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Last updated: 31 October 2012

Welcome to the AutoStar feedback page. This page is intended to provide user comments on using the Meade Autostar #494, #495, #497, #497EP, AudioStar, cables, and 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 for posting. Please use an appropriate Subject Line on your message per the Site Email Etiquette. Thanks. Remember, tips described on this site may invalidate the warranty on your telescope or accessories. Neither the submitter nor myself are responsible for any damage caused by using any contributed tips.

Subject:	re: AutoStar Tracking Speed Accuracy
Sent:	Saturday, October 27, 2012 19:28:08
From:	richard seymour (
First, what version of firmware is running in your 497EP?
(some have bugs, especially with respect to guide-speed operations,
but i *think* that the handbox keys will operate properly)

Next: the Tracking Rate affects the speed of the constant follow-the-stars "sidereal" drive.
If you select ">Lunar", and then visit the Custom screen, you'll see it saying "-35"

That's because the *average* Lunar rate is 3.5% slower than sidereal.
(the 497 and 497EP Tracking Rate screen speaks in "tenths of percents relative to sidereal")

These have no effect upon the slew key speeds.
The slew keys work at the speeds you set with the number keys.
Each of those keys (1="Guide", which is about 67% of sidereal; 2, which
is Twice sidereal; 3, which is 8x sidereal, etc) has a fixed rate which
has nothing to do with the Tracking Rate setting.

If you're finding that the scope is tracking the moon too slowly (i.e.
you have to slew West to keep up), you can try increasing (i.e.
decreasing the negative number) the Custom tracking rate.  Try changing
-35 to -25 or so.

If the scope is moving too quickly (i.e. you have to slew East to
compensate for moving too quickly), then increase the value of the
negative number (so: -35 to -45, for example).

The moon's orbital speed *changes* throughout the month, since it's a
slightly elliptical orbit.  Therefore the Autostar's simple -35 may be
close... but won't necessarily be spot-on.

good luck
p.s. the Audiostar operates in hundreths of percent... on its Lunar rate is -365


Whoops... i forgot:

Are you on a "wedge", or still running in Alt/Az?
In Alt/Az, you're also going to be fighting "field rotation"... the
image in the eyepiece (or on the camera CCD) will be rotating as the
scope tracks across the sky.
For exposures less than a minute or two, it won't show too much of an
effect (at reasonable magnifications).

For long-term astrophotography (more than a minute, depending) you
pretty much have to start actively guiding the scope... that usually
involves an active "guider" camera, or letting the PC sample the image
frequently to see if a target star is drifting across the pixels... if
it is, the guider system commands the Autostar to move a little faster
or slower, updating that tracking adjustment every second or so.
Meade's Envisage software (part of Autostar Suite) does that.
Autostar Suite can be downloaded from:
..and includes the newest Envisage (which requires a Meade DSI camera)

have fun

And more:

HAve you tried photographing a star or planet?

That's a much better test of the scope's tracking quality (it removes
the moon's wonky orbital speed, for one thing).

Another source of tracking error is "periodic error" (PE)... that's an
effect of the mechanical quality of the final worm's thread.
If you skew a polar mount a little away from the pole, and take a long
exposure, you may see the (now tracking too slowly because of the skew)
star trails showing a sinusoidal wiggle along their length... that's the
When the mount is not skewed, that PE will cause side-to-side
trailing... the star won't go out of the field of view, but it will be
"wider" than desired.

The Autostar can be taught to predict and counteract that PE.  Meade
calls the technique "Smart Drive"  (the rest of the world calls it PEC,
for PE Correction).
It only applies to Polar mounting, since Alt/Az adds enough other errors
that simple PEC would simply be swamped.

Start by reading the manual's section on the technique.

good luck


From:	Tim Huggins (
Thank you for that info.  The key was your comment about the Tracking
Rates having no effect on the slew speed keys.  I had been playing
around with the mount and the various settings and had come to the same
conclusion, but it is good to have it verified.
You would think that something that important would merit a major
notation in the instructions, but that users manual has a lot of room
for improvement.   I guess that keeps you guys busy answering questions!
Thanks Again,
Tim Huggins
Mike here: Yep, that is one of the reasons we do what we do.

Subject:	re: Firmware updates for lx80
Sent:	Saturday, October 27, 2012 18:58:45
From:	richard seymour (
Upon which  COM port number does the DSI software see the Audiostar?

What version of Windows are you running?
(and, if Windows 7, is it 32 or 64 bit?)

Another program that's very good at "sniffing out" a connected Audiostar
is Andrew Johansen's MyScope... a free download from

good luck

Subject:	Firmware updates for lx80
Sent:	Friday, October 26, 2012 05:33:56
From:	pat Jones (
Can't get computer to find controller. I can control telescope through
autostar software, but when I go into updater it says can't find
controller. Tried different cables and adapters with no luck. I don't
know if I'm missing something in setup or not. If anyone can help I
would be forever grateful.
Mike here: Are you using a real RS-232 serial port on your computer or a USB-serial adapter. Don't know about the AudioStar, but with the AutoStar, not all USB adapters work reliably. (I recommend Keyspan adapters.) You might try StarPatch (from


Using adapter I got from meade and have also tried starpatch. That's
part of why I am at a loss. I can get my dsi to work and can control
scope through software but can't do updates. Worse yet is I just got
this controller from meade and they said it would have the newest
firmware on it and it has the original. Probably just need to contact
them again and swap it out, just don't like waiting for the return to
get there and then wait again to get it back. I'll just keep trying this
weekend and go from there.
Mike here: There are some recent messages on problems with the AudioStar in the Feedback archives. Search the site for "AudioStar". Some might have solutions for you from the AudioStar experts.

Subject:	AutoStar Tracking Speed Accuracy
Sent:	Thursday, October 25, 2012 15:13:05
From:	Tim Huggins (
I want to thank you for your great website.  You have compiled a lot of
useful information.  I looked for an answer to this question there, but
did not see anything listed.
I have a 8" LX90 ACF 'scope with a 497EP AutoStar, being used in Alt/Az
configuration.  I have discovered the "Tracking Rate" settings for
Sidereal, Lunar and Custom.  But these rates do not seem very accurate. 
When set for Lunar and observing the moon, speed 1 is nowhere close to
keeping up with the apparent movement of the moon.  Speed 2 is very
close, but the moon still creeps out of the FOV at a perceptable rate
(e.g. I need to recenter Copernicus after about 30 seconds).  Speed 3 is
too fast and passes the moon in the other direction.
I understand that some mismatch will occur due to the moon "moving" in
two axes and not just the left/right of the Az axis.  But that is not
the problem as the movement is across the field, not up and down. 
Is this as accurate as the tracking rate gets?  I was hoping to use this
mount for astrophotography, but if this is all the better the tracking
is I'll be limited to exposures of a couple of seconds.
Regards and Thanks,
Tim Huggins
Mike here: Several things affect tracking accuracy. Have you done a CALIBRATE MOTOR and TRAIN DRIVES? Site location accuracy can affect tracking. And accuracy of centering the alignment stars will affect tracking. And while the AutoStar can correct for tripod position issues, the more level the base is, the better the accuracy. A well aligned mount and AutoStar that is properly CALIBRATED and TRAINED should track fairly accurately for visual purposes, including up to several hours. For astrophotography purposes, most telescopes can only track accurately for 2-3 minutes, before star trailing becomes evident.

Subject:	Unable to get USB-Serial working for Meade 80 XTS
Sent:	Friday, October 19, 2012 10:20:40
From:	Chris Skor (
I'm new to astronomy and setting up a Meade XTS 80 on my computer with
AstroFinder #506.  I purchased a Prolific USB-RS232 cable, installed
drivers, set ComPort, under Telescope, comminications to Com3, but Test
Communications I get "Communications Not Established.  Opening Comm.
Port without a protocol".
Can you help please?
Mike here: I'm not familiar with a Meade "XTS" model. But I assume you have the AutoStar #494. Not all USB-serial adapters work reliably with the AutoStar handcontollers. I recommend Keyspan adapters. For more on USB-serial adapters, see the article "AutoStar and USB" on the Helpful Information: AutoStar Info page.

Subject:	re: Autostar 497 on Old Version 26E Not Updatable?
Sent:	Thursday, September 20, 2012 15:52:18
From:	richard seymour (
Hi... (i was on vacation, so this note is a tad delayed...)

The current (and, as Mike suggested, past) ASU (and StarPAtch) should be
able to handle v26E without any problem.
v20Ea was the transition between the "old" and "new"497  memory layouts.

I also second Mike's suggestion that you might give StarPAtch a try
(free from   (.ca, not .com))

Updating a 497 is a far more complex job that simply controlling it, so
the USB adapter may still be an issue

good luck

Subject:	Meade GOTO
Sent:	Thursday, September 20, 2012 07:17:15
From:	Hugh Collings (
I hope you can help or point me in the right direction please?

I have an EQ2 (or possibly 3-2)mount that has been retro fitted with RA
and Dec motors, controlled by a #497 hand controller.

I'm ok with the set up - date,time, daylight saving, site etc - having
owned an ETX-80 before.

I'm good with polar aligning too as I have other GEMs for other scopes.

The aligning is causing me problems though! Not matter what I use -easy
2 or 1 star - the mount slew to the wrong side of the sky. Currently,
Vega is in the west at 9pm but the mount slews to the east. Same with
all other stars. It slews to the wrong side of the sky.

I have reset, calibrated and trained motors, but no effect. I checked
and double checked the settings. I have entered my.Long and Lat from
Google, but still not right.

The fitted with an Orion ST80, so it's not over worked. It was
2nd hand, but from a reputable astronomer who can't explain my problem
either. It worked fine for him and he only live about 20 miles from me.

Can you help please?

Thank you kindly,



Mike here: Sorry you missed the Announcements: Site page on the last two ETX Site updates.
In the meantime, check the Roboscopes Yahoo Group; lots of people there can likely help.

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