Last updated: 30 March 2006

Welcome to the Autostar feedback page. This page is intended to provide user comments on using the Meade Autostar, cables, and the Autostar updater software. See the Autostar Info page for information from Meade and other users on the Autostar, cables, and software. Send your comments and tips to Remember, tips described on this site may invalidate the warranties on your ETX and accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	Autostar controller #497 EXT problem
Sent:	Wednesday, March 29, 2006 22:09:45
From:	Eric Mathews (
I have an older 125ext with a #497 Autostar controller.  It's never been
upgraded, so I bought a #505 cable and proceeded to do the upgrade.  It
appeared to be working just fine, then the controller just went blank.
The scope motor has power, and it has moved a few times with the
controller hooked up.  I've tried turning it on in the safe mode by
holding down the scroll down arrow and then turning on the scope.  I'm
pretty unhappy at this point as I don't want to buy a new 497.  Any
suggestions?  Thanks in advance.

Regards, Eric
Mike here: SAFE LOAD mode is entered using by holding down the ENTER and SCROLLDOWN keys at the same time and then powering on the telescope. You can't just use one of the keys. You will see FLASH LOAD ready on the screen (unless it is a really OLD OLD OLD Autostar). When you see that, then run the Autostar Update application; it will detect that mode and let you reload the ROM. Remember, you will need to re-enter all your settings, CALIBRATE MOTOR, and TRAIN DRIVES.


Thanks for your quick response.  I've tried the procedure w,/ both
buttons several times to no avail.  The controller appears to be totaly
dead.  This is an old unit, I believe about the first generation.  When
I bought my scope, there was a note stating my unit had been upgraded to
the "new" #497.  Any ideas on the best place to obtain a replacement?
Thanks again for your response.

Regards, Eric
Mike here: Ah ha! The original models, and for a short time after that, didn't have the SAFE LOAD capability! You check eBAY or even my FOR SALE page which occasionally have Autostars for sale. Also, you might check Telescope Warehouse (link on the Astronomy Links page).
Subject:	advice for 497
Sent:	Wednesday, March 29, 2006 20:29:56
From:	lawrence fry (
I noticed you are on the board of advisors for Meade4M, and you flew in 
the air force.

My father retired from the USAF, 20 years, as a master sgt, flight
examiner C41 (he was a flight engineer). He served many years in SAC.
When I was a kid, we lived in Bermuda (where he supported air rescue for
mercury and gemini missions), and later we lived in Bangor, where he
served at Dow AFB. He retired from Charleston AFB, and lives in south
Georgia now.

I am handicapped from a car accident, and can only use my roboscope
eq3/autostar 497 from my balcony in Denver. I have an orion 80ED, and
127 mak, and have a lot of fun with astronomy.

Unfortunantly, I cannot get a shot of the north, and only have southern
and western views. Drift aligning is out for me because of the time it
takes, and my handicap. I would like to get how far off my polar
alignment is from the autostar 497 pointing model, but it does not give
this information. A recent post on Meade_Autostar yahoo group seems to
indicate that Meade could actually do this, they just don't want to do

Could you please use your position as a Meade advisor to suggest this
small change in autostar 497? It would be really useful for me. I
understand that Celestron nextar controller is already providing this

Sorry for the complete brain dump.

With kind regards,

Lawrence Fry
Denver, CO
Mike here: Good question. I suggest you also pass it on to Don't expect a response (although some people have gotten them). They like to here directly from users with inputs like this. However, there is a tip you can use. Set up the telescope in the approximate Polar Home position and select an alignment star you can see for the first star. After the Autostar slews to it, reposition the telescope/tripod until you get the telescope pointed as close as possible to the star, then complete the centering using the alignment star. Do a second star normally (ie, don't move the tripod). The repositioning of the tripod for the first alignment star compensates for some of the error in the Home position.
Subject:	about alt/dec & az/ra ratios on autostar 494.
Sent:	Wednesday, March 29, 2006 01:02:57
From:	luis antonio (
first, sorry but i dont speak english, only spanish. i try to say my
question. thanks.

i have a ETX70AT with 494 autostar controler and i lost de values of
AZ/RA and  ALR/DEC ratios. i can recover this values or recalculate.

i can control the ETX70AT WITHOUT connect the autostar to ETX70 ?

very thanks for y you  patient.
Mike here: You can restore the ratios by doing selecting RESET on the Autostar (from the menus). To control the ETX you need to connect the computer to the telescope AND use the Autostar. The Autostar is required.


sorry but i try it in other ETX and this values didn't  changed. Are the
same the another ETX.
Mike here: What "other ETX"?


i have 2 ETX70AT and only 1 autostar 494.
i can use the 2 ETX (one each time) with the autostar 494 without change
the values of Alt/Dec ratio and AZ/RA ratio?

Mike here: So, what values are appearing when you do a RESET?


the same values pressing reset in each ETX.
Mike here: Then I would think your Autostar has the proper values for your telescope.


thanks for yout answer and sorry for my insistence. i have very troubles
for comunicate with you.

it had a autostar with 2 values for Alt/Dec and AZ/RA ratios (both
equals). this autostar is dead and meade send one new with one new
ETX70AT (?). the values of the new autostar they are different that the
first autostar (the dead). i try to connect and reset de new autostar in
both ETX70 and the values don't change in both ETX70.

because they sent a ETX70 with the autostar. calibration in factory of
this values ?

thank you very much
Mike here: Yes, maybe we have lost something in translation! But I'm still confused. Regardless of what the values are, does the ETX GOTO and track correctly?
Subject:	ETX-125 Autostar Question
Sent:	Sunday, March 26, 2006 17:23:33
From:	Dave (
I searched your excellent site before emailing but could not find the
answer to this question:

When I am try to align my new ETX-125 AT (Easy Align or 2-Star), after
the scope slews to the first star and says to press ENTER, I cannot
center the star with the motor by pressing the arrow keys as instructed
by the manual. Nothing happens when I press the arrow keys. Is this
normal? I must manually move the scope to center the star. This doesn't
allow for very accurate centering. Am I missing something obvious?
Best Regards,
Dave Snope
Mike here: You must never move the telescope manually to center an alignment (with one exception, which I'll mention next). Does the scope even slew to the alignment stars? If not, check that the axes locks are "finger tight" and not unlocked OR overtightened. Have you tried changing the slew speed to a faster speed? As to moving the telescope manually, you can pick up the telescope/tripod combination and rotate it horizontally until the first alignment is close to be centered; then complete the centering using the Autostar. This allows for a correction to be made in the HOME position you started with.


Thanks for the quick reply, Mike.

The scope does slew itself to the alignment stars. It just won't let me
use the arrow buttons to slew to center the star.  I can use the arrow
buttons to slew the scope when I am NOT in Autostar alignment mode, for
example when I first power up and skip the alignment process I can use
the arrow keys to slew the scope. I'll double-check my axes locks, but I
believe that they were OK as they were. I will also try changing the
slew speed as you suggested. But right now, I don't hear the motors get
actuated at all when I push the arrow keys.

My next option is to pack up the scope and drive to a dealer and demo
the problem to them.
Mike here: I usually use a slew speed of 7 when centering the alignment stars. By the way, don't forget that you need to a CALIBRATE MOTOR and TRAIN DRIVES on the new scope, and occasionally thereafter. CALIBRATE MOTOR needs to be done whenever changing the power source, including swapping in fresh batteries.


Thanks again, Mike. It was the slew speed. It was on the slowest setting
and I couldn't tell that it was moving. Rookie mistake. Although, one
short sentence in the manual would have prevented my confusion.


Subject:	re: MEADE ETX125EC: Autostar software version
Sent:	Friday, March 24, 2006 19:46:29
From:	richard seymour (
I suspect the "Updater crashing" is in part caused by the ancient
v1.2 in the Autostar.

I believe you will need to -first- update to v1.3, with that
vintage of Updater, and then you can leap to the current v41Ec.

To update to v1.3, download -this- kit from Mike's sire:

That contains -both- the Updater -and- the v1.3 firmware.
Install that updater (it might live in harmony with 3.62,
i don't know... it usually puts itself in a different spot).

Then use -that- updater to install v1.3

Then -remove- that Updater (using windows' uninstall)
and fetch the -newest- Updater (v4.3) from MEade's support page:
Install that, and use it to install v41Ec firmware
(it can fetch it for you, or you can download it from:  )

How to use the Updater is covered at:

good luck

Subject:	MEADE ETX125EC: Autostar software version
Sent:	Friday, March 24, 2006 12:58:22
From:	Minos Minos (
I recently purchased a second hand Meade ETC 125EC telescope with an
Autostar controller. I believe the telsecope is a number of years old
but is in a very good condition. I am however having difficulty in
upgrading the Autostar Controller with the latest software. When I start
the controller it shows the following which I assume is the version of
the software. (c)99 Meade [ 1.2]  I  get a Windows exception/application
error which closes the Autostar Updater (V3.62) each and every time  I
try to update the software or retrieve the sofware from the controller.

Can the error be caused by the software on the controller which seems
old. If that is the case can you suggest any way to update the software.
Will I also be able to update the software since the controller shows
10.1K of free memory It might also be that the error is caused by the
USB to RS232 converter (Mecer) that I use.

Any advice on this will be apprreciated
Mike here: I wouldn't think that the Autostar version would cause the app crash. You didn't say what version of Windows you are using but you might want to try the ASU 4.3 version from Meade's site. Note the comment "If you have previously installed the Autostar Update (ASU) Client Application for Windows, Uninstall the old version before installing this new version."
Subject:	etx 125ec and autostar issue
Sent:	Wednesday, March 22, 2006 20:05:48
From:	rxpc (
I was performing the scopetronics tune-up the other night and I wanted
to test the RA motors to see if they have improved in the tracking speed
#1, but I noticed when I turned on Autostar and entered the
date/time/DST the RA motors started running!  I never noticed this
before of course because I never had the bottom cover off.  Do you know
if this is a problem with Autostar? Or maybe the etx electronics?

I also noticed that by keeping the Autostar very near the motors when
testing the speed, the motors sped up very fast! In fact, so fast, that
I believe they were running faster than #9  Any ideas?  I'm using the
patch 41cc

I appreciate any feedback you can give me.
Mike here: I haven't heard of anyone holding the Autostar near the motors so I don't know if there is any electronic interference or other reason for the speed change. As to the motors running when you power on, was it a single movement (like when you do a CALIBRATE MOTOR) or one or both motors running continuously. Were you able to do normal operations with the Autostar?


The motors run continously and seems to be at guide speed.  I left it
that way for a good 10 minutes and the motor continued to run.
Otherwise, Autostar performs as expected.

I tried this out again last night, after entering the date/time/DST,
Autostar displays "ALIGN: EASY", I decided to press enter, which goes
into the Polar Align procedure and the motor stopped!

I never had a problem with Autostar or scope movement(except at guide
speed #1, which only seems to move in one direction).

Again, thanks for your help,
Mike here: So you are in Polar Mode?


Yes, I always have the scope polar mounted and I make sure Autostar is
setup for polar mount.
Mike here: That explains it. Normal in Polar Mounting Mode.


Ohh, good. I was beginning to think it was the
#497 Autostar controller.  
Your site is an excellent resource and I greatly appreciate your time
and help!

Thank You,

Subject:	ETX 105 Auto align problems
Sent:	Tuesday, March 21, 2006 13:45:14
From:	Graham Gillett (
I've just got an ETX 105 but I have an annoying problem.  My main
viewing area is a Velux window in my attic, not ideal I know,  but I
have put up a sturdy shelf below the window and have a reasonable
segment of the sky to view. There is also a large chimney stack to one
side and therein lies my problem. The auto align's first selection of
target star seems to be always behind this obstruction and therefore
cannot be centered. The second star is OK and although Autostar says 
"correctly aligned", tracking to a chosen star afterwards is way off.
The finderscope is correctly aligned so I am assuming Autostar needs
both stars to be centered for the tracking to work. Is it possible to
choose another bright star in my field of view to align to ? There
doesn't appear to be this option in the manual.
What do you think ?
By the way -----  Very good site !
Regards Graham , Hastings, UK
Mike here: You can just assume the first star is centered. If the Autostar starts from a known good HOME position, and we'll assume it does since you are doing an Auto Align using the LNT, the first star should be close. So just press ENTER when prompted. Center the 2nd star or just press ENTER if you can't see it. However, if there is any error in the HOME position (or date/time/daylight savings) this won't work too well. But you can select another star by pressing the SCROLLDOWN or SCROLLUP keys when prompted to center the alignment star.


 Hi Mike, thanks for your reply, I've found the alternate star
alignment  and on a daylight run it seemed to work. So that should be
sorted. I've just come across another hic-up though. Bought the Meade T
adapter and the Minolta T adapter, both fit perfectly as they are
supposed to, so far so good. BUT, I have a Minolta 7D digital body which
refuses to take a picture because " No Lense is attatched ". BUGGER!!!!

Without a lense on, the internals look the same as my 700si (analogue)
Minolta which does fire without a lense on.

Have you come across this problem before?
Regards Graham


Hi again, please ignore my last request for help, I've fiddled about a
bit more and worked it out.
Thanks again
Regards Graham

Subject:	Autostar update
Sent:	Monday, March 20, 2006 11:16:57
From:	Robin Durant 2 (
I want to update my old model Autostar via my MAC OSX using AstrostarX 
-  Questions - Do I keep the Autostar connected to my ETX125 powered up
or alone with the computer and do I need to reset it before updating. If
I don't need to reset will it retain my settings after uploading.

Robin Durant
East Sussex
Mike here: No need to RESET before the update. BUT I always CALIBRATE MOTOR and TRAIN DRIVES after doing any Autostar update. And since the Autostar gets its power from the telescope base you do need to leave it connected. That is unless you make one the 9V power adapters for the Autostar. See the Helpful Information: Autostar Info page for more on this type of external power source for the Autostar.
Subject:	Motion Control?
Sent:	Sunday, March 19, 2006 17:18:45
From:	Mark Cruikshank (
Hiya Great Website,

would like to know something, am wanting to shoot multiple shots for a
time-lapse using digital stills camera mounted on a Autostar head, is
there a way of programing the head to move wherever you want or is it
all pre-stored in the autostar?  Am taking wide angle shots of the night
sky but want to pan slowly over 4 or 5 hours. 

thank you for your time,

Mark Cruikshank

Freelance TV Cameraman
Mike here: You can set up individual "landmarks" but that doesn't allow you to move the telescope automatically over time. I presume you still want accurate tracking of the sky so you can't adjust the tracking rate.


Cheers for the quick reply,

What i wanted to do was piggyback the camera on the scope and let it
take photos as the mount went on its way, set up one "landmark" and then
another one, then tell it to move from one to another over a certain
amount of time, I am a freelance Cameraman am looking for a certain
shot,,, but dont have the money for a hollywood style motion control

thanks for your time, great site by the way,

Mike here: I haven't checked but you might be able to do this with Mac OS X telescope control software by using Applescript. I'm not certain which, if any, allow Applescript control of the telescope movement.
Subject:	Trouble with the 497 controller on the Autostar
Sent:	Sunday, March 19, 2006 03:18:33
From:	Chris Colwill (
Firstly, let me congratulate you on an excellent and extremely helpful
website.  Although not the first and most likely not the last person to
say so, your site is exemplary in its assistance to fellow users of
Meade telescopes.

Turning to my problem, I have a new Meade ETX125EC telescope.

It appeared to have an old firmware (it appears a 2004 one) so I
attempted to update it.  One of the issues I had was the need to obtain
a USB/serial adapter (I acquired two) as I only had a USB port on my
computers.  I purchased the Autostar connector kit (505) and went to
upload using the Autostar program.

Program could detect the Autostar but could not upload - it came up with
the "try another serial port error and turn off the Autostar and turn on
again" message.

The issue was that my daughter turned off the telescope (even though the
Autostar program on the computer said it wasn't connect properly) whilst
the controller had the words "downloading" on it.  What I think I may
have done is gone to one of the settings in the controller called
download to see if that assisted.

In any event when the Autostar was turned on again, the LCD display on
the controller was corrupted.  I managed to locate a computer with a
serial port, safe "booted" into the controller with the enter and arrow
down buttons pressed at the same time.  I then managed to upload the
latest firmware.  However when the controller was turned on again, the
first line of the LCD display appeared fine but the second does not show
up at all. The LCD screen does however glow red all over and the control
keys work fine in moving the camera.

Although only about 2 weeks old, the controller has been dropped two or
three times on its 'head".

Could a bad flash cause the second row to go or is this likely from
dropping?  Should I try another flash, perhaps with a previous firmware?

Much regards,
Chris Colwill

Mackay, Qld, Australia
Mike here: Dropping the Autostar could have loosen something that could affect the display. Since the keys seem to work it might only be a display problem. It wouldn't hurt to try reloading the ROM again however. It could have been either a corrupted download from Meade's site or a corrupted upload. You might download the ROM file to your hard disk and then do the update using the local file (assuming you let the Autostar Update application to its thing via the Internet). As to USB, see the article "Autostar and USB" on the Helpful Information: Autostar Info page; you will see that only some USB-serial adapters are known to work well with the Autostar, others will have problems.


Thanks for the reply.

The screen was corrupted before the download, but I will try uploading

On your page here:

You refer to the first screen that appears after the download - What
shows on my screen is only "Press 0 to align" - the second row doesn't

I opened up the controller but was buggerred if I knew what to do.

I have ordered a Keyspan adapter so I can connect it to my Powerbook, as
I used a Wintel to upload previously (maybe that was the problem ;)  ).

Mike here: Use AutostarX to upload using Mac OS X.


Sorry to bother again, but I found out that all is not well with the 497

By that, it still controls the telescope, but at one speed, namely the
top speed ( 9 on the controller) - pressing another number e.g. 3, will
show up on the LCD the correct speed, but the camera does not adjust.

My major concern is that the firmware is contained in the telescope base
and not the controller - could you confirm that this is not the
position, as I would hate to have to replace not only the 497 controller
but the base as well.

Also tried a reflash but the second line of the LCD doesn't work.  Took
the LCD apart but all seemed okay.

Mike here: All the firmware is contained in the Autostar #497 handcontroller; nothing in the ETX base. It is possible that those drops you mentioned earlier have taken their toll...
Subject:	Precession Calculations in the Meade Goto Scopes?
Sent:	Saturday, March 18, 2006 11:18:50
From:	Robert Sheaffer (
The question has come up concerning the Celestron Goto scopes: what, if
anything, do they do about calculating the effects of precession? And
Mike Swanson has confirmed the answer: nothing. Celestron scopes treat
all positions as J2000.

So, let's let the "other shoe" drop: What, if anything, do the Meade
Goto scopes do about precession? If I give them a Goto position, do they
assume it is Epoch 2000 and precess it to Epoch 2006? Or do they simply
ignore the effects of precession?

Precession can typically amount to a minute of arc every two years.
Given that people are expecting Goto accuracy of a few minutes of arc,
you can see that this question cannot be put off indefinitely.......


Robert Sheaffer
Mike here: I suspect that it is ignored. Most people don't center the alignment stars with an accuracy of 1 or even a few arcminutes. I don't know if the Autostar II, which is used on the current, more "professional" LX200 models, handles it any differently.


From:	richard seymour (
There are a number of answers to that:
(a) when you enter an RA/DEC pair (from the keypad or via a PC),
 the scope goes -there-.  It expects that -you- have adjusted
 for precession.  (think: this is the correct action if you're
 chasing a comet... the data are -now-)

(b) the LX200gps uses many catalogs (Stars, Deep Sky, etc.)
 They have different base Epochs.  For each of them, the
 Autostar -does- adjust the precession to J-now-.
This also applies to the RCX400 and LX200R.

(c) the 497 Autostar i'm not so sure about... it's simply
been -years- since i've looked at that spot in the code.
It will take me a while to exhume the vintages of firmware
where i chased that thread...

As you say, at the moment it's probably within the normal
error range of the scope's motion.
Meade has the technology, as is demonstrated in the LX200gps,
they merely have to choose to implement it.

have fun


So, when the Meades do their star-alignments, they use "Arcturus 2006"
instead of Arcturus 2000" for their calculations? And then Go To "M57
2006"? The Celestrons apparently can't be bothered to do all this.

If I understand this correctly, the proper action for RTGUI would be:
for Celestrons, always use J2000 positions; for Meades, keep the current
algorithm (precess all Gotos to current epoch). As for the Autostar 497,
well, it doesn't work reliably with RTGUI yet (it'd be nice if I had a
unit to test with), so I suppose that the precession doesn't really

      Thanks to you both,


And more:

[precursor note: i just (-after- writing the following) went back and
read some of the recent message traffic in the rtgui Yahoo group
( ).  The reported Celestron
behaviour is odd.  I'll add comments at the end of this note based
upon those messages]
[they -did- cause me to revise my stance on "what to tell a Celestron",
but i really have no derived-from-firmware data to back that up]

Robert Sheaffer wrote:
So, when the Meades do their star-alignments, they use "Arcturus 2006"
instead of Arcturus 2000" for their calculations?

If you ask it to GoTo Arcturus, an Autostar II will GoTo the calculated
position of Arcturus 2006-03-18:20:25:31, (with a correction for
atmospheric refraction added in, +plus+ an optional SMT correction)
if that happens to be the date and time of your request.

If you ask a 497 Autostar to GoTo Arcuturus, i think it will use J2000.

> And then Go To "M57 2006"?

Same statement as above (substitute "M57" for "Arcturus").

> The Celestrons apparently can't be bothered to do all this.

They do what the 497 does (the 497 may factor in refraction...
i've seen it -nail- very low-altitude targets too frequently.)

If I understand this correctly, the proper action for RTGUI would be: 

Oh? These questions are in support of a commercial product?
Please send appropriate consulting fees to Mike's Site Fund.

for Celestrons, always use J2000 positions; for Meades, keep the current
algorithm (precess all Gotos to current epoch).

It depends what you're sending... if you're sending purely RA/DEC,
i can't believe that the Celestron -then- precesses them as if
they were J2000.  I would think/hope/believe that it goes to those
RA/DEC values.

Add into the mix that you have -aligned- these scopes against the sky.
Hence the scope's idea of where any star is is already shifted as
a result of the user centering the alignment stars.  So precession
will already be taken into account.  The scope's "idea of the sky"
is J-now-, because you just -did- it.
If the Celestron thinks that Arcturus is *there* (J2000), yet the user
centered it (Thereby taking precession into account empirically), then
it doesn't matter... the Celestron's view of the sky will have been
shifted to match the precession.  The same argument holds for the 497
Autostar.   Since the LX200gps shifted its alignment "guess" by the
precession calculation, it's OK, too, since everything is still centered
by the user.

If i were commanding any of the scopes, i'd always send it J-now-
RA/DEC.  Anything else would be wrong.  Second-guessing only leads
to grief.  [i changed my stance on this after reading the threads,
see below]

As for the Autostar 497, well, it doesn't work reliably with RTGUI yet
(it'd be nice if I had a unit to test with), so I suppose that the
precession doesn't really matter........

Define "doesn't work reliably"... what are you telling it (exact serial
commands, please), and where/how does/doesn't it Go?  We can kibitz.
Of the original Meade LX200 serial command set, there are only a few
Rate commands which may not work... and that list gets shorter with
each firmware update.

[Comments after reading rtgui thread:] If you ask an LX200gps Autostar
II for its catalog data, you can get *three* different results for the
 same object:
(a) the raw number from the catalog (stars are J2000, some DSO are
J1950) [added later: but i can't say it ever -tells- you this number.
  They can be extracted from the rom files (painfully), but they're
  never presented to the user in a friendly fashion]

(b) the raw data, precessed (Identify works from these) <-- this is
 what the handset Displays.  The act of selecting the star and
 scrolling into its database entries "sets" it as the next GoTo Target.
 And -that- action is when the precession calculations are carried out.

(c) You GoTo, and ask it for the current RA/DEC.... *this* value will
 have the skewed result of having refraction affect the destination,
 but i'm not 100% sure they factor in refraction in the "i'm pointed
 at RA/DEC yadayada" result.

A 497 Autostar should only provide J2000 numbers, and the GoTo may
toss in refraction, but it won't add in precession.  But since it
was -aligned- to the precessed sky, only some portions will be "off".

Given the J2000-ness, i -can- now see why RTGUI might want to send
J2000 back-precessed commands to a Celestron (and maybe a 497 Autostar).

Many folks use many star-chart programs to drive Meade scopes.
Many asteroid (etc.) hunters use LX200gps's, and have reported
"object on CCD" accuracy of remote-control GoTo's.
Usually LX90 (497 Autostar) users are pretty happy about the GoTo's,
too (they begin to whine about the long-term tracking).

have fun


I erred... RTGUI is freeware  (for Windows PCs only, sorry Mike...).
[never trust my memory for things non-autostarrish...]

have fun

Subject:	Autostar
Sent:	Thursday, March 16, 2006 01:45:27
From:	Robin Durant 2 (
Thanks to your help and your web site I nearly have my ETX125 Gotoing

However I still have problems with backlash which I understand I can
correct by altering the Azimuth Percentage to 15%  BUT my Autostar does
not have Percentage settings on it. It has  (99) 2.0 printed on it so
maybe it is an older version.  My question is, if I update it with a
download via my PC will it add this percentage facility ?

Thanks again

Best regards

Mike here: Yes, you need to update to a more recent version. You can update to the current version via Meade's site and the Autostar Update application. However, the precise percentage you need to set can be a somewhat trial-and-error thing. Be certain to do a RESET, CALIBRATE MOTOR, and TRAIN DRIVE after you do the update. Then see if the backlash is still a problem..
Subject:	autostar 494 serial by Gene S
Sent:	Thursday, March 16, 2006 00:25:04
From:	D.R. Huard (
I found quite a bit information submitted by Gene S on several sites. It
appears, though I could not find all the original messages, that he has
added an RS232 port to the 494 controller. I saw the last updates on However, since I could not find the beginnings of the
project, I had a couple of quick questions.

Does the serial port allow the 494 to be updated in the same manner as
the 495/497?

Does this port allow for complete control of the scope using an app such
as Starry Night in the same manner as the 495/497?

Probably much simpler just to buy a 495/497 on eBay, but hey, I like a
challenge. I am currently working on adding the AS to my old 2080. Like
I said, I like a challenge.

I appreciate any time you put into a response. I apologize if I missed
the information posted somewhere else, I really did look for it.
Thanks again
Doc Huard
Mike here: No, the #494 can not be user updated like the other models as Meade has not released any user-installable updates. But with the more complex #506 serial cable (the simpler #505 cable won't work) you can control the Autostar #494 from a computer that has a RS-232 port.


I was able to find an email for Gene, and asked him the same question. He
gave me more detail on what he was doing. I didn't think that it could
be easily used to update, but I notice he had hacked into the eeprom.
Anyway, got the basic info I needed. I will get a new AS on eBay and
then hack this one for fun.

By the way, last night was my first visit to your site. Just never
looked online for etx stuff. A good site and a great service.




I am going to play with 494 once I get a 495/97 to replace it. Then I
will see if a simple mod will open up the internal RS232 ports that Gene
found and played with. I will update you and the group if I find
anything of interest.


Subject:	Autostar 497 com port problem / 497 cord
Sent:	Tuesday, March 14, 2006 14:36:01
From:	Carleton Gotlieb (
I've seen a couple emails report a "com port not found" error message
when trying to connect the ETX to a serial port on a PC using the 505
cable. I had this problem a month or so ago when I attempted my first
upgrade. I tried everything and finally called Meade and they suggested
a replacement serial adapter. They sent one free and that fixed it, so
the PC now recognizes the ETX.

At the same time I called Meade, I complained that every now and then my
autostar would die and that I thought there was a bad connection to the
base of the ETX. So they also sent me a new cord for the autostar. When
I received it, I immediately noticed they had beefed up the connector at
both ends with additional rubber. In this way, when you move or pull the
cord around the telescope, there is less stress on the connectors and
the connections remain solid, and I haven't had this problem since.


Subject:	re: cable lengths
Sent:	Sunday, March 12, 2006 21:16:36
From:	richard seymour (
Once you have the rs232 signal, it's quite happy to go about 100 feet.
(i have controlled my Autostar/ETX90 with a telephone extension
cord providing the first 50 feet, and a coil-cord headset cord
providing the final 25 feet (the headset cord will plug into the
Autostar's serial socket).

The =spec= for rs232 is only 50 feet, but that's with a large
margin of safety/overengineering.

have fun

Subject:	re: Faulty Autostar, Random Slewing
Sent:	Sunday, March 12, 2006 20:57:21
From:	richard seymour (
The random pulses of motion sounds like at least one
of the main communication wires (or drivers) from
the Autostar to the scope is bad.

One test you can try is to *unplug* the Autostar,
then turn on the telescope. (a "headless telescope")
Does it operate in the same way?

If so, you're seeing an example of the (near-)total
lack of communication.

You could open the base of the telescope and look for
disconnected wires between the power panel and the rest
of the electronics, and open the Autostar and look for
damage near the cable sockets.

good luck

Subject:	Autostar 497 (30e) comm port problem
Sent:	Friday, March 10, 2006 09:40:51
From:	ray maclean (
I have an ETX105 and the astrofinder platform with a serial to rs232
link. When I try to make a connection between my PC and the telescope it
tells me that it can't find the com port (com1). When I try to connect
from Astronomers control panel it tells me Scope I/O failed. Port
already open (error=8005). Looking at my device manager it tells me that
it is working normally. What am I to do?

Thanks for being there. Ray  
Mike here: If you are connecting directly to a real RS-232 port (and not a modem or USB port) then check for a software conflict, such as fax software.
Subject:	Re: etx 125 alinement problems
Sent:	Thursday, March 9, 2006 05:29:30
From:	simon sinkinson (
Thanks for your help mike

I have bought a good star chart and when our weather cheers up I am
going to try try identify the stars  autostar chooses .

Is there a predictable order of stars  it will offer me?

Is there a list I can download of these stars?

As to the version of autostar software my controller has Can i find this
out with out the use of a computer as I don't have a cable yet to
connect the unit to a computer.

thanks again Simon
Mike here: Print out the Autostar alignment star charts on the Helpful Information: Autostar Info page. And the order of the stars selected will depend upon the date and time. You can check the version from the Utility-->Statistics menu item.
Subject:	Autostar
Sent:	Thursday, March 9, 2006 03:09:47
From:	Robin Durant 2 (
Following my quest to reduce backlash on my ETX125 I have found an
article on your site recommending that I use the Percentages on my
Autostar Control on the Telescope set up. On my Autostar I do not have
this "percentages" its missing.  Is my control too old, can it be added,
Mine is (c)99 - 2.0.

Best regards

Robin Durant
East Sussex
Mike here: You should update. You will need a #505 serial cable (which you can buy or make; details on the Helpful Information: Autostar Info page), a RS-232 serial port, and the Autostar Update application from Meade's site. If you use Mac OS X you will need the AutostarX application (see the Autostar Info page).
Subject:	Faulty Autostar, Random Slewing
Sent:	Thursday, March 9, 2006 00:56:52
From:	Roy Meyer (
The other night while observing, with the Autostar nestled on the tripod
velcro, the scope suddenly slewed up a bit, slewed left a bit, then left
a bit more. All random times in-between. 7 secs, 20 secs, 3 secs, etc.
Clearly had a mind of its own. I switched off and called it a night.

The next morning I switched on the scope, cleared the Sun warning, and
while going though the time, date, etc, the scope made small totally
random movements. I tried the direction arrows on the Autostar and they
didn't move the scope at all. All the time the scope was making small
movements up, down, left, right, any which way. I went through the menus
and Reset. The Autostar beeped and went through the Sun warning, etc,
but the random slewing persisted and the direction arrows didn't work. I
hooked it up to my Windoze laptop and this is what I did.

-   I started the Meade ASU and updated to a plain Meade version (33ef).
The whole time the update was progressing, the scope was doing its
random slew at random times. After the update, it still had the random
slew problem and the direction keys didn't work.

-   I started the Autostar in Safe Mode, ( Enter and down arrow )
started the Meade ASU and updated to the same plain Meade version. Same
thing, during the update, the scope did the random slew at random times
and afterwards the slew problem persisted.

-   I started StarPatch Trial and updated to the same Meade version, but
again, during the update, the scope randomly slew at random times.

-   Same thing with StarPatch and the Autostar in Safe Mode.

-   I started Hyperterminal and did a hard reset with Dick Seymour's
boot.rom file. That reset the Autostar, but the problem persisted and
the direction keys didn't work.

-   I checked the Autostar cable with my Ohm meter and the cable seemed

-   I tried reversing the Autostar cable between the scope and Autostar,
but that didn't help.

-   I put 8 fresh AA's in the battery box to try a different power
source, but the scope still randomly slewed at random times and the
direction keys didn't work. ( I normally use a 12v rechargeable battery
pack. )

Mike, what else can I try? Any help will be greatly appreciated.
All the best
Roy Meyer
Mike here: You likely needed to do a CALIBRATE MOTOR. I suspect that the batteries were low, which can cause random oddities unless you do a CALIBRATE MOTOR. Had you done that when the problem first appeared you could have cured it right then. Of course, you should always check the battery level by pressing the MODE key and scrolling the display until you see the battery level indicator. If it is significantly lower than 100% and you don't have new batteries available, doing a CALIBRATE MOTOR will usually cure it. When you change batteries you should also do a CALIBRATE MOTOR to adjust to the new power level.
Subject:	etx 125 alinement problems
Sent:	Monday, March 6, 2006 13:53:47
From:	simon sinkinson (
Thanks for a great site. I have been the owner of a etx 125 for two
weeks bought from ebay. It is fitted with a rikaline gps unit.

This my first ever telescope and last night I saw saturn for the first
time and was truly stunned as was my wife.

My problem is I have followed all the set ups to the letter I think for
alt alt-zimuth positioning and go through the easy aline.

As i am struggling to recognise the stars it chooses I can only hope I
aline the right star.

All seems to be ok and setup completes. I then ask it to go to the moon
this i can plainly see. The problem is  of it goes to the darkest part
of the sky in completely the wrong direction.

Could the small errors in my targeting the right stars in the group it
has given me train the telescope to looked wildly  in the wrong
direction (butterfly flaps his wings and all that) or might i have
bought a dud.

Thanks for reading this and giving a little hope to a middle age dreamer

Simon Sinkinson

New forest   England.
Mike here: If you are having trouble recognizing the alignment stars, print out the alignment star charts on the Helpful Information: Autostar Info page. As to GOTO errors, is the error only on the Moon?


The goto error maybe only on the moon because saturn might have been in
the region it went to last night , This is the only thing i recognize 
at present. Could there be a moon problem.
Thanks a million
Mike here: What version of the Autostar software is installed? If really old you should probably update it.
Subject:	can't change speeds in alt while training drive
Sent:	Sunday, March 5, 2006 16:30:45
From:	Pierre (
Your tremendous success with this fabulous web site makes it large and
therefore a bit tricky to find things in so I hope this hasn't been
asked before (I looked).    I am a beginner but I read a lot before
trying anything!

My autostar 497 doesn't allow me to control slew speed in the alt axis
during training but it does allow it in azimuth!   It's difficult to get
the target object re-centered at full speed.  A tiny tweak on the button
and one can overshoot (and can't go back).  Is this normal?  Might a
RESET help (power down and power up did not help)?

I would also like to ask why there are not more affordable low power
crosshair eyepieces (particularly with illumination) specifically for
GOTO scopes?   It seems a necessity but it costs around $100-- about a
third to a half of the cost of a good GOTO scope with everything on it! 
I can't tell the exact center of the eyepiece (I tried the defocus
trick and it didn't help much).  If proper centering of the target is
important, you'd think the manufacturer would come up with an eyepiece
to help!  Whatcha think?
Thanks again for the wonderful site.  
Mike here: You can't reverse when centering the object used for drive training. But why you can't change the speed is odd. Especially since there is only ONE slewing speed value that affects both axes. Unless you found a bug the same speed should be used for both. When I have changed the speed, both axes have been affected. As to an inexpensive crosshair eyepiece for drive training, you can always use a higher magnification eyepiece (assuming you have one). I have an illuminated reticle eyepiece but have NEVER used it for training; I just normally use the 26mm eyepiece. I guess I feel comfortable seeing the center of the FOV.
Subject:	ETX-105 Autostar error
Sent:	Sunday, March 5, 2006 15:08:39
From:	Randy Fosler (
I have never been able to align correctly with my ETX-105 & Autostar.  I
know how to set it up in Polar and in Alt/AZ mode -- the problem is the
AZ keeps turning until it hits the hard stop.  The Alt works fine.  I
use my Starry Night software to find a good star and then use one star
align.  The scope starts slewing the Alt stops perfectly at the number
shown on Starry Night.  However, the AZ keeps slewing and slewing --
then hits the hard stop.  I have tried reseting the Autostar and then
Calibrating and then Training the drives.  Everything seems to work
fine.  I tried reversing the cord connecting the handset.  I looked at
the connectors and they appear fine.

Any help as to why the AZ alignment slewing is not work is greatly

Mike here: What happens with a Two Star Easy Align? You can even do this test indoors; just assume the alignment stars are centered when prompted to center them.


I had also posted this on the yahoo groups for etx users.  Someone
suggested grease may be blocking the sensor that counts the "ticks" in
the gear.  I was skeptical, but tonight took the bottom off the base and
there was a large glop of green grease covering the sensor!  I cleaned
it w/ a Q-tip and it now works great!

Mike here: Yes, that will cause problems, which is why I wondered if the problem occurred when you did a different type of alignment. Always best to get more data before recommending a solution, especially when the recommendation involves "going inside" where it is easy to damage something.
Subject:	My ETX-125 Autostar handbox is fouled...
Sent:	Sunday, March 5, 2006 13:14:49
From:	Christopher Vanstrom (
First off, I love your site.  I've referenced it a great deal in the
year I've had my own Mighty ETX.

Now, on to business...  I got an ETX-125 w/Autostar almost a year ago.
While it has performed spectacularly viewing-wise, I've always had a bit
of difficulty getting it to connect to my computer.  My laptop doesn't
have a 9-pin port, so I bought a Radio Shack brand 9-pin-USB cable. 
That sort-of worked.

As I understand it, I should be able to control the scope through
Autostar Suite.  I can do that, but only in a limited fashion.  Instead
of being able to use the protocols "Autostar via Comm Port," "Autostar
via Modem," or "Autostar via Network," locate something on Autostar
Suite's starmap and tell the scope to GoTo it, I have to "Connect via
Handbox" and then can only control the scope via the mock-up onscreen
handbox.  That's how it's been since Day 1.

Now, after learning of this fabulous new comet, I decided to try to
update my Autostar --the handbox came with build 30E.  I set the handbox
in "Download" mode, then used ASU to try to update it while connected
via the handbox.  Well that sent everything straight to heck because the
handbox locked up during the download and now when I turn it on, all I
get is:
(C)03 Meade 30E

which is the screen that shows up just before you get "Initializing..."
when the handbox is funtioning normally.  Except that is where it stays.
Keypresses don't do anything, including move the scope.

When I boot the machine in Safe Mode, I get the same screen for a few
seconds, then it changes to:

And I still can't connect to it from my laptop.  I moved it to my
desktop machine, which does have a 9-pin port, installed Autostar Suite,
and again tried to connect to Autostar, but again failed.  I should
probably mention that I don't know exactly which Comm number is assigned
to the 9-pin port, but since ASU has tried to auto-detect over all my
Comm ports, I don't think it's really the issue.  At this point, I'm
lost.  I have no idea where to go from here, or even exactly where
"here" is.  Is all the data on my handbox gone?  How do I fix it?

Any help you can give me would be GREATLY appreciated!

Chris Vanstrom
Mike here: I'm worried about that partial text you get when putting the Autostar into SAFE LOAD mode. It should say something like "FLASH LOAD ready". If it isn't then the flash load code may be corrupted. But just to confirm, put it back into SAFE LOAD and launch the Autostar Update application and try to connect to the Autostar. If it finds it, the ASU should show that it is in SAFE LOAD and allow you to download the update. I suggest doing this from the desktop computer as issues have been reported with some USB adapters (Keyspan and Meade seem to be the most often cited as working reliably).
Subject:	re: ETX/Autostar slop reduction / 
Sent:	Tuesday, February 28, 2006 22:10:49
From:	richard seymour (
Andrew's PEC Editor is now under his webpage, you no longer have
to fetch the file directly (the address is the same as the old file,
 just snip off the file's name):

Answering some of your questions:
the spreadsheet should still be as valid as it ever was.

Andrew's still there (See above), and posts regularly to a number
of Yahoo groups.

The satellite issue may be that you're not used to what you're
seeing... -first- it slews to the -end- of the path (the LOS
point), then it slews to the -starting- point (AOS).
By doing that it's preparing to track and guaranteeing
 it's not going to run into its own travel limits.

have fun


Subject:	Re:ETX/Autostar slop reduction/Satellite Tracking
From: (
I think Dick Seymour once explained the satellite tracking process to me
and it was something like this: when you enter GOTO, the scope slews to
the expected initial position, then on to the final position.  During
the slew, it saves 200 intermediate points in Autostar memory.  When the
satellite rises, it returns to the initial position and begins tracking
between the pre-determined points at the proper rate intervals.

Last summer, I did quite a bit of testing of satellite tracking using
the then-current version of the Autostar software and found it to be
pretty inaccurate.  I forwarded my results to Meade at their request but
don't know if they've made any improvements in later software versions.
If you're lucky enough to pick up a satellite at the horizon, you will
still be very busy making corrections during the pass to keep it in the

My apologies to Dick if I've misinterpreted or misquoted his

Mike Hogan

And more:

From:	Niall J. Saunders (
I am one of the people who revisited the original article on the
spreadsheet approach to Training for the Autostar (497-style) controlled
Meade Scopes. I simply cannot emphasise enough how well the method works
- it really does result in almost perfect training, and I have stripped
down and rebuilt both my ETX-105 and my LX90 drives, and when I repeated
the spreadsheet-based training exercise I ended up with virtually
identical results.

I am so convinced that the results are reliable that, when I recently
had to acquire a replacement Autostar (I bought THREE, just in case) I
simply entered the training data from a previous session, fired up the
scope, and started observing. In fact now that I have my LX90
pier-mounted on a home-brew equatorial wedge, my 'preparation' stage
simply involves switching on the Autostar, entering Date, DST, and Time
(to the nearest minute or so), then releasing clutches to swing the
scope manually round to where I am going to be observing. A quick
shuffle at speeds 7, 5 and three gets an alignment star into the
cross-hairs of the finderscope, and that will always bring the star into
the FOV of my DSI C. A final tweak at speed 1 (which is completely
reliable in response - with no 'creep-after-beep' or 'rubber-banding'
whatsoever) and then an 'ENTER to SYNC' to finish.

All I have to do then is focus (Hartmann mask) and I am good to go till
the Dew kills the night.

And I haven't EVER used an eyepiece on the scope in 2006 - NOT ONCE -
the system is behaving so well that the finder-scope can get the image
onto the DSI, and using High Precision before any 'major' sky-jumps
seems to take care of everything else.

My next-door neighbour has NOT used the spreadsheet approach since he
had to get a replacement Autostar (he has not wanted to load in Dick's
patch kit) and his scope is not quite so responsive as mine - especially
at the lowest speeds. Don't get me wrong, his scope is working quite
happily without having used the results of a previous spreadsheet-based
training session, it is just not 'tight' at the lowest slew speeds.

As far as the latest Autostar software is concerned - all you need is
the associated patch kit from Dick Seymour (to allow you to read and
edit the current Training Values for each axis) and some time - and, the
best results are obtained using a reticled eyepiece (or, even better, a
CCD imager and your mouse cursor (turn the beastie on its back after you
have set a 'target spot' to return to for each training iteration !!)

Perhaps, one day, I will add a Visual Basic macro to the spreadsheet, to
make the process a little bit easier to follow - but, hey, I like to
spend SOME time in the observatory !!

Niall Saunders 
Clinterty Observatories 

Subject:	re: GPS for Autostar 497
Sent:	Tuesday, February 28, 2006 22:01:45
From:	richard seymour (
The Magellean Meridian does not speak the language the
unmodified Autostar needs to hear.

To use a standard GPS receiver with the Autostar, you need
to change the programming of the Autostar so that it will
understand the (NMEA) sentences which the GPS is speaking.

StarGPS offers the software to perform that change:
He will ship to Italy

have fun

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