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Old 28-02-2006, 06:21 PM
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g__day (Matthew)
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Join Date: Dec 2005
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* * * Some Data re Goto Mounts

I thought I'd do this for folk considering their next telescope and pondering how much to spend and how to check their gear assumptions all makes sense when combined.

So attached is a table of data I've found that may be used to check your assumptions, and corrected by folk with more practical knowledge.

The summary insights given to me here by many helpful folk should be listed before we begin:

1. Spend as much on your mount as on your scope if you're considering astrophotography at some point
2. German Equatorial mounts offer far better astro imaging platforms than fork mounts dollar for dollar
3. Piers are far more stable than tripods if mobility isn't a concern (e.g. portable piers! http://www.cloudynights.com/item.php?item_id=1365 )
4. Long exposure means rock solid stability + astro-guiding to keep your scope pointing with enough accuracy
5. Lower (potentially halve) your mounts maximum rated carring capacity to know what it can handle with a full load of CCDs, guiders, de-rotators, and/or other imaging gear

So with that said, lets just check the typical weight (and cost) of common SCTs to give you a feel.

Celestron http://www.celestron.com/advanced_series/index.htm

Aperature (inches) ----- OTA Weight (Kg) ----- Cost ($ RRP)
Code:
         8                      6                 $ 2,118 
         9.25                   9                 $ 2,841 
        11                     13                 $ 4,504 
        14                     20                 $ 9,979
Meade

Aperature (inches) ----- OTA Weight (Kg) ----- Cost ($ RRP)
Code:
 
          7                                         $ 2,300 
          8                      9                  $ 1,579 
         10                     14                  $ 2,085 
         12                     18                  $ 3,740 
         14                                         $ 4,865
So onto the meat - various mounts and their costs for common models, else a import shipping USD/AUD conversions (without adding $150 Fedex + warranties + duties) guestimate for foreign exotics

Brand ----- Model ----- RRP $ ----- Max Load (Kg) ----- Periodic error (arc sec)
Code:
 
Synta       EQ 2         $   199   
            EQ 3         $   299                          +/- 10
            EQ 5         $   500          7               +/- 12
           HEQ 5 GoTo    $ 1,799         10               +/- 15
            EQ 6 GoTo    $ 2,199         25               +/- 20
            EQ 6 Pro     $ 2,499         25 
 
Meade       LX75         $ 1,500         10 
 
Vixen       Skypod 110  $ 2,100           5           http://www.orionoptics.co.uk/acatalog/skypod.html
            SP                                            +/- 30
            SP/DX                                         +/-  8
            GP                            7               +/- 17
            GPD2                         10 
            GP/DX        $ 3,090         10               +/- 14
            Spinx        $ 2,695         11               +/-  8
            Atlux        $ 7,549         22               +/-  8
 
Takahashi  http://www.telescopes.com/specialty_...s--Mounts.html
            EM-1s                         9               +/-  7
            EM-10        $ 2,900          9               +/-  7
            EM-11        $ 6,500         10 
            EM-200       $ 6,700+        18               +/-  5
            NJP          $ 9,170         30               +/-  3.5
            EM-400      $ 11,286         39 
            EM-500      $ 17,627         45               +/-  3.5
            EM-3500     $118,000        160               +/-  ? awesome I suppose!
 
Losmandy (With Gemini GoTo)  http://www.atscope.com.au/losmandy.html
            GM  8        $ 4,000         13               +/-  8
            GM 11        $ 5,650         27               +/-  7
            Titan       $ 11,000         45               +/-  4
 
Valmecha
            VMA150                       35               +/-  5 
            VMA200                       70               +/-  5
            VMA300                                        +/-  2
 
Trassud     ZX4                          45               +/-  3
            ZX7                          75               +/-  5
 
Arcane      A40                                           +/-  6
 
Celestron   CG-5       $ 1,399           13 
            CGE        $ 5,750                            +/- 11
 
Astrophysics  (Plus Digital SkyVoice) http://www.astro-physics.com/
            400 GTO    $  5,130           8.2             Superceded by Mach1
            600E GTO   $  6,430          11.4             Superceded by Mach 1
            Mach1 GTO  $  8,500          20               +/-  7  (in 1 worm rotation per 6.4 minutes)
            900 GTO    $ 11,357          35               +/-  3
           1200 GTO    $ 13,429                           +/-  2
 
Mountain Instruments (+ Losmandy Gemini Go To)  http://www.mathis-instruments.com/
             MI 250    $ 10,000          30 - 36          +/-    ? assume pretty good!
             MI 500    $ 16,700          82
             MI 750    $ 25,500         127
             MI 1000   $ 52,000         205
 
Paramount ME Robotic Telescope Mount http://www.bisque.com/Products/Paramount/
             ME        $ 18,000          68               +/-  1  
http://www.bisque.com/help/paramount...ifications.htm
So lets say I want a decent size scope and mount, say a 9.25" or 11" Celestron which has a bit of weight too it, placing it just beyond what a Vixen Sphinx should be loaded with (sigh). Well I could start with an LD-75 or CG-5 mount or do better by getting a EQ6-Pro mount + skyscan for Go To (Andrews do these) about $2,100. The Pro EQ6 is really just the EQ 6 painted white (to look Japanese) and costing $300 more. Better still would be a Losmandy G-11 plus Gemini $5,000 and maybe up from this is an Celestron CGE (or is that the other way round)? Reviews make it abit hard to tell at the moment!

If I step up to the CGE mounts I fork out another $2,000 for an unknown gain (help out guys!).

PS

High end Vixen tripods cost $900 - $1,200 above those dollars. Mount Instruments don't include tripods (or more realistically piers) either.

PPS

Piers start around $550 (astro online), check compatability with your mount.


Work in progress!

Last edited by g__day; 13-03-2006 at 05:38 PM.
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