Last updated: 31 January 2005
Subject: My Autostar won't talk to my pc Sent: Sunday, January 30, 2005 11:55:56 From: Dave Hoeppner (firstname.lastname@example.org) I ran across your article, dated July 25, 2001, about trouble shooting the com port/checking the cable (How to test communication to an Autostar). I have windows xp on my computer. I tried everything in your article and could not get any of the com ports to work using Hyperterminal. The cable test worked as you described, but still my Autostar will not communicate with my pc. I recently talked to the techs at Meade about this problem and sent my Autostar back to them to have it checked out. When it came back, it still would not communicate with the pc. I have loaded and unloaded the autostar suite program a half dozen time or more, to no avail (also went the Meade site and have the latest update for Autostar Suite). I have also went to the windows site and down loaded the most current .net and directx (9) on my pc. since I have an LPI camera (which is working fine), I'm not sure if this might have created a problem. Well I'm dangling at ropes end and hoping you may have another solution up your sleeve that may solve my problem and get my Autostar talking to my pc. Dave HoeppnerMike here: The most common source of a problem is a port conflict. Typically that comes from fax software, or any software that is keeping the serial port open so that the Autostar software can not use it.
Subject: Very strange Sent: Saturday, January 29, 2005 12:17:35 From: Andrew Sprott (email@example.com) Whilst debugging my NTC code I came across two problems. 1: I have to convert between sexigesimal numbers to decimal which causes a problem. If I send a decimal Azimuth co-ordinate say 4.333333333 etc, I have to convert it to sexigesmal ie., degrees, minutes and seconds. So I would return the integer as the decimal part, Multiply the fraction by 60 and return the integer as minutes etc. The problem is the fraction part, which is .3333333 recurring, is multiplied by 60 to make it magically appear as 20 which is fine. But when I want to convert this to a integer variable, ie., minutes it returns 19. IOW, m:real; minutes:integer; m:=frac(4.333333333)*60; minutes:=trunc(m); minutes is assigned 19, which is strange. But even stranger is the Autostar... It returns the scope position as... 00108# azimuth +3228# altitude sending the following sequence after the Delphi conversion should move the scope a tiny part anti-clockwise... #Sz00107# #Sa+3618# #:MA# but a query returns the scopes position as... 01644# +3617# Shurley shome mishtake as the scope did shurley move 16 degrees clockwise. I hope this makes sense. Andrew SprottAnd from our resident Autostar expert:
From: Richard Seymour (firstname.lastname@example.org) Not strange at all. I don't know what your "NTC code" is, but i'll assume it's a control program for a telescope (497 Autostar or LX200gps AutostarII?) 4.3333 * 60 is 259.999999999 Most "friendly" output-for-people procedures "round" the number to the precision you specify. So it you asked the above to *display* as a "real" number, but with zero digits beyond the decimal point, it would -show- 260. But if you ask it to *calculate* with it, it's still 259.9999999 "Trunc(m)" does -exactly- what you ask it to do: truncates 19.9999 to 19. If you really want "rounding", look for a "NINT" (nearest integer) function, or make it -clear- by simply adding 0.5 before Trunc'ing. (the "trunc" function is probably redundantly superfluous... all programming languages i know of perform an implicit truncation when they convert from real to integer across an assignment statement.) The above discussion does not go into the -second- detail that computers are binary beasts... numbers are carried as powers-of-two, so 0.33333 cannot be -exactly- represented. It will suffer a little bit of truncation of its own, simply due to the way IEEE-754 numeric representation works. It's carried in your PC as (hex)3EAAAAAA, which is -really- 0.33333331 when expanded. Add x00000001 to it (x3EAAAAAB) and it becomes 0.33333334. See: http://babbage.cs.qc.edu/courses/cs341/IEEE-754.html "Normal precision" real numbers are only good for slightly less than 7 significant digits. So 259.99999999 only truly has four 9's (since three digits are lost to the "259"). But even stranger is the Autostar... I'll address -that- in my next note (after i've played with it). (But i'd prefer more context: what version Autostar firmware, what -other- commands are you sending, and have you run an alignment? BIG question: are you in Polar or Alt/Az mode?) have fun --dickAnd more:
If you read the Meade serial command document at http://www.meade.com/support/LX200CommandSet.pdf you'll see that the :Sz command is (theoretically) only supported in the LX200gps and LX 16". But they do say that :MA# should work, too. What is -happening- is that the number you are supplying is being semi-interpreted as an RA setting ( :Sr ), which causes an x15 scaling. (one RA hour is fifteen degrees) I just told my v33Ef ETX90 to :Sz10*00:00#:MA# And it slewed to Az 150*00:00# Fifteen times ten is 150. Therefore, with the current firmware, you will need to send Azimuth angles scaled down by a factor of 15. I'll be sending a note to Meade about this... have fun --dickAnd more info:
Double hmmm.... I can see how to patch it, so that it operates properly. The following two lines, added to my 33Ef patch kit, or simply processed as a "standalone" patch, would fix the :Sz command. R 46ECE 04 3c R 48E13 FF C7 have fun --dick
Subject: Re: My etx 105 overshoots when using arrow keys Sent: Friday, January 28, 2005 03:56:20 From: Joeanddawny@aol.com (Joeanddawny@aol.com) Ok I'll try that. Thanks for your time and thanks for providing such a great website.
Subject: Re: Slewing problems Sent: Friday, January 28, 2005 03:36:40 From: Andrew Sprott (email@example.com) Mike said: > Usually the slew to 90 degrees means CHANGE THE BATTERIES. Err, it is running off the mains. AndrewMike here: Did you do a CALIBRATE MOTORS and TRAIN DRIVES? What power source? Voltage?
Nope, BTW I've flashed the firmware from 30ee to 32ef, but havent tried it yet. Weell, 12v off a battery that is being charged. AndrewMike here: Any time you do an Autostar Update you should at least TRAIN DRIVES. What's the amperage? You will need about 1.5A to avoid problems.
Subject: ETX90EC and Autostar Sent: Thursday, January 27, 2005 17:26:12 From: Qpaul@aol.com (Qpaul@aol.com) I was one of the unfortunate customers that bought one of your ETX 90EC telescopes back when the Autostar was not Included. The scope is GREAT but now having to PAY $150.00 for the Autostar is a real killer!!!! I was wondering which Autostar model number will work with my telescope? #495, #497 ????????? Thanks Paul QuennevilleMike here: See the FAQ page on the ETX Site.
Subject: Slewing problems Sent: Thursday, January 27, 2005 14:17:45 From: Andrew Sprott (firstname.lastname@example.org) I've decided to take NTC off my server for the time being due to problems I'm having with the Slewing function. Because of network congestion, it is possible that NTC will go into an endless loop. I'm trashing the code I had to write to overcome complications with the mouse events. The new code works better and is more suited to latency issues with the Internet. Rather than slew the scope, I'm using the GOTO feature to move the scope by video capture frames. I'm also adding the option to move the scope in steps. This way A: I can check if the scope will go below the horizon and B: using GOTO is much faster than slewing, and also gives more control when the network connection isn't exactly responsive. My ETX 90 is playing up when I try to align the scope, the barrel just goes up to 90 degrees and I have to switch it off. I'm going to try flashing the latest firmware. A question: how can my software know when the Autostar has finished the GOTO. I try to set a timer and check the scopes position until it matches the co-ordinates I told it to go to, but the problem is the tracking changes the position so it may never get to the destination. BTW, people in the UK might be interested in our March 4th Star Camp here at Trefach... http://astronomy.crysania.co.uk Andrew SprottMike here: Usually the slew to 90 degrees means CHANGE THE BATTERIES. As to detecting when the GOTO is complete, I'll leave that to Dick Seymour.
From: Richard Seymour (email@example.com) Send the serial command :D# The Autostar will respond with one or two characters: a (hex) xFF followed by a "#" if it's still moving, and only the "#" if the motion has completed ("creep after beep" can happen, if you're not "tuned"). This is documented in Meade's serial command document, http://www.meade.com/support/LX200CommandSet.pdf the only difference being that the Autostars only return -one- distance bar, irrespective of how much they've still got to go. have fun --dick
Subject: My etx 105 overshoots when using arrow keys Sent: Wednesday, January 26, 2005 11:34:22 From: Joeanddawny@aol.com (Joeanddawny@aol.com) Hi, I've recently purchased a Meade etx 105 and really like it, apart from the fact that when I use the arrow keys to move the scope, it tends to over shoot moments after i release the key. Also, there is a slight time delay from when I presas the key to when it actually starts moving the scope. Any help would be great. Thanks, Joe.Mike here: Have you performed the CALIBRATE MOTORS and TRAIN DRIVES steps as discussed in the manual?
Yes I've done that but it doesn't seem to make a difference. Perhaps I'll try again and see if it helps. In your oppinion are problems with the autostar and arrow keys usually user related and not faults in the way its made?Mike here: Most times it is documentation that is not clear and/or not reading the documentation at all that is the culprit. Sometimes, there can be bad hardware or corrupted software. Doing a RESET, checking the telescope model and mounting mode, CALIBRATION, and TRAIN DRIVES will usually resolve most problems. However, if not, there are many tips on the Helpful Information: Telescope Tech Tips and Autostar Info pages that people have used.
Subject: Polar alignment question for my ETX Sent: Tuesday, January 25, 2005 13:06:33 From: Jim Holland (firstname.lastname@example.org) When I set the autostar setup>telescope>mount>polar mode. Should the RA motor run all the time on my ETX as soon as I set the mode? Also do you still need to do alignments (such as two star) in polar mode? I ordered your book, can't wait to get my hands on it Thanks Jim HollandMike here: Thanks for ordering the book. Yes, you still need to do the alignments so that the Autostar knows WHERE to locate objects if you plan to do GOTOs. But if you want to skip that, you can just set the tracking mode to Astronomical and then the RA motor will start running right away.
Subject: re: Removing old data from auto star Sent: Monday, January 24, 2005 20:37:40 From: Richard Seymour (email@example.com) This question has one "guaranteed correct" answer, and a bunch of "qualified maybe" answers, which vary with model of Autostar and version of firmware. The "guaranteed correct" answer is: use Meade's Autostar Updater (ASU) utility to work with the User Object libraries. It can sort by date, alphabetically, etc., and will show you a running total of how much space you have available. Full click-by-click instructions at: http://www.weasner.com/etx/autostar/guide-libraries.html For a 494 Autostar, that is the -only- way to truly free up space. If you "delete" an object from the 494's Autostar display, it's not -really- releasing the space, it's merely making -that- object inaccessible via the menu system. Only the ASU can "garbage collect" a 494 Autostar. With the 497 Autostar, the answer's a little different: If you have firmware older (lower number) than 3.0b, you -can- delete objects with the keypad, and it -will- release the space. If you have firmware -newer- than 3.0b (inclusive), then it becomes like the 494, and no longer has self garbage-collection capabilities. (Meade took over the space required to add the Autostar Suite functions). Only the ASU can truly "erase" the deleted objects. Satellite data which is over a month old is "obsolete" (you can sort by the Epoch Date) Asteroid data is good for years, Comet data is good for years, but you may want to add new ones as they're found, and delete the ones which are far too dim to be seen for the next year or so. have fun --dick
Subject: Meade DS 2114 ASTA Sent: Monday, January 24, 2005 18:41:52 From: Daryl G. (firstname.lastname@example.org) I recently purchased the above referenced telescope,and am brand new to the hobby. I have the following questions. 1) Does the time have to be re set each time the unit is turned on, even though it has been initialized? 2) Does the telescope have to be aligned each time it is turned on? 3) When setting "Alt/Az home position" and after repositioning the telescope, then pressing ENTER (on the hand box); is it normal for the unit to go into a slew for star alignment? 4) At the end of the slewing maneuver, I notice the movement and the noise from the motor slows way down, and finally there appears to be no movement but a low pitch noise continues from the motor like its is up against a stop and straining, is this normal??? Thanks for your help, Daryl SchreinerMike here: All that you ask about is normal. The Autostar asks for the date and time when powered on. There is no "internal clock" that keeps running when there is no power applied. And since there is no internal clock, the alignment steps are necessary each time as well. HOWEVER there are sleep and park modes. Sleep is a low-power mode which stops the tracking motors but remembers the time and alignment. Park is a way to actually turn off the power while remembering the alignment. Once you have aligned, the motors are running to move the telescope to compensate for the Earth's rotation. You may not see any movement over a short period of time (ever try to watch the hour hand on an analog clock or watch move?). It takes 24 hours to complete one rotation, just like the Earth.
Subject: Removing old data from auto star Sent: Sunday, January 23, 2005 17:09:49 From: Mark Jensen (email@example.com) I was wondering if I should remove old data about satellites so I can have room to add new? I guess what I'm asking is there a list of autostar items that are no longer relevant? Thank you for your site it has been very helpful. MarkMike here: Freeing up memory by removing "user objects" can certainly allow room to add more. But there is no list of "old data" that I'm aware of.
Subject: Upgrade Autostar 2.6Ec ? Sent: Sunday, January 23, 2005 11:06:01 From: Dan Williamson (firstname.lastname@example.org) I apologize in advance if my question has been answered on the site. I bought an ETX90 for my son. The Autostar version is 2.6Ec. Everything seems to work reasonably well. The GOTO's are either good (in the eyepiece) or fair (in the finderscope) . . . depending upon the care with which I set it up for a given night. Guided by the information gleaned from your site, I'm sure it will get better. Being a neophyte, and I'm not real certain about these terms yet, but I seem to have some backlash, rubber-banding, and slow (then very fast) movement using the arrow keys while centering. Again, with practice and trial-and-error, I'm working with it. I'm not worried yet. But two questions arise (and apologies if they are unrelated): First, the Autostar version is 2.6Ec. Would upgrading help GOTO's? If so, to what version? I can't find anything that tells me what I gain by upgrading. From my general experience with software, upgrades are often pointless and I don't want to upgrade unless I'm really going to gain something. Second, I read some interesting material on your site regarding trail-and-error adjusting of the alt-az percents. Is this something I should actively pursue as a means of reducing the above-mentioned problems? I appreciate any guidance you can offer and, of course, your site is amazing. Dan WilliamsonMike here: First off, do a CALIBRATE MOTORS and TRAIN DRIVES. That should solve rubberbanding. Second, upgrading to the current version on Meade's site is helpful (corrects bugs, adds features, and updates parameters). BUT do a RESET, CALIBRATE, and TRAIN DRIVES after ANY update.
Subject: Alignment of ETX-105 Sent: Saturday, January 22, 2005 03:36:09 From: Tony Pagett (email@example.com) A quick question from a newbie with a GOTO scope. Everywhere I read it says I must align my ETX-105 manually and then tighten the vertical and horizontal locks and that I must not use the arrow keys on the autostar. Question: If I followed the procedure below would this not work? After basic levelling and aligning of tripod to north: Manually find Polaris using arrow keys. lower optical tube with arrow keys using small spirit level or a bubble level eyepiece adapter. Switch off Autostar. Switch back on and enter time/date/daylight saving and easy align as normal. Regards TonyMike here: Yes, that would work. By initially pointing at Polaris what you have done is locate True North on your horizon.
Subject: re: Autostar badly overshoots during alignment Sent: Friday, January 21, 2005 19:13:22 From: Richard Seymour (firstname.lastname@example.org) Most likely the problem is dirt or grease masking one of the slots in the encoder disk (a plastic gear-like disk mounted on one end of the motor shaft). You can possibly fix it yourself by opening the base and cleaning it gently with a Q-tip. You can make a definitive test by setting up in Terrestrial mode, then press-and-hold [mode] for 3 seconds. Release. Now scroll down to the Alt/Az display. Now point the telescope at a landmark (great distance not required). Note the Alt/Az readings. Now slew the telescope a full 360 degree circle until it points at the landmark -again-. If it's a blocked encoder vane, the display will only have incremented 350 degrees. If it's two blocked vanes, or a broken/missing tooth, then the display will only have advanced 340 degrees. Remove any batteries before opening the base, be careful of the battery-box wires (they're fragile), and the base is held on by three screws (which may be beneath the rubber feet or little plastic covers) good luck --dickMike here: If it is grease, it can sometimes be cured by unlocking the axes and moving the telescope slowly by hand, hard stop to hard stop, back and forth, several times. That can redistribute the grease.
Not from -between- the encoder vanes... (it might add -more-, though) have fun --dickMike here: Doing nothing or doing something; either helps or hurts!
And an update:
From: email@example.com (firstname.lastname@example.org) Dick, Boy, you certainly nailed it! I did your Az/RA position encoder test and there WAS something blocking the "teeth." It turned out to be a tiny piece of grease-coated styrofoam (it looks like) -- as from a packing "peanut." It salvaged my winter vacation here in AZ (the ETX-125EC is my "travel scope.") I COULD have found targets the "old way," but this is much nicer -- and I don't have to send the scope to Meade when I return home (MN). I had noticed the scope could TRACK at siderial rates OK, even though it couldn't GOTO reliably. I'm guessing the encoders are NOT involved in tracking?? Thank you very much for all your help -- I've used your advice in the past many times from the ETX archives, and references in Doc Grainer's site. Art Kotz email@example.comAnd:
Congrats on getting it going... I had noticed the scope could TRACK at siderial rates OK, even though it couldn't GOTO reliably. I'm guessing the encoders are NOT involved in tracking?? Incorrect guess... the encoders are used, but it's only a 9% error, which is roughly three times the "error" between the moon and the background stars (Moon: about a half-degree drift during an hour). Plus, it's making the telescope too -fast-, and many folks find their drives a shade pokey if they carefully measure them. have fun --dick
Subject: Dead 497 handbox question Sent: Friday, January 21, 2005 12:16:01 From: Damian Kessler (DKessler@sbs.com) First off, just wanted to thank you for the site-it's chock full of useful information. One has to read carefully and sometimes put the pieces together to get it right though. The other night prior to observing I connected the LXD-55 to initialize and train drives prior to taking it outside. It powered up normally and I entered initial data until the 'Easy Align' prompt came up. On hitting 'Enter' here, the handbox display cleared. I powered down and tried again three times. On the last try the handbox just displayed partial characters until I powered off. On the next tries, the box has no response at all. Cabling is good-tried two sets, voltage levels are good-above 9V. I tried firmware safe load and get no response at all from the handset and the Updater doesn't recognize the device as present. So, anyone else experience this? Any suggestions before I pay Meade to fix it? Thanks again for the informative site. Damian KesslerMike here: Since the cables are good and since you have tried SAFE LOAD, I suspect the Autostar is dead. See the article "Testing Autostar Communications" on the Helpful Information: Autostar Info page; it might help.
Thanx for the reply-I figured that the handbox was DOA but I thought there might be something I've overlooked. As to trying to verify commo using Hyperterminal, I looked at that and ruled it out since it acts as if it's not getting any power at all. Even the first times when the display went dead there was still a little red glow around the edges of the display. Now there's nothing. Damian Kessler Applications Engineer SBS Technologies Inc.
Subject: #497 Autostar software Sent: Thursday, January 20, 2005 07:49:41 From: jacques..martinot (firstname.lastname@example.org) I am a french astronom and I have got a LX90 Meade telecope and I have problem with my handbox Autostar #497 software when I am in Polar Mount Mode (all the fonctions are stopped). So I am looking for a french version of the Autostar #497 software. On your web site :http://www.weasner.com/etx/autostar_info.html I have found the version #497 Autostar ROM 2.2Ft But I am looking for a more french recent version (ie: 31F) do you know where I can found it ? Thanks for your help. J.MartinotMike here: Check this Meade Europe page:
Thank you for your help, so I found the good rom file on the meade.de site.
Subject: Autostar keypad problem Sent: Thursday, January 20, 2005 08:29:34 From: email@example.com (firstname.lastname@example.org) Two of the kepayds on the Autostar that came with my DS 2114AT have become detached. They are the up and down arrows at the bottom of the keypad on either side of the Scroll? key. I put the Autostar the wrong way round into the slot on the tripod tray (keypad facing inwards). When it wouldn't come out I rather stupidly tugged at it (tiredness is my only excuse) and these two keys came loose. It's been pointed out to me that trying to glue them back in could render the unit useless by permanently connecting the electrical contacts. Although they work if placed back in their holes, the keys fall out if the Autostar is anything other than horizontal. I asked my local dealer (in the UK) and they said the only option was to return it to Meade in the USA for repair , or to buy a replacement. Both seem like expensive ways of tackling the problem. I'm wondering if anyone else has a cheaper solution - assuming someone else has been careless enough to have this happen to them. GavinAnd:
From: Richard Seymour (email@example.com) About the only middle-of=the-expense pathway i can think of would be to locate someone nearby (or BC&F, or Bill Vorce at Telescope Warehouse) with a -dead- Autostar, and buy it for the keypad membrane. I had never considered this style of damage, and for completely different reasons i use Velcro on the back of my Autostar to hold it places, rather than the clip Meade provides (which i've never installed... it's the least handy thing i've ever seen). Bill Vorce: firstname.lastname@example.org http://www.telescope-warehouse.com/ Be sure to remember to specify if you've got a 494 or 497-shaped Autostar. good luck --dickAnd:
Thanks for taking the time to reply to me. I'll start looking around for a dead Autostar. Congratulations on a superb website. Regards, Gavin Sherriff
Subject: Autostar badly overshoots during alignment Sent: Wednesday, January 19, 2005 21:57:43 From: email@example.com (firstname.lastname@example.org) I have an ETX-125EC with Autostar that worked fine about one year ago. It has not been used since one year ago. Upon attempting to use it now, the slew to an alignment star from the Home Position, badly overshoots the target star by at least 30 to 40 degrees in azimuth (Alt-Az mount), and about 20 degrees in altitude. Leveling and Home Position are carefully set. If I force it back to the correct position and synchronize the star position, it says alignment successful. But any subsequent GoTo command results in about the same large overshoot from the correct position. I am using the Meade AC adapter for a power source, so depleated batteries are not a problem. Date, time, site. mount and target entries are all correct. Is it time to try the Reset, and go through the training of drives, etc.? Ugh! -- or am I missing something? Also, I notice that the Targets setting doesn't stay in the Astronomical setting very well -- i.e. about half of the time when I go back to check settings, it has reverted to Terrestrial. Thanks for any help and thanks for a wonderful site. Art Kotz email@example.com I calibrated the motors with the same results.Mike here: Since you have done a CALIBRATION, I suggest doing the TRAIN DRIVES again. If that doesn't help, then a RESET, CALIBRATE, and TRAIN DRIVES. As to the astronomical settings, does the setting actually change or is it just that when you go to that menu item, it looks like Terrestrial is set? What has the ">"?
Thank you for the quick response. The Targets setting actually reverts to Terrestrial -- i.e. the ">" points to Terrestrial. I checked it again this AM, and it had reverted to Terrestrial. I again set it to Astronomical and will check it later. I'll try the re-training as you suggest, etc. Thank you again, Mike for your help. Art Kotz firstname.lastname@example.org
And an update:
Status Report: This is a second reply, since I've reset, recalibrated, retrained, etc. with no success. I called Meade Customer "Service," and they think it s a problem with the telescope's position encoders. Since I'm away from home for several months, I'll return it when I return home. I HOPE it can track objects that I find by trial and error -- I'm testing that now. Thank you again for your help and wonderful reference site.Mike here: But does tracking continue even though the ">" shows Terrestrial (which is what would BECOME selected if you press ENTER)? I suspect you are just seeing the result of a "bug/feature" that has been around a long time.
As usual, your intuition and insights are dead-on! Even though the ">" points to Terrestrial, the motors ARE grinding away. The surrounding noise masked it normally, but after your letter, I listened carefully and could, indeed, hear the motors tracking. I CAN, of course, put it in Terrestrial mode for training the drives, but after entering Astronomical once, it STAYS there even though the ">" points to Terrestrial after a power-down. Must be a strange bug as you suggested. Thanks again, Art Kotz email@example.comMike here: Just a point: there is no need to go into Terrestrial mode to TRAIN DRIVES.
Subject: re: etx alignment question Sent: Tuesday, January 18, 2005 21:14:54 From: Richard Seymour (firstname.lastname@example.org) If you have properly done the Setup > Telescope > Train Drives procedures, the Autostar -learns- the amount of backlash in your gear system, and properly accounts for the back-and-forth slewing. Instead of playing with the blocks every time you go out, why not put small bricks or concrete blocks IN your garden, buried to depths which will give you "instant level" when you place the tripod upon them? This would lower your setup time even more. have fun --dickAnd:
Thanks for the suggestion. I will need to check with the head gardener about burying bricks but if she agrees then I will do it! Thanks again...
Subject: re: updates for autostar Sent: Tuesday, January 18, 2005 21:08:44 From: Richard Seymour (email@example.com) To qualify Mike's answer: it is not possible to update a 494's firmware programming. it IS possible to update the User Objects (Comets, Asteroids, Satellites, Tours) with the 506 cable. See: http://www.weasner.com/etx/autostar/guide-libraries.html it is also possible to control the telescope with the 506 cable. Programs such as TheSky, StarryNight, Cartes du Ciel (free!), and AstroPlanner (cheap!) can do it. However, you asked: Meade Autostar # 494 to set it on equatorial mount What model of telescope do you have? Some models (such as the ETX60 and ETX70) can be set to Mount>Polar with the 494. There -is- a 494 (the front panel says "Starfinder") which is programmed to work -only- with a German Equatorial Mount (GEM) for the Meade 4504 and 114EQ/DH4 models. These can be found on the "used" market, or from William Vorce at Telescope Warehouse http://www.telescope-warehouse.com/ (he will ship to Germany). If you can get a 495 or 497 Autostar, they are easy to adapt to GEM. have fun --dickAnd:
Thank you for information clear skies Oliver
Subject: updates for autostar Sent: Tuesday, January 18, 2005 14:41:51 From: oliver peter (firstname.lastname@example.org) heres Oliver from Gnzburg, Bavaria, Germany I've seen your pages for the first time and im closed to set it to favourites... can you give me some answers referring/in case of/ to an update for the Meade Autostar # 494 to set it on equatorial mount. can you help me? clear skies OliverMike here: There is no update for the #494 Autostar.
Subject: etx alignment question Sent: Tuesday, January 18, 2005 12:56:23 From: Kelleher (email@example.com) Like many visitors to your site I've been working to optimise my ETX set-up procedures with the aim of reducing time, increasing accuracy and hence increasing productive time and the enjoyment factor of astronomy. I have three markers in my garden that show exactly where the tripod feet should stand to point exactly North. I keep the 'scope permanently mounted on the tripod. I have shortened the spring under the eyepiece holder on the Meade tripod which allows the holder to drop and rotate without the screw needing to be fully undone. This in turn allows the tripod legs to fold part of the way in which makes fitting through doors easier when I carry the assembly in and out of the house. I use blocks under the feet to get the whole assembly level and in all have reduced setup time from ~30 minutes to ~10 minutes. However, I have a question about alignment stars and backlash. I searched your site and found the following: Subject: Re: ETX-125EC report Sent: Monday, October 11, 1999 10:07:28 From: firstname.lastname@example.org (Kevin P. Kretsch) Re: Wayne Gatschet's ETX-125 report, 10th October 1999. [...] When the alignment star is in the eyepiece field of view, position it to say, the south east edge of the vield of view. Then use ONLY the North and West buttons for centering. This removes all the backlash in the gears before the alignment is completed. Once centered using only these two keys, then press ENTER as normal. I have found that this helps tremendously with accuracy. (As I recall, somebody said that Celestron tell people to do this in the Nexstar manual, so it's not just an ETX thing.) Regards, and clear skies, Kev. Should you do as suggested and position the alignment star in the south east corner or do you think you should try to only drive in one direction in Az and one in Alt once the scope has finished slewing to the alignment stars? At the moment I often overshoot on the first pass (because I'm impatient and choose too high a slew speed!) and end up going back and forth a few times to exactly centre the star but I wonder if this is adding backlash errors to the alignment as the scope turns first clockwise and then anticlockwise etc. Any thoughts please? Thanks for the great site and for any feedback...Mike here: That is a valid technique but personally I don't do it.
Subject: etx125 calibration procedure Sent: Tuesday, January 18, 2005 10:31:37 From: M.Camargo (email@example.com) Great site!! I just purchased a Etx125 and have a question for you. I noticed in your web site that plenty of problems are resolved with "calibrate and train drives" for a answer. I understand how to train the drives but what exactly do you do to calibrate? In the Autostar(#497) menu I have a option to "calibrate motor". When I try this option the telescope moves side to side then up and down. Then it stops. Is this option you talk about?? Thanks, MattMike here: Yes, that is the CALIBRATION step and that's all it does. Well, it does some other things so that the Autostar knows how to communicate with the motors.
Subject: Select polar mode with my 20 button 497 Autostar controller? Sent: Monday, January 17, 2005 12:09:48 From: James Edgar (firstname.lastname@example.org) I'm a new user with a two day old ETX 105 EC. I'm attempting to set-up and align in polar mode, however, the instruction manual that came with the telescope only describes how to set up using Alt/Az mode, i.e. horizontal and pointing North. I've noticed that the older? (8 buttoned) controller has screws in its back that one can remove to select the Alt/Az or Polar mode. I know how to set up the polar "Home" position, but I don't know how to perform alignment in this position. i.e. the computer still seems to think its in Alt/Az mode. How can I do this with my controller/Autostar version? Regards, JimmyMike here: You need to set the Autostar mount mode in Polar (from the Setup: Telescope: Mount menu). For how to align, see the alignment tips on the Helpful Information: Autostar Info page.
Subject: re: ETX90 with #495 and resetting Sent: Saturday, January 15, 2005 10:53:30 From: Richard Seymour (email@example.com) If the "495" is happily running -now- with your ETX90, then it already has been loaded with 497 code. So a RESET should be safe to perform. A normal 495 will flat-out refuse to operate if attached to an ETX90, it will display "Use ETX Autostar with this model" and freeze. If you have -that- situation, then a Safe Load key sequence at power-up will at least let you preform a firmware update. That is: hold [enter] and [scroll down] as you apply power. (read the "Damaged Handbox" help page in the Autostar Updater) have fun --dick
Subject: re: Random Slews Sent: Saturday, January 15, 2005 10:48:08 From: Richard Seymour (firstname.lastname@example.org) What i detect a lack of in your tale of random slews as power levels changed are the critical words: "performed a Calibrate Motors" As the voltage levels change, the LEDs used in the encoders get brighter or dimmer, which affects their operation. I run my ETX with an AC Adapter which can put out 15v, and from the interal AA cells which can drop to 8v. If i get random slews, or "Motor Unit Fault" messages, my first line of attack is to perform a Setup > Telescope > Calibrate Motor. Excpet for cases of truly dead batteries, that fixes it (as it's designed to). For the background on "what's happening", read: http://www.weasner.com/etx/autostar/as_info.html have fun --dickAnd:
From: Zoltan Beldi (email@example.com) Hi Richard, Thanks for your quick response. I'm sorry that I omitted to mention that I had performed several complete resets, calibrate and train functions thinking that it would be the solution as it has been for others. However, it never appeared to for me. I did also omit to mention that a little while ago I committed the cardinal sin of connecting the external power reverse polarity.... My neglect to mention that was mainly to not have to admit to being basically stupid. Nevertheless, as you can imagine, it took out the scope but the Autostar appeared to still function. The damage to the scope appeared to be restricted to a burnt track that supplies the Autostar power. After replacing the track with some Kynar (wire-wrap) wire, function returned albeit with the random slews. So, I guess it's possible that I might have an electronic problem on the drive board (though it does seem confined to the Dec axis in common with many other posts on the ETX site) but I didn't have sufficient operational experience with the scope prior to the burn-up to be sure that it wasn't like that before. At the present moment, the scope is working pefectly at any voltage between 8V-11V so I'm probably not going to chase it any further unless it starts to misbehave again. My post was motivated by trying to understand the post by Joe Schlatter where he had exactly the same problem on external, but not on internal batteries. It could be postulated that it too was a "voltage' problem. Anyway, i guess this is all good stuff on operational aspects of a great little scope. I really appreciate yours and Mike's input. Kind regards, Zoltan
Subject: re: Autostar 497 error Sent: Saturday, January 15, 2005 10:32:59 From: Richard Seymour (firstname.lastname@example.org) It's -possible- that the 497 keypad simply needs to be cleaned. You can open the 497 by removing the 4 screws on the back, popping the case open (catch the little red LED cover from the top!). Then remove the two screws which secure the white display back reflector. You can now lift the circuit card away from the rubber keysheet. Gently clean the solder contact pads with a pencil eraser. Gently clean the black rubber contact dots on the keysheet with a dry Q-tip cotton swab. Reassemble, being careful with the display's flexible cable, and remember to put the red LED cover back in. If there was a piece of conductive material/dirt across any key's contact pad, it can prevent operation of the keys. Ritz Camera is clearing out their 495's (which can be upgraded to 497's with a firmware download) for $40. You can call their 800 number 1-800-52FOCUS and ask for part number 51-395-1079, which is the Autostar 495. They had fewer than 20 left on Friday. good luck --dickAnd:
From: Manish Panjwani (email@example.com) Dear Dick, Thank you very much for your very detailed response. Sorry for not responding earlier. I was out of town over the weekend and saw your email this afternoon. I did exactly what you suggested - an lo and behold - the controller now works! :) I got the ETX for my neices in FL and was visiting them for a few days. Hence, I really wanted to get everything up and running for them before heading home. Now, thanks to you both, I will be able to achieve that tonight. Thanks a million once again for your most gracious help. Best wishes, Manish
Subject: Random Slews Sent: Friday, January 14, 2005 05:50:40 From: Zoltan Beldi (firstname.lastname@example.org) Firstly, thanks for the great site. Has been enormously useful. I'm responding to the random slew fix posted by Joe Schlatter. I too had exactly the same symptoms and like Joe, running from the internal batteries "cured" the symptoms. So, like Joe, I ran an external power cable to bypass the external plug. I add here that the problem manifested itself when the ETX-90 was running from an external 12V gel-cell battery via the external power jack. Imagine my disapointment when the problem continued unchanged following the mod. I tried everything I could think of, but no change. Then, I downloaded a new version of firmware for the 497 controller (updated to 323f) and voila the problem disappeared ! Why hadn't I tried this before ? It tracked flawlessly for the next few days until I detected that the scope slew rate was slowing down. Checked the 12V battery and found it was down to 7.8V, so that meant it had to go on charge for a few hours. The battery indicated 13.1V after the charge and I re-deployed expecting a good nights observation. Yep, you guessed it, the mis-behavior returned in all its former glory. However, this time I had a clue what the problem was. It was a reasonable bet that the external voltage was too high, so a quick trip to my junk box and out came a voltage regulator that controls output voltage to 8.2V. On connection, no further problems occurred and all function of the scope and 497 appeared to work as advertised. Re-applying 12V re-introduced the random slew every ten minutes or less. My guess is that the high voltage is more likely the problem than the connector. I would be interested to hear if any-one else has seen the problem in this light. Cheers Zoltan Beldi Perth Western Australia.
Subject: ETX90 with #495 and resetting Sent: Friday, January 14, 2005 01:35:05 From: Cenneth Andersson (email@example.com) I have and ETX-90EC delivered with Autostar #495. If I make a RESET, will it then go back to a factory setting not compatible with my ETX-90? If so, what to do then if you can't connect for an update? Which are the proper values to enter in Az/RA Ratio, Alt/Dec Ratio, Az/RA Percent, Alt/Dec Percent and Tracking Rate for a ETX-90? Thanks for any comments. Cenneth AnderssonMike here: According to Meade's info (http://www.meade.com/support/auto.html), it is not compatible. You should update BEFORE doing the RESET. Then you will have a #497 and all will be OK.
Subject: ETX70 and PEC Sent: Wednesday, January 12, 2005 11:28:53 From: A. San Nicolas (firstname.lastname@example.org) I recently bought a Meade DSI to use with my ETX70. I've had some success with it at exposures upto 21 seconds, 30 seconds works though there is some elongation of the stars. I decided to try the PEC in the latest Autostar update (Build_32Ei, haven't tried the patch yet) to fix this and get longer exposure times. But when ever I turn on the PEC the star drifts to the left on my screen. If I've worked this out right it means the drive is running slower with PEC on. I've trained the PEC, updated the PEC, erased and re-trained the PEC, but I always get the same result, drift with PEC on. I have given my ETX a good tune-up (thanks to your great site) and have achieved good polar alignment. GOTO's are good and the scope tracks well with PEC off. Any help/tips would be much appreciated. The weather has finally cleared for the next few days, perhaps I'll try loading the patch this evening... Thanks, Tony.
Subject: Re: Fast Slew Disrupts Encoder Reading - ETX 125 Sent: Tuesday, January 11, 2005 14:08:02 From: Dave (email@example.com) I've had the scope back and they fitted a new az gearbox. That seems to have done the trick by slowing down the scope in azimuth. When I disengage the clutch, it seems much "tighter" than before when it was very loose. Whether that is a long term solution I don't really know; if it does "loosen up" as it was before, I might get the same problem back again. Any idea how long the scope should take to complete one revolution on maximum slew speed please. At the moment, mine takes 1min 17sec. Power pack voltage is 12.8v. Does that seem about right? Thanks very much for your help, it is a great site and I don't know what the world's ETX owners would do without you. Keep up the good work! Regards Dave OwensMike here: I haven't timed mine but that sounds about right.
From: Richard Seymour (firstname.lastname@example.org) "Maximum speed" is purposely undefined by Meade (but hinted at somewhere in the specs). Max Speed is simply the battery voltage applied to the motors. So the power supply will directly affect it. Speed 8 is 3 deg/second, so a full 360 spin would be 360/3=120 seconds (2 min). So 1 min 17 sec certainly sounds reasonable. > At the moment, mine takes 1min 17sec. Power pack voltage is 12.8v. > Does that seem about right? By the above, yes. have fun --dick
Subject: RE: Motor Fault by one of reader Sent: Monday, January 10, 2005 17:14:58 From: Leung Henry (email@example.com) First thing first. GREAT WEBSITE. I encountered the same problem four months ago. I tried everything. Nothing works. Lucky for me, it was under warranty. I suspect is the software for the 497 controller. Try to download the latest patch before senting back to Meade for service. Henry
Subject: RE: ETX125 Easy Align issue Sent: Monday, January 10, 2005 16:59:39 From: Arthur Caracciolo (firstname.lastname@example.org) I went thru the train drive sequence this afternoon and I notice something it maybe because I wasn't rushing, but when the telescope moves it is very slow and quiet, compared to when it is moving to alignment stars. I think it was moving before and I didn't notice it, I am embarrassed :-) The telescope is probably in better shape now for having gone thru the training anyway. I am about to go out now to see if I can have a session it was clear before Thanks again Arthur CaraccioloMike here: Yes, it is quiet and slow. You can speed it up but I don't recommend that.
Subject: autostar 494 case Sent: Monday, January 10, 2005 11:53:26 From: Jack O'Connor (email@example.com) The keys on my etxat70 Autostar 494 were requiring that I press them very hard to the point where they almost wouldn't respond at all. I know how to clean them but I couldn't figure out how to open the case. I emailed you and you replied, (very promptly, thank you), that I should just pry it apart with an appropriate tool. I did so and it worked! I cleaned the keys and reassembled the case with rubber bands to hold it together and everything works fine. However, the rubber bands are just a band-aid fix. I noticed when I took the case apart that it had been glued together at the seam/joint between the two halves of the case. I would like to glue it back together but I don't know what kind of glue to use. I assume that I may have to repeat the cleaning procedure at some future time and I want to use the proper type of glue - one that will safely hold the case together, but also allow me to take it apart if I need to clean it again. Can you tell me what kind of glue Meade uses for this purpose? Thanks ......... Jack O'ConnorMike here: Glad that you got the Autostar working reliably. As to the glue, I don't know what Meade uses. But obviously you should not use model airplane (plastic) glue or Super Glue.
Subject: Re: AutoStar #495 vs AutoStar #497 Sent: Monday, January 10, 2005 00:59:16 From: Cenneth Andersson (firstname.lastname@example.org) Thanks for your answer. I thought maybe there was a difference in memory size. Model #495 has a database with 1500 object while #497 has 14000 objects. Since they differ in price with $50 and I have bought and paid mine as a #497 I was interested to see how I could check what is actually delivered. Cenneth AnderssonMike here: The original software had a small number of objects; later versions increased that to >30,000.
Thanks, but, just to get it definitely right. I understand your answers as there are no hardware differencies whatsoever. It is just a matter of software, and, the software and the database in #495 can be updated to the 30 000 objects in #497 through the Meade site. I will understand if you find me a bit meticulous. CennethMike here: Yes, the #495 becomes a #497 after updating. All the same objects and capabilities are there. For more info, see the article "Autostar Models" on the Helpful Information: Autostar Info page.
Subject: AutoStar #495 vs AutoStar #497 Sent: Sunday, January 9, 2005 14:33:03 From: Cenneth Andersson (email@example.com) I have seen that there are two different models of AutoStar. Model #495 and #497 respectively. How can I find out which model I have? Are there any differencies regarding their connection to a PC? Thanks for any comments. Best regards Cenneth Andersson SwedenMike here: Essentially there is no difference. You can upgrade the software that shipped on the #495 to make it a current #497 using the software from Meade's site. Once upgraded you can use any #497 PC/Mac software.
Subject: RE: ETX125 Easy Align issue Sent: Sunday, January 9, 2005 11:28:26 From: Arthur Caracciolo (firstname.lastname@example.org) Great site appreciate all your hard work maintaining it I have a new ETX125, when i try to do an easy align (I think my home position is correctly done) it get pretty close to the first star, but when I try to move it to center it nothing happens when I push the arrow keys What am I doing wrong? Thanks in advance Arthur CaraccioloMike here: Have you tried to increase the slewing speed?
As a matter fact yes, when I pressed 9 it said max? But I am not getting movment Arthur CaraccioloMike here: Have you done a CALIBRATE and TRAIN DRIVES?
That is my next step, it got dark already, and its cloudy nights I think I try training drives tomorrow in the daylight I'll let you know thanks again Arthur CaraccioloMike here: Working with the telescope indoors is perfectly acceptable when learning a new system.
Subject: Question on aligning the AutoStar Program Sent: Sunday, January 9, 2005 02:49:36 From: Steve Horner (email@example.com) Excellent Site, It gave me hours of insight before buying the ETX90. I recieved the ETX90 a couple of days ago, but have been unable to get the AutoStar functionality to work. When it goes to look for the first star it starts pointing directly upwards, eventually it collides with the side brackets and gives a fatal error on the screen. Any thoughts. Ive reset it a couple of times with the same results. Steve HornerMike here: Did you CALIBRATE and TRAIN DRIVES?
I calibrated the scope, and it seems to have fixed my issue. thanks Steve HornerMike here: Thought that might be the case.
Subject: Thanks for your answer. Sent: Thursday, January 6, 2005 08:18:26 From: chasiotis elias (firstname.lastname@example.org) Mike thanks very much for your help, now everything is o.k. EliasMike here: Glad that solved the rubberbanding.
Subject: re: Fast Slew Disrupts Encoder Reading - ETX 125 Sent: Wednesday, January 5, 2005 21:18:22 From: Richard Seymour (email@example.com) I agree with Clay: dirt on an encoder vane or two. (in Azimuth, this will create -exactly- a ten degree error in readout for a 360 degree spin, if one vane-gap is occluded) But the reason i wrote is to clarify the internals: Meade does NOT regulate the 12v line, except for bringing it down to 5v for the electronics. The motors (and LEDs) are fed (via FETs) full battery voltage, whatever it may be. Thus the need to Calibrate if you change power sources (Mains adapter vs. battery, for example). have fun --dickAnd:
From: Dave (firstname.lastname@example.org) Hi Mike and Richard (thanks for your input) As a final test before sending the scope back, I decided to carry out an accuracy test with the external power pack connected. I picked a spot and lined the the eyepiece cross hairs on it, with the az readout showing 000.00. Then I slewed the telescope at Speed 8 clockwise 360 deg whilst monitoring the Az readout on the handset. When I had made a full rotation, the readout was 000.00. It was as error-free as I could tell. Next having selected Speed 9, I reversed the rotation 360 to get back to the beginning. The readout should have been 000.00, instead it was still reading 240 deg!!!! So, it is definitely something to do with motor speed. Thanks both of you for your help, I will keep you informed as to progress. The importers here are very good and I expecte to have the scope back within three working days Regards Dave
Subject: re: Autostar and alignment troubles Sent: Wednesday, January 5, 2005 21:11:45 From: Richard Seymour (email@example.com) First off, the Autostar cable is -definitely- bad. Either call Meade for a replacement, or build a replacement. The cable should be reversable end-for-end without a change in the operation of the system. The fact you can't shouts "bad cable" (and it could have pins/wires shorted together, as well as open). Replace the cable before making any other judgements about the system. It could also be a -combined- problem: such as a mis-plugged connector -inside- the telescope base, plus a flakey HBX cable. (p.s. Rigel and Betelgeuse are too close together for a good alignment... try Betelgeuse and Kocab) have fun --dickAnd:
From: Bob Gutkowski (firstname.lastname@example.org) Thanks for the advice. I figured the cable was bad. I made a new cable from a LAN cable I had (following the directions on your site). I can now reverse the ends of the new cable without issue. One question I have - does the Autostar recieve feedback from the motors as the scope is rotating or is the distance of rotation souly determined by the Autostar. If the problem continues and elimiting the cable, would the issue be with the Autostar or the telescope. Hoping for some clear skies this weekend to try everything out. Again thanks for the assistance.Mike here: No direct feedback; the Autostar counts the "pulses" from the encoders.
Er, "both" (and Mike's answer could be wrong or right, depending upon interpretation). The Autostar sends a speed command to the motor controller cards (which are inside the telescope). The actual count-the-ticks circuitry is on the motor controller cards themselves. Every so often (at least once per second) the Autostar asks the motor controller card how many ticks have accumulated since the last request. It receives an absolute number (the in-motor counters don't clear). A full rotation of the telescope (lock to lock) exceeds the in-motor counter's capacity, so the Autostar does the "carry" operation to maintain the grand total. The Ratio settings are actually "ticks per arcsecond", and the student is welcome to convert those to how many ticks are a full circle (or, again, lock-to-lock) for -your- telescope. (example: an ETX90 can turn about 500 degrees, and it can maintain sub-arcsecond accuracy through that entire range, with a Ratio of about 1.36 ticks per arcsecond. That's 500 (degrees) * 3600 (arcsec/degree) * 1.36 ticks/arcsec which yields 2,448,000 ticks ... and other models can generate over four times that number. The speed communication from the Autostar to the motor controllers are roughly: an address byte, a command byte, 3 data bytes, and it expects an acknowlegement byte. The encoder communication is controlled by the Autostar, so it sends an address byte, a command byte, and then expects 4 bytes to return (three for the encoder count, one status byte). But the Autostar does not watch a continuous encoder "tick" stream over its cable. have fun --dickMike here: Thanks for the clarification/expansion Dick!
Subject: Question about a serious tracking problem. Sent: Wednesday, January 5, 2005 06:48:19 From: chasiotis elias (email@example.com) I want to ask you about a tracking problem that my ETX recently had. After i center the image and usually after repeated use of Enter to Sync mode (at high magnification video capture this is necessary), the image is gliding slowly but then is suddenly pulled back to the initial place with violent move and a small noise inside the motors(usually every ten seconds). This makes planetary photography very difficult because Registax cant properly align the frames and the result images are awful. It does not happen every time but i am worried if i have caused a big problem by overdoing it with Enter to Sync. Thank you in advance. EliasMike here: I doubt you have caused a problem but heavy use of the SYNC command. But does the problem happen even when you don't SYNC? Anyway, this sounds like "rubberbanding"; the cure is usually to reTRAIN DRIVES.
Subject: Motor Training Sent: Tuesday, January 4, 2005 01:45:25 From: Terry Godfrey (firstname.lastname@example.org) I train the drives on my ETX125 (Autostar 2.6) every few months, more out of habit than necessity, however I was surprised to read in your book (Maintaining and Retraining on page 185) that it is necessary to do a RESET first. I had always assumed that a fresh training session overwrote any previously stored information. Could you clarify the situation as my Meade manual does not mention the need for RESETing. Best regards Terry Godfrey Oxford, UKMike here: RESET only needs to be done when things act up. But you should CALIBRATE whenever you change power sources, including changing batteries.
Subject: Autostar and alignment troubles Sent: Monday, January 3, 2005 21:32:32 From: Bob Gutkowski (email@example.com) Great site. Need some advice. Just got an EXT-90 with an Autostar 497 as a gift. I've done a Calibrate and Train Drives (both axis) a few times. Everythings seems to go find. When I try and Align the Autostar (2 stars) the problems begin. I set up the telescope by the book (north / level). The unit always finds the 1st star with no problem -say Rigel (the telescope is turning clockwise). When the Autostar moves to select a second star (turning counterclockwise) no star to be found in the site. I manually selected 2 stars - Rigel - no problem. Then I selected Betegeuse, expecting a movement to the east. The telescope swung around to allmost NE. In some cases the telescope continues in the counterclockwise direction until it has a hard stop. The manual controlls for moving the scope operate without error. The batteries are new. I'm trying to determine if its the Autostar, cable or the telescope. I've checked the pins in both the Autostar and the telescope - they look OK. I've ohmed the cable - no problems found. The solder joints on the autostar look good. Haven't done anything to the telescope other than checking if the pins are bent. Here's the kicker - If I reverse the ends of the cable, the Autostar is dead. I can reverse the ends again and I'm back to where I started. I tried playing with the connectors - no change. It seems the Autostar dosn't know how far the telescope is turning in the counterclockwise direction. Have you heard of this issue?Mike here: A question: Have you done the rotation to the first hardstop then back CW about 120 degrees to North? Also, when manually selecting Alignment Stars, they need to be at least 90 degrees apart. Finally, if those don't help, do a RESET, CALIBRATE, and TRAIN DRIVES. For more on alignment tips see the Helpful Information: Autostar Info page.
Thanks for responding so quickly. I have been rotating the telescope all the way CCW to the hard stop and then CW until the fork was aligned with the Computer control. I did a Reset, Calibrate and Train Drives again (both axis). Still having problems when the scope moves in the CCW direction. The moves too far CCW - missing objects by 40, 60, 90 and even 180 degs. - and the distance seems to be randam. When selecting a 1st alignment star that requires the scope to rotate CW, the scope is always right on. If the 1st star is in the CCW direction, the scope usually doesn't even come close. Am I still missing something in the setup? Any other suggestions? Thanks for the assistance. Bob GutkowskiMike here: This is odd. What happens if you do the Easy Alignment?
When I did Easy Aligment the scope usually started to rotate in the CW direction first. Always lining up close to a star (Rigel in one case, which I know). With some slight adjustments, the star was centered. The scope would then rotate in the CCW (I can't recall what stars - did this a few times) but there never seems to be a star in sight. In one case there was a star close, so I centered that star (not knowing for sure if it was the correct star but it was the only one even close). I selected Rigel as an object to view. The scope rotated CW but not even close to Rigel. I then selected Saturn knowing it was in the east. The unit rotated almost completely north. In one case when using the Easy Aligment and the first star was centered after rotating CW (Southeastern sky). When the scope slew to the 2nd star CCW, it actually rotated compltely around and hit the hard stop in SW sky. The scope was aligned correctly (rotating fully CCW and then back to have the fork aligned with the Computer Control). The Autostar sounds like a great feature - capablity to track an obect and find new objects. It's something I'd really like to have work. Going to have some cloudy skys for the next few days. Should have a chace to check the night sky out again this weekend. I did a test the other day selecting Rigel as the first star and Deneb as the second star. Dialed in close to Rigel no problem, slewed to Deneb in the NW sky. I didn't think it was even close but I selected the star closest to center. I then proceded to togel between viewing Rigel and Deneb beleiving the scope should turn CW and CCW approxiately the same distance. The scope did not find Rigel at all - stoped in the eastern sky. I noted how many degres the scope turned CW (110 deg). Then when slewing back to what the scope selected as Deneb the scope rotated about 130 deg. Using this new starting point, the scope would always turn 110 deg CW but would progressively turn further and further in the CCW. Eventually the scope hit the hard stop in the CCW direction. This was gift from by father inlaw. I going to see him this weekend and have him try all the adjustment from the top (just to make sure its not me). Bob GutkowskiMike here: Since you did not get the "Alignment Failed" message the Autostar must think things are OK. So, at this point one thing to try is reloading the Autostar software. You will need the Windows Autostar Update application from Meade's site (or the new Mac OS X app) and the 3.3Ef ROM file. You will also need a #505 serial cable (and perhaps a serial-USB converter). You can buy or easily make the cable (see the Helpful Information: Autostar Info page). Alternatively, you could contact the dealer for an exchange.
Subject: Fast Slew Disrupts Encoder Reading - ETX 125 Sent: Monday, January 3, 2005 14:45:01 From: Dave (firstname.lastname@example.org) I've had a look at your site (brilliant) but I can't find anything on my specific problem. If I use an external power supply (either mains powered or a battery pack) both nominally 12v (but in effect around 12.85), the slew speed on the "goto" function is so high that the azimuth encoder does not read correctly. I tested this by checking the azimuth readout on the Autostar after holding down the mode key and then scrolling to display Alt and Az readouts. If I use the eight AA batteries, all is well, but with a full 12v (or just over), it just won't keep up with the speed. I have switched the telescope to "quiet slew" which slows it down so that all is well, but it seems a bit "naff" to be to have to do this. When using the Autostar to slew the scope, I only get the faulty reading when on the highest speed (9), 8 and below are fine. Of course the problem is that on a GOTO, it automatically selects the highest speed to initially slew the scope. Consequently it just keeps driving in azimuth as the encoder can't detect when the correct position has been reached. Any ideas please? I shall keep "quiet slew" selected for now so I can use my new 12v Battery Booster Unit. Best regards and thanks for a great site. Dave Owens Chesterfield EnglandMike here: When you switch power sources, are you doing another CALIBRATE and TRAIN DRIVES? You should.
Hi Mike, thanks for your prompt reply. I tried that and it's still the same. It will only work on "quiet slew" or manually on any speed less than 9. On "goto" is misses everything completely and on manual slew on high speed, I can actuall see that the readout is incorrect when it is slewing. Can you suggest anything else please? I heard that Clay Sharrod runs his at about 18v!!! so I don't think it's the battery as at max it is only 12.85v. I really don't want to be running the system on AA batteries as I will want an electric dew system one day. Could this be a system fault or is there perhaps another answer.Mike here: Have you tried updating to version 3.3Ef (even if that version is already installed)? Maybe the Autostar is slightly corrupted and reloading it would fix it. Otherwise, I'm at a loss as to the cause.
Thanks Mike, it's still the same and any "landmark" tests are around 20% out!! I think I'll return it to the retailer and get them to sort it out. Regards Dave OwensAnd this from Dr. Clay:
From: P. Clay Sherrod (email@example.com) Hello Dave... Interesting issues here. Note that I have used, and recommend using, the ETX with voltages up to 15.2 but NO more than that; 18 V will fry the system very quickly. At about 13.5 to 14.5 v. is optimal. However, the problems you are encountering are not voltage related and since speed seems to be a major factor I suspect very strongly that you have debris or grease in either the encoder tick wheel or the sensing light which rides over the wheel; investigate this in the base of the scope very carefully.....the small battery wires will break if you are not careful with the bottom plate. The encoder wheel is a small white spoked wheel far to the lower left of the entire motor/reducer gear assembly and up in the far recesses of the base...use a flashlight to investigate; you can turn the encoder wheel by turning one of the larger plastic gears that protrudes from the plastic reducer gear housing to inspect the total span of the encoder....bet you have grease or a piece of lint in there. Let me know what you find. Clay -------------------- Dr. P. Clay Sherrod Arkansas Sky Observatories Harvard MPC H41 (Petit Jean Mountain) Harvard MPC H43 (Conway) Harvard MPC H44 (Cascade Mountain) http://www.arksky.org/And an update.
The UK distributor is picking it up tomorrow. He has come across something like this before. As an ex-control systems engineer, I'm assuming that there should be a 12v regulator somewhere on the electronics board so that if a car battery or mains adaptor is used then, it will regulate down to 12v exactly from a nominal input voltage. If this regulator was not working correctly then of course any external input voltage above 12v would certainly cause the electronics to malfunction. I'm sure they will fix it and naturally, I'll let you know the outcome. Regards Dave
Subject: Re: Autostar instructions Sent: Saturday, January 1, 2005 08:45:07 From: Robert Stenstrom (firstname.lastname@example.org) No luck with calibration and training. Just bought the autostar on astromart. Contacted the seller yesterday. He used it with an etx 70ec. Could this be the problem? BobMike here: I presume it is a #497 Autostar (the model with the number keys). Have you set the telescope model and mounting mode to be your telescope? Did you try the RESET?
How do I command reset on the autstar? I preuiously set the model andmounting mode. Thanks for your help so far. BobMike here: SETUP>RESET
Subject: Autostar Easy align problems Sent: Saturday, January 1, 2005 07:54:00 From: Steve veness (email@example.com) just wondered if anyone can help with a problem I have come across since downloading the latest Autostar software (33Ef I think). I have retrained the motors but when I try Easy Align the scope slews towards the first star but never gets there & never beeps to ask me to centre. Instead it continues to slew by 7 or 8 degrees RA/Azimuth at the time then pauses for 5 seconds before slewing again, and so on. Because the weather has been cloudy since Christmas (I live in the UK!) I was doing a 'dummy' align during the day but I am sure I have done this before with no problems. Any advice would be gratefully recieved. Thanks Steve Veness (using my wife's email, hence Judy@.... !)Mike here: Do a CALIBRATE and then TRAIN DRIVES. If that doesn't solve it, do a RESET. This will restore the Autostar to "factory defaults" so you will have to enter your location, and do another CALIBRATE and TRAIN DRIVES.
Thanks - will try that.
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