ETX-90EC USER FEEDBACK Last updated: 29 September 2000

This page is for user comments and information specific to the Meade ETX-90EC. Comments on accessories and feedback items appropriate to other ETX 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:	 Help
Sent:	Thursday, September 28, 2000 09:13:39
From:	kahunadad@earthlink.net (Brian)
Mike I think your site is just fantastic.  I am new to the hobby of
astronomy and love it.  I am however frustrated right now with my ETX. I
must tell you that I am the type of person that must have all the bells
and whistles when I get into something.  I know that this is not
necessary in Astronomy and that a working knowledge is better than all
the electronics for the most part.  Here is my plight and I woas
wondering if you could help me or post it on your site to have others
see where I am making my mistakes (sorry this is so lengthy)

I have the ETX 90 with autostar (I have updated to the 2.0 version)
Meade tripod
26mm lens
barlow and 9.7 mm lens

Here is my problem....I take the scope and tripod out side do the
alignment process to prevent the scope from hitting the hard stops (you
know spin it counter clockwise till it stops then back clockwise till
the arm is over the control panel) and point it due north (I cannot see
Polaris due to a tree a large one) but I have looked at maps, used a
compass and a GPS unit to verify that I am looking north (I can see the
stars of the big dipper that point to Polaris so I know I am close).  I
tilt the tripod head to 41 degrees (I live in Toledo Ohio) level the
tripod and start autostar.  I then select say a star, hit enter, then go
to.....the scope starts to slew (counterclockwise) trying to get around
to the star and hits the hard stop before it gets there.  thats
it....any ideas......

Added later:

it is on the west side.  When I turn it clockwise from the Hard stop I
am turning it maybe 180 degrees....maybe a little more maybe a little
less..I am following the instructions that came with the tripod but
sometimes it acts weird......batteries are new....i just am lost....

And:

same thing...the scope tries to slew the wrong direction...if it went
clockwise it would have to turn 360 degrees to get there but at least it
could do it instead of hitting the hard stop...

Subject:	 ETX-90EC Questions
Sent:	Wednesday, September 27, 2000 15:06:45
From:	edmitiu@flash.net (Ed Mitiu)
Hi!  I've been researching the Meade ETX-90EC.  It looks like a lot it's
a lot easier and more interesting to use than a regular telescope! . . .
had one of those already, but it was too difficult to find things in the
night sky and too touchy to focus and keep that way.

What kind of tips or advice can you offer me on buying a used model? Are
there any updates or improvements to the ETX-90EC that I should know
about?

I know of a guy who is offering his used ETX-90EC with the following
things included:

  # 497 Autostar Computer Controller
  # 825 8x25mm Right-Angle Viewfinder
  # 880 Table Tripod
  # 1244 Electric Focuser
  26mm Super Plossl Multicoated Lens

The # 1244 Electric Focuser . . . does the ETX-90EC come standard with
this.  If not, is it necessary . . . or recommended . . . to have the
electric focuser?

Is the # 497 Autostar Computer Controller included with this model or do
I need to purchase it separately?

And how about the tripod? . . . I've heard that it make using the unit
quite a bit easier . . . is that right?

This guy says he's only had it out of the box once and never did any
actual viewing with it.  Any ideas on what a fair price for this would
be?

I understand these are a lot of questions, but I would sincerely
appreciate any information or insight you could give me.

Thanks . . .

Ed

Subject:	 Using AC supplies with the ETX
Sent:	Sunday, September 17, 2000 12:59:19
From:	boudreau@eng.umd.edu (Paul J. Boudreaux)
I saw the email from Anonymous on Sep 15, 2000, USER COMMENTS ETX90
about how he/she had connected an battery powered electric drill charger
supply to the ETX. Most of these recharger power supplies are not true
DC level supplies. They often are merely half wave pulse rectifiers
designed to pulse charge NiCd batteries. You need a full DC level (no
pulses) to operate the ETX with an external power supply. When people
want to use an AC power supply with the ETX, be sure you have a true DC
output and not a pulsed DC level. Perhaps that is what happened to
Anonymous?

Paul Boudreaux

Subject:	 Re: Anonymous and the fried ETX***ETX90 E/C Section***
Sent:	Sunday, September 17, 2000 12:08:02
From:	dad@headplant.freeserve.co.uk (Damian Davis)
I've just read the posting from Anonymous (15 Sept), regarding the use
of an X-acto drill power supply, and the subsequent demise of his ETX.
This is sheer supposition, based on 25 years experience as an engineer
with a world famous Broadcasting Corporation based in Britain, but I
suspect that the nominal 12V from the X-acto PSU is nearer to 18V when
it is off load, dropping to 12V when driving the drill. The ETX will
take much less current than the drill (when the motors are not running),
so the voltage experienced by it will be about 15-18 volts, which is
probably enough to send it into the next world. These small 'battery
eliminator' type of power supplies are not regulated, and rely on the
load and their own internal resistance to give the stated voltage,
similar to your 12V car battery dropping to 8V while turning the starter
motor.

Others be warned!!   Use the Meade device, or a *regulated* PSU (9 volts
seems to avoid motor runaway, and is perfectly adequate), or take the
plunge and buy 8 NiMH rechargeables and the appropriate charger. (they
last longer than NiCads, and have less of a 'memory' effect)

If you want to use a PSU that you have 'lying around', then use a
voltmeter to measure the off-load voltage, as this is more like what the
ETX will experience, but if the PSU is a low power output one, then the
voltage will drop alarmingly when both motors are slewing, and you may
well get the 'Motor unit failure' (low battery) message as the ETX
stops. Best get the proper one.

Cheers,

Damian Davis, London.

Subject:	 ETX-90EC further review
Sent:	Friday, September 15, 2000 20:31:23
From:	Tim.Sheets@AMCG.com (Sheets, Tim)
It's Tim Sheets.  I normally write you from my home email, which is
tim@columbia.total-web.net.  Please post this latest installment of my
review of the truly "Mighty" ETX90-EC w/Autostar...

Well, after 2 weeks of ownership of my ETX, I finally encountered a few
hours of relatively good conditions for giving this little beauty a real
go at the skies.  The skies have been clear for several days now, but,
of course, the moon was nearly full and had been rising right at
nightfall. Tonight, I got in a good 2 hours of really putting the ETX
and Autostar through it's paces.

As I mentioned in a previous post, the alignment of the Autostar is
rather easy once you get the mount (table) level.  I set the scope in
it's home position, told it the date and time, and chose easy alignment.
Within a few seconds the scope had slewed around to the bright red star
Arcturus.  The star, though not visible in the eyepiece was easily
centered in the finderscope, and in turn, in the eyepiece.  Next, the
Autostar decided upon the much dimmer Alpharatz.  Once again, the star
was slightly out of the field of view of the standard 26mm Plossl, but
was very obvious in the finderscope.  A couple presses of the
directional keys centered the star, enter was pressed, and the scope was
successfully aligned.

I was set up in my rural, yet suburban back yard.  Street lamps and
neighbor's porch lights added to the light pollution.  However, the sky
was quite clear, with the beautiful Milky Way dim, but readily visible.

With no reference materials or charts with me, I decided to go after
some of the more well known objects.  I started with M13, the Great
Globular Cluster in Hercules.  After calling up the object in the
extensive database of the Autostar, and pressing "GOTO", the scope began
to slew towards the target. After a few seconds, the BEEP of the
Autostar indicated that the object had been found.  Foregoing the
finderscope entirely, I went straight to the 26mm eyepiece.  There it
was, not centered but well within the field of view, the fuzzy ball of
light that I expected to see.  After a couple of presses of the slew
keys, the object was centered.  Even through my light polluted skies,
the ETX gave me a wonderful view of this famous globular.

Next, off to one of my favorites.  Looking up, Vega, in Lyra was obvious
about 2 degrees from the zenith.  Alright, I thought to myself, let's go
after the most famous of planetary nebulae, M57, the Ring Nebula.  Once
again, the Autostar slewed the scope to the object and placed it well
within the field of view of the eyepiece.  This particular object made
the strongest case yet for the quality of the optics in this great
device.  At only 48X, under light polluted skies, the Ring shape of this
nebula was readily obvious with averted vision, and visible on occasion
when looking right at it.

Over the next hour or so, I viewed the Eagle nebula, the Dumbbell
Nebula, the Andromeda gallaxy, and a host of other deep space delights. 
All were readily visible, and within the eyepiece's field of view after
the Autostar slewed to it.  Though little detail could be made out of
the objects, I suspect this was more a problem in my light cluttered
location that with the resolving abilities of the ETX.  Of about 15
objects I asked the Autostar to find for me, 12 or 13 were within the
inner 50-60% of the FOV immediately upon the completion of the slew. The
other couple were visible, and only one was on the extreme edge of the
FOV.

I am simply overwhelmed with the accuracy of the Autostar, and the
optical quality of this scope.  I would strongly recommend it to anyone
as a first scope, or as a portable device for easy trips to dark skies.

One note of disappointment.  Though the tracking provided in Alt-Az mode
by the Autostar is certainly usable, it is far from perfect.  After
placing one of several globulars that I viewed into the eyepiece, I
stepped away from the scope long enough to have a smoke.  Upon
returning, the object was still in the field of view, but had drifted
from center to the outer third of the FOV.  I suspect utilizing an EQ
mount would remedy this situation

I hope to travel to darker  skies tommorrow evening.  If conditions are
better, I may provide one more review.

Thanks for allowing me to share this most pleasurable experience with
you folks!

Tim

Tim Sheets
NT/LAN Administrator
American Color Graphics, Inc.
Brentwood, TN

Subject:	 Fried electronics
Sent:	Friday, September 15, 2000 18:09:38
From:	Anonymous
Greetings (and kudos for the great site),

My question to you is where do I go for information regarding the
following?

I made a DC adapter following the ../techtips/power2.html instructions.
The power source I used is an old 12V X-acto hobby drill power supply.
Polarity of the DC adapter tip was correct. I fried my etx. From what I
recall of my college electronics course some 20-odd years ago, only the
impedence of the circuit determines the drawn amps; should be able to
plug it into the Grand Coulee Dam and the circuit would only draw the
amps it needs. So why the fry?

My etx's board was flaky before I started: it wouldn't come up in
RA-track mode, handbox unresponsive, had to flip on and off again 5 to
10 times to get its attention. (I really, really, don't like to flip the
power on and off. Electronic components like it even less.)

Does Meade not disconnect the batteries when a DC source is present in
the adapter socket? Did I zing the board with 24 volts?

Any thoughts?

Subject:	 surge in RA drive when adjusting at slower setting
Sent:	Tuesday, September 12, 2000 01:53:29
From:	chris@mail.eiscat.rl.ac.uk (Chris Davis)
Thanks to the enthusiasm of yourself and the good people who contribute
to your pages, I have got back into astronomy as a hobby having pursued
it as a profession for the last 10 years (can't tell you which star is
which, just a hand wavey explanation as to how they work!).

I have had my ETX90 EC for about a week now, running on the table tripod
and powered by batteries and without Autostar. I've been blown away.
This scope is far better than the cumbersome 4" refractor I used as an
undergraduate student.

Anyway, last night I was after M31. The scope was tracking fine and was
trying to centre the image by setting the hand-controller to the slowest
speed. At what seemed like random occasions however, the depression of
the RA control would result in the scope slewing at (what sounded like)
high speed and the image was momentarily lost. In under a second, the
scope regained its senses and tracked at the slower speed again, but I
now had to back track to where I was before I attempted the fine
adjustment.

I seem to remember seeing someone enquiring about the same 'feature' in
your archives but, as these are so extensive, and I read through quite a
few of them (therefore not leaving an obvious trail), I now can't find
it again!

Does this behaviour ring any bells?

Cheers,

Chris.

Subject:	 ETX90/EC Second Session
Sent:	Thursday, September 7, 2000 20:41:08
From:	tim@columbia.total-web.net (Tim Sheets)
Please add this to my previously submitted initial observations of the
ETX90/EC...

After 2 nights of complete cloud cover, the skies opened up last night
night enough to get in some more use of my new ETX90/EC.

As I stepped out of my house with ETX in hand (note, hand, singular,
very light, at just less than 9 lbs.),  2 bright "stars" rather close
together in the eastern sky stood out strongly, as though they didn't
belong.  Hmmm, Jupiter and Saturn perhaps.  As the area on my patio that
I generally consider to be the area that I will do most of my viewing
has a large row of very tall trees to the east, I decided to go ahead
and sit the ETX down on my steeply sloped driveway as to avoid the
obstruction and take a look at these objects that are so near and dear
to most of us who enjoy the night sky.  In a matter of seconds I had
centered the first of the two objects in the 8x21 viewfinder.  It was
readily apparent even through the viewfinder that my assumption of this
being a planet was correct.  However, I did guess incorrectly as to
which was which.

Through the 48X 26mm standard equipment plossl, Saturn was small but
brilliant.  With less than perfect skies the Cassini division was not
visible, but Titan was obvious.  Once again I noted the incredibly clear
optics of the ETX.  After looking at this, my favorite object above all
for several minutes (or was it hours?), I slewed the scope down to the
other bright "star" and sure enough, there was the Jovian giant, in all
it's glory.  Once again, through the only eyepiece I currently own, the
image of Jupiter was small but breathtaking.  3 of the four moons were
obvious, and no less than 5 bands were visible on the disc, the cloud
bands of Jupiter's atmosphere of course.  Wow, the more I use this
little wonder, the more I am impressed with the quaility of the optics.

Ok, enough of the Solar system, let's get out in deep space.  I took the
scope down to the patio and placed her on the patio table.  This is
where my story gets frustrating.  After 2 hours, well past midnight, on
a work night, and many attempts at aligning the Autostar computer, I had
to give up.  It seemed no matter how much care I took in attempting to
properly set the scope in it's proper home position, the alignment stars
were never anywhere near the fov of even the finderscope after the ETX
slewed to the "approximate" position that it thought the star's should
be.

After coming inside, and, though completely exhausted, reading
extensively on the topic of alignment from Mike's great site, I believe
I have realized my problem.  From what I gather, reasonably accurate
leveling of not only the OTA, but of the scopes mount (in this case, the
patio table) is critical.  I can say for certain that my patio, and
therefore patio table, being on a hill, is far from level.

The skies are completely overcast again tonight, but as soon as they
clear, we'll get a level out, and get that table leveled and try again.
More to come....

Tim

Subject:	 ETX90/EC First Night
Sent:	Monday, September 4, 2000 19:57:05
From:	tim@columbia.total-web.net (Tim Sheets)
Well, I finally got up the nerve to tell my wife I was going to by a new
telescope.  I had decided on the DS114/EC as the cost was not overly
prohibitive.  But what I really wanted was the ETX90/EC.  Well, I got to
the mall, and walked in to the Discovery Channel store.  I pointed at
the DS114 to the sales guy and asked him to get one out and I'd take it.
While I was waiting for him to return, I was pleasantly surprised to
see that this local store had knocked the price of the ETX down to $507
in order to compete with a sale that the Natural Wonders store is
running nation wide.

So, after a little prodding I convinced my better half to allow me to
buy the ETX90EC and #497 Autostar instead of the DS114EC and the #495
Autostar.

After visits to several woman's clothing stores and such (had to go
wherever she wanted after having just spent $700), I drove my new little
toy home.

Straight out of the box I was overwhelming pleased.  The unit came very
well packed and it was obvious that everything was there and in good
shape.  This is truly a wonderful looking little device.  I installed
the batteries and hooked up the standard hand controller.  As was
expected, I pressed the buttons and the sweet little scoped moved on
command.  One note of irritation is that the drives seem to have enough
play as to cause a delay in full movement speed.  For example, when
pressing up, at full speed, the scope hesitated for a moment, then moved
slowly at first, and finally full speed in the up direction.  Though
this is a bit annoying, I don't see it as a problem. Also, the gear
noise that is commonly complained about was blatantly audible, but
certainly not too loud as to become annoying.  I simply don't see it as
an issue.

Well, at this point, it was early dusk.  I decided to hook up the
Autostar and take her outside to run the required one time training of
the Autostar to match the specific gears in the scope.  Easy as pie.
First you aim the scope at any specific distant terrestrial object, then
tell it to start, it moves the scope a bit to the left, then tells you
to move it to the right using the directional keys to recenter the
object and hit enter.  Once you've accomplished this in all 4
directions, the training is complete.

I was frustrated as the sky was still very hazily overcast and though it
was nearing darkness, I couldn't see a single star.  My 10 year old
daughter quickly pointed out however that the moon was readily visible.
Hmmm, ok, sounds good.

I used manual controls to center the moon in the 8X21 finder, then moved
to the 26mm eyepiece.  I had to recenter the moon as my finder was not
aligned well, but this was my doing.

Once aligned, I was in awe.  The terminator presented hundreds of
beautifully displayed craters, as well as many Maria.  Even through hazy
skies, the presentation of Luna was overwhelming.  Quite obviously
superb quality optics.

Now, if this darn haze will go away before I have to go off to bed.

Will write more as soon as I get some clearer skies.  Tonight, perhaps,
but not likely.

Tim Sheets

Subject:	 Re: Power Source Modification
Sent:	Wednesday, August 30, 2000 10:05:19
From:	watt@okisemi.com
I have a similar problem that was reported by Ron Marriotti on 3/20/00
titled "Power Source Modification" under technical tips - Misc.

With my ETX90/EC, I also have the dec motor drive wildly 5 to 10 degrees
when the Meade AC adapter is used. It usually occurs within 10-15
minutes of alignment and tracking.  I also spoke with Meade tech support
and they had only two suggestions:  Use a surge protector and live with
battery power only.

I bought the Radio Shack RF filter, and a surge protector that Meade
tech support suggested.  Never a problem with batteries.

I was excited to build Ron's voltage regulator and put it inside of the
AC adapter housing after setting the voltage at 10V as specified.

When I turn-on the scope, I see the power LED light momentarily and then
go out. Went back to battery and see no problem, so I assumed that the
regulator voltage was a bit too low.  So I tried 11V, 12V, 13V and went
to the max that the regulator would put-out (14.5V).  Still the LED
lights and then goes out.  The raw voltage from the AC adapter is 15.5V.

I'm not sure why Ron was able to get the 10V to work and mine doesn't.

Anyone else have this problem?

Any further commentary regarding the fix?

Thanks for your effort in the web site.  It sure is a great asset to ETX
users.
 
-Phil Watt

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