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Celestron GM-11

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#1 WOBentley

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Posted 20 June 2010 - 11:37 PM

Anyone heard of this? Supposedly a Losmandy G-11. Is it upgradeable to go-to? Will it take upgraded worms? In good condition any idea of value?
Came across one and want to be fair (but may be out of my range), but don't know enough.
Thanks
Dave

#2 gnowellsct

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Posted 21 June 2010 - 12:10 AM

Has to be post-1992 to take the worms, if memory serves.

You'll want to make sure it has two screws to lock the altitude setting. If it doesn't, HGM will retrofit for a reasonable fee.

Greg N

#3 urbanMark

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Posted 23 June 2010 - 03:08 AM

I have an older G-11 that says "manufactured for Celestron by Losmandy". The mount is labeled "G-11" NOT "GM-11". Searching the Losmandy Yahoo group I can find reference to the "GM8" and the "G-11", but no "GM-11". Not to say there wasn't a GM-11, but I can't find it.

So, assuming what you have found is the "G-11" made by Losmandy for Celestron, then everything should be upgradable to current specs...but for the definitive answer, call Scott at Losmandy and ask. AFAIK the upgraded worms fit all G-11's, regardless of age.

If the mount has the Gemini controller, then it is likely the older style - which meas you will need a relay box or optocoupler when interfacing to most autoguiders - not a big deal.

#4 gnowellsct

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Posted 23 June 2010 - 07:35 AM

You'll also want to upgrade the old Hurst motors to SAIA if it is the stepper mount, somewhere around $100 to $150 for both; brass worms if you want "better but not best" tracking in RA: $50 per axis; $300 if you want the Losmandy single worm block, for astro-photography; $500 if you want the Ovision, which currently has the most aftermarket parts; about $50 to get the second altitude lock, which is something of a "must" (requires trip to Hollywood General Machining); all these things are optional, the mount will work as is, but some of them make a difference. The SAIA motors keep the image steady at higher powers, no vibration, the second altitude lock keeps you from losing polar alignment; the worm gears are mainly a photography thing. But an older G11, not having these upgrades, if it does not have Gemini, should be discounted relative to more recent versions. Around a grand to 1100 would be reasonable territory given the hassles involved in getting it up to current specs.

You'll probably want a newer polar scope.

If you bought the stepper version new for example you would get the SAIA motors, you would get brass worms, you would get the second altitude lock, all for around $2200 to $2400 depending on options. You might sell it five years later for $1800.

You're looking at $500 or so in upgrades to get your older version up to the standards of a newer used model.

regards
Greg N

#5 WOBentley

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Posted 23 June 2010 - 08:19 AM

Thanks All
This has been extremely useful!
Dave






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