Last updated: 31 January 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:	Re: Electric Focus
Sent:	Tuesday, January 29, 2002 14:24:52
From: (Clay Sherrod)
To:	Mike
Welcome to the world of vibrationless focusing!  The electric focuser is
truly a "must have."  Regarding a cover, you are going to leave it set
up in the house and carry out??

My best cover is a good soft cotton pillow case!  It doesn't look
pretty, but it is wonderful and lets the moisture breathe out from under
it; NEVER cover the scope with plastic, indoors or out!

For short term outdoor storage I strongly suggest one of the nice
soft-lined black BBQ-grill covers available at Lowes or Home Depot! 
They breathe, look great and last a lifetime!

Good in warm and cold weather!

Clay Sherrod
  ----- Original Message ----- 
  Dr. Sherrod: 

  I summoned up all my courage & installed the 1244 electric focus on my
  new Meade ETX-90EC yesterday. What an accessory! It is nothing short
  of great. SO much less vibration induced by focusing. My wife really
  likes it too, I've been working on teaching here how to FOCUS since we
  got a Nikon F in 1972!  Again, thank you for your alert to all the
  unsuspecting "about-to-install-it" out here. Too bad Meade did such a
  marginal (at best) job of writing instructions.

  We plan to leave the telescope/tripod set up & ready to use, any
  suggestions for a cover? It will get too dusty quickly without one, I


Subject:	re "Finderscope is useless." 
Sent:	Tuesday, January 29, 2002 4:28:28
I just got Meade 6x30 finder from the Telescope Warehouse for about $20.
The skinny end fits into the existing holder on the ext90ra, tho the
wide portion of the tube sticks way out. It's secure enough as is and
even stayed aligned after I tapped it around a bit to test it.

For me, this turned a miserable experience in a pleasant one (locating
objects).  I can SEE things thru it, including the crosshairs.


Subject:	New User Having Trouble...
Sent:	Monday, January 28, 2002 18:24:20
From: (Daren Jackson)
Reply-to: (Daren Jackson)
Hi, Great site.  I have been a lawnchair observer for years now but
never through a telescope; got a 90 w/autostar for Christmas (thanks,
dh).  I have had only about 20% success so far, but am hopeful now that
I have read throroughly some of the tech tips on your site.  Still a few
concerns though.

1.  "Finderscope is useless."  I lined it up terrestrially but could
barely see Jupiter through it and then still had to hunt for him.  I
cannot see Sirius even through it.  What is wrong and how can I learn to
use it.

2.  Degreasing the clutches/gears.  This is absolutely intimidating and
I refuse to open the thing up, I'll break it, I swear I will.  It also
angers me my new scope is so fraught with problems, things like 72 cents
worth of washers are needed?!?  Can I expect acceptable decent
performance without going to all that trouble or should I just sell the
thing now?  (I'm definitely NOT an engineer!!)

3.  Entering time into autostar.  I have set up my home site longitude
and latitude, now the question is, do I enter the time OFF THE CLOCK
(EST) and autostar will compensate for me being at 80* longitude, OR do
I enter True Local (apparent) Time, e.g., tell autostar it's 7:40 when
the clock is reading 8:00 EST?   Furthermore, if it takes me, on
average, 10 minutes to finish aligning from when I started, should I
enter the time as 10 minutes later than it is at commencement to
compensate for my slowness?  i.e. when does autostar's clock start

I would appreciate some help, I really do want to learn to use the
thing, but I need some success soon!  Thank you.

Maxie Jackson
Mike here: The finderscope is a wider angle scope for locating bright objects. You will be able to see planets and stars through it but since it is only 8x magnification you won't see any details on the planets (although you might see one or more of the Moons of Jupiter). It is intended to be used as a "sighting scope". Of course, it needs to be aligned with the main telescope so that when an object is in the corner of the crosshairs the object is centered in the telescope's eyepiece. As to degreasing, don't worry about that or washers unless you ABSOLUTELY POSITIVELY WITHOUT A DOUBT know that you have a problem that could be fixed by some tinkering. I've never felt need to do this on my scopes. Can the telescope's performance be improved by making the improvements suggested on the Site? You bet (or you can completely ruin it). You can also soup up your car but do you want/need to do that to drive to work? For the Autostar, use your real local time (don't over think things...). And it does keep track of the time.
Subject:	RA slewing speed problem
Sent:	Sunday, January 27, 2002 8:45:27
From: (penburyst)
Thanks for the great website. I find it absolutely essential for
anything to do with my ETX.

Recently my ETX 90EC has been behaving very strangely.  When using the
scope with my autostar(firmware version 23eb).  When I key in a new
speed on the autostar the the Dec rate changes to the appropriate speed.
 However, the RA rate often stays at 9, regardless of what I enter as
the desired speed on the autostar keypad.  The RA and DEC speed change
just as they should on the standard electroninc hand controller.  I've
tried RESET, but this made no difference, I tried changing batteries and
it seemed to sort it out, So I immediately changed back to the set I had
just taken out and it was still ok!  However, the scope does seem to be
eating batteries at the moment!  I never know when this problem is going
to happen.  Sometimes it won't slew properly RA all night, sometimes
just reinitializing sorts it out.

My scope first started doing this one very cold night about three months
ago, I was running firmware 2.2er at the time.

Could it be that my my scope is somehow draining batteries very quickly,
leading to voltage drops?

Any suggestions greatly recieved.

Michael Morris.
Mike here: That's odd. Don't know why only the RA speed would stay stuck when the DEC speed changes. One suggestion, especially on cold nights, occasionally run the scope through a full rotation to loosen the gear grease. Also, batteries are less efficient at low temperatures so using an AC Adapter might help.
Subject:	ETX-90RA Motor Drive
Sent:	Wednesday, January 23, 2002 19:17:25
From: (Skip Copp)
I recently purchased an ETX-90RA as a second more portable scope (I also
have an 8" SCT) and find that I use the ETX more than the 8".  I have a
question concerning the motor drive.  The instruction manual notes that
when the motor drive is first turned on there is about a minute delay
before the drive takes up the internal backlash, which appears to be the
case.  It goes on to say that when switching from viewing one object to
another (after the motor drive has been on for over a minute), once the
RA axis is locked the motor drive takes hold "within a few seconds."  
This "few seconds" seems to be upwards of 10 to 15 seconds, during which
time an object can completely drift out of the field of view at higher
powers.  Is this normal or is there something that can be done to reduce
the time for the scope to resume tracking?

By the way, great site.  Don't know how you keep up with everything but
you certainly have a super forum for exchanging ideas, disseminating
information, answering questions, and resolving ETX problems for people.
Mike here: Some lag is normal but I don't recall seeing a 1 minute lag on first use nor a 10-15 second lag on subsequent uses. Before I added the Scopetronix Microstar II+ to my original ETX (now known as the ETX-90RA), I never had a major problem centering the object, locking the RA axis, and having it track. As to improving the ETX-90RA, there are several articles on the Telescope Tech Tips page.
Subject:	My very first Jovian shadow-transit!
Sent:	Wednesday, January 23, 2002 14:36:39
From: (martyn)
Yesterday evening (22nd of January 2002) at 22:55h UT, I was training my
ETX 90RA + sp15mm on Jupiter after a splendid evening of observing the
moon. The sky was somewhat hazy, sometimes clouds would rush! past, it
was quite windy. Three moons to the East of the planets. North- and
Southpole darkening: yes, NEB SEB: yes clearly visible. But now, at 83X
I seemed to see a tiny black dot right on the northborder of the
Southpolar darkening well to the right of the central meridian. As it
was still there after five minutes I realized this must be a shadow
transit. It was pitchblack and seemed to almost float "above the
clouds". I plugged in the sp9.7mm to make things a little bigger and
yes, clearly the seeing was not good, but this shadow just sat there 
steadily. This WAS a shadow from one of the galileian moons. I packed
up, went back inside to go sleep but first check out which moon threw
it's shadow here. It turned out to be Ganymede, and was just clearing
Jupiter as I opened my astronomical yearbook while I read in
the tables. This shadow was so easily visible I was quite surprised. I
never saw this before as I never looked for a shadow's a
spectacular sight.

observing from the Neterlands
52 28.37N  6 24.44E

Subject:	ETX-90RA Question.
Sent:	Sunday, January 20, 2002 9:20:28
From: (Ralph Encarnacion)
I saw your site and I must say that it is wonderful. I just bought the
ETX-90RA from that store in Tenn. that has them for $189.00 What a deal!
I saw an article on your site that shows that you can modify a DS-60EC
by taking off the scope and mounting the ETX in its place. Since I
figured that the ETX-90 is a lot wider than the DS-60, I just wanted to
make sure that the DS-60 was not a misprint and that the ETX does
actually fit in the same spot. I have a chance to buy a DS-70EC with the
Autostar for $175. That should give me even more room to make it work I
hope. My next question is can the Autostar 495 be converted to a 497 and
what would it take to do the conversion. If not, I can get the DS-70EC
for $125 without the Autostar. Then I was thinking of buying the 497
separately and using it with the DS-70EC, but I don't even know if it
will work with it. All of Meade's advertising says is to get the 495 for
the DS series scopes and the 497 for the ETX series. Can the 497 work
with the DS-70EC?
Mike here: You should ask the author of that article about the fit. As to upgrading a "495" to a "497", yes you can using the current software from Meade (as long as you have a #505 cable). As to what models can be used with what telescopes, see the article "Autostar Models" on the Autostar Information page.
Subject:	eyepiece
Sent:	Friday, January 18, 2002 16:59:31
From: (One-Stop Baby)
I have searched the internet  and downloaded your eyepiece database but
I still cannot decide on my next eyepiece for my etx90-ra .  I just
bought it last month.  The skies here in New Mexico are amazing.  My 9mm
with a 2x barlow is as clear as can be.  I want to push my etx a little
over 300 power.  I think I can because of the clarity of viewing here. I
am a newbie so I may be wrong.  I was thinking about an 8 or even 7mm
eyepiece with my 2x barlow.  I would like an eyepiece with a wide view.
Am I pushing it?  Is this possible?  I would greatly appreciate an
expert opinion.  Thank you!  Love your site too!  Best on the net for my
scope!  I will be sending you pictures in the next couple of months too
(if you want them) when I can afford the camera mounting system.  I have
a cannon rebel I want to mount to it...

My usual email is but I can respond from this one too.

Thank you sincerely for your reply,
Wade Holbrook
Mike here: I only have the 9.7mm along with the 2X Barlow. I don't have a real short eyepiece for use with the ETX-90RA. You might want to look at the Accessory Reviews - Eyepieces page for some short eyepiece comments.
Subject:	more questions
Sent:	Wednesday, January 16, 2002 13:23:22
From: (Bob Vilums)
I wrote you yesterday about the 70at Astrostar issues.  I spoke with my
telescope dealer, and he talked me into getting the 90EC with exchange. 
He is refunding me 100% on my 70At and selling me the 90EC for $449.00. 
This seemed like a good price in comparison to most places I've been.  I
also bought the 497 Autostar controller.  I will have to wait for the
tripod for another paycheck.  Hopefully I won't have the same issue with
the 90ec as I was having with the 70at regarding the Astrostar
controller.  But, I do have a question for you.  I had already purchased
a case, the 2x 124 barlow, and PL 4mm eyepiece.  The case will be easy
to return, but I bought the eyepieces kind of far away.  Will these
eyepieces work with the 90EC?
Thanx once again,
Mike here: Have fun with the new scope! And the eyepiece and Barlow Lens should work. Just keep in mind the maximum theoretical magnification of a 90mm telescope (180X) vs what you'll get with the 4mm (312X). You can exceed the max on good nights on bright objects but they will still appear fuzzy and dim.
Subject:	Slop in Dec on ETX-90RA
Sent:	Wednesday, January 16, 2002 12:32:23
I recently purchased a new ETX-90RA.  It was out of collimation and
after reading the info on your site I decided to send it in to Meade. 
Now it is much better.

The other problem is slop in Dec Axis.  The shaft with the dec
adjustment knobs has considerable end play which results in considerable
slop in the Dec axis.

The main problem with this scope is vibration.  When I try to focus the
scope, the vibration prevents me from seeing the image while focusing.  
Last night I took the scope off and just mounted it as a spotting scope.
 This way there is no problem so I may just continue to use it this way.

I did look over your site for info on this but couldn't find it, maybe
you could point in the right direction.


jon isaacs
Mike here: See the "ETX Hints, Tips, Projects, & Products" on the Telescope Tech Tips page for info on the tune-up for the RA model DEC axis. As to vibration, you didn't specify how you had the ETX mounted; on its tabletop tripod legs, a photographic tripod, the #883 tripod from Meade, or just sitting flat on its base. The more sturdy the mounting the less vibration will be a problem.
Subject:	ETX-90 on an ETX-70 base?
Sent:	Wednesday, January 16, 2002 11:57:10
From:	GAndoos@DCMDE.DCMA.MIL (Andoos, Glenn)
Great Web Site!
Question: Can I mount an ETX90RA tube on my ETX70AT fork mount. If so,
where would I purchase just the ETX90 Tube.

Mike here: Won't work unless you make your own "tube adapters" to convert from the -70 tube to the -90 tube. You can buy just the ETX-90 Spotting Scope model however.
Subject:	ETX90EC-problems with
Sent:	Tuesday, January 15, 2002 4:03:09
From: (Chris  Cooper)
I really enjoy your site. I hope you can help me with a problem with my
new scope.  After using it for only 10minutes it stopped moving
sideways, and it refuses to move. It sounds like its trying to move, but
all that happens is it moves a fraction and then stops. I have the lock
on and I replaced the batteries. I also undid the lock and moved the
scope and then locked it again .
Mike here: Some thoughts come to mind. Does this happen with the Autostar or the standard handcontroller or both? Could the azimuth lock be overtightened? If the lock is OK try unlocking the axis and moving the scope from stop to stop 2 or 3 times to loosen up the lubricant. Let me know if this helps.
Subject:	Problem with my new ETX90-EC
Sent:	Monday, January 14, 2002 21:37:55
From: (Mark VandeWettering)
First of all, let me thank you for your excellent website.  I'm learning
lots about my new toy.

I'm having a problem getting accurate tracking on my ETX90 w/ Autostar.
I've been mostly using Alt-Az Easy Alignment.  Sometimes it will work
very nearly perfectly, and track (say) Jupiter very near the center for
up to a half and hour.  Sometimes however, when I jog the controls in
the Azimuth direction, I will get period "corrections" that continue
every five or ten seconds or so.  The symptom is basically that the
object appears stationary for three to five seconds, then shifts right
for three to five seconds, then freezes and repeats.  It seems to be as
if the backlash corrrection was being invoked periodically.

I'm sorry if this is a well known problem, I'm still digging through
your website.  Thanks in advance for any help that you might have.

Mike here: I don't recall that specific problem being reported. I would guess that reTRAINing the drives would clear it up. Let me know.


Thanks, I've mucked around with retraining it, but the problem seems to
persist.  I am going to go ahead and do the mechanical tune up on the
thing this weekend, as the RA backlash seems pretty excessive (the dec
axis seems pretty good), stick in some fresh batteries and see if that
helps.  I'll probably also try flashing in the latest software (I'm
running 22EH).

Thanks again for your terrific website.  I'll keep ya posted.

Subject:	re:  Electronic Controller Modes
Sent:	Saturday, January 12, 2002 18:37:19
From: (Ken Cowell)
The exact problem occurs with my new ETX -90EC.  My vendor replaced the
Electronic Controller, but still, it may work and it may not. Generally,
I have to plug it in multiple times to get it to work.  The problem is
only in the cold - inside it works fine - and I think it has something
to do with the abiblity to maintain contact of the metal parts of the
plug and metal parts of the port.  Since my controller was replaced, i
think it is in the contacts within the port.  I am going to give it a
while, since the problem is inconsistent.
Ken Cowell

Subject:	ETX-90EC Barlow
Sent:	Tuesday, January 8, 2002 10:41:23
From: (Steve Pilewski)
Great site! I'm an absolute novice so forgive me if this is completely
non compos mentos- Will a Meade model #124 barlow work properly on the
90 EC? I know its supposed to use the #126, but I got a #124 for free
from an unfortunate who lost most of his optics in a fire. I have used
the lens on a few sessions (with the 26 mm) under what I thought were
fair to good conditions with ok results- I.E. no horrible problems with
focus, color or clarity. The point of sharpest focus does seem a trifle
elusive, but not much more than without using the barlow. Is this
Thanks in advance
Mike here: Since you've been using it, it must be working. If you can change the focus to either side of infocus, then it works. The problem with some Barlow Lenses and some telescopes and some eyepieces is that you may not be able to reach a focus before running out of focusing travel. (Steve's email address generated a "User unknown" when I tried to reply to him. Apologies, Steve.)

Subject:	New User's Experience, ETX90/EC
Sent:	Friday, January 4, 2002 23:54:05
From: (James Krehmke)
Again, many thanks for your most informative site!

I am an almost complete neophyte, having taken one astronomy course in
college in the '60s. In late November, I purchased an ETX90/EC at my
local camera shop.  It appeared to have never been used.  That was the
weekend of the Leonids, the LAST weekend before a record-setting stretch
of rainy days here in Oregon.  The first partially clear evening, I
quickly set up and tried to observe the only object I could see - the
moon!  Unfortunately, the Meade finder is useless when the scope is
pointing almost straight up!  Duh! Who came up with that design. 
Anyhow, RAIN, RAIN, RAIN. I occupied my time studying your site in
detail and ordered the Meade angle finder and a 9.7mm eyepiece.  More

Finally, the Saturday night after Christmas was totally clear here with
calm air.  So, out to the patio.  The moon is BRIGHT!  Screwed around
getting the finder scope aligned.  Now, go for an easy target.  Jupiter
is right there! WOW!  I can actually see cloud bands there.  This is
amazing!  Moons, too, lots of them!  Next target, Saturn.  Found it with
my binoculars and WOW! RINGS! Think I could see some cloud bands, too.

I'm blown away with this little scope's performance, but will probably
have to wait another 6 weeks to observe again. Time to borrow a GPS and
get the Autostar squared away.

Forgive this little rant, but I just had to share it with someone who
might understand!


Dallas, OR

Mike here: Regarding to the Finderscope, different designs work for different people in different orientations. Yes, the straight-through doesn't work on alt/az mounted telescopes (almost any) when pointed near the zenith and right-angle ones have you looking perpendicular to where you are trying to sight. Both have their limitations.
Subject:	ETX upgrade
Sent:	Friday, January 4, 2002 23:19:53
I have a question for you: I have an early ETX (I guess ETX-90), bought
shortly after Meade came up with it.  It is the type which has 3 legs
screwing into the base, one of which adjusts in length for your
latitude. It has only a polar drive powered by 3 AA batteries.

I would like to know if I could get an upgrade keeping the optics as
they are (may need a little going-over and tune-up) but either replacing
the fork mount with a modern one with Alt-Azimuth drive and Autostar
control (or something similar) or upgrading the present fork mount to
that capability. Does Mr. Sherrod do that ?

Having read from your website that he works on ETX's (no matter how
old), I would appreciate your advice on this subject as well as a price
estimate if this upgrade is feasible.

Thank you beforehand !  Jacques Linder  /

P S I tried Mr. Sherrod's e-mail address but it didn't work. I hope
yours does.
Mike here: See the FAQ for upgrade info.
Subject:	Etx 90 mirror alignment
Sent:	Friday, January 4, 2002 11:58:06
From: (Michael McDonald)
Great site. I usually do bird watching and astronomy with refractors,
but I got an ETX90 to do some astronomy. One of the things I noticed is
that if I remove the eyepiece and look into the optical tube, one or
more of the elements appears to be out of alignment since I do not see a
stack of concentric circles as you would see when visualy collimating a
reflector. Can you tell me if this is normal? If it is not, do you have
any advice on aligning the mirror/lens elements?

Mike here: Well, it should be essentially as you describe but the real test is a "star test". See the "Collimation Test" article on the Telescope Tech Tips page. If there is a significant problem you can collimate the telescope yourself (using the tips on the Site) BUT unless you are willing to take the risk of making things worse and then having to have it send to Meade anyway for recollimation, don't do it.
Subject:	ETX 90M
Sent:	Wednesday, January 2, 2002 21:30:47
From: (Tiffani Brown)
I've now owned my Orion XT-8 for two years now. After many
modifications, It now has excellent views of the major planets, yet the
double edged sword has struck...the clearer the image is at high mags,
the more I use high mags, therefore the object leaves the field that
much quicker!

I do alot of star parties for kids, and I found my Dobsonian to be a bit
clumsy for this task. I decided on an ETX-90 M (despite the fickle
press) due to the promise of sharp lunar and planetary images and the
motor drive, both indespensible features in a telescope aimed at
entertaining the little troops. My wife had the foresight to forgo the
#883 tripod for the #884, which looks like it could support the LX-90!
The setup is light, solid as Plymouth Rock, and quite easy to use! The
motor drive is a revelation, but what does a large reflector owner have
to say about the optics? My wife says Jupiter's bands look orange in the
XT-8, but I was pleasantly surprised to see 2 large and 4 small bands
with the ETX at 160-200x! The moons were different sized pinpricks, and
some low-level detail presented itself at times! The Orion nebula showed
a seagull shape, and the 4 "trap" stars at every mag. The moon at 200x
showed INCREDIBLE surface detail, and no image breakdown up to 277x! The
XT-8 was CLEARLY outclassed here! At first I thought the Moon's image
was similar in both scopes, until I gave the ETX's focus knob that extra
tweak, And all that extra tiny surface detail jumped out at me! WOW! By
far, the most pleasant surprise came from the planet Saturn. At 160x,
the Cassini was visible all the way around, as was the large banding on
the ball. Incredibly, the area where the ring passes behind the ball was
so sharp and defined, that a 3-D effect was realized! I couldn't take my
eyes off of it!

This fine observing session was not in the desert, but in my own
well-lighted back yard, in Irvine, CA! I have looked through many
telescopes, including theTV Ranger (the ETX's arch rival) and I thought
I was jaded by my well-tweaked XT-8, but I couldn't be more satisfied
with the ETX. I bet there will be alot more ooo's and aaah's at my next
star party!

Subject:	re:  Electronic Controller Modes
Sent:	Tuesday, January 1, 2002 12:24:11
From: (Richard Seymour)
You wrote:
>   No matter what I try, pressing, or pressing and holding the Mode button
> on the controller does absolutely nothing.  The Mode button will not produce
> multiple lights on the controller, steady, blinking or otherwise.

If the controller -never- illuminates any LEDs, then it's either (a) broken
or (b) not receiving power.

(b) can be addressed by wiggling connectors, making -sure- the ETX end 
 "clicks" into position, and (if you wish) opening it and checking with
  a voltmeter.

(a) is dealt with by calling Meade.. they'll send a replacement.

>  The telescope attempted to track the star, but appeared to be moving too
> fast and in the wrong direction.  

That could "simply" be the state your telescope adopts when it doesn't
see any controller at all.  Try unplugging the controller and powering up.
If you see the same motion, then i'd suspect (again) lack of power to

good luck
From: (Ron Duca)
Thanks Dick and Mike.

At the time of my message, the controller would illuminate only the four 
speed LED's.  I could cycle through and use those just fine.

In the process of setting up and taking down my scope, I had plugged in and 
unplugged the controller several times, but still only had use of the slew 
speeds.  I could not select the correct Hemisphere and the unit would not 
automatically track properly.  I decided to try one more thing.  Previously, 
I had always plugged the controller in before turning on the power.  This 
time I turned the power on before plugging in the controller.  I can't 
explain why, but it began to work properly.  I am quite relieved, and happy 
now.  I can track things like Jupiter and Saturn as they move across the 

Thanks again for your assistance.

From: (Richard Seymour)
Truly bizarre... when it does the initial calibration slews,
are they in the same order and direction as a "(should be) 
normal" power-up?

(i think it's Right (CW), then Up)



I'm pretty sure the initial calibration slews are Right, then Up.  That
has not changed.

Having to "hot plug" it was just a one time thing.  Since then, it has
worked properly when I plug the controller in before powering up.

I know it's bizarre, but it's working properly now and that's good
enough for me.
Mike here: As this is a serial connection, I would suggest NOT plugging in while the power is ON. You run the risk of damaging the Autostar, the ETX, or both. But glad you got things working!

Feedback Archives

Check the Feedback Archives for previous editions of the ETX-90RA and ETX-90EC User Feedback pages.

Return to the top of this page.

Go to the ETX Home Page.

Copyright © 2002 Michael L. Weasner /
Submittals Copyright © 2002 by the Submitter