Jump to content


Photo

LXD750/650 controller

  • Please log in to reply
12 replies to this topic

#1 CharlieB

CharlieB

    Vanguard

  • *****
  • Posts: 2102
  • Joined: 11 Dec 2007
  • Loc: Southern NH

Posted 19 August 2013 - 03:17 PM

I know the Meade LXD 750 & 650 must have, at some time, been available without the 1697 Computer Drive System as the instructions for installing the system are in the original user's guide. I was wondering if anyone knows what kind of control system was available before the 1697? And if so, was it used in other Meade mounts? I ask because I blew C2 in the power control board and was using the mount manually until I received a package of 35v 6.8 mf tantalums to replace it and other well-know culprits. It would have been nice to have some drive mechanism, even if it was not-goto.

#2 jrcrilly

jrcrilly

    Refractor wienie no more

  • *****
  • Administrators
  • Posts: 33887
  • Joined: 30 Apr 2003
  • Loc: NE Ohio

Posted 19 August 2013 - 05:43 PM

Those mounts were offered in three versions, though by far the most common included the #1697 goto system. Another option was tracking-only. It used the same motors but a simplified internal controller and a simple handbox. I've only ever seen one of those. It was also offered (at least on paper; never saw one) as a manual-only mount with no drives. That version actually had the motors inside but not connected to anything.

#3 CharlieB

CharlieB

    Vanguard

  • *****
  • Posts: 2102
  • Joined: 11 Dec 2007
  • Loc: Southern NH

Posted 19 August 2013 - 06:51 PM

Thanks for the great information. When (if) the mount every really dies, I'll take the knobs off and grind a flat spot on them for flex cables. It worked quite well manually and takes a load rather well. When I had the mount apart, I was pleased to see well-designed and well-made boards - quality you don't see very often any more. Sure wish they'd used higher voltage caps, though. Man, was there ever a lot of smoke from that little capacitor! Fortunately, that was all that went. It happened when I connected the 12-18v adapter (without checking the output voltage first). My error and I got very lucky.

#4 southmike

southmike

    Mercury-Atlas

  • *****
  • Posts: 2876
  • Joined: 22 Nov 2004
  • Loc: Fayetteville, NC

Posted 19 August 2013 - 11:44 PM

Open your controller and wrap a piece of duct tape around the ribbon.. At way if it blows it won't blast a hole through the ribbon..

#5 southmike

southmike

    Mercury-Atlas

  • *****
  • Posts: 2876
  • Joined: 22 Nov 2004
  • Loc: Fayetteville, NC

Posted 19 August 2013 - 11:48 PM

Which leads me to another question if you blew the power control board..even the dummy non goto version would probably not function....
Would not be as hard to rig up a fix.but just saying.

#6 jrcrilly

jrcrilly

    Refractor wienie no more

  • *****
  • Administrators
  • Posts: 33887
  • Joined: 30 Apr 2003
  • Loc: NE Ohio

Posted 20 August 2013 - 01:01 AM

Which leads me to another question if you blew the power control board..even the dummy non goto version would probably not function....


There's no separate, independent power control board. Each controller incorporates its own. If he replaced the #1697 with the tracking-only controller the only parts that would remain in place are the motors and encoder boards.

#7 CharlieB

CharlieB

    Vanguard

  • *****
  • Posts: 2102
  • Joined: 11 Dec 2007
  • Loc: Southern NH

Posted 20 August 2013 - 10:44 AM

I didn't make it very clear that the board I was referring to is the first of the two that are sandwiched together inside the mount - the one with the voltage regulator. I had already replaced the tantalums in both of my handboxes. I also had shielded the ribbon cables, although I do have one of the replacement cables Ron Sampson made a few years back - just as extra insurance.

#8 Skywatchr

Skywatchr

    Mercury-Atlas

  • *****
  • Posts: 2663
  • Joined: 03 Jun 2006
  • Loc: North-Central Pa.

Posted 22 August 2013 - 05:16 PM

Hi Charlie, I converted my LXD650 to use Autostar (and Audiostar) so you do have options just in case. :grin:

#9 CharlieB

CharlieB

    Vanguard

  • *****
  • Posts: 2102
  • Joined: 11 Dec 2007
  • Loc: Southern NH

Posted 22 August 2013 - 10:25 PM

I've only read about that conversion kit. Is it still available?

#10 Skywatchr

Skywatchr

    Mercury-Atlas

  • *****
  • Posts: 2663
  • Joined: 03 Jun 2006
  • Loc: North-Central Pa.

Posted 24 August 2013 - 05:42 PM

Yes it is still available. Go to the website http://tech.groups.y.../LX200Autostar/ and send George a message.

#11 CharlieB

CharlieB

    Vanguard

  • *****
  • Posts: 2102
  • Joined: 11 Dec 2007
  • Loc: Southern NH

Posted 25 August 2013 - 08:15 PM

Thanks! Will do.

#12 JAT Observatory

JAT Observatory

    NOT a Wimp

  • *****
  • Posts: 9477
  • Joined: 20 Feb 2005
  • Loc: In the Primordial Soup

Posted 05 September 2013 - 09:04 AM

I have a LXD650 and I can't decide if I should just replace the caps or go with the AutoStar upgrade.

#13 CharlieB

CharlieB

    Vanguard

  • *****
  • Posts: 2102
  • Joined: 11 Dec 2007
  • Loc: Southern NH

Posted 07 September 2013 - 08:58 AM

If you need a few 35v tantalums, let me know. I have a few left over.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics