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Last updated: 31 October 2011

This page is for comments and user feedback about ETX telescopes. ETX models discussed on this page include the ETX-60/70/80/90/105/125 (EC, AT, BB, Premier Edition). This page also includes comments and feedback of a general nature. Comments on accessories and feedback items appropriate to the ETX-90RA, 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:	Re: ETX-125 won't stop RA slewing during align
Sent:	Sunday, October 30, 2011 19:31:56
From:	Howard Fink (
Calibrate Motor did not help.  A Reset of the Autostar, then Calibrate
Motor, then Train Drives.  I aligned on Vega and Capella with a 25mm
reticule eyepiece.  After a successful alignment, Jupiter landed right
on the crosshairs.   Prepared to take my first RGB images, and the
filter wheel jammed, so only R.  

Howard Fink
Mike here: Yeah, next cure is RESET, CALIBRATE, and then TRAIN. Glad that worked.

Subject:	Meade LX90/ETX control panel 15-6305-00 rev B/C
Sent:	Thursday, October 27, 2011 02:57:01
From:	Michael & Caroline Rice (mc DOT rice AT bigpond DOT com)
I have a dud control panel circuit board (15-6305-00 rev B) in my LX-90.
It's the older 8-pin version (rev B): hard to get!

I can source 10-pin (rev C?) panels fairly easily and economically (though I
do have an ETX 8-pin on order from Bintel, I'm worried the scope may suffer
the same injury in future). Bintel did advise me that the ETX and LX-90
panels are the same, apart from having pins for the battery on the LX-90 vs
wires on the ETX - easily solved. Their tech didn't seem to know about the
10-pin & 8-pin panels being interchangeable, I've found that out on your
helpful site since placing my order.

Looking at I'm
concerned the description from Andrew:

	"The pin closest to the "corner" of the board stays as 12V.
	The extra pins are towards the middle of the edge and should remain disconnected"

is not consistent with the picture which places the extra Aux connector near
the corner of the board:


Can anyone clarify for me? -------------------------------------- BTW my problem is intermittent momentary external power failure. A friend had the same problem and traced it to the centre-pin of the 12V socket, which was loose. Mine is loose too. It seems that it will be far quicker & easier to replace the board than try to source a similarly-sized socket and do a desolder/resolder job. The cause may have been traction movements affecting the power lead, such as winding the cords around the tripod, or wayward children tripping on the lead! -------------------------------------- Thanks for any advice, Michael -------------------------------------- PS congratulations on an awsome site; I found info here that inspired me to make my own #505 cables. Michael & Caroline Rice CEDAR VALE AUSTRALIA


From:	P. Clay Sherrod (
I am going to have to actually look at a circuit board when I get up to
the shops on the mountain; however, not ALL LX90 and ETX main power
panel boards are interchangeable; I would be quite careful in that
assumption before continuing. Hopefully one of us will get back with you
soon with some guidance.  I trust the Bintel techs without hesitation
and if they have any doubts about the applicability of your boards I
would go with their judgment.

Dr. Clay
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West


Thanks for your prompt reply! FWIW, here's a pic of my board.

Interestingly, I note that each connector-cable colur sequence is opposite.
I reckon the RA cable went in backwards at the factory! And, red and black
are reversed compared to the sample pics at Weasner's page. Not that it
matters, but they may as well have been all grey...


Michael Rice

And more:

Actually, here's yet another colour sequence for your entertainment...



Your board and this one shown (LX90) are the same boards.

Dr. Clay

And more:

From:	Andrew Johansen (
Just seen this conversation and will clarify a bit

> I have a dud control panel circuit board (15-6305-00 rev B) in my LX-90.
> It's the older 8-pin version (rev B): hard to get!

 Firstly, the 8 and 10 pin boards "are" totally interchangeable.

> Looking at I'm
> concerned the description from Andrew:
> "The pin closest to the "corner" of the board stays as 12V.
> The extra pins are towards the middle of the edge and should remain
> disconnected"

 But just before that bit of the quote was

 "The extra pins ARE for the LNT/AUX but it wont work
 as an LNT feed unless both ends are connected
 ( ie there is a new power panel connector to go with
 with extra pins on the DEC card )"

ie At that point in the thread, ( it must  have been pre coffee )
I was assuming he was talking about the ETX DEC card
( i hadn't twigged that he was really talking about the power panel. )
For the DEC card, my comment is correct, 12V is in the corner.

> is not consistent with the picture which places the extra Aux connector 
> near the corner of the board:

 The picture of the control panel as posted is correct "nomenclature" wise.
 but re

> Interestingly, I note that each connector-cable colour sequence is 
> opposite.
> I reckon the RA cable went in backwards at the factory! And, red and black
> are reversed compared to the sample pics at Weasner's page. Not that it
> matters, but they may as well have been all grey...

 I use several testbench sets of Meade cards and motor sets
and cant afford  to get confused, so as noted below,
i made my own set of cables.
I use the same colours for the same function,
no matter what i'm working  with.
( and for me, red and black means 12V and ground :-)  )

> I made very specific comments about Meades non specificness here  ie

" I have attached a picture of the connections for an ETX125PE control
 panel. This is from my test bench, so i cant guarantee what colours your
 cables are, ( or what orientation your plugs are ), and Meade are very
 bad at any consistency here. ( Ie on all my 497 type scopes, Meade use
 Black for 12V and red for ground???? )"

"I mentioned Meades penchant for mixing  up colours of wiring.
One is my pre PE ETX (top) and one is a PE ETX (bottom)
 note how the blue/yellow wires swap over in the PEs DECcables?????
 ( Its not a pinswap, just a complete cable transposition, colour wise )
Can be very confusing."

I have since seen some more different colours used in
 an LX90, where the red and black
cables were actually used as clock and data?????

You need to set the plugs as 12V to 12V irrespective of colours.
Maybe i do need to make a diag without colours to go with the pictures :-)



OK thanks, that makes sense about the DEC board so I've got it clear in my
head now. 

Tempting, then, to source a 10-pin board while they're easy to get though
I'll put Bintel's 8-pin in first when it arrives.

BTW for my LX-90, the connectors on the DEC card are central, not near any
See attached (blurry) pic.

I did indeed note your comments about Meade and cable-colouring. It would
drive you mad. Maybe they work in explosives on the side ("cut the red wire,
NO! the BLACK wire...")
Tempting, in my case, to open up the scope base and flip the RA cable over
at both ends (or swap the ends over) so the colours are at least in the same
order as the DEC side but it will still leave +12 as black. Which would
really bother me... But there's a saying about things which ain't broke.

Michael Rice


> BTW for my LX-90, the connectors on the DEC card are central, not near any
> corner.
> See attached (blurry) pic.

Correct, and yours only shows the 4pin connector.
The LX90s with GPS and or LNT have 6 pin boards like
in the attached piccy of my testbench.

> I did indeed note your comments about Meade and cable-colouring. It would
> drive you mad. Maybe they work in explosives on the side ("cut the red 
> wire,
> NO! the BLACK wire...")

Thats why i tried to emphasise in my post that you MUST note/check/match
the 12V pins, irrespective of colours.
In my piccy, the red wires are 12V.
The newer cards have polarised pin connectors
but the old ones dont, so you have to be careful when "playing".
You really need to see/confirm "both" ends of each cable if in doubt.

> Tempting, in my case, to open up the scope base and flip the RA cable over

Dont be tempted ;-)

> at both ends (or swap the ends over) so the colours are at least in the 
> same
> order as the DEC side but it will still leave +12 as black.

Just leave it as is and ensure 12V goes to 12V ;-)




That's a lovely test set-up 

Thanks to all for your help & advice

Michael Rice

Subject:	Thank you for your ongoing support of your fellow LXD and ETX owners
Sent:	Wednesday, October 26, 2011 08:16:45
From: (
Just wanted to say thank you for your ongoing support of your fellow LXD
and ETX owners like me.

I have an LXD-75 and am really enjoying learning to use its features. As
you know Meade manuals leave out some needed information to new users.

Rock Taber
Atlanta, Georgia

Subject:	ETX-125EC - Novice!
Sent:	Wednesday, October 26, 2011 08:15:42
From:	Luis Novo | Bioground (
So far my experience with telescopes has been limited to a very humble
Celestron Powerseeker 114EQ (114/900). Last weekend I saw this Meade
ETX-125EC on ebay and couldn't help bidding...and I got it. Here's the
slideshow of the scope:

I trust it is in good used condition, at least that's what the vendor
(with high ebay reputation) said. I paid 323 for it.

It doesn't include a power supply nor autostar.

Given this information, what would you advise me to do next? Probably this
is very nahive from me, but does this telescope operate in a manual mode?
(without using the motor/autostar) Or will I have to get the power
adapter and autostar to see if it works?

Kind regards,

Lus Novo
Mike here: If the standard (non-AutoStar) EC handcontroller was included, then you can slew the telescope up/down/left/right. It will track if you mount the telescope in polar mode. Without the AutoStar, you won't have GOTO capabilities. You don't need an external power supply; use internal batteries. If you didn't get a manual, see the ETX FAQ page for info on where to get manuals.


thanks for your prompt and kind reply.

It seems that I'll have to buy the autostar to try then eh? The standard
EC handcontroller is not included, and I can't find any online...just
autostars. Do you know any website other than ebay where I could find
2nd hand accessories for it?


Mike here: Try Telescope Warehouse (link on the Astronomy Links page). There is also AstroMart. By the way, be certain you get a #497 AutoStar and not a #494 AutoStar. If you can find one, a #495 AutoStar can be upgraded via software to a #497; you just need a #505 serial cable (easily made) and a RS-232 serial port on your computer.


Alright, thanks again! I'll get back to you once I have everything.
Hopefully it'll work.




Sorry to bother you again. Is this the basic handcontroller for the
etc-125ec you mentioned earlier today?

MIke here: That appears to be for the Meade Focuser, not the telescope. The one for the telescope will have four arrow keys and four red LEDs.


Oh...but would this focuser be helpful as well? Also, the telescope
doesn't have any tripod. Do you think this one would fit?
Mike here: That table top leg set is for the ETX-90, not the -125. I'd recommend at least a Meade #884 tripod. As to the Focuser, that is something you might consider later. But it had some reliability problems. If you do get a Meade ETX Focuser, it should come with its controller. It will also work with the AutoStar #497.


Ok, thanks Mike. Once I have the autostar I'll get back to you. Thanks
for your tips and patience!

Regards from Switzerland,


Subject:	Re: Meade 6x30 Finderscope
Sent:	Monday, October 24, 2011 13:07:02
From:	Den (
Great web site, I put my ETX-90 away many moons ago due to personal
commitments. I have found your site VERY helpful in getting the old girl
back into working order. I did find the Meade 6x30 finder scope mode
interesting as I had one of these scopes in my 'junk' box and never
liked the finder that came with the ETX. I was VERY hesitant to cut
bracket as described and found that my Dremel tool with a sanding drum
did a fine job removing enough plastic from the inside of the ETX
bracket that the 6x30 scope fit in with room for adjustment leaving
plenty of plastic on the bracket. A little smoothing by hand and then a
lot of time aligning and I now have a very useful finder scope.

Thought this maybe a helpful suggestion.


Subject:	ETX-125 won't stop RA slewing during align
Sent:	Sunday, October 23, 2011 19:51:59
From:	Howard Fink (
I have an ETX-125 about ten years old.  I tried to do an alignment,
but the Right Ascension just does not stop, the telescope rotates
until it runs out of cable.  If I spin it back while slewing, it keeps
going, and going.

The Train drives in RA runs at top speed, while the DEC train drive
runs at slow speed.  Any ideas on what is going on?

Howard Fink
Mike here: Do a CALIBRATE MOTOR; that will usually cure this.

Subject:	What's the difference between etx AT and etx PE?
Sent:	Sunday, October 23, 2011 15:12:47
I learnt that the etx PE has a Level North Technology but the etx AT
I've found the price of both of them.The PE is more expensive than
AT.So,is the Level North Technology very important ?
Mike here: If you can find True North and level the telescope tube (by eyeball generally), then the LNT is not required.


So,is there any other difference between them?
What's the latest one in etx family?
Mike here: See the ETX FAQ page on the ETX Site for info on models. The PE is currently the most recent model ETX.


Should I set AT precisely to the north? Or will it influence the
Mike here: Using the ETX should be fun. Eyeballing is usually all that is required. But the more accurate the Home Position, the more accurate the initial alignment star positioning.

Subject:	[none]
Sent:	Saturday, October 22, 2011 06:04:01
From:	Dave (
I purchased a Meade ETX 90 back in Nov. 96 Is there any upgrades for
this as far as being upgraded to a computer driven. If not what is it
worth. Still have original box and never used very much. Thank you in
Mike here: First, apologies in not getting back to you sooner. You rmessage was classified as SPAM due to the blank subject line. PLEASE read the Email Etiquette page on the ETX Site Home Page to learn more about submitting to the ETX Site. Thanks for understanding. As to upgrading the drives in the ETX-90RA, JMI used to sell the NGC-microMAX and NGC-MAX (see the Accessory Reviews: Miscellaneous page) but I don't know whether they still do. Alternatively you might find an ETX-90EC base minus the OTA on eBay or at Telescope Warehouse (link on the Astronomy Links page). Or you could remove the OTA and with the proper mounting hardware, put it on a tripod. But if you want to sell it, it could bring about $200, up or down from there depending on condition and accessories.


I was thinking about selling it, if there wasn't a upgrade. I was
thinking about $300.00 I have 1 extra lens and camera adapter. I have
original box and I hardly ever used it. I paid $635.00 for it. 

Mike here: I'll be happy to post a FOR SALE ad if you like.

Subject:	Can not focus my ETX 105
Sent:	Tuesday, October 18, 2011 13:22:17
From:	Mta472 (
Last November I pruchased a used ETX 105.  It did not come with any
eyepieces, so I used mine.  About the only eyepiece I could focus it
with was my 32 mm Televue plossl - and only if I cranked the focus knob
all the way clockwise.  The rest of my EP's are University Optics and
only one worked.  

Like an idiot I suspected the eyepieces and not the scope, so I bought a
used Celestron 30 mm, a used Meade 18 mm and a used Televue 8 mm.  All
are plossl design.  The ONLY new eyepiece I can focus with is the 30 mm
Celestron - once again with the focus knob cranked fully clockwise. 

Any dieas as to why I can not focus this scope and suggestions as to
what to do?

Mike here: It sounds like either the focus shaft or the primary mirror cell has moved. If that's the problem, you will have to disassemble the rear of the ETX OTA and check the focus shaft. The articles "Focus Shaft Fix" and "Doc G's ETX OTA Guidescope & Disassembly Photos" on the Helpful Information: Telescope Tech Tips page may help.

Subject:	RE: ETX 90 Question
Sent:	Monday, October 17, 2011 08:20:18
From:	Steve Ferguson (
I did a redistribution of the grease as you suggested,  I did not feel
any obstructions.  I also reset the motors from the Autostar and did a
drive train calibration.  This seems to be working well.  I was able to
track Jupiter for an hour with no error.  Thank you for your help.  I am
an Electrical Engineer so if you ever need any help please let me know.


Subject:	Re: Etx 90
Sent:	Sunday, October 16, 2011 14:23:48
From:	Richard Elbe (
Your page was super helpful, found the needed links and will be ordering
the replacement parts soon. 


Subject:	Etx 90
Sent:	Saturday, October 15, 2011 14:18:46
From:	Richard Elbe (
ETX90 purchased in 2006, broke it out for use for the first time in 2
years ( I travel a lot.) was going through the motions for setting it
up. During the leveling phase, it gave a fault error. Discovered a
busted gear inside ( I have an image.) Do you know if it is possible to
just order the gears from Meade or of a listing that I can replace the
gears after market?

Mike here: Meade does not typically sell repair parts to users. Try Telescope Warehouse (link on the Astronomy Links page on my ETX Site). Also, there is an article about gear replacement sources on the Helpful Information: Telescope Tech Tips page.


rgr that and thanks!


Subject:	ETX 90 Question
Sent:	Friday, October 14, 2011 06:43:01
From:	Steve Ferguson (
I love your web site.  I bought a used ETX-90EC and your site had helped
me to get it into great shape.  Sometimes after I align (polar or
alt/az) the motor drove will be tracking an object and the telescope
will jump up a few degrees.  After this happens the telescope is out of
alignment and I will have to start over again.  Any idea why this
happens?  Also I am looking for a cap for the photo port.  Meade does
not sell it.  I did read it was a 34.6mm but have not located one yet. 
I am using a plastic cover for now.  Thank you again for all of your
Steven R. Ferguson 
Sr. Electrical Engineer, 
Mike here: There can be a few culprits for the jump, some bad. But the easy one to fix is to redistribute the lubrication. Unlock both axes and slowly move the telescope by hand, up and down, and rotate it horizontally from hard stop to stop, back and forth. Do this several times. While doing that, if you feel any resistance to movement, STOP. There could be an obstruction. If it is a wire you don't want to cut it. If there is an obstruction, you will have to open up the mount to determine the cause. If the problem remains after redistributing the lubrication then there is possibly a broken gear, broken or loose gear mount, or loose main bolt. You will have to open up the mount to check.


Thanks for the info.  I will try that.  I was also reading on your site
that you should calibrate the motors when switching power supplies.  I
just bought a celestron power take and used it last night.  I will also
re-calibrate this evening.


Subject:	Cleaning eyepiece filters
Sent:	Wednesday, October 12, 2011 09:48:09
From: (
I have looked at your site on cleaning telescopes and eye pieces but can
you use the same "solution" on colored eyepieces? I didn't know if their
coatings required any other special treatments. 

Chad Jewell
Mike here: I am sure Dr. Clay Sherrod's cleaning solution is safe for filters, but lets ask the good Doctor.


Thank you. I recently recieved my Meade 4000 Eyepiece/Filter set and
most are clear but a couple are murky. I didn't know if it is "dirty" or
a cloud defect in manufacturing. 


From:	P. Clay Sherrod (
The solution will work just fine, but actually it is far easier for
small surfaces such as a filter to use ONLY pure (91% or higher)
isopropyl alcohol and a Kleenex tissue for best results; never use the
same tissue twice....keep changing for a dry surface always against the

Dr. Clay
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West


Excellent. Thank you both for your help and knowledge. 

Subject:	RE: New to Telescopes  First Time Buyer
Sent:	Monday, October 10, 2011 09:24:35
From:	Hein, Walter J (
Thank you very much for your considered response.  This is helpful in
getting me focused on the right issues.  You might even consider
amending your comparison blog with these words.  Thanks again for your


Walter Hein
Mike here: I have noted on many occasions that the best telescope is the one that gets used. If the telescope is too large to move or too cumbersome to set up, it ends up unused.

Subject:	New to Telescopes  First Time Buyer
Sent:	Friday, October 7, 2011 18:06:35
From:	Hein, Walter J (
I'm buying a telescope for my girlfriend for Christmas.  I've narrowed
it down to the Meade ETX 90 or 125. I've read your comparison review
recommending the 125 and 90 if budget dictates.

My question is, for a first time user (i.e. someone who has never
touched a telescope before) is the 90 more than adequate or will we/she
out grow it rapidly and wish I'd stepped up to the 125 in the first
place? I don't think this will become a major hobby...but rather a
seasonal interest (Seattle) for a few hours a week.  I hope I'm
wrong....just trying to be realistic.

Thank you in advance for anything you care to share.


Walter Hein
Seattle Washington
Mike here: Part of the answer depends on expectations of what you will be able to see through a telescope. Both telescopes can provide years of enjoyment. But the larger aperture telescope will provide more magnification of bright objects and allow for slightly fainter objects to be more easily viewed, even from light polluted skies (although arranging for the lights to be turned off will enhance your viewing and health). While there is not a significant size difference, the ETX-125 is a larger telescope and may be difficult for some people to easily move around. That can result in the telescope staying inside, or worse, in a closet. On the other hand, if the ETX-90 does not live up to the user viewing expectations, then it can end up in the closet too. Decisions, decisions, decisions.

Subject:	ETX-125EC "Right  Tube Adapter"
Sent:	Thursday, October 6, 2011 16:50:05
From:	Ron Harries (
I have read "Jordan Blessing's excellent piece on"EXT/EC Tune Up" plus
anything else I could find on the Right Tube Adapter. (This is the
plastic piece that connects the OTA to the right wing of the 125 and
also acts as the Dec. clutch). Jordan suggest that a repair kit can be
purchased from "Meade" and "ScopeTonix". I phoned Meade and they don't
have the kit anymore, also, I tried to email ScopeTonix but the
addresses they give on there, up to date, web site will not work. I have
also checked with Telescope  Warehouse with no luck.

So, at the moment I'm relying on the CU glue that I used to glue the
spindle back on the right tube adapter. Little worried that with all the
cracks in the plastic, this fix is not going to work for long.

I would be most happy if anybody that reads this has an idea of were I
could get a replacement part.

Thanks in advance for any help you can give me

Ron Harries,
Salmon Arm, BC
Mike here: That article is very old; no one sells that part anymore. However, you may be able to fix it yourself; see the article "ETX-90EC DEC fix (Right Tube Adapter repair)" on the Helpful Information: Telescope Tech Tips page.

Subject:	ETX 125 Parts
Sent:	Wednesday, October 5, 2011 00:41:50
From:	Ron Harries (
I have just purchase a 125EC on EBay. I was unable to get the Dec.
clutch to firm up, so, I started taking it apart. The more I took it
apart the more little pieces of black plastic kept falling on my bench.
It turns out that both the Declination Clamps are either shot or getting
that way. I think super glue may solve the problem for a while but, as
both clamps have cracks and replacement will be necessary.

Do you have any leads on where I can get the parts. Also, do you know
what the black plastic really is and the best glue to use.

Ron Harries
Salmon Arm, BC
Mike here: It sounds like the Right Tube Adapter has failed. You may be able to fix the problem; see the article "ETX-90EC DEC fix (Right Tube Adapter repair)" on the Helpful Information: Telescope Tech Tips page. For a replacement part, try Telescope Warehouse (link on the Astronomy Links page).

Subject:	Re: question re Meade EXT-125 EC
Sent:	Tuesday, October 4, 2011 14:42:33
From:	P. Clay Sherrod (
Yes, I now know what you are referring to; is the right tube adapter
what is damaged entirely?  The swing arm to which you are referring is a
stand-alone part and does not include the gears, so you are saying that
the two bolts that attach this swing TO THE TUBE have pulled through the
Note that even the newest PE models of the ETX also have the plastic
swing arms (right OTA adapter), but the interior of the fork arm is
indeed made of metal as you suggest.
Dr. Clay
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West 

Subject:	Calculating eyepiece FOV for proper true north polar alignment
Sent:	Tuesday, October 4, 2011 14:41:00
From:	Kenny G. Dubuisson, Jr. (
I'm looking to calculate the actual field of view (FOV) for an eyepiece
on my scope, to understand actual vs. apparent FOV and to know if the
FOV means edge-to-edge like I'm assuming or center-to-edge...sorry if I
missed it on the site.  I'm working on improving my polar alignment
procedure and need to know the closest eyepiece I have to 1 deg as it
looks like it is my largest eyepiece, my SP 40mm, which gets me to 0.88
deg on my 125-EC if my calculations ate correct.  I see a problem in my
procedure in that my 883 tripod is set to true north but I've been
aligning Polaris in center of 12.4 mm SP and not true north as my
variation is 55' W here.  I need to figure this all out to be able to
move Polaris in my FOV for proper alignment.

Thanks again,
Mike here: First, yes, FOV is measured across the entire diameter of the view. Next, see the "Eyepiece Simulator" on the Buyer/New User Tips page for an excellent online calculator. As to apparent vs true FOV, see this description.


So I'm figuring if I use the SP 40mm on my 125-EC with a 0.88 deg FOV, I
should move Polaris approx 104% from the left edge (with reverse image)
of the FOV to meet my 55' offset?  Sorry for bugging you yet again but I
hope to pay all your time back by writings docs with combined info.  
Thx so much again
Mike here: Well, things are a little more complicated than that. Polaris is not precisely at the North Celestial Pole, but is about a degree away. That means its position rotates around the NCP throughout the night. So, not only do you need to adjust for your local magnetic variation, you would need to adjust for the day of the year and the time of day. There are programs that will calculate this offset for you (don't ask, I don't use any). However, you may be making things more complicated than necessary. For most purposes, just eyeballing where True North is by sighting on Polaris or by using a magnetic compass and adjusting for your local magnetic variation, is likely to be adequate. The AutoStar, once aligned, can compensate for any pointing errors.


Ah, ok.  I've still got Goto and tracking errors after working through
probably 120-140 printed pages off the site so I thought my alignment
was the culprit.  I'm trying to get to astrophotography long exposure
tracking accuracy and trying to find my probs  I'll continue to play
with it. Thx again
Mike here: Keep in mind that you need to be polar mounted for long duration exposures. If you want to really precise polar alignment, use the "drift method". See the Helpful Information: Observational Guides/References page for some articles on that.

Subject:	ETX-70 Issues
Sent:	Saturday, October 1, 2011 20:05:15
From:	John Colby (
I am having troubles. I just got an etx-70. The declination will only
move down, not up. The azimuth does not work properly and even when
locked the base still rotates. any ideas?

Mike here: You didn't say if the telescope was new or used so I'll assume it is new. Have you done a CALIBRATE MOTOR and TRAIN DRIVES? If not, do those. Be certain you are not over-tightening the axis locks. You can damage them if you do.


It was used, when i got it the declination knob was broke, but i fixed
that. I'll try calibrating the motors. Thanks


Hello, The Declination will move down, but not up and will not move left
or right and the base still swivels even when locked.

Mike here: Lets check the motors. Unlock both axes and run the slewing motors in all directions. Can you hear them operate?


yes they do operate, when moving the scope up there is a whining sound,
moving it down and left and right it sounds normal just doesn't seem to
be catching.

Mike here: It would appear that the locking mechanisms may be broken (both axes) and there may be some obstruction (altitude axis) You will have to open the base and right fork arm to check. There is an ETX-70 Repair Guide on the Helpful Information: Telescope Tech Tips page.

And an update:

Well, it all works. The altitude axis was broke due to the knob being
broke, once i tightened it a little more it worked fine. As for the
azimuth, i'm not sure. I took it apart looked and everything seemed ok
and put it back together, now it all works good, just need clear skies
to test. Thank you for your help

Subject:	question re Meade EXT-125 EC
Sent:	Friday, September 30, 2011 18:14:22
From:	Andrew Szabo (
My mount for the above telescope has developed a mount problem.

The right-hand bracket (from gazer's perspective) is a housing that
includes a gear linking it to the slewing system.  The housing is
plastic.  The two Allen bolts have pulled through, together with pieces
of the plastic housing.

I called Meade.  The plastic housing was later replaced with a metal
housing (better idea), but the parts are not interchangeable.  There is
no replacement stock for the plastic part.

Do you sell a part or recommend a fix for this issue?  Alternatively, do
you recommend a replacement mount such as Celestron, and would any be
essentially a bolt-on and offer other advantages?

Andy Szabo

Mike here: Sorry to hear your Right Tube Adapter (RTA) has failed. As noted on the ETX Site Home Page, I am not a dealer for anything. However, you can find some repair articles for the RTA and DEC gear mechanism system on the Helpful Information: Telescope Tech Tips page. Alternatively, you could remove the OTA and put it on a different mount. There are some articles about that on the Telescope Tech Tips page.


Thanks for your kind response.  Two questions concerning your repair and
"supercharging" services, as I understand them from reading online:

1.  Do you think you would be able to repair the RTA, for example, by
replacing with the metal RTA that I understand Meade later used with the
mount?  What would be the
cost of such a repair, including shipping?

2.  What about #1, plus "supercharging," which as I understand it might
involve updating of Autostar database and optimization of optical
settings within OTA. 

Mike here: That is Dr. Clay Sherrod's service. I have directed your email to him.


Thank you; I am much obliged.


From:	P. Clay Sherrod (
Hello to all....exactly what is an "RTA?"
Please note, Andrew, that the complete information regarding Supercharge
is available on the link on Mike Weasner's site....I will be
happy to discuss repair possibilities, but I need to know details on
what is needing repair and which model ETX that you have.


Dr. Clay
Arkansas Sky Observatories
MPC H45 - Petit Jean Mountain South
MPC H41 - Petit Jean Mountain
MPC H43 - Conway West
Mike here: RTA = Right Tube Adapter (part of the part the holds the OTA to the right fork arm)


Certainly.  I mean the Right Tube Assembly (RTA) on my ETX-125 EC.  This
RTA includes gearing that links to the slewing mechanism of the mount.
The RTA housing if made of plastic for this model, made in 2001.  Later,
Meade switched to a metal housing.  The RTA attaches to the OTA via two
allen bolts.  The two allen bolts have pulled through, together with a
collar of plastic from the housing.  I have read online that this
happened to others as well.  


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