Meade LX200 Classic RA runaway
Posted 26 January 2014 - 12:01 AM
Hi all. Thanks to letting me part-take in this site. I have read a few posts and realized I needed to be here.
I just bought my first telescope (10", LX200 f/6.3, 1600mm on Alt-Az) to start doing AP with. I have been doing wide angle AP with general camera equipment and really wanted more 'reach'.
I bought this knowing it was going to be a fixer upper based on it being a runaway. I thought I would either send it off to be fixed, fix it myself by learning how it all works or just ditch the fork and mount and get a decent EQ for it.
Was hoping to hear if anyone knows who to turn to in properly diagnosing what is wrong so I can keep the cost down on repairs.
My ultimate goal for this scope is to do stack long exposures of nebula, galaxies and whatever else in reach of this particular scope.
I hope I didn't post in the wrong section, sorry if I did. just a noob.
Posted 26 January 2014 - 01:16 AM
I had an LX90 that was doing this. Replaced the controller and solved it. That isn't always the case though. First off the 200 uses a different controller(handpad). I've heard of it also being a problem on motor boards. Like I said try the other thread or ask a moderator to move your question there. You would be better served with an GEM/EQ mount for imaging unless you have an exceptional example of a LX200 but that is my opinion.
Posted 26 January 2014 - 09:10 AM
Posted 26 January 2014 - 02:35 PM
Scroll down to the bottom and on the left side look for the topic ... "RA Axis/Drive Concerns (Tracking)" which has a lot of info on the RA runaway problems.
Posted 27 January 2014 - 03:06 PM
Posted 28 January 2014 - 11:35 AM
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Posted 29 January 2014 - 12:54 AM
Posted 29 January 2014 - 10:42 AM
Posted 29 January 2014 - 11:57 AM
Posted 29 January 2014 - 12:56 PM
They said it would probably cost me $600 to have it sent off for repair. I don't know about you, but shipping a big piece of optics like this is not something I feel comfortable doing, especially if it UPS/FedEx/DHL. I know several electricians and I&E techs that would be able to help diagnose and repair this. No need to send off and risk damaging it. I would rather drive it myself. That being said, I wonder if their is a repair shop around Seattle.
I know that there's an electronics wholesale supply warehouse in Olympia that does minor electronic repair, however I am not sure if there's one in Seattle.
I think the $600 that Anacortes Telescope quoted was - I believe - the repair cost to have it sent to Meade down in Irvine, CA. That being said, Meade has distanced themselves from repairing the older LX-200 Classic models because the electronics in them are getting harder to source (yet usually, runaway problems are usually traced back to potentiometers that have gone out of adjustment or a bad capacitor).
There is an astronomer in Arkansas by the name of Dr. Clay Sherrod who does a "Supercharge" service on all of the older Meades, but to have it done on a 10-inch LX200 Classic is about $600 - and then you have to pay for shipping to and from Arkansas. And repairs are extra depending on the parts he has to source, plus labor, etc.
By the way, welcome to CN, Eddie!
Posted 29 January 2014 - 11:32 PM
Posted 30 January 2014 - 10:34 AM
Posted 30 January 2014 - 10:39 AM
Posted 30 January 2014 - 01:21 PM
This is the encoder signal before and after before and after rebuild. I'm a JD, Jim. Not an EE!
Those look like exactly the same signal only the O-scope triggering isn't set correctly in the top pic.
Posted 31 January 2014 - 05:07 PM
If this is a classic (sounds like it) then the most often overlooked issue is a bad connection. Carefully check the wires on the "punch down" connectors which connect the motor assembly to the rest of the scope.
Look at the bottom of this thread for a picture and discussion that occurred years ago among the MAPUG mailing list about RA and DEC runaway and the motor assembly.
Also a link to the MAPUG archives. Great LX200 classic resource, with some of the best of the old MAPUG mailing list. There is further discussion there on runaway as well.
Our LX200 was built in 1992. Still going strong with mostly just minor PM. I repaired our runaway years ago, it was the el-cheapo connector.
Posted 04 September 2014 - 03:53 PM
Bruse Johnson's Astronomy pages - Bruce (now sadly deceased) explains how the LX200 classic's RA & DEC work and how to trouble shoot them, especially run away problems. This is an excellent site for the LX200 classic series of Meade telescopes, especially, if you are a do it yourself type.
Posted 11 September 2014 - 03:02 PM
I'd bet the handbox curly cord or it's connectors is the first thing I'd check.