Last updated: 23 January 2006

This page is for user comments and information specific to the Meade ETX-90RA (originally known as the "ETX Astro"), the ETX-90EC, and the ETX-90AT. 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: Comparsions between ETX90EC and a 90 Refractor
Sent:	Saturday, January 21, 2006 08:15:03
From:	John Harry (
Mike, thankyou very much for taking the time to reply. I will do
comparisons but must now go back to your site for more research!
Many, many thanks,
John Harry
Mike here: Decisions, decisions, decisions...
Subject:	Comparsions between ETX90EC and a 90 Refractor
Sent:	Friday, January 20, 2006 13:49:53
From:	John Harry (
I am a keen reader of your site and it has been of massive interest. But
before I go out and buy a ETX 90 (or a 105), what would convince myself
in upgrading to an ETX over my current Skywatcher 90mm refractor?

Many thanks and hope you find the time to answer, as all sites I have
visited have no comparisons to standard telescopes!

John Harry
Mike here: Compare the focal length, mount, GOTO, computer control, along with your current and future uses of the telescope. That should help you compare Apples to Apples.
Subject:	Mounting an ETX 90 on a DS 90ATA
Sent:	Friday, January 20, 2006 10:30:58
From:	Dan James (
Thanks for helping out on my previous inquiries.  Here's one more! My
son has a DS 90ATA and he has decided to take a winter hiatus from using
it, at least when it is cold out.  I don't like using it, for the most
part, due to its CA.  I will stick to my other scopes.  Is it possible
to mount the ETX's OTA piggyback on the DS mount?  I guess the question
is two fold. First if I piggybacked it with the 90ATA mounted with it,
would that be too much weight?  Apparently, the OTA on the ETX is
slightly larger than that of the ATA.  Therefore, the ETX will not fit
in the cradle of the mount. I would rather stay away from ripping it
apart, since my son will be wanting to use it.

My other option is to remove the ATA from the mount and use the
piggyback mount on the OTA bracket, on the mount.  Second question, if I
did either options, would I be able to align with the ETX and get proper
tracking?  I'm not too concerned with GOTO, I just want to be able to
track lunar and planetary viewing.

I'm still not getting my 90RA to track properly, I believe my Dec
circles tend to move.  I see there some links on the site for this, I
will need to look at them.  Plus, the tripod I'm currently using isn't
the sturdiest and has some movement in it, though there is less since I
got my EZ focus.

Thanks for your help.

Dan James
Mike here: Yes, you can piggyback one OTA on the other. HOWEVER, that didn't work out too well for me when I piggybacked an ETX-90 OTA on an ETX-90 as can be seen here:
Subject:	Screws size needed
Sent:	Thursday, January 19, 2006 20:30:37
From:	Luis Balanzino (
I purchased an ETX-90 OTA without the drive base. So, there were four
holes for the screws which I covered with tape. I would need to know the
size of them, in order to fill the holes. Are they special from Meade,
or generic ones are good also?

Thanks in advance,

Mike here: They are probably standard size but I don't have an accurate way to measure it.
Subject:	First time ETX 90 buy
Sent:	Wednesday, January 11, 2006 05:42:04
From:	Dan James (
I just bought an ETX 90 off of ebay. It is supposed to be in excellent
shape.  I have never used one, but have always had interest in them. 
Anyway, I have attached a pic. of it.  It looks like an older model, no
GOTO.  I looked at your site for some specific info on this scope.  Has
much changed with this one and the ones offered now, other than mounts?
Also, would I be able to be put this onto a GEM?

Thanks for your help,

Dan James

Mike here: Yes, that would seem to be the original ETX model, now known as the ETX-90RA. This is the model that I started with back in 1996, which then prompted me to create the ETX Site. You can find a lot of info on the ETX-90RA on the ETX Site; anything dated from 1996-1998 is directly applicable to the ETX-90RA as the EC models didn't come out until January 1999. However, many accessories and tips are applicable to all ETX models and may be applicable to the ETX-90RA as long as it is not an Autostar-specific acccessory or tip. The optics of the ETX-90RA are the same as on the current model ETX-90 (minus UHTC). It is only the mount/drive/electronics that are different. Yes, you could attach the OTA to a GEM but you will need some sort of a mounting brackett.


Thanks Mike.  I just wanted to be sure the same before I started looking.

Subject:	ETX 70 - 90 conversion
Sent:	Tuesday, January 3, 2006 07:38:14
From:	Richardson, Jonathan (
Please can you help out.

I have used an ETX 90 WITHOUT computer guide for two years or so and
have purchased an ETX 70AT over Christmas for my children. Is it
possible to mount the 90mm telescope on the 70mm base. If so, where do I
find the access to the securing nuts / screws for the yolk mechanism.
Has this major overhaul been documented anywhere on the site?

Appreciate the help 

Many thanks and Regards
Jon Richardson
Stuttgart Germany
Mike here: See the article "Putting ETX-90 on ETX-70 forks" on the Helpful Information: Telescope Tech Tips page.

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