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Last updated: 20 February 2010
This page is for user comments and information specific to the Meade ETX-90RA (originally known as the "ETX Astro"). Comments on accessories and feedback items appropriate to other ETX, DSX, 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 for posting. Please use an appropriate Subject Line on your message per the Site Email Etiquette. Thanks. Remember, tips described on this site may invalidate the warranty on your telescope or accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	ETX-90RA Dec slowmotion knobs
Sent:	Thursday, February 18, 2010 18:00:33
From:	H* Schaeffer (
Does anyone know how the knobs are put on the ETX-90RA slow motion
tangent shaft?  Are they glued on or simply pressed?  To put my question
another way, if I try to prise the knobs off the shaft, will they come
loose, or will I break something?

Harden Schaeffer W4YND
Mike here: Good question! I would have thought they had setscrews but I just checked mine and no setscrews.
Subject:	ETX-90 Secondary Baffle Out of Position?
Sent:	Monday, February 15, 2010 19:43:10
From:	James Watson (
I recently acquired an ETX-90 from a friend who no longer had space for
it. I noticed after I got it home that the baffle around the aluminized
secondary mirror spot seemed to have slipped down the front of the lens.
I've attached some pictures of the front lens and a view down the
eyepiece line of sight. Have you seen this before and is this something
that can be repaired? If it can be repaired, is this a repair that Meade
would perform or is there someone or some business in the Dallas, TX
area that you know of that performs telescope repairs? Thank you for
your time and insight.
James Watson



Mike here: This was a problem with some of the very early ETX models (back in 1996). Mine had the same problem and Meade fixed it (back in 1999). But they no longer repair this model. If you want to try the repair yourself, see the articles "ETX-90RA Secondary Baffle Fix" and "Re-attaching the Baffle" on the Helpful Information: Telescope Tech Tips page. Don't forget that you will likely need to recollimate the optics after making the repair; there are articles on that on the Telescope Tech Tips page. If you don't feel up to the repair, contact Dr. Clay Sherrod regarding his "Supercharge" telescope service (link on the ETX Home Page).
Subject:	Re: ETX90 Classic - polar alignment at 12 deg latitude
Sent:	Sunday, February 14, 2010 07:09:40
From:	Chris (
Since my last E-mail I have made a very simple wooden mount for the
ETX90 from 12mm plywood.  It's very lightweight, is fastened together
with wood screws and is easily dismantled for transportation (forms a
mini "flatpack!").  Since it is intended only for the holiday
destination I carefully cut the vertical supports for the mounting base
to the correct angle for that latitude (N 12 deg 10 arc minutes). All I
need then is to fasten this construction to a plank (which hopefully I
can find at my holiday site) around 50cm X 30cm should be OK, clamped to
a table, to provide adequate stability.  The magnetic deviation is just
under 11 deg during March 2010 so I pencilled in a couple of lines to
facilitate north pointing with the aid of a magnetic compass as I will
not be able to see Polaris from my holiday site.  I estimate if I do all
of this carefully and level the plank I fasten the telescope mount to,
the alignment should be better than half a degree and good enough for
reasonable observation.  I plan to try some astro-photography with my
LPI as well.  I am not so confident, however, that this will be as
successful as I would like so I'll delay sending you a photograph of my
simple construction until I have verified in the field if it really
works!  At least it should keep me occupied during the hours of darkness
on what I hope will be otherwise a "sun drenched" holiday!
Kind regards,
Chris Connor.

Subject:	Can I make my ETX-90RA into a GOTO scope with an ETX-60AT mount?
Sent:	Tuesday, February 9, 2010 21:49:07
From:	Michael Hamende (
I've recently purchased an ETX-90RA and I want to turn it into a GOTO
scope.  I've found an ETX-60AT that I can get for pretty cheap and I'm
curious if putting the 90 in the 60 mount will be straight forward or
will I have to do a good bit a finagling.  I'm quite mechanically
inclined but I'm hoping I can easily swap the mounts and then sell an
"ETX-60RA" (of which I will of course fully disclose my tinkering) on
ebay and then have a nice goto scope.  Any insite will be much

Best Regards,

Mike here: See the article "Putting ETX-90 on ETX-70 forks" on the Helpful Information: Telescope Tech Tips page. Mounting the ETX-70 OTA back on the ETX-90RA forks will be more challenging.
Subject:	ETX90 Classic - polar alignment at 12 deg latitude COMMENT
Sent:	Sunday, February 7, 2010 12:59:40
From:	AOL CPCooke (
Hi regarding Chris's Caribbean trip I've been living in the Cayman
Islands for 4 years with my ETX90. The Only way without GOTO I've had
any luck with is with the original large  ETX Tripod bought as an
accessory, which has also travelled with me over a good part of the
globe too. Its not that much of a burden. As for my current latitude its
just a little off 20 degrees which is the last crude setting on the
tripod latitude scale. It works pretty well considering that at first
glace it leans over at an alarming angle. I did toy with buying the low
latitude extension legs but I seem to remember at really low latitdutes
you will run into weight distribution problems ( ie it wall fall over!)

Have a good trip, the planets are great at this latitude .And by the way
take plenty of mosquito spray - much more important !!

Subject:	ETX90 Classic - polar alignment at 12 deg latitude
Sent:	Thursday, February 4, 2010 08:37:39
From:	Chris (
I'm planning to take my ETX90 classic (no GOTO!) on a holiday trip
shortly to the Caribbean area where the latitude is about 12.5 Degrees
North.  My intention was to construct a simple wooden wedge to support
the telescope for polar alignment at this latitude  but as it's very low
I wonder if there are any problems I should consider.  Any answers or
comments from anyone that might aid me in making some reasonable
observations are most welcome.

Kind regards,

Chris Connor. 
Mike here: See the articles "Low Latitude Wedge" and "#884 Tripod at Low Latitudes" on the Helpful Information: Telescope Tech Tips page. Since all the telescope weight will be held at the severe angle, be certain you use strong material and bolts. Also, be certain your tripod can handle the mass offset or mount the wedge with the center of gravity of the wedge and telescope centered over the tripod.


Thank you for the prompt response, Mike.  Interesting article which
gives me some food for thought.  I'm not planning to take a large tripod
(too much luggage!) and instead use a table to which I hope to clamp my
"wedge."  The problem to be solved is how to construct a simple,
'portable' wedge to do the trick in the next 2 weeks!  Thank you for
pointing me in the right direction.
Kind regards,
Mike here: For a tabletop wedge, you will need some sort of counterweight OR a long Polar leg (with a counterweight) for stability. Meade used to sell a low-latitude polar leg for the ETX. It had a weight on it as I recall.

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