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Economical mount for SCT OTA

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#1 jrhargrove

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Posted 25 March 2013 - 09:27 AM

Hello,

I am new to the forum but not to visual astronomy. After a long absence, I am thinking about buying a mid-aperture telescope; in the past, I have owned an 8" SCT, 4" refractor, a 15" dobsonian, and several small Newtonians. I am considering a dobsonian or perhaps SCT. Aperture, optical quality, and portability are most important to me; I have no need for go-to capability, and the purchase of a complete SCT with mount and electronics is more than I would like to spend.

My question concerns alternative mounting for a SCT. Can a 9.25, 10, or 11" SCT OTA be mounted on a simple alt/azimuth style mount? If so, would it be economical and advisable to do so? I would appreciate any and all opinions and guidance.

Thanks and best regards,

John Hargrove

#2 Mark9473

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Posted 25 March 2013 - 09:34 AM

See this recent thread: link.

#3 jrbarnett

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Posted 25 March 2013 - 10:11 AM

"Can a 9.25, 10, or 11" SCT OTA be mounted on a simple alt/azimuth style mount?"

Well yeah, but a simple alt-az style mount capable of handling those OTAs is going to cost as much as a number of GOTO mounts that can also handle those OTAs, and the GOTO mount has the hugely important added bonus of tracking. The longer the focal length of the scope, the tinier the true field of view and the harder it is to put objects in that field of view and tor track them manually. If cost is what has you thinking manual alt-az, I'd say "think again" because cost won't be what differentiates the alt-az from the GOTO mounts capable of handling those OTAs.

Good luck!

- Jim

#4 hfjacinto

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Posted 25 March 2013 - 10:21 AM

A 9.25 can be mounted on a GC5 (barely), the 10 and 11 you need at least a CGEM/Atlas type mount. A T-REX would also carry of the OTA's mentioned.

#5 jrhargrove

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Posted 25 March 2013 - 07:44 PM

Thanks to all of you for your responses.

John

#6 cavefrog

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Posted 25 March 2013 - 10:40 PM

I think one alt/az manual mount capable of handling a C-14
is a Stellarview M7. It runs around at $900 I think/

Theo

#7 cavefrog

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Posted 25 March 2013 - 10:43 PM

I think one alt/az manual mount capable of handling a C-14
is a Stellarview M7. It runs around at $900 I think.
But, as an alternative, one can build a 3" pipe mount with the same capability for under $100! granted, it wouldn't be as smooth as the M7, but it would be a lot less expensive.

Theo

#8 daniel_h

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Posted 26 March 2013 - 12:10 AM

Unistar basic would d it with rings & a tripod, only 299 without guide handle, add 100 for the clamshell mounting

#9 rmollise

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Posted 26 March 2013 - 07:29 AM

A 9.25 can be mounted on a GC5 (barely), the 10 and 11 you need at least a CGEM/Atlas type mount. A T-REX would also carry of the OTA's mentioned.


Sort of, maybe. The CG5 is (I assume that is what you mean) is perfectly adequate for the 9.25, and I've had a lot of fun with a C11 on one. Certainly the C8 is better on the mount for long exposure imaging.

As I have said before, there's nothing I like less than a long focal length scope on an undriven alt-az mount. ;)

#10 hfjacinto

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Posted 26 March 2013 - 11:32 AM

Uncle Rod, I am a firm believer in the XW Budhha and his saying: "You can never overmount a telescope but you can sure undermount"

Personally I was never too happy with the CG5 and the 9.25 even with Anti Vibration pads, when I got the CGEM, I was much happier, but rock solid is a C8 on an Atlas/CGEM. I think a C11 really needs a CGEM as a start or preferrably a CGEM DX. I am thinking of a CGEM DX for my 9.25.

#11 Geo.

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Posted 30 March 2013 - 04:23 PM

The Giro III will handle a C11 with the Atlas/CGEM tripod and some counter weighting. Mine is German made, but I guess they are now Chinese, selling as the "ES Twilight GIRO-III/Azimuth double mount."

I see that Tech2000 has developed their own product to replace the Giro line now that ES owns it. Tech2000 "Giro Cube" Telescope Mounts see: http://www.tech2000a...giro_G3_mounts/

#12 rmollise

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Posted 30 March 2013 - 04:30 PM

Uncle Rod, I am a firm believer in the XW Budhha and his saying: "You can never overmount a telescope but you can sure undermount"

Personally I was never too happy with the CG5 and the 9.25 even with Anti Vibration pads, when I got the CGEM, I was much happier, but rock solid is a C8 on an Atlas/CGEM. I think a C11 really needs a CGEM as a start or preferrably a CGEM DX. I am thinking of a CGEM DX for my 9.25.


If you like the CGEM, that's fine. My CG5 does well enough that my Atlas stands in a corner, lonely and ignored. I'm lazy, you see. :lol:

#13 Mark9473

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Posted 30 March 2013 - 05:54 PM

The Giro III will handle a C11 with the Atlas/CGEM tripod and some counter weighting. Mine is German made, but I guess they are now Chinese, selling as the "ES Twilight GIRO-III/Azimuth double mount."

Tele-Optic in Germany still sells the real deal.






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