Last updated: 30 June 2001

This page is for user comments and information specific to the Meade ETX-125EC. 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 125
Sent:	Saturday, June 30, 2001 11:38:30
From:	GoRon325@aol.com
Thanks again for the great site. I don't seem to be able to find a
review that compares the JMI instafocus to the Meade e-focuser side by
side. Is using the autostar to focus really worth it? It seems scrolling
through the menu would be cumbersome. The JMI attaches to the handset
making it convenient to reach.

I am new to astronomy having purchased my 125 in March. The performance
of the go-to has opened up the heavens to me beyond my expectations.
After two unsuccessful attempts at setting it up I sat down and studied
the material on your site. I have not experienced one night since that
the goto hasn't worked properly. If I have a problem it is usually
related to leveling properly. I always make sure the tube is level 360
degrees around by loosening the clamp and manually moving it 90 degrees
at a time and checking for level. Currently I am using the eh version
software. I use the 12 volt adapter with a jumper battery that is
normally put in the trunk for emergencies. This seems to make the scope
slew smoother. By putting the battery on the tray in the weak #883
tripod it helps keep things steady.

One last question, should I leave "high precision" on in the handset? I
was told that Meade was working on debugging some problems with that and
the "enter to sync" function.

Ron Thomas
Mike here: We don't have a side-by-side comparison. Since I have neither I'll have to leave the answer to those that do. As to HIGH PRECISION, I rarely use it or even find it necessary.

Subject:	ETX-125EC
Sent:	Friday, June 29, 2001 12:00:27
From:	sorensen@spiderworks.net (Doug Sorensen)
I have an ETX-125EC that has the following symptoms:

1. In default mode, the horizontal motor (left/right) will only travel
at one speed - no matter what speed is selected.  This is true with
either controller; however, the vertical motor (up/down) seems to react
properly to speed changes.

2. In polar aligned mode, things are really wrong.  If you touch either
horizontal control (left or right), the telescope goes about 2 inches in
one direction.  Strangely, it doesn't matter which direction you choose,
it will go about 2 inches in that one continuous direction.  So, in the
polar aligned mode, I have absolutely *no* control over horizontal
motion.  Again, vertical motion seems fine.

3. When I have the AutoStar connected and attempt to go through its
initial "set up", it rotates the scope briefly and then returns the
message "Motor System Failure".

I have rebooted, re-initialized (via AutoStar) and tried both
controllers countless times; and in each case, the results are
absolutely consistent.  Also, I have tried both new batteries and an AC
adapter with the same results.

Any ideas?


Mike here: I would suspect that perhaps the wiring in the base has been cut or otherwise shorted in strange ways. I'd suggest contacting your dealer (if a recent purchase), Meade, or perhaps you might want to consider Clay Sherrod's Supercharge Tune-up.

Subject:	ETX 125 Polarity
Sent:	Friday, June 29, 2001 6:39:21
From:	rocrow@itl.net (rod crowte)
A really basic question I`m afraid.
Having just bought a new 125 I need to know the polarity of the centre
pin on the DC in to the scope base. I want to use a 12v mains adapter
with selectable polarity - and I don`t particularly want to get it the
wrong way round !

Having read and followed the advice in the"tune up" pages, I can only
agree that everything was smothered in lubricant - EXCEPT for the RA
worm and wheel which was bone dry, and had been adjusted into the most
forced meshing by use of the grub screws behind the worm.

The wires going up to the Dec drive through the keyed slot in the base
bolt were twisted to the extreme around the bolt and the insulation had
been torn through the black wire leaving about 1/8" bare wire.

It was not possible initially to remove the setting circle knob as the
threaded insert in the fork arm was simply rotating with the screw.
Having finally managed to remove it - the thread cutting was so poor
there was no way the insert would have resisted the force required to
turn the screw into it.

The other small problem that I have yet so solve is that when reversing
direction on the Dec drive, the change in torque direction causes a
momentary twisting motion on the fork arm at right angles, ie if the arm
is horizontal then there is a visible vertical rotational movement of
the arm. This would appear to come from the worm wheel which can be seen
to tilt on the arm when the drive direction is reversed. I haven`t come
up with a solution as yet - but maybe one of the many experts on your
excellent site may have seen this before and be able to give me a clue.
There may of course be adequate resistance when the OTA is refitted and
effectively both form arms are joined.

Apart from that I think it is terrific !


Rod Crowte
Mike here: Copying from a previous reply from me on the center pin: "I just did a search on "polarity" and noted that in a previous email reply I stated:
'According to reports, the center is positive." If you search for "power supply" (using an "exact match" setting) you'll find lots of references. Also if check the Telescope Tech Tips page you'll see several items on power supplies.'"

Subject:	Rating the ETX125 on what you see in the sky
Sent:	Thursday, June 28, 2001 15:33:04
From:	marbla@naisp.net (Blais Klucznik)
Just wanted to comment on my LEARNING CURVE with telescopes in general
and the ETX125 in particular.

After having a marvelous night a couple of nights ago, darn dark skies
for my location, last night was probably one of the worst nights for
searching the sky from here in SE-MA.  It was hot, humid and hazy.  The
conditions deteriorated as the night progressed.

I could see almost none of the objects we were able to see comfortably a
couple of nights ago  Even Mars was rather hazy in our scope.

Now if this had been my first time out with the -125 I certainly would
have been disappointed with its performance but I've since learned to
give any telescope a fighting chance.  This only makes scope comparisons
more difficult because unless you are co-located  and viewing in
parallel there are just too many other variables to consider.  At least
I now realize this after experiencing the remarkable differences one
notices depending on the night sky.

Once again the GOTO feature is working so good that I used a 12.6mm
eyepiece all night long.  Darned if the GOTO object was not somewhere in
the eyepiece.  Sounds too good to be true.  For this I thank Dr. Clay,
Jordan Blessings and fellow contributors to this great site.

Hope the gang's skies are better wherever they may reside but watch out
for the mosquitoes.

Blais Klucznik

Subject:	etx-125
Sent:	Thursday, June 28, 2001 9:41:31
From:	gonzosc1@netzero.net (gonzosc1)
I picked up my 125 last Thursday (June 21st), its been solid cloud cover
since! but I was still in a good mood. I got the scope at a going out of
business sale at natural wonders. $610 for the scope, $30 for the
autostar, but they were out of Meade cases. believe it or not I talked 
the salesman into a free celestron case. anyway since the clouds are
keeping me from viewing up, I tried viewing other things and was amazed
at the scopes power. that night I was on the net looking for info about
the scope and came across this site( awesome site). I read all the tech
tips and than started to compare my scopes performance to what this site
says it should be.

I could not believe the different. after checking my scope I find
"slop", a lot of it. I had over 5 degrees of movement in the DEC, and 2
in the RA. So I printed out all the tips for a tune up and was ready to
have a go at it. after opening the scope and looking around at
everything the one thing that stood out the most was the clutch

So after doing all the checks and fixes listed here on this site I can
now say that I have only 1/2 degree movement on the DEC, and the RA is
rock solid at "0" degrees. today I will train the motors and when the
clouds brake I can try an alignment.

I would like to thank all who posted tech tips. and will say thanks for
this site.  Robert

Subject:	help
Sent:	Wednesday, June 27, 2001 12:11:56
From:	mickpotter@lineone.net (Michael Potter)
I have just purchased a second hand etx 125  but I am having some
problems your site was great (unlike the manual)for setting up the home
position in polar alignment mode but when I try and move the scope with
the hand control   the motors turn for a while before any movement
occurs  which is quite jittery  at first this makes setting up with the
Autostar virtually impossible but I have been able to enjoy some planet
gazing   i.e.   Jupiter Saturn and more recently Mars (at opposition) I
would say the results are better than the meade 8 inch schmidt
cassegrain that I used to own.
any ideas on how to sort out my motor problem ?
would appreciate any help
regards Mick   --Maidstone   Kent   England
Mike here: It sounds like you are experiencing some severe gear backlash. You might try rotating the ETX in azimuth hard stop to hard stop and back several times. Perhaps the used scope sat too long and the grease needs to be redistributed. If you have the Autostar, you can make some adjustments in the "percentages" (see the Autostar Information page) which might help. If you really want to tune it up, see the ETX Tune-up Service (linked on the ETX Site home page).

Subject:	Great night last night
Sent:	Tuesday, June 26, 2001 14:01:14
From:	marbla@naisp.net (Blais Klucznik)
Just wanted to say that we had some of the clearest skies over SE-MA
then we have had for a long, long time.  My wife and I had a great time
capturing about 1 dozen Messiers plus a number of other objects.  The
views were great for a scope as small as the ETX125.  We only used this
one scope last night.

The ETX125 performed magically for not one GOTO object was out of the
view of the 26mm eyepiece.  Maybe not centered but great.  This is
certainly more than I expected.

Great night for us.  Hope it's a great night for you folks tonight.

Blais Klucznik

Subject:	ETX125
Sent:	Saturday, June 23, 2001 21:31:49
From:	jostumpjr@mindspring.com (Joe Stump)
I don't have a set of calipers. Would you happen to know the focus shaft
diameterfor the ETX125EC?
Mike here: I measured my ETX-125EC focus shaft. There is a large portion closest to the back wall and a smaller portion where the knob attaches. Those diameters are 6/32-inch and 5/32-inch, respectively.

Subject:	template for the ETX 125
Sent:	Monday, June 18, 2001 15:36:43
From:	c.zurevinski@home.com (Conrad Zurevinski)
Does anyone have a template for the ETX 125 that you can ovrlay on to a
hard case, so you can pluck the cubes out for a exact fit.


Mike here: Check out the "ETX Outline for Hard Cases" on the Telescope Tech Tips page.

Subject:	etx amazing performance
Sent:	Friday, June 15, 2001 15:44:54
From:	nunosilva2000@yahoo.com.br (Nuno Miguel de Freitas Silva)
It's Nuno from Portugal.

I'm writing to report the amazing performance of my etx 125ec last
night. It was the first time since i bought it (about 10 months ago)
that every object i gotoed in the autostar was placed in the 26mm e.p.
field of view not very far from the center and i was even able to goto
to objects with the 26mm+2xbarlow configuration without having to
correct its position. I chose about 30 different objects (stars, deepsky
and planets) very apart from each other (like Deneb and Spica). To test
the altitude drive accuracy i used objects near the horizon and close to
the zenit since the telescope was in the ALT-AZIMUTH MOUNT. What made
this possible were the corrections i've been doing in my etx that i'm
going to report next. Mike etx website and Clay Sherrod reports and
suggestions really helped me a lot in some procedures, as well as other
etx owners reports.


-when rotating the axis by hand you can feel that in
some positions its harder to move the telescope than
in other positions;
-In the "harder to move" positions the drive takes
more time to change the rotation direction at a
certain speed (bigger drive reaction time) but there
is less looseness in the axis (don't confuse looseness
in the axis with looseness in the drive gears!);
-In the "easier to move" positions the drive reaction
time is little but the axis is too loose. This second
point means that you can't have the axis firmly
vertical (if using alt-azimuth mount), since the
weights in the OTA (such as eyepieces) will incline
the axis and the accuracy will be lost;
-Although the autostar new version 2.1ek can correct
the drive reaction time, it can't correct different
reaction times.

Clearly the main problem here is the irregular axis
rotation. It didn't take me long to find out that the
source of the problem was the big nut that secures the
axis. The poor quality nut wouldn't tighten the axis
bearing ring uniformly because of the nuts irregular
thickness (thicknesses differing about 0.20mm (from
11.98mm to 12.20mm)). So what i did was to glue a thin
piece of metal to the regions where the nut thickness
was lower. When i retightened the nut the axis was
rotating much more uniformly and the reaction times
were also much more uniform.
When tightening the nut notice this: if the nut is
considerably tightened the axis' looseness will be
smaller but the motor will have difficulty to move the
telescope and possibly causing motor failure. If the
nut is less tightened the looseness in the axis will
be bigger but the motor will move the telescope easier
and with small reaction time.
The difficulty to move the axis is due to friction in
the bearing and in the teflon ring that can only be
seen openning the axis. If the second is dirty, like
mine was when i first openned the axis, you should
clean it, since the friction will be much higher.


-The OTA moves about 1 degree or more in the altitude
axis when you press it a little or change weights
(like eyepiece configurations);
-When changing the rotation direction the telescope
moves to opposite direction a little bit before it
acctually moves to where you want (for example, if you
are moving up, stop and press the down button it first
moves a bit up before it goes down);
-The autostar altitude coordinate system has an error
of 1 degree when rotating 90 degrees (it would display
a rotation of 89.0 degrees when actually moved 90.0
degrees) even when the drive was well trained and the
lock firmly locked. This means that if the telescope
was aligned with a star near the horizon and you goto
to a star near the zenit it would be complitely out of
the 0.71 degree field of view of the 26mm e.p..

As suggested by some etx owners i cleaned the surfaces
where there should be friction (as between the main
gear and the plastic piece that secures the OTA) but
that didn't elimitate none of the problems. What i
found out was that there was looseness between the
axis components, such as the plastic pink piece and
the piece that secures the OTA. So i used a teflon
tape between the surfaces to solve the problem
although it would increase the friction between the
moving componets. The motor has more difficulty to
move the axis but the looseness problem was fixed. The
second problem was solved too.
The problem with the coordinate system error couldn't
be solved even when the first two problems were solved
and the drive was trained correctly (i reset the
autostar and followed Clay Sherrod procedures). So i
desperately changed the altitude ratio to see what
happened. I found out that changing this i could
adjust the coordinate system scale and correct the
problem (changing from 01.36889 to 01.35600). Of
course the 01.35600 rate probably only works well with
my etx and in the alt-azimuth mount. In the polar
mount i think this change wouldn't work since there is
no linear deformation of the materials when rotating
from 0 to 90 degrees. I also believe that if my OTA
was perfectly equilibrated it wouldn't be necessary to
make this change.

Many procedures are not explained here but are very similar to other etx
owners' procedure, such as Clay Sherrods. Ill try to report more of my
etx performance and modifications and i hope that other etx owners learn
something from my experience with my etx and solve their problems too.
From:	sherrodc@ipa.net (Clay Sherrod)
Nuno - fantastic!  That is quite a GO TO performance!  I like your
suggestions and the methodical way that you proceeded to fix your
telelescope; your modifications are very important and it is necessary
for all ETX users to note that such changes are different for EVERY
telescope; your deduction and ability to discern exactly where your
problems were are to be commended; I know it took a great deal of study
and examination of the telescope.  I think that much of what you did,
however, is going to be (should be, actually) beyond the scope of what
most owners should do as far as "getting into the guts" of the

I am very happy that the telscope is working so well for you and I look
forward to - as I am sure that Mike Weasner does - your continued
contributions to the web site!

Clay Sherrod

Subject:	Re: Re: ETX 125 Finderscope
Sent:	Tuesday, June 12, 2001 6:42:28
From:	saber@dircon.co.uk (Saber Properties Limited)
I had mine angled outward till now but found it uncomfortable to use.

Is there a mount such as a piggy back mount that would enable me to use
a straight finderscope say a 7x50 elevated a few inches above the etx's

If there is can you advise where I can get one and what f-scope might
you suggest.


From:	sherrodc@ipa.net (Clay Sherrod)
Sam - contact Scopetronix and tell Jordan what you are trying to do. 
You CAN mount a finder via a piggyback unit.  Good luck!

Clay Sherrod

Subject:	ETX 125 Finderscope
Sent:	Monday, June 11, 2001 11:32:26
From:	saber@dircon.co.uk (Saber Properties Ltd)
To:	sherrodc@ipa.net (Clay Sherrod)
Long time no speak.

Believe it or not, today is the first time I've attached the equatorial
mount onto the heavy duty tripod, even though I've had it for some
months now. (I've been very busy building an extension to my house)

After some practice I'm also getting the hang of alligning the
finderscope, this however is where my problem is. I use my right eye
when I use the finderscope and the main eyepiece, so when I am using say
my 9.7mm eyepiece, which is much lower than the finderscope, I keep
hitting the f-scope with the left side of my face and this a) knocks it
out of allignment and b) prevents me from getting close to the eyepiece,
which is a necessity with a high power lens.

Any advice?, can you scope be moved to the right side of the main tube,
(I notice there is a hex bolt on the right side as well) if it can do I
need a right sided bracket to hold the finderscope?

Oh, One other thing (in the words of Inspector Columbo) does the eq
mount need adjustment at the 0-60 guage on the side of the mount, in
relation to my location on Earth?

I look forward to your pearls of wisdom and to some good views of Mars
which is now coming into view.

Best wishes,

From:	sherrodc@ipa.net (Clay Sherrod)
Unfortunately the finder situation is one with no remedy.  I use a
barlow with EVERY eyepiece, except very low power to put the eyepiece
high enough to get it out of my face!  That works very well and good
barlows make for good viewing as well.  I would not try to move the
mounting bracket.

You must angle the entire telescope fork assembly in the wedge to YOUR
LATITUDE WITH THE BASE PLATE level on the wedge.  Merely aim the fork
arms north and then tilt upward until the scope reads your latitude with
the one bolt attached to the bottom of the tilt plate;  THEN you should
tweak the entire assembly without unclamping the scope (home position)
until you can get true celestial north (see my "KOCHAB'S CLOCK" for
accurate star alignment on Mike's ETX site. 

Good Luck!

Mike here: I have the finderscope eyepiece angled to point outward so I don't breathe on it when looking through the main scope eyepiece. This position also keeps my face from hitting it.

Subject:	Another fine night with the ETX125
Sent:	Saturday, June 9, 2001 13:06:23
From:	marbla@naisp.net (Blais Klucznik)
Just a little note to say that my ETX125 worked like a charm again last
night and the wee hours of this morning.

During the afternoon I reloaded v2.2eh and purged the LibTour.ROM of all
its data.  Then I entered a number of Clay's tours, for the
constellations we would be visited by, and set the scope up out of

When we were able to see Polaris I did an AZ-EL two-star align, once
again using Clay's suggested method, and the scope performed like a
champ all night.

We saw, albeit they were extremely faint, M10, M57, M81, M82, M92, M94
and NGC6229.  M81 was barely perceptible but we could tell that it was
elliptically shaped.  On all the others their appearances were obvious
compared to the sky background but very faint.  Going to try them with
the 90mm as soon as my wife and I build up a little reserve stamina. 
The moon did appear about 11:00 PM so that didn't help the dark-sky
situation. Before finally calling it quits we did a GOTO to Mars.  It
set it almost centered in the eyepiece and tracked it for 15 minutes.  I
felt that not needing to trim the scopes position during that time
interval was remarkable.  Then, unlike the previous night, a GOTO to the
moon put it right there.

Now all this from a past non-believer.

I did notice, with amusement, that the GOTO rotated in arcs never
approaching the CCW stop no matter where we commanded it to go.  Yet,
after a number of GOTO commands all over the RA coordinates I did notice
that, on its way to SPICA, rotating CW, that the GOTO ran into its CW
stop and because of the size of the fuse I use for my 12V battery. 1/2A,
the fuse did pop.  So, after checking for a short with an ohm-meter, I
replaced the fuse with a 3/4 ampere, rotated the scope, by cursor
control, CCW until the OTA was facing east.  Then I replaced the 3/4A
with a replacement 1/2A and had no problem for the rest of the morning. 
Just a little note on the value of fuse I use.  As you know choosing a
value that protects motorized circuits cannot usually be determined by
steady-state currents.

Hope all you folks have a good weekend.  Once again our skies look
pretty good but after two consecutive long nights and mornings, and
being 66, we are pooped.

Blais Klucznik
And more:
In my note earlier today I mentioned popping a 1/2A fuse last night
while the ETX125 was attempting to rotate CW while in a mechanical stop.
I would just like to expand a bit on this size fuse.

As this fuse is solely to limit the 12vdc battery current to the ETX125
I suspect it will provide very little protection to the 497 Autostar
itself.  Thus, in the next few days, I am going to measure the current
drain of the 497 and fuse the handbox separately.  This should be a
steady state current, more or less, and I suspect the 497's current
demand on the 12vdc battery will be substantially below 1/2A.  So I
probably will end up using two different size fuses for better
protection.  After all this is the purpose of a fuse.

Will submit a note when I finish the measurement.

Subject:	ETX-125EC
Sent:	Wednesday, June 6, 2001 12:52:42
From:	d.birmingham@worldnet.att.net (David Birmingham)
I have been doing some in depth reading on your site and have found a
great deal of useful information. my thanks to Dr. Sherrod as well. I
have found a number of articles which either have downloadable files or
sketched of the 90EC outline, but I have not yet found one for the
125EC. I opted to get the Sears version of a case you have listed on
your site and as I sit here waiting to get a fully functioning 125EC I
would like to start obtaining the materials to make the packing for the
inside. Is there such a thing on the site that would have the 125EC
dimensions for relief cutting foam?

On another note. I was also reading information on lights for night
observation and illumination. Being a lightweight backpacker I have
scoured the web for equipment that would fit that bill and have been
using one item I found that would be perfect for astronomers. Photon
Micro-Light lights are about as small as a light can be, and operate on
a watch battery for a very long period of time. While backpacking I use
one of PhotonLight's red lights. All of their lights utilize light
emitting diodes which of course never burn out and the lights carry a
life-time guarantee. Small enough to add to your key chain, with
attached split ring, they are not much bigger than a nickel. If anyone
would be interested the address is;



Subject:	Follow up on "2 Scopes"
Sent:	Tuesday, June 5, 2001 22:14:28
From:	EricB@cascadewholesale.net (Eric Berglund)
I was just reading the mail of the Australian who had the two scopes. It
is interesting to note that your 26mm eyepiece says Taiwan on it and is
a greenish tint, the one that came with my scope says Japan and has no
tint to it that I can tell.

Just something interesting...


Subject:	 Interesting Comments on the ETX-125
Sent:	Monday, June 4, 2001 13:35:17
From:	marbla@naisp.net (Blais Klucznik)
As both my wife and myself have made our comparisons of two scopes
known, a 90mm & 125mm, and we are darn sure we are not speculating I
thought you might find the following comments interesting.  These
comments were included in the Sky & Telescope Test Report for the
ETX-125 published in October of 1999:

            "On several nights I set up the ETX next to my home-built
            4.2-inch f/6 Newtonian, my favorite 'quick-look' instrument.
             Using the same magnification, I found an obvious difference
            in performance -- the Newtonian showed the Martian surface
            markings with greater certainty than did the 5-inch
            Maksutov.  The red planet seemed drained of low contrast
            detail in the 5-inch view.  This is most likely the
            consequence of the 125EC's large central obstruction --
            nearly 40 percent the diameter (of) the aperture.  An
            obstruction this size has the effect of reducing the 5-inch
            scope's contrast to that of an optically excellent
            unobstructed 3-inch instrument.  (see 'Rules of Thumb for
            Planetary Scopes --I' Sky & Telescopes July 1993, Page 91)."

            As you folks know our opinion all I can say is Hmmmmmmm.


Blais Klucznik
From:	RMOLLISE@aol.com
Well, contrast  as in this review and image brightness as in your posts
are two are two entirely different things. And also, depsite efforts to
quantify what the effect a central obstruction of a given diameter has
upon contrast, this is still very much a subjective affair. In my
experience, once an obstruction of _any size_ is added to a telescope,
including a Newtonian, much of the "damage" is already done. But, be
this as it may...the truth of the matter is that obstructed
telescopes--including the ETXes--are capable of excellent performance on
the planets, the hardest test for any scope contrast-wise. Assuming: the
scope is collimated and cooled and the seeing is good. This is not
speculation. I've been doing visual observing of the Solar System for 35
years and have been quite pleased with the images in the 125.

There are compromises inherent in the MCT design, just as there are in
any telescope design, including refractors. It offers a very compact OTA
featuring very long focal length. The optics IMHO are also quite good,
in my tests (slightly) besting a C5, Celestron's legendarily good SCT
OTA. Some folks might be more willing to put up with the chromatic
aberration inherent in an achromatic refractor. In my experience,
though, the resolution-robbing excess color of a short/medium focal
length _achromat_ is more damaging to high resolution imaging/viewing
than even a considerable central obstructon. By the way, folks have
experimentally removed the baffle from the 125 secondary and have  not
noted any detectable contrast improvement.

Rod Mollise,
Author of _Choosing and Using a Schmidt Cassegrain Telescope_
And this reply:
From:	marbla@naisp.net (Blais Klucznik)
Hello Rod,

I cut & pasted your recent message rather than do a REPLY-ALL because
I'm not much of a fan for a reply that has a vertical border on the left
side.  Just personal preference.

Now to your note:

> Well, contrast  as in this review and image brightness as in your posts are
> two entirely different things.

I realize that we are now teetering on the border of semantics but I
seem to think that the two are somewhat related.  If I cannot see an
object in a telescope then contrast has no meaning.  Once one can
actually see an object then a degree of contrast can be ascertained,
albeit, subjectively.

> And also, depsite efforts to quantify
> what the effect a central obstruction of a given diameter has upon contrast,
> this is still very much a subjective affair. In my experience, once an
> obstruction of _any size_ is added to a telescope, including a Newtonian
> much of the "damage" is already done. But, be this as it may...the truth of
> the matter is that obstructed telescopes--including the ETXes--are capable of
> excellent performance on the planets, the hardest test for any scope
> contrast-wise. Assuming: the scope is collimated and cooled and the seeing is
> good. This is not speculation. I've been doing visual observing of the Solar
> System for 35 years and have been quite pleased with the images in the 125.

This is not my line of expertise Rod but I will say that your comments
here make sense.

> There are compromises inherent in the MCT design, just as there are in any
> telescope design, including refractors. It offers a very compact OTA
> featuring very long focal length.

This principle sort of holds true no matter what you are designing. 
Compromising is the name of the game.  One can certainly move around
rather freely with a short-tubed telescope while the longer tubed
devices present a mobility problem.  So if you want a small package then
more compromises have to be made.

Have a good night or rather morning.  Thank you for your opinions and
reasoning behind them.

Blais Klucznik

Subject:	Interesting item on eBay web site item#1603527798: 
Sent: Sunday, June 3, 2001 4:33:23 From: np149@tir.com Look what is for sale on eBay with reference to you and Dr. Clay! Keep up the great work. Nick P. I saw this item for sale at eBay, the world's largest personal trading community, and thought that you might be interested. Title of item: "SUPERCHARGED" MEADE TELESCOPE ETX125 PACKAGE Seller: kilawila Starts: Jun-02-01 08:18:13 PDT Ends: Jun-09-01 08:18:13 PDT Price: Starts at $900.00 To bid on the item, go to: cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1603527798 Item Description: Offered for sale is a better than new-in-the-box "SUPERCHARGED" ETX 125EC (Meades's 5 inch Maksutov telescope) as a superb package. Package includes tripod, special mounting plate, Autostar go-to system and many accessories. Scope and accessories are all less than 6 months old. Sharp operation and sharp looking. The telescope has just come back from a comprehensive 83-point evaluation and "supercharge" performed by Dr. P. Clay Sherrod, a retired astronomer/mechanical engineer/educator. The evaluation and performance summary of virtually every aspect: from electronic to mechanicial, to optical quality is included. The Autostar has been upgraded to the very latest firmware, which is not available right out of the box. The "SUPERCHARGE" corrects many factory caused performance issues (such as too much heavy grease in the mechanical parts: See http://www.weasner.com/etx/techtips/tuneup_service.html for details). The telescope is mounted on a heavy duty Bogen 3068 tripod with a video panning head allowing for operation in either alt-az or polar mode via an "ETXpert" mounting plate equipped with a mag-light holder, 3 eyepiece holders, durable bubble levels, a compass and a hand-held computer cradle. There is a small dent (cosmetic) in one of the tripod legs. Selling to buy a larger scope. Photos show telescope set up for piggyback photography and set up for prime focus solar photography. The latter setup works great for lunar photography without filter. Sorry, camera not included. EQUIPMENT: * ETX 125 EC $895 (price new: includes finder scope, 26mm Possel eyepiece * Autostar $95 (price new) * Supercharge $150 * Bogen tripod Model 3068 and panning head $275 * ETXpert mounting plate $99 (price new) OTHER ACCESORIES: * ScopeTronix Flexi-Focus $34.95 (NIB) * 45 Erecting Prism $49.95 (price new) * T-Adapter $34.95 (price new) * Hard Case $149.95 (price new) * Orion Solar Filter(+5) $99 (price new) * Homemade Solar Skreen solar filter (+5) $25 * JMI Piggyback Camera Mount $39.95 (price new) * AC/DC Adapter Power Cord $35 (price new) Also included are 4 three-ring binders filled with technical tips on the ETX from: http://www.weasner.com/etx/menu.html and some practical tables on astrophotography. Scope will be shipped in original packaging. Shipping to US only. Buyer to pay actual shipping costs, estimated at about $60. Money orders, cashier's checks, billpoint, paypal. If you have 0 feedback or negative feedback please email me before bidding. Thank you!!

Subject:	Re: 1/2 inch nylon and 1inch stainless steel
Sent:	Saturday, June 2, 2001 8:51:35
From:	sherrodc@ipa.net (Clay Sherrod)
To:	dave
First, let's review the most current sizes:  you need a 1/2" o.d. fender
washer (stainless) and a 3/4" nylon (o.d.) flat washer.

The stainless is installed first, up against the trunion post; the nylon
rests flat against the setting circle; NOW, Meade has several modified
scopes out there and you might need to measure first.....you want the
washers to ROTATE WITH THE OPTICAL TUBE ASSEMBLY in declination as it
turns and NOT be restricted by the stationary fork arm...

This is ONLY for the ETX 125.  The ETX 90 (and 60-70) does NOT need that
bushing pair and it is detrimental to its operation!

Hope this helps!

Clay Sherrod
    -----Original Message-----
    Silly question clay but must the nylon fit inside the stainless steel 
    ie is half and one inch inside or outside diameter
    This is to tighten the dec axis

Subject:	2 Scopes
Sent:	Saturday, June 2, 2001 2:55:11
From:	hbeng@smartchat.net.au (HB CIVIL)
I must commend you on your great web-site! My 125 ec finally arrived in
Australia last week after 2 months of agonising waiting for the US mail.
They stuffed up and sent it by ship, thats why its covered in barnacles?
It took so long that I gave up on it and ordered another one, so now I
have got two! Thankfully both of them had the 2 pieces of foam placed
between the OTA and the top of the base of the scope, so they are the
current series. Two beautiful etx scopes in one week...cannot complain
about that!

I noticed that the 26mm eyepieces are different coloured. One has light
blue glass and the other an emerald green. Also when I reflect light off
the front of the lenses, the blue one seems to have some specks in the
glass or coatings, as if there is some faults like bubbles or maybe
holes in the coating? The blue one also seems to reglect light off the
face whereas the green one seems to absorb it? Also the rubber eyecup is
wider and flatter on the bluish eyepiece and  the word TAIWAN is stamped
on the chrome barrell on the greenish one and nothing on the blue? Do
you know which one I should keep, and why they are different coloured
and marked differently to each other?

Otherwise both scopes look fine although I have only tried Scope 1 
looking at the beautiful split of alpha centauri and a peek through the
clouds at mars. Its been cloudy since I got the scopes and so i've only
managed a few hours of viewing so far.

Scope No. 2 had both of the circles on the fork arms loose when you
loosened the alt knob, but that is no major issue. I have done some
testing of motors on both scopes on a benchtop to see if any differences
in sound or operation. When cold, scope 1 seems to not move for a while
when turning horizontally, then eventually starts to move and behaves
normally. This has happened a few times but eventually it seems to go. I
checked the knob on the base for tightness and it was ok. Scope 2 seems
ok but the whining of the motors seem to be loud then soft then loud
again, as it goes round. The scope keeps turning but the sound changes
back and forth.

I suppose I am trying to pick the best scope and eyepiece to keep, and
probably sell the other. I have not looked at stars or planets on scope
2 yet but it seemed ok on terrestrial objects. Some advice on which one
to keep would be appreciated, or maybe some other tests to perform
before I make the final choice.

Regards and best wishes from Nick B from the land downunder!
Mike here: If both eyepieces say "MEADE SUPER PLOSSL 26mm LP MUTI-COATED" either one is probably OK. The 26mm eyepiece that came with my -125EC also says Taiwan and has a greenish tint to the coating. There are no specks or bubbles. One scope's mechnicals may be tighter than the others but both should loosen up with use (distributing the grease on the gears). If you use the Autostar (assuming you bought one) and use the scope in Alt/Az there were be some sound variation as the drive motors move the scope in two directions. If you are just using the standard handcontroller in polar mode (not terrestrial) only one drive motor runs and that should be constant. The same applies to the Autostar in polar mode. In any case, I would give the scopes a couple of weeks of real use. Of course, after that you'll be honor-bound to sell the second scope as USED. If you don't use it, you could sell as still NEW but opened.

Subject:	90mm refractor vs ETX-125
Sent:	Friday, June 1, 2001 14:43:08
From:	marbla@naisp.net (Blais Klucznik)
Several weeks ago I started a minor foray on this user group site by
stating that, according to my wife's and my observations of the stars
using both a 90mm refractor alongside the ETX-125, we both felt that we
could see slightly dimmer objects, and better resolution, with the 90mm
than the ETX-125.

Well several additional weeks have gone by and now, with a dozen or more
tandem observations with both these scopes at the same location, we are
convinced that you can see dimmer, more resolute objects on the 90mm
than we can on the ETX-125.

As most of the replies I received from the group were extremely
skeptical of our findings I thought I would pass along a few additional
tidbits of info that may explain why this is the case.

The ETX-125 is advertised as a 125mm SCT or a minor derivative. Thus the
ETX-125 has a maximum possible light-gathering area of 392.7 square mm. 
But the so-called 125mm ETX has an obstruction of 34.925mm for its
secondary mirror or 109.72 square mm.  So 392.7 - 109.72 = 282.98 square
mm of light gathering ability.

Now the 90mm refractor has an unimpeded 282.74 square mm of light
gathering capability.  So just in these numbers alone the 90mm refractor
is essentially the same as the ETX-125.

Now also consider that each and every time light is reflected we have a
loss in light intensity.  There are two light reflections on an ETX-125.
 Only one refraction on the 90mm.

As I cannot speak, scientifically, about the comparative optical
qualities of each scope, specifically the mirrors used, it is just
interesting to note that my wife's and my experience with these two
scopes are verified by the math along with the physics of optics.  We
should and do see more faint objects with the 90mm than we do with the

Have a good weekend skygazers.

Blais Klucznik
Mike here: Thanks for the update. The ETX-125EC is a Maksutov-Cassegrain, not a Schmidt-Cassegrain, although the designs are similar. And yes, the central obstruction does prevent some light from reaching the objective. But aperture size also affects the maximum usable magnification. And telescope focal length also comes into play on how well a given telescope does a given job. And, as you correctly noted, so can the optical design.


From:	rseymour@wolfenet.com (richard seymour)

> [comparing] a 90mm refractor alongside the ETX-125, we both felt that
> we could see slightly dimmer objects, and better resolution, with the
> 90mm than the ETX-125.

and then you provide a good analysis of the effectively equal clear
aperture of the two scopes...

What you left out (in favor of the refractor) is that the secondary
mirror of the reflector also damages the image quality in other ways.
(the black dot you see when you de-focus).

This is why refractors, or off-axis reflectors (no obstrucing
secondary) are -far- preferred for detailed planetary observation.

The central obstruction will cause a "softeing" (loss of crisp detail)
in the center of anything you look at.
For stars, which have no detail, that's not a problem.
But for anything with detail, it is.

The same effect can be seen with a 500mm  mirror lens telephoto
if you take photographs of birds ... the feathers lose their crisp
detail in the very center of the image, whereas the surrounding
feathers (or grass or leaves) will be visibly crisper.

--dick (very uncrisp)
From:	marbla@naisp.net (Blais Klucznik)
I hope you folks aren't taking me as negating the 125 optics for I am
not.  I was just trying to determine a more plausible reason as to why
the 90mm is our preferred scope compared to the 125.  Nothing else was

As far as focal length et al is concerned Mike, it becomes a mute issue
if the scope is limited in capturing light.  This was a point I was
trying to make in my original note.

As a disclaimer I will NOTE as CLEARLY as I can that I am no optics
expert and probably will never be one.  The battle, not of the sexes,
but of the two scopes is right here in Attleboro between my wife (90mm)
and myself (ETX-125).  It's just that we both agree on this one.

Things will be better, if the sky cooperates, when we get out 12-1/2
Dobsonian.  Maybe we'll get a more realistic feel as to what actual part
the glass plays in the scheme of things.

Have a good weekend all.  We have a very lovely but completely clouded
firmament here in Attleboro and it's expected to hang in there for a few
more nights.  At least we can catch up on our email.

Blais Klucznik
And this point:
From:	RMOLLISE@aol.com
In a message dated 6/2/01 12:29:26 AM Central Daylight Time, marbla@naisp.net writes:
            As far as focal length et al is concerned Mike, it becomes a
            mute issue if the scope is limited in capturing light.  This
            was a point I was trying to make in my original note.

It's not a moot issue if you don't use an eyepiece that delivers the
same magnification in both scopes when you do your comparisons!

Rod Mollise,
Author of _Choosing and Using a Schmidt Cassegrain Telescope_


I am fortunate in being able to correspond with many of the folks who
use Mike's ETX User's Group.  No matter what points or issues are
discussed, and in some cases we disagree on some points, the folks here
have always been courteous and well-mannered.

Even in those few cases where there is a difference of opinion I find
myself expanding my knowledge of telescopes, and astronomy, by
investigating those points of view others may introduce.

I find this a very pleasant experience.  Once again I thank the members
of this fine group.

Blais Klucznik
From:	marbla@naisp.net (Blais Klucznik)

I'm not exactly sure what you mean here.

> It's not a moot issue if you don't use an eyepiece that delivers the
> same magnification in both scopes when you do your comparisons!

For instance:  The ETX125 has a FL of about 1900mm whereas the 90mm's FL
is 1000mm.  That is about a 2-to-1 ratio.

Using a 12mm eyepiece the 125 should have a magnification about 2x that
of the 90.

Are you saying to run a comparison I should use a 12mm in the 125 and a
6mm in the 90mm ?  If so, what is the purpose of this type of test?  If
not so then I don't understand your statement.

If you use a 12mm eyepiece in both scopes, sure, the image will always
look brighter in the shorter focal length scope. How are you going to
evaluate image brightness? A higher magnification image will always
appear larger and dimmer. In order to see which scope "has brigher
images" you must have both instruments at exactly (or at least close to)
the _same magnification_!

Rod Mollise,
And this:
From:	marbla@naisp.net (Blais Klucznik)
I see what you mean now.  I do think I may have done this but because of
the different combinations of eyepieces and two different scopes, with
no notes taken, I cannot be sure.  So next time we have some unclouded
skies at night I will make a comparison, with notes.

Let's see now: "Unless one speaks with numbers little information is

I think this may have been Lord Kelvin but I'm not sure.

Blais Klucznik

Subject:	ETX-125 Tracking Noise?!
Sent:	Friday, June 1, 2001 11:30:59
From:	gaudetr@nbnet.nb.ca (Robert R. Gaudet)
I just recieved my ETX-125 EC scope today, and I was wondering if it is
normal for the tracking mode to be noisy....it sounds like the scope is
growling. I would expect slewing would make noise, but tracking???


Rob Gaudet.
Mike here: In Alt/Az mode there are two motors running to move the scope in two directions at the same time. That may sound like growling. In Polar mode only one drive is running so the sound should be somewhat less. But for a new scope it may sound loud until the mechanical parts settle in.


Even when it "SEEMS" to be tracking....that's another problem, it
doesn't seem to be tracking well, at all. Did a two star alignment with
Vega and Arcturus, went back to vega, perfectly centered, but the scope
is not tracking, it is in siderial tracking mode....any input would be
appreciated, so far it is looking like a returned scope on Monday. It's
a shame too, because the optics are great.
Mike here: Some questions: 1. Does the Autostar have at least 2.0 software in it? 2. Did you set the proper location, date/time/Daylight Savings, telescope model, mounting mode settings? 3. Did you TRAIN the drives when you got it home from the dealer? 4. Is the base reasonably level (assuming Alt/Az mode)? If all the above is OK, try RESET on the Autostar and then start over, including TRAINING. Who knows what condition the Autostar's memory was in from instore use.

Subject:	ETX125 RA Hard Stop
Sent:	Friday, June 1, 2001 5:18:04
From:	cbrown666@hotmail.com (Charlie Brown)
First, the usual words about your site : great, huge mine of

I read through the whole archive but could not find a solution to my
problem though.

How is possible to access the hard stops of the RA axis ?

My scope would not turn more than 3/4 of a turn before hitting the hard
stops. I put it upside down to remove the bottom plate and reach the
motor but no hard stop in view. When I put the scope back in the proper
position, it was then able to do the normal 1 3/4 turn ! A click is now
to hear when the scope passes over the position where it would hit the
stop before. I think there is something loose in there or the hard stop
has not been set properly.

The optics are great and I do not want to send it back to Meade. I would
therefore like to open it without breaking everything :o(

Any hint would be much appreciated.

Thank you,

Mike here: I suspect you were not hitting a hard stop but something else was catching. There have been reports that a wire has gotten too close to a gear (and even been cut) so you may have been touching a wire. Look more closely inside at the position where you hear the click. If a wire has been damaged you should probably return to the dealer (if new) or Meade for repair. Alternatively, you can take advantage of Clay Sherrod's Supercharge service.


I will check closer around the position to find what could be wrong. If
I can't find anything I will then send it to my dealer.

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