Last updated: 31 March 2005
Subject: repairing the focuser on ETX-60 Sent: Wednesday, March 30, 2005 19:25:05 From: firstname.lastname@example.org (email@example.com) I was given a damaged ETX 60 (about 2 years old) and hope to repair it. It was knocked over into a "free fall" onto the front of the tube while mounted on its tripod. The result was that the focuser acts as if "stripped" -- the focusing knob only occasionally and slightly engages, and otherwise the moving part of the tube slides freely and smoothly. The small plastic collar at the base of the focusing shaft (where the shaft enters the housing) is cracked. Is this user repairable? I am fairly mechanically competent. Or must I send it to Meade? Thank you, Chuck PalusMike here: Check out the article "ETX-70AT Repair Guide" on the Helpful Information: Telescope Tech Tips. It may help you.
Subject: Re: etx-70 motor fault Sent: Wednesday, March 30, 2005 04:37:59 From: nakis mameletzis (firstname.lastname@example.org) thanks alot again ,for the reply.I tried everything but the dec motor doesnt response at all....i called the factory where i had took the scope (5 years warranity)and they told me that the only thing they can do ,is to give my money back....about 200 euros..Now what?should i take the scope and give it to an enginear,is it worth it...?Ihave to to tell you again that my main scope is a Meade Starfinder equatorial reflector 8" with motor at R.A..the small etx was a good scope for traveling and you could also do some job with astrophotos ... Well......i am looking forward for your reply in my last hours with the etx.... Thanks a lot again...Mike here: If the motor doesn't run then one possibility is that a wire has become disconnected or cut. You could open the base and see if you see a wire that is disconnected or broken.
Subject: ETX-70 Easy Align problem Sent: Thursday, March 24, 2005 04:53:11 From: Thomas Friedmann (Thomas_Friedmann@raytheon.com) My ETX-70 scope has developed a quirk in the Easy-Align set-up. It locates and aligns to the first star, but when it attempts to go to the second align point, it slews for about 2 minutes until it is pointing almost straight up and gives me the confirmation beeps The drive motors sound like they are continuing to search for the second location. I tried replacing the handbox and batteries to no avail. Any suggestions? Tom FriedmannMike here: Have you tried replacing the batteries? Low batteries can cause similar problems. When you replace the batteries, do a CALIBRATE MOTORS.
Thanks. I repaced the batteries, but did not recal the drives. Will try that.
Subject: etx-70 motor fault Sent: Saturday, March 19, 2005 15:41:52 From: nakis mameletzis (email@example.com) Congratulations for your fantastic site.. I have an etx-70 for aboyt 3 months.everything look to work well untill today.i was trying to take some pics of the moon with my zenit slr camera adapted on the focuser!1 of all the etx mount can not hold the camera very well and i have to tight the dec very hard...2:problem and the most serious is that after trying to do an alt/az alingment the motor stoped and a message appeared in the Autostar screen:Motor unit fault!!!What i should do now ti fix it???is it seroius?battery problem or telescope drives??? i am looking forward for your reply ...... Nakis...Mike here: I suspect the weight of the camera is causing you to tighten the axes locks too much. Remove the weight and lock the axes normally and see if the problem goes away. If you really want to use the camera you should probably add a counterweight; see the Helpful Information: Astrophotography page for lots of tips on counterweights.
Thanks a lot for your imidiate response.... The problem still exists even if the camera isnt on the scope.The aligment i did last night was normal(no camera)but the same message MOTOR UNIT FAULT...if you have any idea i would be very pleased to hearing from you(sorry for any mistakes -i live in Greece)... I am looking forward for your reply Nakis!!!Mike here: Have you tried fresh batteries? If you do change the batteries, do a CALIBRATE MOTORS. If that doesn't solve the problem, do a CALIBRATE MOTORS and then TRAIN DRIVES. That should clear it up. If not, DO A RESET, CALIBRATE MOTORS, and TRAIN DRIVES.
I triyed almost everything and i really dont know what to do, the problem still exists .i noticed that the Alt motor (dec)does not responce at any movement i try to do with the autostar hand contoller.when training drive the scope moves only at Az (RA)and when i callibratate motors the scope moves only RA and when going to calbrate the other motor....MOTOR UNIT FAULT.....again... If you have any last idea on what other left to do ,i would very thankfull to hearing from you,and thanks a lot for the responce i take from you in my messages.... A dissapointed etx user......:( .......Friendly Nakis!!!Mike here: When you tighten the Altitude axis lock, does the tube stay put or does it want to fall back to the base? If it won't stay put then the Right Tube Adapter has likely failed.
Subject: Is it oke to put a PST on a ETX-70? Sent: Saturday, March 19, 2005 14:21:06 From: Chaim Dijkstra (firstname.lastname@example.org) I have a question: can I put a Coronado "Personal Solar Telscope" on a piggyback on my ETX-70? Is the 1,8 kg Coronado PST not to heavy for the ETX-70 fork-mount? My ETX-70 Instruction-Manuel doesn't say anything about what the maximum weight is that the mount can carry... I don't want to buy a Coronado PST before a know it for sure; I am only 14 years old and a telescope is a lot of money for me! I would appreciated if you can advise me. Chaim Dijkstra, The NetherlandsMike here: As seen in my comments on the Accessory Reviews: Filters page, I have mounted mine on an ETX-90RA. I have not had any problems with that. I don't have a piggyback adapter for the ETX-70 so can not check that model.
Subject: ETX70-AT Battery Problem! Sent: Wednesday, March 16, 2005 17:13:54 From: Dale D Penkala (email@example.com) I have communicated with you sometime ago about an issue that I needed help with and was able to get the information. It was on a ETX90 M. I currently have a customer that has a ETX70-AT. His son went to change the batteries and pulled the battery wires right out of the scope. I figured that the wires were sodered onto the circuit board somewhere so I removed the inside panel to expose the board and wires. Sure enough there is a square white box that is sodered to the board were the wires just slide into and clip with a spring clip of some sort from the top. I got the board out and unpluged the one wire that goes into the dec axis but I still don't have enough room to put the board out to get to the white box that is on the board. My thought was if I can get more slack in the wires that go into the base I might be able to get it fixed. So my question is how do I get the base off one of these units? I have removed the 3 screws that are under the 3 rubber pads on the bottom but that just holds some kinda plate to the bottom inside the base. I removed the center bolt that comes up through the unit and has the locking lever on the top of the base between the forks. I looked through your website looking for a battery wiring problem but I didn't see any one with that specific problem. Can you help direct me somewhere to show me a fix or at least help me get the base apart to get some slack in the wires that go to the circuit board? Any help would be appreciated! Thanks Dale Penkala DBA Astronomy Products & Services Auburn, MI USA www.speednetllc.com/dbaastronomyproductsMike here: The articles "ETX-70AT Repair Guide" and "Inside the ETX-70AT" on the Helpful Information: Telescope Tech Tips page might help.
Thanks for the help! Dale
Subject: Re: Comet Machholz Calculations on the ETX-70 -- still more Sent: Monday, March 14, 2005 18:56:11 From: Thomas Henry (firstname.lastname@example.org) Here's a bit more data. No doubt about it, the ETX-70 isn't very accurate with this comet. The skies cleared here, and I recovered the comet after some spiraling. Cartes du Ciel predicted the position as 8 hours, 43 minutes and 84 degrees 18 minutes. I found it at 8 hours, 36 minutes and 84 degrees, 10 minutes. Very accurate, indeed, so the old elements seem to be holding reasonably well! The internal ETX-70 calculation, on the other hand, is off by some 50 minutes of RA and 40 minutes of declination. Not very good. Have any of you had success with comets other than this one? That might give us some good info to suggest a cause. Thomas HenryMike here: Have you tried a different comet?
Good idea. I just tried P/2004 X1 Linear for comparison. The calcs for Cartes du Ciel and the ETX-70 are within one minute of each other in both RA and declination! Note that X1 Linear is far away from the pole just now. This fits with my original hunch that comets close to the pole give the ETX trouble, probably because the tangent function explodes near 90 degrees and because of limited floating point accuracy in the ETX versus a PC program like Cartes du Ciel. Opinions? Thomas HenryMike here: Could be a pole problem! Might be worth reporting to Meade at email@example.com (just don't expect a response).
Subject: Comet Machholz Calculations on the ETX-70 Sent: Sunday, March 13, 2005 21:57:16 From: Thomas Henry (firstname.lastname@example.org) After too long being an indoors type, I stepped out tonight with binocs and found Comet Machholz easily. I decided to dust off the ETX-70 and get ready for tomorrow night by punching in the orbital elements, which you can find here: http://cfa-www.harvard.edu/iau/Ephemerides/Comets/2004Q2.html Upon checking some sample calcs against Cartes du Ciel, I see that the RA is off by nearly an hour. I suspect this has something to do with the Epoch of Osculation not being quite the same as what the ETX-70AT asks for, namely the Epoch of Elongation. Am I close? There's no doubt about the other parameters. And in fact, in the past I've had good luck punching in data for the minor planets and finding them accurately. Has anyone else had trouble with the comet calculator in the ETX-70? A little bit of dither I can understand, but an hour of RA is a bit much to tolerate. Could it be because the comet is so close to the pole (tangents close to 90 degrees, that sort of thing)? While I'm at it, does anyone know how to pick off the absolute magnitude number from the file of elements mentioned above? It would be fun to see just how close the ETX-70 can come in its predicted relative magnitude calculations. Thanks, Thomas HenryAnd more:
I went over all the settings in my Autostar again, and I must have had something wrong earlier, for now I am in fact able to get a more accurate tally on the comet. (I wasn't watching carefully, but I think I saw a 9 flash by instead of a 0 somewhere. It's heck to have aging eyes!) I'm off by only 19 minutes of RA now, and a piffling 16 minutes of declination which I think is acceptable. The comet should wind up within my low power eyepiece. Still, I'd be curious to learn how other people have faired with this, or other comet/asteroid calculations. It be nice to get a more accurate computation. Thomas HenryAnd:
I tried a few more things today, while waiting for the clouds to clear. When computing Comet Machholz, the ETX-70 is still off by 50 minutes of arc and 39 minutes of declination compared to Cartes du Ciel. Would some else be willing to try it and see if you get something similar? I'm guessing one of three things: 1. Because this is close to the pole, the approximation to the tangent function becomes increasingly off. (Tangent grows without bound there). 2. The ETX-70 routines aren't as good as Cartes du Ciel, maybe for space reasons. 3. The ETX-70 floating point representation isn't as good, and is prone to more rounding errors. With the errors, I'm predicting that the true position and calculated position will lie within a 2 degree circle, which is certainly do-able with a low power eyepiece. But wouldn't it be nice to know what's going on? Any other ideas? Thanks, Thomas HenryMike here: How old are the elements you are using?
I agree. But the point is that Comet du Ciel comes up with values that are virtually identical to those in Sky and Telescope, while the ETX-70 is off by the amounts I indicated. In other words, the same elements (even if old) are given to each each piece of software and yet these yield different results. Best wishes, Thomas Henry
Subject: Using Palm OS 5.2.1 to control ETX 70AT Sent: Thursday, March 10, 2005 10:32:20 From: Gary Crossley (email@example.com) Thanks for all the hard work you put into your site. What is the latest word on using a PDA operating Palm 5.2 to control a 70AT. I know people were having trouble with the special cable, but I couldn't find if the bugs have been worked out. Thanks, Gary Crossley Mechanicsburg, PAMike here: With the right cable (#506) and the right Palm connectors, it should work.
Subject: re: How does the ETX 70 hook up to a power tank? Sent: Monday, March 7, 2005 21:49:32 From: Richard Seymour (firstname.lastname@example.org) A problem with using an ETX70 with a power tank is that the ETX70 is designed for 9 volts, not 12. So the power tank will be a little bit of "overkill". The voltage regulators throughout the system will be running hotter, and i don't know if you'll be exceeding the motor's design ratings. have (careful) fun --dickMike here: The Meade AC Adapter for the ETX-60/70 is 12VDC 1000mA.
Ah... i wasn't aware of that... the one which came with mine long ago was 9v So PowerPack without worry! have fun --dickMike here: Mine was received long ago too!
Subject: How does the ETX 70 hook up to a power tank? Sent: Monday, March 7, 2005 10:58:39 From: MRANDMRSPEPI@bellsouth.net I am new to the hobby and I am going to have a long viewing session in the near future. I was thinking of buying something such as a Celestron power tank for said viewing session. How does the ETX 70 hook up to the power tank ? Do I have to buy the Meade AC power cord ? I currently use regular batteries as my power source, but I don't want to be taking the scope apart in the middle of a long session to put new batteries in. Many thanks, MichelleMike here: You would need the matching connector for the battery pack inside base of the ETX. You should be able to get one from Radio Shack. Then just make a cigarette lighter connector cable with that connector on the other end. See the Power Supplies section of the Helpful Information: Telescope Tech Tips page; info there should help.
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