I recently aquired the OTA for a Meade short-tube 4.5". I believe they use a barlow in the focus tube to lengthen the focal length to something like 1000mm....
I had thought about building a 203mm f4 telescope for imaging from old starfinder tube and extra parts I have lying around. If I done this what size secondary...
hi kevin, i believe the program that can help you is in the files section- newt25.zip. it's been awhile since i used it but i believe that is the one. with the...
On 17 Feb 07 Kevin wrote: "I had thought about building a 203mm f4 telescope for imaging from old starfinder tube and extra parts I have lying around. If I...
You've been pointed to some good sources. I run a spreadsheet I have, and it suggests a secondary minor axis of 60mm. I'll be interested in what you find from...
The best article is one I wrote for ATM journal which is included in a collection of best articles- titled "The Best of Amature Telescope Making Journal-Volume...
In a message dated 2/18/2007 1:42:50 PM Eastern Standard Time, drgenovese@... writes: building in the ability to slide the primary mirror forward or...
No No!-the focal length does not change!-if you have an 8" F/6 the prime focus will be 48" from the primary. Suppose with the stanard setup the focus is 5" out...
I was able to find a few sparse comments on these telescopes. There aren't many around. I think there are about 250 18 inchers and I believe they told me once...
"There aren't many around. I think there are about 250 18 inchers" Do you know for sure that figure is really for real? I'm sure that you are telling what...
... that you are telling what you believe to be the truth, but 250 scopes that large and expensive, for our little bitsy hobby? ... High-End Dob production,...
Dear members, At the risk of sounding like a total newbie, I'm preparing to step up to a bigger & better scope that is much more versitile than what I have...
... the ... all ... seem ... purpose ... astrophotography. ... the ... logic ... than ... HI LEW I BOUGHT A LXD75 SN-10 AND I LOVE IT. I PUT A ORION 80MM...
On 28 Feb 07 Lew wrote: "I'm looking at three different scopes: The Celestron C10-N GT, the Orion 10 EQ w/Atlas mount and the Mead LXD SN-10 AT(Schmidt-Newt.),...
Lew, I can't comment on the other scopes, but I have had a Celestron C10N-GT for over a year now and am very happy with it. The views are excellent, and the...
A must see! http://www.astro-physics.com/index.htm?whatsnew/madeinamerica Triple-check your local broadcast time. "My advice is free and worth every penny!" ...
Hi group, Confusion about this. For now I am not trying to understand why the offset should occur, just what you see during collimation. The cross hairs of the...
. If the diagonal reflection appears offset, then the spider reflection should also be slightly offset too, correct? Both are slightly offset relative to the...
Dear Group: Any input would be welcome. I looked through a friends 12" newtonian tonight and noticed two things: 1). His inside focus was absent a secondary...
...Views were poor and I've ruled out pinched optics, astigmatism and cool down as being issues. I'm guessing he may have an undercorrected mirror, but do...
On 28 Mar 07 "Dave" wrote: "Confusion about this. For now I am not trying to understand why the offset should occur, just what you see during collimation. The...
... If the diagonal itself is center mounted on the spider--yes. ... Given a centered diagonal on a centered spider, yes. ... If the star is defocused enough,...
Hi: I have a 10 inch Newtownian and was looking for an automatic tracker. Found one which was quoted at over $1,000 U.S. Does any one know where I could buy a...
Hi, This might be what looking for, and this just came up on Astromart http://www.astromart.com/classifieds/details.asp? classified_id=494927 . Good Luck, ...
... a ... one for $699 + shipping. I have one and it is the best thing i ever did to my Dob. You can control it with the padel that comes with it or you can...
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