of the scope I feel is quite
good and with care should last for many years. I am really enjoying your
website and have found many useful suggestions.   Sorry if this is
longwinded but feel free to edit as you think might be necessary.

Many Thanks,
Ron Haverfield
Tulsa Oklahoma
36.154N  95.993W

Subject:	ETX Identification Question
Sent:	Saturday, May 24, 2003 13:14:29
From: (Alan Bush)
I want to get started with gazing and I just purchased a used ETX from a
local camera store how can I identify the model (ETX60, ETX90,etc.)?

I can tell you the following .

It does not have AutoStar capability.

The specifications in the owner's manual are:


The instruction manual refers to it as an ETX Astro Telescope,

The manual has part #14-1010-00 and was printed in 1996.

I have looked all over the   site
and cannot determine what I purchased and what it's worth?

Can you assist?

Would a photo of the unit help you?

Thank You.

Alan Bush
Mike here: That is the original model ETX, now as the ETX-90RA. And no, it is not upgradeable to the Autostar capable model. New models of the ETX-90RA sell for $250.


Gracias - I really appreciate the response.
By-the-way ... your book is like the Holly Grail.

What do you think an original ETX in good condition is really worth.

Mike here: Hard to say; maybe $150-200 if in really good condition and complete.
Subject:	ETX-90 OTA dimensions
Sent:	Thursday, May 22, 2003 11:27:44
From: (Dave Wallace)
I'm about to construct a mount for an ETX-90 OTA and I was wondering if
anybody has a set of dimensions or a dimensioned drawing for the OTA. 
Specifically, I need to know the distance from the optical axis to the
bottom of the "foot" that would be used to attach the OTA to a camera
tripod, as this is where I plan to attach the OTA to my mount.  (Knowing
this dimension will tell me where the declination axis must be.)

It seems strange that Meade sells the OTA and doesn't provide the
detailed mechanical drawing needed for the customer to integrate it into
his own project.  But I suppose there are reasons...
Mike here: Check the article "ETX Outline for Hard Cases" on the Telescope Tech Tips page. The first one may have what you need.
Subject:	questions about ETX-90RA
Sent:	Tuesday, May 20, 2003 08:48:03
From: (Kyle Barger)
I wonder what people's thoughts are on the EXT-90RA.  I have tried out
enough telescopes that I think I know what I want--a small, portable
scope that can give good views of Jupiter and Saturn.  I have an
ETX-70AT now, and it's a nice little scope for what it is, but I'd like
some more aperture and focal length for planetary viewing.  So I was
wondering about the ETC-90RA model... they're going cheap, and I hardly
need the "go-to" function of the newer EC models to find Jupiter.  But
I'm concerned about the mechanical quality... people seem happy with the
optics, but I have read mixed results about the drive motor & other
mechanics.  Does anybody have any comments?
Mike here: My ETX-90RA is still my most used telescope. It is the original ETX that I purchased in 1996. You can see mine and some others comments about it under the Impressions section of the Buyer/New User Tips page.
Subject:	ETX90EC report
Sent:	Monday, May 19, 2003 13:43:27
From: (Bernhard "Rendelius" Rems)
After selling my ETX70AT to a friend, I got a Nexstar 4 a couple of days
ago, but returned it to the dealer just after the day I first tested it
(there are some very bad things about this scope, in my opinion,
especially with the drives and the GOTO, but thats a different story) in
exchange for a ETX105EC  which was backordered 3-4 weeks at the store.
This is where good relationships to your dealer jump in  he gave me a
ETX90EC to have something to observe until the ETX105EC arrives :-).

I thought I should tell you my initial impressions with the ETX90EC.
From the optical quality, this is a VERY nice scope and can do a lot for
its size. Under my heavily light polluted skies, it performs remarkably
nice. After training the drives and properly aligning it (using Polaris,
not a landmark), the two star alignment moved the first star into the
FOV of the finderscope, the second one into the FOV of the eyepiece.
From then on, every single object I slewed to was in the FOV of the 40mm
Plssl I use for casual observing, and it would have been in the FOV of
an 18mm Ultima as well. The trick I use is to use found objects to
realign the scope from time to time, but only with stars, not with solar
system objects or deep sky objects (for obvious reasons).

The ETX90EC with UHCT is a real winner, in my opinion  and I am looking
forward to the 105 :-)

Kind regards,
Bernhard Rendelius Rems
Managing Director RPGDot Network

Subject:	etx astro telascope
Sent:	Saturday, May 17, 2003 21:16:22
What are the diffrences of the etx astro telascope and the etx 125 ec

I noticed that  in your picture with the etx astro telascope it is much
much bigger then the etx 125 ec. Which one is stronger.

please email me back as soon as posable
Mike here: Have you noticed the size of the eyepiece in that photo of me and my ETX-90? It is bigger than my head (that's a clue...). Anyway, the ETX Astro (the original ETX model, now called the ETX-90RA) has a 90mm objective vs the 127mm objective of the ETX-125EC. The focal length is 1250mm vs 1900mm. The EC model is Autostar capable and the RA model is not. The ETX-90RA is more portable than the ETX-125EC.
Subject:	Missing something.
Sent:	Thursday, May 8, 2003 06:11:03
From: (Derek B. Small)
Great site.  I look at some of the pictures for example Jupiter on your
site and wonder why I can't get anywhere near the detail I see in the
pictures with any  combo of eye pieces I have for my ETX 90 EC with the 
UHTC option.  I have had what I believe some pretty clear nights for
viewing. For example I have been unable to see the GRS on Jupiter or the
Cassini division on Saturn.  I have the Meade eyepiece set along with a
quality barlow, having tried about every combo I am at a loss as what
could be wrong.  After reading the review in Sky and Telescope of the 90
my scopes performance is vastly different. Any help?

Mike here: Seeing the GRS is difficult. When it is visible (due to the planet's rotation) it is still a faint pink spot. In the ETX-90 it is challenging but can be done. The Cassini Division is also somewhat challenging but can be done when seeing conditions are good. Unfortunately, if you weren't trying when Saturn was near the zenith, it has almost become too low in the west now. You might want to look through the "Telescope Performance" articles on the "Observational Guides/References" page. Also, the User Observations for some actual reports. Finally, comparing photographs to what the eye will see is not a good idea. Photographs can show more or less details, depending upon many factors.
Subject:	Re:  Please help if possible
Sent:	Wednesday, May 7, 2003 15:20:45
Thank you very much your reply. I will try to do any what i can without
danger. Thank you the link too. Best wishes from Budapest.


Csaba Szabo

Subject:	RE: Mounting ETX90-RA on a Telepod?
Sent:	Wednesday, May 7, 2003 08:10:41
To: ('')
The ETX-90RA has two holes for 1/4-20 bolts in the mounting plate on the
bottom, and the Telepod has two holes in the cradle for 1/4-20 bolts.
Unfortunatly, they don't match. However, you would be able to mount the
ETX OTA to the Telepod using one of the holes in each. The Telepod is
designed to hold OTA's that are considerably heavier than the ETX, so
that should work ok.
Hope that helps.

Thanks for the fast reply! This, together with Mark's reply was just
what I was looking for. I remember seeing the page on your site a couple
of years ago, but I forgot. I assume the removal for the ETX RA is
basically the same as for the ETX EC?

Mike here: Yep, same attach points.
Subject:	Mounting ETX90-RA on a Telepod?
Sent:	Tuesday, May 6, 2003 17:57:05
From: (Michael Kothe)
thanks for offering such a great resource!

I was wondering how easy it would be to remove a ETX90-RA from its fork
mount and mount it on a telepod mount. I think I remember seeing
somewhere that there is a little block attached underneath the ETX90 OTA
with a couple of holes, is that correct? Do you know if these holes can
be used to mount the OTA onto a Telepod head, if there is an adapter
available to do so, or if I would have to rig something up?

I tried asking this on saa, but got only one response directing me to
your site. A search on Telepod gave only one unrelated match, so I think
this has not been covered yet.

Thanks for your help,

Mike here: Check the bottom of this page for info on removing the OTA. And yes, there are two holes on the bottom to attach a photographic tripod or head.
Subject:	Please help if possible
Sent:	Tuesday, May 6, 2003 15:59:05
I would like to ask your help about an ETX-90RA telescope. I get this
like a gift from an American friend. I was incredibly happy, when
arrived,but unfortunately after unpacking i found the telescope in
unusable condition. The packing and the scope too, look like an
absolutely new item, and the box contents all the pieces of the set. The
only problem the focuser. The focus knob turn freely without focusing at
counterclockwise direction,and about 360 degree at clock- wise
direction, also without focusing effect,then stopped. I try the
telescope any eyepieces, but this isn't matter, because the focus look
as if the nearest position. Please help me, what can i do,that i can to
use this scope. On the telescope no any damage anywhere,and the only
problem the focusing. Please mail to me,that what is to be done?

Thank you all in advance,and best wishes from Budapest (Hungary).

I waiting your reply with hope.

Best regards

Csaba Szabo
Mike here: Check the small setscrew in the side of the focus knob (use one of the small hexkeys that came with the telescope). It could be loose. If that is not the problem then it is a more serious problem. Are you comfortable disassembling your telescope (and voiding any warranty)? If so, see the article "Focus Shaft Fix" on the Telescope Tech Tips page.
Subject:	re: ETX-90EC and autostar
Sent:	Saturday, May 3, 2003 21:37:12
From: (Richard Seymour)
Quiet slew works on all models that the Autostar knows about.
(it just limits the speed to "8" on the keypad).
DS, ETX, LX90  and LXD55

There is a bug in earlier firmware versions, if you have an LXD55,
having Quiet Slew ON can mess up Messier GoTo's
(how's that for an odd cross-confusion?)
I haven't checked my notes, but i think that was v25Ea.

have fun

Subject:	Re:  Hey mike, a question please.
Sent:	Saturday, May 3, 2003 16:42:07
From: (Hamil Cooper)
I wasn't rally that scared. I think you said that the RA model had one
motor and the EC model had two.  I just took mine apart about an hour
ago and found only one motor, in the base.  I wondered if I lost one
somewhere :-).

As to my problem, I think it needs a trip to Meade. First I did a sloppy
initial setup before a two star alignment and had troubles.  The next
day, I paid careful attention to my initial setup using a compass, and
level during the day when I could see better. Then when I tried the
alignment, the first star, Arcturus, was in error by about 5 deg in Az. 
I know I didn't have an initial setup off that much, maybe a degree but
no more. The alignment appeared to work, but when I tried to go to
Saturn and Jupiter the pointing wasn't even close. The next day, I did
some careful testing.

I set everything to Az = 0 and then used the Autostar to move to Az= 90.
However the actual movement was about 95 deg. Given how the electronics
work, i.e. measuring distance moved by counting pulsed from the encoder,
there is no reason for this large of error. I lowered the "ration"
number by 10% and the 0 to 90 deg slew worked well, but when I tried a 0
- 180 slew, there was a few degrees of error. Dont know why there should
be a non-linearity like this.

By the way, do you know how to use the MS (slew) , the Sr (Rt Asc) and
Sd (Declination) commands to move the ETC90/Autostar to a star?

Mike here: Compass? Did you correct for your location Magnetic Variation? That could account for several degrees of initial pointing error. The CALIBRATE function tunes the Autostar to the encoders. So if the movement is off I'd suggest doing a CALIBRATE. By the way, since you have been tinkering with other settings, I would suggest doing a RESET first to restore the factory default settings. Check that the correct telescope is selected. As to the commands, see the Autostar Information page.


Yep, 14.5 degrees here in Glendale, Ca.
I've tried the Reset, calibrate, and train a few times. same errors.

but to be sure, I'll do it again.

I think I found most of the commands I need from the Meade website.
Seems they have missed a few though.

From: (Richard Seymour)
The ETX90ec has two motors... but only one is in the base.
The other is in the fork with the clamping knob.

Mike's posting about the ETX90RA is correct, and complete.
The ETX90ra has -only- one motor.

Your ETX90ec has two motors, just like the "Dual motors" Mike
referred to in his posting.  He simply didn't specify their 

Your bad slewing may be corrected by doing a 
 Setup > Telescope > Calibrate [enter]

It may also be occuring due to grease on the light source or
pickup of the encoders, as well as upon the disk itself.
But try a Calibrate first.

good luck, don't panic

Subject:	Hey mike, a question please.
Sent:	Saturday, May 3, 2003 15:41:50
From: (Hamil Cooper)
Mike.. You scared me...

After reading your response below, I thought I had a ETX90 RA since I
had only a single motor in the base.

AS it turns out, I have a ETX90EC, at least that is what the battery
cover says,  and it has a single motor. What gives?

Now here is a problem I am having with my ETX90EC, maybe you can help.

After performing a 2 star alignment, the scope would not point.  I
checked all the usual suspects, i.e. site, time, daylight savings,
targets, calibration, train, etc.  Then I discovered that when I use the
Autostar hand controls and move my unit 90 degrees in azimuth, the unit
turns about 95 degrees, not good eh.

First I tried changing the "ratio" number.  After getting the 90 deg
slew better, I tried a 180 degree slew and it was bad.  Then I opened up
the base and did a visual, particularly looking at the encoder gear on
the motor.  It was not blocked.  I am out of ideas and planning on a
shipment to Meade next week if I dont get any better ideas.


	Subject:        ec/ra question
	Sent:   Monday, April 28, 2003 19:46:20
	From: (Chrisdg)
	I have a quick question.  What is the difference between the EC and the
	RA?  There seems to be a large difference in price.
	Thanks for the great site.
	Mike here: The ETX-90RA is the original ETX model, circa 1996. It has a 
	single motor to track objects in Right Ascension. Slewing is done manually 
	as is pointing at objects. The ETX-90EC (released in 1999), and later, the 
	ETX-125EC and ETX-105EC, has dual motors for slewing in both Right 
	Ascension and Declination but you still have to know where objects are 
	located in the sky to be able to slew to them using either the 
	handcontroller or the Autostar. The Autostar GOTO computer controller is 
	optional for the EC models (however, under a special deal currently 
	running, the Autostar model #497 and the #884 tripod are included). With 
	the addition of the Autostar, the ETX has automatic GOTO capabilities; you 
	select an object from a menu of objects and the Autostar slews the 
	telescope to that object. Also, with an Autostar the telescope can track 
	objects when mounting in "polar mode" or in "Altitude/Azimuth" mode; 
	without the Autostar, tracking requires a polar (or equatorial) mount. The 
	ETX-90RA and the ETX-90EC have the same telescope tube and optics, only the 
	drive system and electronics are different. And before you ask, no, there 
	is no upgrade from a "RA" model to an "EC" model.
Mike here: Don't know why my answer "scared you". If you can use an Autostar with your ETX-90, then you have the ETX-90EC model. As to the problem, have you recently updated the Autostar (the current version is 2.6Ed)? But regardless, doing a CALIBRATE and TRAIN DRIVES could resolve the problem. If that doesn't do it, do a RESET, then CALIBRATE and TRAIN DRIVES. Let me know.
Subject:	ETX-90EC and autostar
Sent:	Friday, May 2, 2003 06:40:39
From: (Jeff Richerson)
Great Site and I have almost read your book.  Very helpful and gives
much detail to the workings of the scope and autostar that Meade leaves

I am having trouble getting the Autostar to align when I do not use the
quiet slew option.  I have version 2.6ec.  I believe that it is the
stepper wheel might not be working right.  I noticed that at high speeds
the counter was not reading all the movement.  (Move 10 degrees but the
computer thinks it only moves 1-2 degrees).  Moving at slower speeds
gives an accurate reading.  I have reset, calibrated, retrained in that
order a couple times, with not much differences.When I align without
using the quiet slew option the scope goes until it hits the hard stop.
Can I use canned air to blow out the stepper wheel?  Also is it a larger
problem than that?  I do not really have an issue with using the quiet
slew other than it takes longer to set up and GOTO.
Mike here: First step would be to upgrade to the current version (2.6Ed). That should clear up any corruption in the Autostar. Following the upgrade I would suggest doing the RESET, CALIBRATE, and TRAIN. I wouldn't do anything mechanical unless the problem persists following the upgrade. If it does and if the telescope is new, I would suggest contacting the dealer for an exchange rather than risk damaging something internal. Quiet slew shouldn't affect anything (in fact, I did not think that worked with ETX models, only LXD55, but haven't tried it on an ETX).

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