Last updated: 28 February 2003
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:	ETX 90EC
Sent:	Thursday, February 27, 2003 20:25:24
From: (Richard C Jones)
I hope you can help me. I just purchased a new 90EC and I seem to be
having a problem. I've read the manual and many posts on your site great
site, but I still can't figure it out. As soon as I turn on the scope it
starts to slew clockwise and up. The AutoStar initializes and goes
through its routine; sun warning, date,time.....align (all the time the
scope is still slewing) accepts input but has no control over over what
the scope is doing. It slews till it reaches the hard stops, motor keeps
running, I get worried and turn it off.

Any ideas?

 casey Jones. 
BTW thanks for posting my ETX 70.
Mike here: Check the cable and connections. Also, does this happen with the standard handcontroller?


Thanks for getting back to me. I've checked (visually) the connections
and cable and seems ok. This is one of the Meade Specials with the Free
tripod and Autostar and does not come with the standard hand controller.
Mike here: I didn't know the special didn't include the standard handcontroller. Bummer. OK, lets deal with this in this order: Turn on the ETX with the Autostar connected. When you get to the point to enter the date/time, etc., just keep pressing MODE until you get to the Setup menu and then scroll to the RESET select and press ENTER to reset the Autostar. It should initialize again; this time go ahead and enter accurate date/time, etc. Once you get to the SETUP menu scroll until you see TELESCOPE and press ENTER; select the ETX-90EC and press ENTER. Now MODE out until you get back to SETUP-->TELESCOPE and then scroll to ALIGN. Select the alignment mode you like (I always use Easy) and go through the alignment steps. Let me know if this helps.
Subject:	Meade ETX 90EC Drive noise
Sent:	Thursday, February 27, 2003 18:49:26
From: (Donald A. McAfee)
I just received a new ETX 90EC. It arrived in good shape - no obvious
shipping damage, however, the drives make a lot of noise. I have a Meade
10 in LX200, and other scopes with DC drives and none sound this loud. I
can hear the RA (AZ) drive change in pitch slightly with each
revolution. The Dec (AL) drive actually growls and almost grinds - it
fades considerably when I touch the slew buttons as if the gears are
being unloaded. When I slew at max speed the motor whine seems normal
and maybe my LX 200 is just an loud during slew.

The Autostar GOTO works well and tracking seems OK though probrably not
good enough for photography. I suspect that the Dec drive vibrations
might even be visible on film.

The concern is during tracking and the possibility of excessive wear and
early failure, as well as just plain disturbing to be under the stars
with all this racket. Is this a problem of all ETX 90's or could mine be
a lemon?
Mike here: Yes, the ETX drive sound is louder AND different than the LX200 series. Whether yours is louder than normal for an ETX is hard to say via email! When using the Alt/Az mode, obviously both drives are running to provide tracking. For astrophotography of any significant duration you might see field rotation as well as extra blips in the tracking due to the stepping in Altitude and in Azimuth. If you really want to try longer duration astrophotography you would want to mount in Polar mode and thereby avoid those problems. You would still likely need to apply some manual corrections to tracking.
Subject:	Meade ETX 90 series
Sent:	Tuesday, February 25, 2003 6:56:03
From: (Clark, Harland L)
I'm new to the telescope world and getting ready to purchase a
telescope. Can you please explain to me the difference between the 90ETX
RA and 90 ETX EC.

I know that the RA model does not have the "Autostar" but what does that
actually mean?
Mike here: The RA model only has a single drive motor to track in Right Ascension. The tracking allows objects to stay fixed in the eyepiece; it compensates for the Earth's rotation, which causes objects in the sky to rise in the East and set in the West. The EC model has the same optics as the RA model but adds drive motors for both axes. When placed on an equatorial mount, this allows the RA tracking motor to compensate for the Earth's rotation plus you get the benefit of being able to slew in both axes using the standard handcontroller. If you then add the Autostar to the EC model (which is included with the current Meade deal going on), you have the option of mounting in equatorial (or polar) mode or in Altitude/Azimuth mode and using the Autostar to track objects regardless of the mounting mode. The Autostar also contains a database of some 30,000 objects (not all of which you'll be able to see with the ETX-90); you can select these objects and the telescope will GOTO them for you instead of you looking up their coordinates in the sky or mapping their location out on star charts.

And another one:

From: (Schlatter)
I apologize for being a bit dense -- but -- my question concerns
differences and similarities between the ETX-90EC and RA.

As I understand it, these are the SAME TELESCOPE.  The difference is:
-- 90EC is a GOTO scope with the 495/497 hand controller.
-- 90RA is manually operated -- you move it up and down/declination by
hand, while the azimuth/RA/right and left can be moved by a motor
controlled by pushbuttons.

Will the RA fit on the field tripod that came with my ETX-70?

If the optics are that good, with the RA selling for $169.00 (bare
bones) to $299.00 (with tripod and one eyepiece), how could I go wrong
with the RA? Unless Meade drops the price on the EC again.

Joe S.
Mike here: Well, you almost got it. The optics and telescope itself are the same; it is the base that is different. The RA model does have a motor drive for tracking in Right Ascension but slewing is manual in both RA and Declination. It would fit on the tripod BUT you would likely not be happy with the (in)stability and vibrations that the heavy telescope with higher magnification would exhibit.
Subject:	ETX-90-RA Focusing Problem with New Scope
Sent:	Sunday, February 23, 2003 14:58:42
From: (Larry Martinez)
Just bought from Apogee's Ebay Auction an ETX-90-RA; am using a Parks
30mm Eyepiece Lens with it - agree with previous complaints about the
standard 4000 series 26mm Meade eyepiece that came with the scope. 
About 10 days after first use outside on a dry but otherwise normal
40-degree evening with great views of Saturn and Jupiter, I was going to
re-aim the viewfinder scope here at home.  After setting the scope up on
the table and aiming out the window, I noticed that the focusing knob
was very tight, actually screwed "in" all the way.  After unscrewing it
with my fingers, it seemed to work okay.  But trying out both eyepieces
revealed a lack of sharpness - always a slightly double image in the
middle of the field of vision.  Any suggestions?



Larry Martinez, Associate Prof.
Dept. Political Science
California State University,
Long Beach, CA
Mike here: Since you say the double image is only visible in the center of the eyepiece field-of-view that would seem to rule out collimation problems. If there were collimation problems it would probably get worse near the edge of the FOV. I wonder if there is something coating the flip mirror. To check this, flip the mirror to the horizontal position, remove the rear port cover, and hold the eyepiece up to the port. It will be difficult to hold it steady in focus but try it. See if you see the double image there.

And an update:

It always helps to Read the Freaking Manual - sure, enough, trying to
use the scope inside DOES distort the images!

I stand corrected!  Thanks for a great service to all us newbies!

Mike here: No problem. Using a telescope through a window is always something that people try. Good tip to not expect great views!
Subject:	Meade etx90ra
Sent:	Saturday, February 22, 2003 5:40:02
From: (Simon Pegler)
i have just purchased a New ETX90-RA,i have had a quick look at the web
site to answer my questions but have not found the answers Yet

I live in the UK and need to know the size of the middle leg so i can
set my scope up correctly, it came with a table tripod for 28 to 42
degrees and im at 50  degrees im going to make a leg.

Also i would like to know the lowest usable magnification and the best
high magnification for looking at Jupiter and Saturn, the scope came
with a 25mm plossl.

Any help would be very appreciated.
Mike here: I don't have the exact formula handy for that; you could tilt the base to your latitude (angle from horizontal = 90 - latitude) and measure it. Alternatively you could make or buy a tripod and/or a wedge; see the Telescope Tech Tips page and the Accessory Reviews - Tripods page for some ideas). See the FAQ page for the maximum theoretical magnification and the formula to calculate magnification. See the Buyer/New User Tips page for some eyepiece suggestions as well as the Accessory Reviews - Eyepieces page. About the lowest magnification will be around 20X (a 40mm eyepiece combined with a focal reducer). On the high power end, keep in mind that atmosheric conditions will affect the quality of the image as will letting the air in the telescope cool down (called reaching "thermal equilibrium"; about 1-1.5 hours for the ETX-90).
Subject:	ETX-90RA
Sent:	Friday, February 21, 2003 16:14:21
From: (Susan D. Clark)
On a limited budget, is the ETX 90RA A GOOD PRICE AT $180.00
Mike here: If that is for a used one, see the Dealer Specials page on my ETX Site for the current price on new ones. Whether the price is good for you depends upon whether the ETX-90RA is right telescope for you. You need to decide HOW you want to use it and WHAT your expectations are for a telescope. Keep in mind that there is no upgrade to an "EC" model which allows use of the Autostar GOTO system.
Subject:	Help
Sent:	Friday, February 21, 2003 3:52:42
From: (Jason K Jackson)
First of all my I say what a helpful and very useful website.

I was wondering if you could give me some advise.

I'm looking to buy my first telescope but im unsure which to buy.

Iv narrowed it down to two Meade telescopes the ETX70-AT and the

The ETX-90EC being twice the price of the ETX70-AT in the uk. The
ETX-90EC that iv been looking at comes with the 497 Autostar controller
and the 884 Tripod the ETX70-AT comes with the 494 Autostar controller
and a Tripod

with the ETX-90EC there is also an offer on at the moment that you can
pay an extra 90 and get a set of 7 Super plossl eyepieces and alloy

The main info im looking for is if I will see much more with the
ETX-90EC that I wont see with the ETX70-AT?

one last thing I take it that its worth investing in a dew shield.

Mike here: There is significant difference in the focal length of the those two telescopes. That means more magnification with a given eyepiece with the ETX-90. The ETX-70AT is more a wide field instrument for observing large area of the skies. You need to decide HOW you want to use the telescope and WHAT your expectations are. See my ETX-70AT comments on the Helpful Information: Buyer/New User Tips page. Then look at the User Observations page for more reports. Yes, the eyepiece deal is nice, as is the ETX-90 deal going on right now. A dew shield is a nice addition if your area is dew-prone.

And an update:

Thanks for the reply.
I think I'm going to go for the ETX-90.

I know there's a lot of accessories for the ETX range, but I was
wondering if there is anything in particular that I should get. So far
I'm looking to get the cable that links it up to a pc and also a camera

Mike here: What accessories to consider will depend upon what you want to do with the ETX. See the Buyer/New User Tips page and the Accessory Reviews pages.
Subject:	ETX 90RA = ETX 90EC?
Sent:	Thursday, February 20, 2003 10:24:25
Hello again.  Thanks for the tip.  Basically, the subject tells-all.  Is
the 90RA = 90EC and Autostar is the only differece or are their any
minute improvements on the 90RA that make the 90EC any better or about
the same in terms of the scope itself?  Is it worth getting the 90EC
over the 90RA just becasue of Autostar, because I'd wind up paying at
least another 100+ dollars.  Now that the 90EC came out, I can get the
90RA real cheap on eBay.  Thanks.

Mike here: The ETX-90EC has been out since 1999. Besides the Autostar capability, it has dual electric drives instead of just the tracking drive that the RA model has. But the optics are the same.
Subject:	Meade ETX 90-RA
Sent:	Wednesday, February 19, 2003 12:21:34
Hello!  I was searching through your webpage about ETXs and I was
wondering if the ETX 90-RA is adaptable with AutoStar.  Also, whats the
difference between AutoStar and Starfinder?  Thanks.

Mike here: See the FAQ page for upgrade info. The Autostar is the current line of GOTO computer controllers from Meade.
Subject:	EHTC Worth It?
Sent:	Saturday, February 15, 2003 17:36:47
From: (Mark Cordeiro)
Am a beginner and looking to buy ETX-90 for my kids and I.
Is the EHTC worth it? Does it really let in 15% more light? Can't afford
the ETX-125 so thought the EHTC coating on the 90 might make up for the
smaller diameter.
Any input appreciated.
Mike here: At the 2nd Annual Mighty ETX Star Party last October I had a chance to look through an ETX-90 with and without UHTC. The difference was noticeable. For a more scientific test, see Dr. Clay Sherrod's report, linked from the Announcements --> Meade page on my ETX Site. It won't make up for the different sized aperture but will help over an ETX-90 without UHTC.
Subject:	Terrestrial use
Sent:	Saturday, February 15, 2003 17:08:57
From: (charles)
Is the Meade ETX-90 good for terrestrial distance views of mountains and
lakes and wildlife?  Can it be used for terrestrial photography as well
as astral?  Does the UHTC version of Meade's ETX90EC Astro Maksutov
Cassegrain Telescope provide better or worse terrestrial viewing than
the standard lense? Is a reversing eyepiece needed for terrestrial
viewing?  Does the Dew shield improve terrestrial viewing?
Anyway, the ETX-90 can be used for terrestrial viewing. In fact, Meade sells a "spotting scope" version without the fork mount and drives for just that purpose. Many people use the ETX-90 for "birding" and other terrestial use, including photography. It can be used without the "erecting prism" unless the left-to-right reversed image bothers you. I saw a report in the current Sky and Telescope magazine about a slight yellow-ish tint in an 8" Schmidt-Cassegrain telescope with UHTC but no one has reported it here with the ETX models. It shouldn't make that much difference for terrestrial viewing. The dewshield would have no impact on daytime viewing except to reduce stray light getting into the telescope.


I had looked at the ETX manual and it went into some detail about the
terrestrial use, but not enough and it always helps to get personal

I live in Seattle, overlooking Lake Washington, with wildlife during the
day and wonderful star filled sky (when it's not raining/foggy/cloudy),
which is why I'm looking for a dual purpose telescope.

It sounds like the ETX-90EC is an excellent dual purpose telescope,
which is what I am looking for and the package deals from Meade right
now give it a very appealling price.

I appreciate the knowledge you are sharing.

Mike here: There are several ETX users in Seattle.
Subject:	ETX90 dissapointments
Sent:	Friday, February 14, 2003 7:00:01
From: (Peter Thejll)
I am a dissapointed ETX90EC owner, and  am wondering what to do.

Straight out of the box the telscope simply never did what I bought it
for - 'the Go To' stuff. My telescope is in the 'nowhere near' category
- I set it up following the manual and some of the very good tips on the
training problems found on these excellent home pages, and then I try to
go for a target and I must be off by 10 or 20 degrees. How in the world
is this possible? Is it really necessary  to take the telescope bearings
apart and follow all the 90 gazillion difficult steps listed in these
pages? I am not very adept at technical stuff with screwdrivers and
lithium grease (whatever that is?!), and I am not in a position to ship
the telescope anywhere for maintenance or supercharging, and I do indeed
feel that this should not be called for with a telescope right out of
the box. I just wanted to buy a nice telescope and USE it.

I know there are many out there who have had dissapointing experiences
with telescopes - some of them with Meade ETX's - is there anyone who
had all these problems with an ETX90EC and is now happy? What did you

Hoping glumly for some encouraging suggestions,

    Peter Thejll
Mike here: Errors of around 15 degrees are typically caused by an incorrect setting of the Daylight Savings. Check that. Also check your Site location. Lastly, does the error also happen when the alignment stars are slewed to? Using Magnetic North instead of True North can make a significant difference in some locations. Usually, it is just a matter of checking your settings, being certain you have properly TRAINed both drives, and starting with the proper HOME position. Let me know. And no, you don't need to make mods right out of the box. Most users are likely perfectly happy with the performance.
Subject:	UPDATE: Re: A few questions about the ETX-90RA in one about the 26mm eyepiece supplied with the EXT-90RA
Sent:	Wednesday, February 12, 2003 11:37:50
just an update o my EXT-90RA with the broken forks. Got a replacement
base from Mike at sightandsoundshop and everything is working great.

Replaced the broken forks on the original base last night. Hoping the
weather holds and can do to viewing tonight.


S. Ratzlaff 

Subject:	ETX-90EC
Sent:	Monday, February 10, 2003 16:02:32
From: (James Kirkpatrick)
I am the proud new owner of a Meade ETX90EC. I have taken advantage of
the current offer on the complete set of Super Plossl's and I am
awaiting their delivery. I have a question and would value your time and
opinion. Certain details I have read say that the 90EC has a maximum
magnification of x325. I have also read that you divide that focal
length of you scope by the eyepiece mm (e.g. 1250/5mm = 250. With a
barlow this should make x500). Please could you possilby advise on how
to achieve maximum maginification especially for planetary observation.


Jim Kirkpatrick, Audlem, England.        
Mike here: See the FAQ page for info on maximum magnification.
Subject:	The ETX 90RA clock drive and the newer Meade eyepieces
Sent:	Sunday, February 9, 2003 21:02:56
From: (James Booth)
I purchased my first telescope (a Meade ETX 90RA) in December.  It was
at a price I could afford, and I am very happy with the sharpness of the
optics.  Its compactness and portability have allowed me to get out
under the stars much more often than my friend - who bought a 6"
refractor at about the same time I got my ETX.

The mechanical construction of the base and clock drive, however, is
problematic.  When I first tried to use the clock drive, the motor would
not even run.  The problem turned out to be a bad connection in the
battery holder closest to the slide switches on the circuit board.  I
pried on the connector a little with a small screwdriver and then put
the battery back in.  Problem solved.  Next night out, I was able to
keep Saturn in the eyepiece (at 48X) for over an hour!  A week later I
got it out again, and the clock drive was not working anymore.  This
time I could hear the motor running, but it didn't move the scope at
all.  It has stayed that way until now.  I was looking through this site
for some info and saw Dr. Sherrod's recommendation for a "sticky" RA
knob.  Although that is not my problem, I rotated the scope on the base
several times by hand.  I then turned the clock drive on and locked the
RA knob to a snug tightness.  Amazingly, the RA moved almost 15 minutes
and then stopped.  It has been sitting there for almost an hour now
without moving from that point. I don't really want to send it back to
Meade.  Not only would I be without a scope for a while, but if the
drive is inherently unreliable and unstable - it might flake out on me
again after being fixed.  Does anyone have any suggestions?

I also wanted to add my comment to what Dr. Clay Sherrod said about the
new Meade series 4000 Super Plossl eyepieces.  They are indeed junk!  I
made the mistake of ordering a 32mm eyepiece with my scope so I could
have a wider field of view.  The eyepiece had some kind of gritty
material all over it when I first removed it from its protective
capsule.  It is manufactured in China and seems to be of lesser quality,
but I did not have another 32mm eyepiece to make a fair comparison with.
I returned it to Anacortes Telescope for a refund.  The Series 4000
26mm LP Super Plossl that was included with my ETX is made in Japan
quality, and I am very pleased with what I see through it.

James Booth
MIke here: Your telescope is under warranty. I would suggest contacting the dealer where you purchased it and get an exchange. But if you don't want to do that, it sounds like something may be catching. Does the telescope rotate freely (with the RA axis unlocked) through several rotations in both directions? Thanks for the info on the eyepiece.


Yes, it does rotate fairly freely by hand with the drive unlocked. 
There does seem to be a spot in the rotation where you can feel
something dragging a little.

I talked to a cusomer service representative at Meade today.  He said
that the clutch in the drive is bad, and that I must return it to Meade
to be fixed.  So, I guess I will send it back to Meade.

Thanks for your help and your great website.

James Booth

Subject:	Daisy Red dot finder attachment
Sent:	Friday, February 7, 2003 11:07:39
From: (dhoward)
I purchased a Daisy red dot finder and attached it to my ETX 90/RA
easily and securely by using a piece of metal dryer vent hose clamp
which happens to be 3/8 inch wide just like the dovetail pistol mount
that the daisy sight is designed to be used with. I drilled two small
holes in a 2 inch piece of the metal hose clamp, which I cut off with
tin snips, to line up with the upper screws on the finderscope mount. I
screwed in the finder scope adjustment screws through the holes in the
hose clamp and aligned the finder, then clamped the Daisy sight onto the
hose clamp and aligned it easily with the windage and elevation
adjustment screws. This seems easier and less permanent than using hot
glue and also more secure and stable than using zip ties or hose clamps
around the OTA.

Subject:	A few questions about the ETX-90RA in one about the 26mm eyepiece supplied with the EXT-90RA
Sent:	Wednesday, February 5, 2003 23:19:34
I have a couple of questions regarding the ETX-90RA.

Some background first. I purchased one of these a couple of weeks ago. I
had to return the first one to the dealer because of a problem with the
RA motor drive. The second unit arrived with both forks cracked. The
OTA, base and motor are fine though. So I called Meade for replacement
parts after seeing how simple the design is.

I've received the replacement forks from Meade today and need to find
out how to remove the declination manual adjustment knobs and screw worm
mechanism from the right-hand fork. The knobs don't have hex screws
which tighten to them to the worm screw. Evidently, according to the
Meade support folks, the knobs just screw off with some force required.
The folks at Meade stated they'd send the declination mechanism if I
couldn't get the old one off of the cracked right-hand fork. Apparently,
the newer style manual declination knobs use hex screws to tighten up to
the worm screw mechanism. I hope this makes sense to those who have seen
the internals of this mechanism.

Q1:  How do I remove the old style manual declination worm screw and
knobs from the fork?


The 26mm eyepiece included with this second ETX-90RA appeared to have a
problem so Meade shipped a replacement eyepiece at the same time that
they shipped the forks.

Here comes the second question.

The original 26mm eyepiece shipped with this second EXT-90RA has model
number 07175-03 with the designation on the box and eyepiece of "26mm-LP
Super Plossl". The replacement 26mm eyepiece sent by Meade has model
number 07175-02 with the designation "26mm Super Plossl" and is a bit
longer in length than the 07175-03.

Q2:  What's the difference, if any, between the #07175-03 26mm-LP Super
Plossl and the #07175-02 26mm Super Plossl besides the length? What does
the "LP" stand for on the #07175-03?

It's been overcast so I haven't been able to try out the new eyepiece.


Mike here: "LP" might stand for "low profile" since you say it is shorter. But I haven't seen that specific designator.


From: (Clay Sherrod)
The new 26mm Plossl eyepieces are horrible quality...plain and to the
point. Just horrible.  That is the primary difference.  They are still
Plossl design in the pure sense, but the optical glass has incredibly
poor refractive quality and the correction is absolutely unacceptable. 
Nearly all show great coma and serious astigmatism to the edges (nearly
the outer 1/4 area total....) of the wide field of view.

I have been very disappointed in the new design and sourcing of these
eyepieces; it is obviously a cost-saving venture on Meade's part,but the
eyepieces are not worth the metal that they are mounted in.   And, as
you are well aware, I had been a strong supporter of the Meade 4000
series Super Plossls for years until they changed their supplier.


I do not suggest outright removal of the worm drive assembly; the unit
can be adjusted and tightened with the three Phillips head screws
provided and within easy access.  Removing the components from within
the ETX, particularly the newer models, is going to result in damage,
plain and simple...either wiring or misconfiguration upon putting back
into place.

In essence, Meade is making these scopes more and more tamper-proof.

Dr. Clay
Arkansas Sky Observatory
MPC/cbat Obs. H43 / Conway
MPC/cbat Obs. H41/ Petit Jean Mt.
And an update:
I was in contact with Meade again today, as I've been unable to remove
the knobs on the manual declination worm screw. The tech at Meade
confirmed that the knobs are press fit and according to the tech, I'll
have to send the entire scope back to them for repair as they no longer
manufacture the manual declination assembly for the ETX-90RA.

I purchased the scope from Sight and Sound Shop, so I'll call tomorrow
and see if I can get the right-hand fork with the declination assembly
from there. Hopefully, I can. This will allow me to use the scope until
the replacement part arrives.

I don't really want to send the entire scope back to Meade as it will
take nearly a month for the repair. In addition, the OTA, mirrors and
motor drive are fine and I don't want to take a chance that I'll get a
dud if they replace the scope. Also, shipping it again both ways may
introduce other damage.

I've been looking over your site and already have fixed a couple of
things like the little rubber pads which fit under the RA scale, etc.

I initially bought the ETX-90RA to use it as a telephoto lens. Always
wanted one with a long focal length. So when I found out the EXT-90RA
was only $180 as opposed to the same item in spotting scope
configuration at B&H Photo for $400, I jumped on the deal. The added RA
motor and fork assembly is pure gravy. Still I'd like it to work

My wife, son and I looked at the Moon, Jupiter and Saturn the other
night. Found M43, one of my favorites, and this has really peaked my
interest again in astronomy.


S Ratzlaff
So then, I may have one of the "older, better" 4000 series Super Plossl
26mm eyepieces? Hopefully, since it's a number lower on the product
numbering scheme ... :>} this will denote the older design, maybe?
Mike here: Sounds like.
Subject:	ETX-90EC
Sent:	Tuesday, February 4, 2003 10:25:14
From: (Bartley  Neal)
Can you use a standard 12v 500Am AC/DC converter instead of buying the
Meade version.

Mike here: Barely. You may experience Autostar errors if you use an Autostar. The Meade is rated at 1.5mA. Also, you will need a regulated power supply.
Subject:	meade etx90 ra astro telescope
Sent:	Monday, February 3, 2003 15:42:41
From: (Willian)
I saw your very good website about ext telescopes, and now i will order
a etx 90 ra astro telescope, but i think that is a old model, because
there is not any information about this model in meade website...but for
i decide to buy this old model...i have only doubt....meade etx90 ra
astro telescope have a motor drive, ok? it is will work in south

thank you !


Willian souza

Sao Paulo - Brasil

Willian Souza
Mike here: The ETX-90RA is the original 1996 version of the ETX telescope. It has a motor drive for tracking in Right Ascension but must be equatorially mounted to track. The Declination movement is manual. It will track in either hemisphere. It can not be upgraded to the current EC model and can not use the Autostar. However, you can find a lot of information about the ETX-90RA on my ETX Site as that is the model that started this web site back in 1996 shortly after I purchased the ETX.
Subject:	Altitude Buzzing
Sent:	Sunday, February 2, 2003 19:56:25
From: (John Welch)
I'd like ask about a cure for altitude motor buzz. It's the one thing
that prevents high resolution viewing from my ETX 90EC w/autostar and

You have the patience of Job and are revered by all ETXers.

John Welch
Phoenix, AZ
Mike here: Not certain what you mean by "buzz". Can you elaborate?


Microbuzzing of the altitude motor while tracking in alt/az. The
oscillation destroys planetary and double star image detail.
Mike here: There are several performance enhancements on the Telescope Tech Tips page. One suggestion: don't overtighten the axis lock.
Subject:	re: A couple of "newbie" ETX90 questions
Sent:	Friday, January 31, 2003 22:55:46
From: (Richard Seymour)
Q1:  21Ek was pretty good.  From an ETX point of view, 26Ec adds Polar
satellite tracking, pretty much completely replaces the  SAO database
(due to a selection error in their first pass at it).

Q2:  Try increasing the percentage settings... overcoming the backlash lag 
is what it's there for.  Background at:

have fun

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