Last updated: 27 November 2002
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:	Looking for old ETX-90RA info
Sent:	Wednesday, November 27, 2002 19:08:49
From: (Jose Manuel Fernandez)
Can you give me the price range for an ETX-90RA in mint condition? Do
they still sell as new equipment? (I'm buying one back from a friend
that never used it)

Also, does anyone have a .PDF version of the manual for the 90RA?


Mike: Kudos on your efforts. And many thanks for your help all these years..

Mike here: Many Meade dealers sell new ETX-90RA telescopes for under $200 (USD). Check the Dealer Specials page on the ETX Site as well as dealers like Shutan Camera and Video, Scopetronix, and Oceanside Photo and Telescope. Meade has an HTML version online at
Subject:	etx-90ec
Sent:	Tuesday, November 26, 2002 19:45:15
Thanks for the info on the etx-90ec.  I'm thinking about buying one for
the family for christmas and appreciate all the time you put into
publishing this info.  I know very little about scopes and astronomy and
I'll be honest....your experiences kinda scare me.  It looks like the
etx-90ec is not as user friendly as advertised.  Would you recommend
this scope for a beginner?

john fields
omaha, ne 
Mike here: What are your expectations for a "user friendly" telescope?
Subject:	Dec motor jerky
Sent:	Tuesday, November 26, 2002 11:06:10
Hi Is there a site which explains how to strip down an ETX90EC in
laymans terms (step by step big colour photos would be nice) as my
telescope has got a problem with the dec motor being jerky the motor
runs  but the O.T.A. stays still the it will move in a  jerky manner
into position: I suspect a clutch problem: I would greatly appericaite
any feedback.

Thanks steven
Mike here: See the Telescope Tech Tips page on my ETX Site for lots of info.
Subject:	etx-90
Sent:	Monday, November 25, 2002 19:12:59
From: (Sally &Graham)
Hi guys,
I just wanted to say thank you for you help and assistance in getting my
scope up and running, I used it for about an hour last Sat nite - until
the batteries went flat and the cloud closed in.
Many thanks

Subject:	etx scope
Sent:	Wednesday, November 20, 2002 15:53:15
From: (vikram alladi)
My name is Vikram Alladi, and I am an amateur astronomer.I live in New
Mexico where we have some really good skies.  I had a chance to read
your book titled "Using the Meade ETX", which I purchased through Sky
and Telescope. I found a lot of enthusiasm and passion in your
descriptions and explanations regarding ETX scopes. Sharing the same
feelings I wish to say that I am the proud owner of an ETX 90EC, with an

I have been doing some viewing and I find it to be a very good scope,
with a good deal of accuracy. However I have one problem. I am fine with
the alt-az mode. However when I want to do some viewing in the polar
mode, the problem comes. Putting it in the home position is next to
hell! I align my viewfinder and eyepiece with a terrestrial object,.
When I put my OTA parallel to the fork arms, I cannot look through my
viewfinder, because the base of the telescope is in the way of my head.
I normally  use both my eyes in bringing the celestial object to the
center of the crosswires in my viewfinder, before I look for the same in
my eyepiece. I wanted to try with a right angle viewfinder, which Meade
is selling for the 90ECs. I am thinking that it will be a waste of
money, because again I cannot use both my eyes when I am centering it on
polaris. Do you have any shortcuts or methods to circumvent this
problem. Please write to me, if you do.

Thank you,

Sincerely yours,

Mike here: The straight-through finderscope is difficult (if not impossible) to use in some orientations. A right-angle finderscope can help but so can one of the 1X or "red-dot" finderscopes. See the Accessory Reviews - Finderscopes page for some ideas.
Subject:	Help Please - A Fix
Sent:	Wednesday, November 20, 2002 3:17:04
From: (Jim and Laurie Oswald)
I recently purchased the ETX-90 RA with the 884 tripod and also have the
same problem. I did find a fix that works for me.  I took the cover
plate off the scope and mounted it on the tripod (with out the scope)
then scribed where the hole of the switch goes on the tripod base.
Remove the cover plate and drilled a hole in the tripod base and shaped
it to allow me to turn the switch off and on without removing the scope
from the tripod. I keep the batteries in all the time and only turn it
on when I'm ready to start my viewing session.

Hope this helps

Jim from Wisconsin
And this:
From: (Jordan Blessing - ScopeTronix)
In response to the post from (Dennis Swindle) I
wanted to make one point.

If I remember correctly from the days of designing the MicroStar II
drive corrector the ETX Astro RA motor runs on precisely 1.8V to track
at the proper speed. The circuit board is more than just a battery
holder and should not just be bypassed. He should connect his 4.5v power
supply to the proper (+) and (-) endpoint battery terminals, not
directly to the motor or it will run way too fast. He can then just
leave the power switch on and cut power to the scope to turn it off.

Jordan Blessing
ScopeTronix Astronomy Products, Inc.

Subject:	re:  worth upgrading from 70EC to a 90EC?
Sent:	Tuesday, November 19, 2002 7:40:50
From: (Richard Seymour)
Although Training when you move your Autostar to another scope is
desireable, you may find that Calibration is -required-.
(and painless... it only takes Setup > Telescope > Calibrate [enter])

Failure to Calibrate can generate Motor Unit Fault messages.
Failure to Train only leads to minor pointing inaccuracies.

Setting the Telescope Model can also be handy

I move my 497 between an ETX70 and ETX90 frequently.

have fun

Subject:	HELP please!
Sent:	Monday, November 18, 2002 14:49:17
From: (Dennis Swindle)
What an incredible site you have developed!

I recently purchased the ETX-90 RA with the 884 tripod. However, with
the scope mounted on the tripod, the on/off switch for the drive is
impossible to access. What a hassle!

Because I want to leave the scope on the tripod 90% of the time, I would
like to create an Alternative Power Source lead that I can plug in to a
wall socket at will, leaving the power swith at the base of the ETX on
the "ON" position most of the time (batteries removed, of course). I
read about the following mod in your tech tips section:

"Drive Alternative Power Source
From: Conrad Kussner (

To run the ETX indefinitely you can use one of those laptop chargers
that take 110V and change it to precisely 4.5 Volts DC. (*I have a Radio
Shack 4.5 v power inverter.*). In the base, unsolder the leads to the
motor and hook 2 color coded wires from it to the wall of the base and
install a small jack w/ correct polarity (check with meter) there. Then
cut the plug off this new charger and solder on a matching male plug to
fit jack you carefully installed in the plastic base." (*Initial portion
of article.*)

This may be a dumb question, but the article never mentions how or what
to hook back up to the motor after you unsolder the leads to the motor
and hook 2 color coded wires from it to the small jack on the wall of
the base.

Can you help me here? Can I just run the wires from a jack on the wall
of the base directly to the leads on the motor without unsoldering the
wires leading from the internal battery compartment?

Any help will be appreciated!


Dennis Swindle
Warren, MI
Mike here: I think he was referring to mounting a power plug (jack) in the side of the ETX base and running the wires from the motor to that. You will need to cut the wires from the battery. You could reroute them to the jack as long as it cuts out the battery connection when the AC is connected.


Thanks very much for the reply. I hope I'm not being a pain, but I have
another question. If I run the wires from a (soon to be) power plug
(jack) in the side of the ETX base to the motor and cut the wires
leading from the battery to the motor, will the motor run in the right
direction for the N. hemisphere, or am I totally oblivious to something

Thanks for your patience and your INCREDIBLE web site. (Nothing like it
on earth!)

Mike here: Since the wires are DC, I suspect that the orientation of the wires will dictate the direction of the motor. But I'm not an electical engineer.
Subject:	worth upgrading from 70EC to a 90EC?
Sent:	Monday, November 18, 2002 9:18:14
From: (Schmidt, Wayde R.         UTRC)
I currently have an ETX-70EC with 497 Autostar.  Seems it might be
worthwhile to upgrade to a 90EC, but can I just transfer the Autostar?
Any other suggestions?

Mike here: The #497 works with the ETX-90EC. Just remember to select the new telescope and TRAIN the drives. You'll like the higher magnifications you'll get from the ETX-90.
Subject:	ETX a Wonder scope??I'm still left wondering...
Sent:	Friday, November 8, 2002 7:21:48

   * I chose an ETX 90RA as a first scope after spending some
     time observing with 10x50 bino's. Had high expectations from all
     internet research, but have been largely dissapointed with
     planetary viewing using the supplied 9 and 25mm MA eyepieces. Now
     I'm thinking I shoulda'; bought the 8" dob.

   * Saturn appears quite small and totally without detail ( just a
     bright yellow disk and rings).
   * Jupiter also appears really small and without any detail.
   * Moon looks cool though.( the magic focusing clothes-pin works

Am I expecting too much from a 90mm  f13 scope???I understand film
accumulates photons and  photographs look far better than the actual
eyepiece view.Would better quality eyepieces help with detail. Or is
that all there is my friend?

   * I have the meade 2x barlow but find it all but unusable with the
     9mm. (You have to look at just the perfect angle to see anything at
     all ).

   *  I did order a copy of your book from amazon yesterday,  maybe it
     will provide some insight. Lately, I mostly leave the ETX  inside
     and just grab my bino's...

Haven't found a club in my area so I'm on my own (shivering in
wisconsin)out here.  Thanks for any light you can shed...

Mike here: It is likely your expectations for planets is too high for the ETX-90. You can see lots of details on some planets; with Saturn you should be able to see Cassini Division in the Ring as well as the shadow of the ring on the planet and the shadow of the planet on the ring (during good seeing). At times you can even see one or two cloud bands on Saturn; more on Jupiter. If planetary work is your prime purpose then the ETX-90 is the wrong telescope for you. If a general instrument that is highly portable suits your needs, then the ETX-90 can be the right choice.
Subject:	Re: Christmas specials and other Meade ranting?
Sent:	Friday, November 8, 2002 1:30:56
From: (Clay Sherrod)
To:	Dave
Hello - sorry about the ETX woes...not sure what "RTA" designates, but I
wish you had written before you you opened the base; the wires are
indeed delicate and put there is such a way as to "booby-trap" the user
if he gets in the scope.

The random slewing is a problem of connection; most ETX scopes will
exhibit what you describe exactly for example if the Autostar is not
even plugged into the side panel.  Likely your Autostar OR its cable is
bad; sounds like a bad connection on the wires on either end of the
Autostar coiled cord to me.

I do not do warranty work, and it sounds like whoever worked on the
scope before did not address the problem at all, or perhaps made it
worse....there is no one north of the border that does the Supercharge. 
I bet if you were to call Meade, they would send you a new Autostar AND
coiled or the other is bad, I guarantee it.

Take the scope to a computer shop where they repair electronics...they
have special equipment that can reach those tiny couplings for the
broken wire.  Best of luck!

Dr. P. Clay Sherrod
Arkansas Sky Observatory

  ----- Original Message ----- 
  From: Dave 
  Subject: Christmas specials and other Meade ranting?

  I am a disgruntled ETX-90 Owner.

  I live in Thunder Bay, ON.

  I have recently received my ETX back from my dealer in Toronto (Khan
  Scope).  It was repaired for a bad RTA, when I got it back, it seemed
  to work fine.

  A couple of weeks late I've been now experiencing some "wankey"
  operation of the unit.  I turn on the unit, and right away it moves in
  the "up" direction.  It seems to randomly move up, and sideways,
  sporadically.  Also the left and right buttons an the autostar do not
  seem to work.

  I've checked the batteries they are OK.  The cable between the
  Autostar 497 and the unit seems OK. (although it sticks in the scope
  side and I've never been able to get it out) seems to be OK.  So
  failing that, I decided to look inside at the 2 wires that connect the
  power supply to the board.

  They seemed OK, but in the process I ripped the black one out of the
  board side.

  So, here's my question.  If I sent the unit to you for a supercharge,
  would you look at these couple of problems that I have?  The unit is
  under warranty still, but I think that the cost of sending it to my
  dealer vs. sending it to you would be minor.  I'd rather not worry
  about the warranty (depending on repair costs) and just have you fix
  the unit as you do the supercharge. Actually do you know if opening
  the bottom of the scope constitutes a void warranty?  Are you
  authorized to do warranty work?

  Also, do you have any specials for your neighbors to the North?  The
  exchange rate really kills us up here.  Your supercharge service ends
  up being $350 CDN  ( I can get a couple of nice eyepieces for my
  homemade 10" dob for that price).  Any counterparts up here?
Mike here: I agree; since the batteries were OK it was most likely a bad connection someplace. The simplest is to swap the Autostar cable; if that solves the problem then it was a bad cable or connector.
Subject:	ETX 90EC - problems with slewing the scope
Sent:	Tuesday, November 5, 2002 1:18:50
From: (Yair Wiener)
Since I have purchased the scope a long time ago I have encountered some
problems with moving the scope in slow speed. The scope moves just fine
when moving up and down but it looks like it stuck for about 2 second
when moving to the sides and when it frees it "jumps" to the side. I
should mention that after the scope starts to move it moves correctly
and smoothly. After I finished moving it takes some time for the motors
to kick back and compensate for the earth movement. I find it very
annoying lately since I have just started with astrophotography using
web cams. Does it seems like a problem ? should I contact my dealer ?
Thanks in advance,

Yair Wiener
Mike here: Are you using the standard handcontroller or the Autostar? In either case it could be that the axis lock is too tight; try a very slightly looser position. Or it could be that you just need smooth out some of the grease; do this by rotating the OTA around the axis, hardstop to hardstop, several times in each direction. If these don't work there are some more serious things you can check for as discussed on various tips on the Telescope Tech Tips page.

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