Last updated: 31 October 2001

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: ETX 90 EC problems with DEC and tracking
Sent:	Wednesday, October 31, 2001 14:01:48
From:	penburyst@on-edie.net (penburyst)
Disaster has struck!!!!

First I downloaded the latest Autostar updater software (ASU v. 3.0) and
the latest firmware build from the Meade website.  I also loaded the
Dick Seymour's patch for that build from your website.  Then I bought
the #505 cable set.  I read the none-to-clear download instructions from
my auotstar manual, the Meade web site, and also got some extra stuff on
it from your excellent web site.  I connected up all the cables, turned
on my computer and the ETX90 and aligned the scope.  I loaded the Sky
Chart software which was bundled with the cables, Fine.  I tried the
scope on a demo version of Skychart III by Southern Stars and it
controlled the ETX 90 just great. From then on it was downhill! Next I
loaded the ACP package.  It froze every time I tried to connect to the
ETX.  Conscious that the trial version of ACP that comes with Sky Chart
only has full functionallity for 30 uses, I decided to give up for now
and see if uploading the latest version of the Autostar firmware would
help. I started the ASU package and put the Autostar into Setup/Download
mode. Then I pressed 'Connect' on the ASU package.  It said I had no
memory on the Autostar and then just froze.  Nothing.  After waiting for
well over an hour.  I gave up and had to turn the ETX off   I thought,
well it won't be the end of the world, I can always use the safeload
function.  But try as I might, I can't get my Autostar to do anything! 
I plug it into my ETX, turn the scope on and nothing!  Not a light, not
a beep, nothing, dead, it is no more, it has ceased to be, it has
slipped this mortal coil.  It;s stuffed it!.  Even the little LED at the
top of the Autostar doesn't even work!

I've tried pressing ENTER and DOWNSCROLL buttons then turning on as
suggested in the Safeload instructions, nothing.  I've tried changing
the batteries, reconnecting to the PC, pressing buttons in different
orders, To add insult to injury, the ASU program now says it can't find
the COM2 port.  I know this COM port is ok because my modem runs off it.
 I'm pretty certain I got the download sequence right, but to be
perfectly honest I can't be absolutely sure.

I've tried uninstalling and then reinstalling the basic ASU package with
no effect.

I can run the ETX from the normal electronic hand controller ok.

So far so I've tried everything but getting on my knees and praying to
it Is it the Autostar, the cables, the scope, my computer, or my brain
that's caused the problem?

Any suggestions on how to revive my Autostar gratefully welcome.

Michael Morris

PS: Are Meade guarantees transferable and how long is the guarantee on an
Mike here: If the Autostar won't power-up in SAFE LOAD mode perhaps it was too old to have that capability, although reports of ASU 2.4 (and presumably later) were that it would update 1.0c that you reported having. If so, you'll have to contact Meade. If there is NOTHING on the Autostar when powering up normally then I wonder if the cable connection is bad, which would have nothing to do with the update attempt. Check the connections; if bad contact Meade. Warranty is one year as I recall.

Subject:	Re: etx90 loose knob
Sent:	Tuesday, October 30, 2001 3:36:29
From:	Typec2@aol.com
I tried the washer and it eliminated the slop in the knob, but the scope
didn't rotate as freely. If I loosened the knob just a bit the scope
swiveled freely, but the knob wobbled again. I decided to just live with
the knob as is since it still seems to work ok.

On another note. Should we expect to see Jupiter's GRS with the ETX90?
I've been trying to see it using the time table from S&T.
(http://www.skypub.com/sights/moonplanets/redspot.html) I've had some
good clear nights with Jupiter straight over head with no luck. Pretty
sharp images with 12mm and 9mm eps.


Mike here: The Great Red Spot is more a very pale orange spot and so hard to pick out, especially with small scopes. Using filters under excellent seeing conditions can help.

Subject:	ETX 90 EC problems with DEC and tracking
Sent:	Thursday, October 25, 2001 15:11:25
From:	penburyst@on-edie.net (penburyst)
I have recently purcahsed a secondhand ETX 90EC with Autostar version
1.0c.  I have experiencing two problems, possibly related.

1)  The DEC axis seems to 'jump' some times when it first start slewing.
2) The image shakes on a about once a second when the scope is tracking.

Are these related? And have you any ideas on how to fix them? 

PS  Great web page, keep up the great work.

Michael Morris  (UK)
Mike here: See if you can arrange to upgrade the Autostar to the current version (2.2Et). If you don't have the necessary cable, you can make or buy one or ask someone else to do this for you. Jumping on slewing can be caused by too-tight locks. So check that you are not overtightening them. You don't say HOW you have mounted the ETX. But lightweight tripods and/or polar mounting can cause the drive motors to affect image stability.


Thanks for the advice, I've ordered th #505 cable set today.  I'll let
you know how I get on.  the ETX is mounted in Alt-Azi mode on a #883
Meade tripod.

Subject:	RA problems with ETX90M
Sent:	Monday, October 22, 2001 8:05:43
From:	AMANT@kochind.com (Aman, Tim)
To:	Typec2@aol.com ('Typec2@aol.com')
Hey Bill....

You know, I just got an ETX90M myself and had something like this

I took the knob off and discovered that the hole that the setscrew goes
in was not completely punched thru!

With a heavy paperclip I was able to poke thru the remaining aluminum
and then clean out the debris.  Once it was tightened back down again it
works like a champ!

Now if I can just figure out why the DEC slo-mo control works OK going
down but I have to tighten the lock a bit to make it go up.... Weird...

Hope this helps!

From:	Typec2@aol.com
I talked to Meade and they're sending me a new shaft, tho neither of us
thought it would work. Someone suggested a washer under the knob as a
possibility. I'd have to find something thin and large enough. He used a
Lego piece. I let you know.

Subject:	etx90m (ra)
Sent:	Saturday, October 20, 2001 0:09:11
From:	Typec2@aol.com
I just got an etx90m (ra). It seems to be working ok. The only thing
I've found wrong is the slow motion az control knob. It's loose and
wobbles around. It tried to tighten it with the supplied allen wrench,
but found out the set screw was already tight. It still functions
perfectly fine.  I checked thru the archives on this site but didn't see
any mention of this problem. Are they all like this?
Mike here: The knob/shaft should not be loose nor wobble around. You might see the "ETX-90RA Right Ascension Play Fix" article on the Telescope Tech Tips page and see if anything there might help.


Thanks, Mike. I did check that out, but, it seemed to be more about the
worm and pinion gears at the other end on the knob shaft. From the photo
it looks like that might still be the way to get at the loose part.
Since I've only had it for 2 days and it functions properly I'm not real
anxious to get at it right away.
And this:
BTW, I set the ETX90 on the Meade Deluxe field tripod, did a
semi-accurate polar alignment (I can't see Polaris) by looking at a map
of my town and using a satellite photo of my neighborhood 
(http://terraserver.homeadvisor.msn.com/default.asp). This way I can
move around my yard and use a distant landmark for North without having
to use a compass all the time. In a test with the 25mm ep it tracked for
over an hour without much drift.

Much better than my dob. I also have the etx60, but I just never
bothered the use the auto tracking in it.

I really like the etx90. I was looking for something bigger than my 60
and easier to use and move than my 6" dob. I also didn't want to spend
much more money. (I bought all these scopes this year. If I'd found this
90 in the beginning at this price -$324 with tripod- I probably would
only own one.)  One reason I decided on it was because I thought I saw
somewhere that you said it's the one you use most frequently. Figured
that was a good recommendation.

Thanks again,

P.S.  I saw the Cassini Division regularly the last 2 nights!!! Great!!!
Could never get it on my dob.
Mike here: Yep, the ETX-90 is a Mighty telescope!

Subject:	binocular website
Sent:	Wednesday, October 17, 2001 14:59:36
From:	PaGamondes@wanadoo.fr (PaGamondes)
Thanks for your answer, it's a great help for me
to know where looking for ideas, for my knowledge 
If you want to look at something called "binosaurus",
here's a japanese website you can browse:
(click on TATSURO MATSUMOTO'S SITE to get in)
Thats the reason why i believe that "home made binoculars"
is possible.
Best regards.

Subject:	New ETX-90EC...
Sent:	Tuesday, October 16, 2001 12:29:59
From:	amatthew@catc.net (Alan & Brittney)
I just ordered a new ETX-90EC for 409.99 from PAC-2000.com.  It seems to
be the best deal i could find...what do u guys think?

My question is can i use the 495 autostar controller that i have on the
new ETX??  The 1400 database controller is off of a ds series scope.  
Think i read somewhere about changing the gear ratios for alt and az for
it to work right...is this true?

Thanks in advance for any thoughts u may have on this....

Alan Matthews    
Bismarck. AR    
Mike here: Sounds like a good price. If you can upgrade the #495 to the current 2.2Er ROMs I think you should be OK. Just select the ETX from the telescope list after you plug in the Autostar to the ETX. Don't forget to TRAIN the drives.

Subject:	focal reducer
Sent:	Tuesday, October 16, 2001 12:28:34
From:	PaGamondes@wanadoo.fr (PaGamondes)
Hi,  i'm a french amateur astronomer
(a beginner) and i'd like to know if the 
Meade 6/3 focal reducer can be fitted 
on my ETX90.
 what do you think about two etx90 mounted 
as binoculars on a 883 tripod?
( excuse me for my very bad english,
but i've not learned since the end of school, 
and it was in 75!

Best regards.
Mike here: I think you would need an SCT adapter to mount it. See "SCT Accessory Adapter" on the Accessory Reviews - Miscellaneous page. As to a binocular ETX, well, yes, it could be done if you have a good dual mounting plate and you keep the tripod at its lowest level (for stability and reducing vibrations. Of course, then you have to orient the scopes to get the eyepieces at the same distance apart as your eyes. Sounds like a nice project; send me results when you do it.

Subject:	ETX90 - diffraction pattern question
Sent:	Monday, October 15, 2001 17:47:41
From:	martyn@starmail.co.za (martyn)
There is something I would like to ask your opinion about, if I may.
First I would like to say, your site is great. I keep coming back, your
site enriches the ETX experience for me.

At the moment of this writing it is 02:00h at night, checked out some
starclusters, Saturn and Jupiter(still low)and I have just been
performing a star-test on the ETX90RA with SP6.4mm eyepiece and looked
at capella and several other bright stars - the result was the same on
every star. This is the first time I did this since I got the scope 3
months back. This startest has raised a question which I would very much
like to ask you. Since the views are still fresh in my mind I decided to
write them down right now.

Here's the thing: 1) (I am looking into the eyepiece from right behind
the OTA) An infocus star exhibits a diffractionpattern of which only the
'left' side of the pattern is easily seen, the right side of the pattern
seems to be 'unlit'. In-focus the pattern does not seem obviously

2) When focused past infinity, the diffraction pattern is no longer
symmetrical, the airydisc is placed off-center. If the left side of the
pattern is 0 and the right side of the pattern is 10, the airydisc would
be about at position 6.5 or 7. Wobbling the eyepiece in the holder made
no difference.

3) When the focus is brought back (on a nearer distance - is that called
outside focus?)so that I can see the air moving a bit, the
diffractionpattern is nice and round and symmetrical.

4) Views of the moon are very nice, Saturn seems okay, cassini-division
is not easily seen with SP9.7mm or SP6.4mm, jupiter shows it's two
equatorials(not too crisp) and not much else except a hint of
polardarkening. But then again, Jupiter is still low.

So Mike, my question is, is the shape of my diffraction pattern normal?
and to what degree could this influence observing? Thank you very much
in advance, your advise will be very much appreciated.

Very best regards,
From The Netherlands
Mike here: Regarding the diffraction patterns, you could be seeing the effects of thermal non-equilibrium. For the best results, depending upon the temperature differentials, you need to let the scope "cool down" for about an hour (ETX-90; longer for larger scopes). Also seeing can affect the quality of the views (can't see the Cassini Division, for example). See the articles "Star Testing Your Telescope" and "Seeing Conditions and Transparency" on the Observational Guides/References page for more info.


Thank you so much for your very quick reply. I appreciate it enormously
as I have now "quieted down" after reading the sections on Startesting
and seeing conditions. I'll be performing more startests under possibly
even better circumstances(better seeing and longer cooldown-time) and
see how things work out. The scope is not very bad [at all] it's just I
want everything to be perfect. (can't always have what I want all the
time, right?). Anyway, I think it's not worth it to send the scope to
meade for dead-center recollimation right now. Maybe in the end it'l
turn out just fine anyway. Thanks again for your insights and keep up 
the excellent work.

Best regards


Subject:	Solar filter
Sent:	Sunday, October 14, 2001 16:52:39
From:	mxgraham@optonline.net (Maria X Graham)
Can a 3.5 to 4 inch fit on a EXT 90 or must I get the bigger size from
thousand oaks.

Thank you for your time. 
Another happy ext user.

I have some pics 


Anthony Graham
Mike here: The ETX-90 is a 3.5-inch aperture. Just ensure the aperture is fully covered and that the solar filter is securely attached to the telescope.

Subject:	etx-60 etx-90 compatibility
Sent:	Saturday, October 13, 2001 22:33:17
From:	Typec2@aol.com
I was considering upgrading my ETX-60 to the ETX-90. I know they both
use 1.25 eyepieces. I heard the #882 Standard Field Tripod will support
the 90.

I was wondering if the 494 autostar controller will work with the 90.
Anyone know?
Mike here: You may have vibration problems with the lighter-weight tripod and you can't use it in polar (equatorial mode). As to the Autostar, see the Autostar Models article on the Autostar Information page.

Subject:	Thanks, and help (please)!
Sent:	Sunday, October 7, 2001 16:46:06
From:	rgallaway@satx.rr.com (Bob Gallaway @ RoadRunner)
I've had an ETX-90EC since 1999 and have visited your site often since
then. Thanks for all of the very useful information!

I'm having a backlash problem in the RA axis of my ETX. The Autostar
doesn't seem to have a backlash setting (although there ARE items like
Az Aspect?) that I can find. I read that one of your contributors had
this problem with his ETX-125EC which was remidied by removing the
bottom plate and tightening a couple of set screws that tension the
worm-gear assembly (or something!). Does the same apply to the ETX-90EC?

Thanks again for the generous contribution to those of us floundering
the darkeness (literally!).

Bob Gallaway
Mike here: If you can update the Autostar to the current version of its software (available on Meade's site) you will get the backlash adjustment capability. If you want to work on the inside of your telescope base, see Clay Sherrod's "Performance Enhancement" articles on the Telescope Tech Tips page.

Subject:	Help Me!! PLEASE
Sent:	Tuesday, September 4, 2001 11:09:30
From:	sorcini@tiscalinet.it (danilo)
Hy Mike, I'm italian boy, Danilo, can you help me?
Please answer to my question:
I purchased an etx90ec about last week, with some accessories: 3 oculars
26mm, 9mm and 5mm all Plossl and nebular filter B, the questions is: can
I see some deep sky object (galaxy, nebulosity o star cluster) with my
etx90EC? It's possible see orion nebular or andromeda galaxy?? Please
tell how can I see that deep sky object, wich is the best ocular to see
deep sky, advice me on wich are the best object that I can see with my
Thanks So Much, I'm really sorry for my english!
Thanks Danilo from Roma
Mike here: Yes, you can see many Deep Sky Objects with the ETX-90EC, including the Great Nebula in Orion (M42) and the Andromeda Galaxy (M31) and many more. For many, the 26mm will be your best eyepiece. Until you get familiar with how the objects will look in your ETX-90, using higher powers on these faint objects will just make them that much harder to see. Several planets and the Moon also make great objects for the ETX-90. Look at the Observational Guides and References and the User Observation reports on the ETX Site for more info.

Subject:	Focusing Question for ETX-90
Sent:	Monday, September 3, 2001 22:02:11
From:	dragallant@home.com (Dave & Yvonne Gallant)
First I must complement you on a FINE site.  It has been very helpful to
a new ETX-90 owner.

The question that I have deals with the focus knob on the EXT-90.  My
wife & I have different eyesight, so we constantly are adjusting the
focus between us. When we turn the knob to focus a star,  the image
seems to slide across the field of view in the eyepiece, and then we
have to recenter it.  We focus it back for the other person and it
slides back the other way and again we need to recenter it.  Is this
normal?  or should the image stay relatively centered when we turn the
focus knob?
Mike here: The image should shift "slightly"; this is a result of the telescope design. However, it should not be that noticeable unless some optical component is out of alignment OR you are using a very high magnification. But I've never really experienced much image shift with my ETX-90 at any magnification. If you think it is excessive, you might want to exchange it with your dealer if it is that new.

Subject:	Scopetronix RTA
Sent:	Monday, September 3, 2001 14:21:43
From:	dcpolet1@optonline.net (DennisP)
Do you know about  the aluminum Right Tube Adapter from Scopetronix? I
was looking on the site and it seems like a good idea to replace it.

Any Thoughts
Dennis Poletto 
Mike here: It was a "short run" item from Scopetronix. Contact Scopetronix if you want him to make more. He needs to know how many ETX users would be interested.

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