Last updated: 28 April 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:	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.


Thanks for the quick reply.

I understand that the optics are the same (EC/RA), but I can't figure
out the price difference.  I plan on buying a 125 soon, but I want to
use a 90 as a spotting scope.  Does the RA accept the erect image

Thanks again
Mike here: Other than the UHTC option, the price difference is mostly for the base with the dual drives and electronics. Yes, you can attach alternative finderscopes.


Excellent,  to sum up then,  the optics are identical (no UHTC option
for the RA), Different drive mechanisms (RA not upgradable), and it does
have the standard tripod mount on the tube (same as the EC).

That really clears it up for me.  Thanks
Mike here: Yep, you got it!
Subject:	ETX-90
Sent:	Monday, April 28, 2003 12:02:56
From: (Eric Neumann)
I just bought a new ETX-90 and it came last Thursday.  I was so excited,
I think that I got a really good deal.  Amazon is selling the UHTC
version for $517 and this includes Meade's deal with Autostar and the
Deluxe Field Tripod.  However...

Just out of the box the Autostar doesn't work.  I followed the first
time power up procedure to the letter and although the controller seems
to function normally (menus, etc.) the drive motors run wide open
alternation from alt to az and back.  Great frustration has since
insued.  I called customer service and they are sending me a new
Autostar, but I have to wonder if these guys have any quality control. 
BTW the optics seem to me (a beginner) to be pretty darn good.

Just found your website today.  I think I am going to like it very much.

Clear skies,
Mike here: Could be a bad Autostar (for any number of reasons). Let me know how the replacement works out. Don't forget about Meade's $99 eyepiece deal. It has been extended to June 30.
Subject:	UHTC on the Meade ETX-90EC
Sent:	Sunday, April 27, 2003 16:12:23
From: (Adrian Ion)
I am a beginning teenage astronomer who is having some difficulty in
assessing how much to spend on my very first telescope. I noticed that
adding the UHTC option on the ETX-90EC costs an extra $50. I read on
Meade's website that UHTC can increase the total light transmission to
the telescope's focus by as much as 20%. So, in your opinion, is UHTC
something that a beginning teenage astronomer should invest in? Will I
notice a large difference, say, when observing the rings of Saturn or
the craters on the Moon with the UHTC option?

Thank you,
Adrian Ion
Mike here: On bright objects you won't notice much difference but on fainter objects you would see a brighter image with the UHTC. I've compared the views through an ETX-90 with and without UHTC. There was a distinct difference.
Subject:	New ETX90C
Sent:	Friday, April 25, 2003 20:08:44
From: (David Robinson)
Great site...  I found it doing a google search.  I am searching the web
because yesterday I purchased a ETX-90EC from  Couldn't
resist the special for the tripod and Autostar.  Now I have to wait for
delivery. Hope I don't regret not going for the UHTC, but I am lucky to
get the spouse to hand over the dough for the standard model!  I first
feel in love with the ETX scope when I saw it in a SAM's Club warehouse
some years ago.

When I was 20 (1975) years old a co-worker needed cash and asked if I
would give him $50 for his telescope.  I thought the wood box it came in
would be worth the money so I bought it from him.

Of course the first object I tried was the moon and it blew me away when
it zoomed across my view and was gone.  I did not anticipate that. Where
the heck did it go?  I looked up and it was right there!  I quickly
learned to use the rest of the controls on the scope!  It also amazed me
to see the craters of the moon so clearly.

Alas, my early astronomer days were numbered.  I had the scope in the
trunk of my black car and the hot Texas heat soon did it in; the lens
fell out.  I never did try to fix it.  I still have the scope somehwere,
I like the box....

When the new scope arrives, a co-worker who owns a 6" Newtonian will
assist me setting it up.  We are in a rural setting in southern MD and
it should be great viewing.

Your site has helped me already on my first visit.  I have had a Kodak
DC280 digital camera for three years now and enjoy digital technology,
but figured I would have to break out the old AE-1 SLR to take pics. 
Your site has shown me that I can use my digital with an ScopeTronix
Digi-T adapter. Thanks!

Question: while looking at your site pics, I see a lot of folks using a
2X Barlow lens with their ETX90's.  What is that?  I do plan on
purchasing the $99 lens set Meade is offering right now.


Neat seeing the pics from folks outside the U.S. on your site.  Maybe
someday, I will have a pic worthy of your site.

David D. Robinson
Mike here: With the eyepiece set you likely won't need to purchase a Barlow Lens. They double (or triple) the magnification provided by the eyepiece they are used with. There are even variable magnification devices. But try out your eyepiece set; it will provide nearly all the magnification values you will probably want to use.
Subject:	etx90ec
Sent:	Friday, April 25, 2003 16:48:46
From: (alexfalconer)
Hi, I've looked at you're web site and I am very impressed with the
detail and content.I must confess that I am not technically minded and
don't understand some of the jargon, but I have been interested in
astronomy since I was at Primary school.

Recently I purchased a Meade ETX 90 EC but due to other commitments I
have not been able to use the telescope as much as I would like to.I
live in the middle of a city (Edinburgh, Scotland UK) where the light
pollution is terrible. I have read some of the reports on tripods in
your web site and as I don't have a tripod at present I was wondering if
you could recommend a tripod that is easy to use and understand.

I realise that you must be very busy, but if you could spare a few
minutes to reply I would be very grateful.

Thank you
Mike here: I don't know if the tripod deal is going on in the UK but in the US a #884 tripod is included along with an Autostar with current purchases of the ETX-90, -105, and -125. See the Accessory Reviews - Tripods page for more info.
Subject:	Re: purchase of etx
Sent:	Tuesday, April 15, 2003 05:43:42
From: (Dave Knutsen)
I did buy an ETX90 with the higher coating on the optics.  Thanks for
the advice.  I'm having some trouble getting it aligned but your site
has some helpful info.  I do notice that when the telescope slews
(mostly in the horizontal direction if I remember) there seems to be
slippage  (like the clutch in a car slipping when first engaged) then
the motor causes the telescope to "jump" ahead.  Can this be a source of
my alignment problem? Or is this something that initializing will take
care of or is this normal?
Mike here: Could you be overtightening the axis lock? That can cause the "grabbing" you are experiencing. Don't forget to CALIBRATE and TRAIN DRIVES.
Subject:	Meade ETX90 with autostar
Sent:	Sunday, April 13, 2003 12:37:55
From: (Ronnie Blazer II)
I received my new ETX90 a few weeks ago. I have only been able to use it
twice due to poor weather. So far, I am frustated and disappointed.
Autostar is overshooting objects and missing them. The tracking is poor.
The eyepiece bundled with it is of seemingly less quality than "lesser
quality" eyepieces that I own. I will start off with just one question
and then maybe get back to you. The Meade manual says that the finder on
the scope can be focused by loosening the locking ring. The ring on my
finder scope will NOT move. Can this finder REALLY be focused? If so,
how do I REALLY do it.  Thanks for any help.
--- Ronnie Blazer II
Mike here: You may need to use something to "get a grip" on the ring; I've used a rubber jar-lid opener for such things. As to the other, be certain to look through the alignment tips on the Autostar Information page.
Subject:	new problem with dec axis!
Sent:	Thursday, April 10, 2003 22:08:23
From: (Avtar Roopra)
I found the cause of my declination axis slack problem - one of the
small screws clamping the OTA to the assembly that mounts the OTA to the
forks had worked loose somehow.  I tightened that and the problem was
solved.  However I now have found another problem!!!  When my scope is
tracking (in Alt/Az mode) the object 'flicks' in the declination axis.
By that I mean that over a 9 second cycle, the object drifts down the
field of view by a few minutes of arc and then flicks back to center.  I
can hear a very delicate click as the object flicks back to center.  I
hope nothing is broken (a gear tooth or something!!!).  Do you think
this is something that a 'ETX supercharge' could fix?  Thanks for your
time mate.  Your site is a Godsend!

Cheers mate

Mike here: Thanks for the update. Glad you solved the initial problem. As to the other, have you done a CALIBRATE and TRAIN DRIVES? I don't think that will fix the clicking sound (which doesn't sound good) but worth a try. As to the Supercharge, I'm sure Dr. Clay could make it better than right.
Subject:	re:   purchase of etx
Sent:	Thursday, April 10, 2003 21:53:02
From: (Richard Seymour)
The scope i had (years) before i bought the ETX90ec was a Celestron C-8.

Both before i added the Autostar, and certainly afterwards, i used
the ETX90ec more in one month than i used the C-8 in two years.
And portability was a major factor of that... 
Both sites were in-city, lots of light pollution.
(but it's much worse now than in the C-8 days)

Then i got the Autostar... and started using the ETX90 more in
a -week- than i'd used the C-8 in a year...
It was simply that much fun... the Autostar completely wiped out
the problems that city light pollution gives when you're trying
to find something... and the eTX90's f/13 optics yields a fairly
dark sky background.

Sure, it doesn't grab the light of the 8", but it's sidereally
driven, so you don't have to manually hunt to keep a dim object
in the eyepiece while your eyes pull it out of the mud.

And then there are the "frills"... the Autostarred ETX90 can
track satellites... it can show -details- on the ISS (solar panels,
trusses, -color-)

It's a real grab-and-go scope... a handful of AA cells and you're
all set for plopping it on a rock in the boondocks...

(yes, now that i have a 10" LX200gps, the lil' ETX90 goes unused
many evenings... unless i'm chasing satellites, then they run
in parallel.. but the ETX90 is -still- the scope which gets to
ride in the car for camping trips...)

You could also consider the ETX-105 ... a -little- bigger, a little
heavier, but more aperture... 
But the ETX90 qualifies as hand-carry on airplanes...

have fun

Subject:	question
Sent:	Tuesday, April 8, 2003 12:16:49
From: (Robert Carden)
I read the reviews of different red dot finders... I have used Telrad
with a Meade dob and prefer this sort of finder to a finder scope. 
Which red dot finder do you think works best on etx90 ?

Mike here: The Telrad is large for the ETX-90. The Quikfinder sticks up some. The LightScope has a small vertical size. So, it comes down to features (the Quikfinder has several nice ones) vs size (the LightSight is smallest).
Subject:	purchase of etx
Sent:	Tuesday, April 8, 2003 08:18:51
From: (Dave Knutsen)
I have been in amateur (backyard) astronomy for 5+yrs but live in the
San  Francisco Bay Area, which is extremely light polluted.  I built my
own 8" Dobsonian scope from scratch a few yrs ago and it works extremely
well.  But with growing back problems and the heavey scope + setup
times, etc. it sits alot.  I am so busy in life that I rarely can find
the time now to pull it out, set it up, go through the frustration of
not being able to find the object(s) I want to observe.   I've been
ready to "throw in the towel" at certain times but the call of the
heavens pulls me back.  I probably use my 10x50mm binoculars more than
the scope.    I've been thinking of buying an ETX90 (now since there is
a good sale on) so it would be: 1. quick setup and takedown,  2. go-to
functionality,  3. good optics.  But can I expect much of a letdown
going from 8" down to 90mm?  I would assume the magnification would be
decent at 100-150x which is about all I use for my 8", but would the
loss of light render it less than good in such a viewing area?  The idea
of computer control is also appealing, since most of the finder charts I
get from the software  assumes too much.  Any thoughts from your
experience?  Thank you, 
Mike here: Yes, you will loose brightness and clarity with the stepdown from 8" to 3.5". But you'll gain a lot of portability and ease of use. So that's a tradeoff you'll have to decide on. I'd recommend a UHTC model.
Subject:	ETX 90EC with Autostar
Sent:	Monday, April 7, 2003 11:46:16
From: (Tim Leal)
After reading your great website and a couple of reviews, I decided to
spend my hard earned redundancy money on a new ETX 90EC scope last
month. I have a quick question and would appreciate your feedback if you
have the time.

I am generally having a great time with this scope and have seen many
objects that I previously have not seen. However, when I am trying to
centre an object I am having the following problem:

If the object is on the right hand side of the field of view and I press
the left button (any speed setting) to move the object towards the
centre, the scope will move downwards before slewing left to such a
degree that the object moves completely up and out of the field of view
and I then have to spend time re-centering the object. This is rendering
the left button useless and I find myself 'circleing' the object before
I can view it!

The clamps are as tight as I can get them (to the point where I am
afraid of cracking the plastic) and I have spent much time 'training'
the drive.

Does my scope simply need a tune up as described on your site or do I
have a problem that requires the scope to be sent back to the dealer. I
have not spoken to the dealer yet as I feel that they are only there to
shift boxes and I would not get knowledgebale help from them.

I realise that you may get a lot of unwanted support mails so I will
understand if you ignore my query! Thanks for a great site and keep up
the good work!

Tim Leal
Mike here: I don't ignore any emails (spam gets deleted unread though). First, do a CALIBRATE on the Autostar, then do a TRAIN DRIVES (both Azimuth and Altitude). That cures most ills. Second, DON'T overtighten the locks; that will cause damage and create too much friction (causing errors). Third, if the Autostar ROM has something older than about 2.3, you should update it to the current version (2.6Ed). Let me know if the CALIBRATE/TRAIN helps. If you do upgrade the ROM be certain to reTRAIN the drives after the update.

And from Dr. Clay in response to a similar query:

From: (P. Clay Sherrod)
I certainly do work on scopes from the UK often; it is just a matter of
you setting up a temporary Fed Ex account to handle the  shipping both
ways. Your problem sounds like there is way too much binding between the
worm gear and the drive gear in the declination axis (altitude).  There
are three small screws that are accessible once you have taken off the
tube assembly and the right OTA adapter (see the Tech Tips on Weasner's
site....) I would try loosening the back one and one of the two closest
to the gears and gently rocking the scope just a bit while loose; once
done, tighten them back up again being careful to not strip them have too much torque between the two gears.

Best of luck!

Dr. Clay
Arkansas Sky Observatory
Harvard/MPC H43 (Conway)
Harvard/MPC H41 (Petit Jean Mountain)

Subject:	Slack in the declination axis
Sent:	Saturday, April 5, 2003 12:55:20
From: (Avtar Roopra)
Thanks for a great site.  Really is a gem!  I have a question about my
ETX90.  I've had it for a couple of years now and the declination motion
has started to show a fair amount of slack (2-5 degrees) even with the
lock engaged.  Is there a way I can tighten this up or do I have to mail
the scope and get a 'Supercharge' service performed?

Your friend

Avtar Roopra
Mike here: See the Performance Enhancement articles on the Telescope Tech Tips page.
Subject:	Can I add an "Autostar" controller to ETX90?
Sent:	Thursday, April 3, 2003 22:49:22
Thanks for keeping such an excellent web-site!

I am just going through the process of buying a second-hand ETX90 (An
original mid 90's model). Can I add an "autostar" to it? & if so, which


Richard Ravn-Listowski
Mike here: There is no upgrade path from the original ETX model (now known as the ETX Astro M or ETX-90RA) to an Autostar-capable model. However, you can see the Telescope Tech Tips page for ways to attach the OTA to another mount that does have Autostar capabilities (DS or ETX-70).

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