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10" f9 APO

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#51 John Fitzgerald

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Posted Yesterday, 03:30 PM

Sounds like larger refractors would not fare well in a standard dome, like Ash Dome, due to thermal issues.  I like domes for refractors, due to protection from dew, local lighting,  and wind.  But, how do you insulate the dome itself?



#52 Jeff B

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Posted Yesterday, 08:57 PM

Sounds like larger refractors would not fare well in a standard dome, like Ash Dome, due to thermal issues.  I like domes for refractors, due to protection from dew, local lighting,  and wind.  But, how do you insulate the dome itself?

Yeah, each type of observatory has its advantages and disadvantages.  Our Parks District's 8.75" F12 achromat is housed in a fiberglass dome that sits on top of a heavily insulated silo style base.  The interior walls are indeed cool but heat builds above the walls, enough so that we get thermals out of the shutter slit for the first hour on top of the scope cooling down.  

 

However, interior dew or frost have never been issues and it is subjectively much more comfortable in the dome as our bodies don't radiate nearly as much heat as they do when we are outside.  I too have been thinking of ways to insulate the dome itself but I don't want to make the thermal situation any worse.  The first thing is to paint the outer surface with aluminum paint.

 

Jeff

 

BTW, I still have not given up on the idea of a LZOS 9" F9 objective with an ATM OTA as an interim scope before the TEC is ready.

 

Jeff


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#53 fate187

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Posted Today, 06:42 AM

DPAC it is then, it was mentioned here. Looking forward to it! Hope you have a flat large enough Jeff :D. And looking forward to observing reports. It should come handy for the next planetary season in 2022, the scope I mean :).

 

best wishes


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#54 zjc26138

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Posted Today, 09:58 AM

I think I need to make a trip to southern Ohio to see this 10" apo in person. :)



#55 StarAlert

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Posted Today, 10:03 AM

I would make a point to stop by if I was in the area. lol.gif



#56 stevenwav

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Posted Today, 01:23 PM

I wonder if Yuri will be bringing his 10" f/9 to the Winter Star Party in February - he is very accommodating and that is a great opportunity to catch a gander of the views in hopefully fantastic conditions. I had a great view of Jupiter with it a few years back. I'm excited for you Jeff!


Edited by stevenwav, Today, 01:25 PM.


#57 Astrojensen

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Posted Today, 03:59 PM

I wonder if I will ever get the chance to look through a 10" apo in good seeing. 

 

 

Clear skies!

Thomas, Denmark



#58 dothead

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Posted Today, 04:44 PM

... My only real thing that gave me a bit of pause is the fact that TEC and APM 10" F9 triplets are both air spaced designs and I have some mild concerns regarding the thermodynamics of such a larger aperture air spaced objective. ...

 

Jeff

In this respect, the 10" F12  CaF2 doublet offered by Aries Optical would be an alternative ...



#59 BRCoz

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Posted Today, 05:08 PM

Star party at Jeff's next year!   LOL

 

 

Enjoy the scope.


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#60 39.1N84.5W

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Posted Today, 05:20 PM

Star party at Jeff's next year! LOL


Enjoy the scope.


He runs two different observatories with big refractors... I think a Warren County star party in 2022 is a GREAT idea!

#61 CHASLX200

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Posted Today, 07:06 PM

I wonder if I will ever get the chance to look through a 10" apo in good seeing. 

 

 

Clear skies!

Thomas, Denmark

I have never even seen a 7" APO ever in my life. They are just not in FL i guess. 



#62 Jeff B

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Posted Today, 07:25 PM

I wonder if I will ever get the chance to look through a 10" apo in good seeing. 

 

 

Clear skies!

Thomas, Denmark

Me too!  grin.gif



#63 Jeff B

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Posted Today, 07:26 PM

In this respect, the 10" F12  CaF2 doublet offered by Aries Optical would be an alternative ...

Unfortunately, that's just too long of a scope for my situation.

 

Actually, I almost got an Aries 10" F9 FL triplet objective a few years ago Markus was offering for sale at an extremely attractive price (for a 10" F9 FL triplet anyway).  It had a small cleave at the very edge of the FL element outside the light path that Valery smoothed out.  Valery really encouraged me to get it.   But I chickened out.  Actually, I didn't know at the time that being on a corner lot, I had an exception to the zoning rules which allows me to have a "detached accessory" structure in my side yard.  Normally such structures are relegated to the backyard, which in my case just would not work.  If I had known that at the time the objective became available, I probably would have gotten it.

 

Jeff


Edited by Jeff B, Today, 07:36 PM.



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