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Favorite used telescope ad

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#1926 Joe1950

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Posted 22 January 2016 - 10:43 PM

With that eyepiece/prism/barlow arrangement, you can have the scope outside and view while inside. Good for us cold climate observers. :coldday:


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#1927 TCW

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Posted 26 January 2016 - 10:23 PM

Bosh and Loud --- https://phoenix.crai...5396508654.html



#1928 Joe1950

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Posted 26 January 2016 - 10:50 PM

That musta have been quite a dust storm there in Phoenix.


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#1929 PaulEK

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Posted 27 January 2016 - 11:42 PM

Yeah, I just don't get folks like that: less than one minute with a dust cloth would make it look so much nicer, which would mean quicker and more offers. It's like they don't want it to sell.


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#1930 PaulEK

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Posted 27 January 2016 - 11:42 PM

Of course, the lack of concern about spelling is even harder to fathom.


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#1931 TOM KIEHL

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Posted 28 January 2016 - 11:32 PM

OH MY ! :nonono:

" It's old and ugly but is fully functional. I removed some unnecessary material to lighten it up."

 

LINK


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#1932 TSSClay

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Posted 29 January 2016 - 08:13 AM

It looks like some of the unnecessary material removed was the main mirror!!! :shocked: :shocked:  That would lighten it up!  Edit - I should look at all the pictures - the mirror is in a box separate.

 

Too bad - that is only a couple of miles from where I work.

 

Clay


Edited by TSSClay, 29 January 2016 - 08:14 AM.

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#1933 TOM KIEHL

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Posted 29 January 2016 - 09:01 AM

If the glass is any good  , the mirrors could be good candidates for a truss project . The rest is Fire Wood . :ohmy:  



#1934 BigC

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Posted 29 January 2016 - 09:13 AM

I see nothing wrong with the cut-outs;quite like much construction seen in industry.If it REALLY bothers  then the holes can be covered with thin,lightweight material.The Coulters weren't sold on beauty of packaging but as affordable light buckets at a time most hobbyists couldn't afford big scopes.I buy it if closer and Dobs of similar and larger weren't already in my possession.



#1935 BigC

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Posted 29 January 2016 - 09:18 AM

Of course, the lack of concern about spelling is even harder to fathom.

I'll bet "auto-correct" did its dirty work again..My phone will show the message as I wrote it but send a "corrected" version on pressing send!Guaranteed to make the sender look like an idiot by radically changing a message.I discovered you must add any unusual words to the system dictionary in order to prevent this. My previous phone allowed turning off the auto-spell and auto-suggest but haven't found how in my new one.(Moto E).



#1936 Ben H

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Posted 29 January 2016 - 02:54 PM

I see nothing wrong with the cut-outs;quite like much construction seen in industry.If it REALLY bothers  then the holes can be covered with thin,lightweight material.The Coulters weren't sold on beauty of packaging but as affordable light buckets at a time most hobbyists couldn't afford big scopes.I buy it if closer and Dobs of similar and larger weren't already in my possession.


Tubes are funny things. Even when using relatively flexible materials, like cardboard, they are able to maintain their rigidity due to the way forces are naturally balanced. When you start cutting holes, especially GREAT BIG MURTHERING HOLES as seen above you compromise much of that rigidity allowing the tube to flex. 

Now, I'm sure you're thinking in your head that this isn't much different in practice than a truss telescope, but please note no one uses 1/2" thick cardboard trusses! I strongly suspect in testing you would find the collimation changes significantly not only between zenith and horizon, but even over changes of 15 degrees in altitude. 


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#1937 Joe1950

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Posted 29 January 2016 - 05:23 PM

Here is a CELESTRONE Scope that must have been used with some very, very heavy eyepieces.

 

https://philadelphia...5416782473.html


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#1938 TOM KIEHL

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Posted 30 January 2016 - 12:18 AM

Here is a CELESTRONE Scope that must have been used with some very, very heavy eyepieces.

 

https://philadelphia...5416782473.html

It's a Italian  version  Celestron


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#1939 BigC

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Posted 30 January 2016 - 05:49 AM

 

I see nothing wrong with the cut-outs;quite like much construction seen in industry.If it REALLY bothers  then the holes can be covered with thin,lightweight material.The Coulters weren't sold on beauty of packaging but as affordable light buckets at a time most hobbyists couldn't afford big scopes.I buy it if closer and Dobs of similar and larger weren't already in my possession.

Tubes are funny things. Even when using relatively flexible materials, like cardboard, they are able to maintain their rigidity due to the way forces are naturally balanced. When you start cutting holes, especially GREAT BIG MURTHERING HOLES as seen above you compromise much of that rigidity allowing the tube to flex. 

Now, I'm sure you're thinking in your head that this isn't much different in practice than a truss telescope, but please note no one uses 1/2" thick cardboard trusses! I strongly suspect in testing you would find the collimation changes significantly not only between zenith and horizon, but even over changes of 15 degrees in altitude. 

 

Cardboard or particle board;there is a difference.Square tube  versus round tube,cutouts will affect each differently.I would like to see an engineering analysis and/or actual use of the scope in question to reveal sag and collimation changes.The owner does claim it works post modification.I know I have been shocked by how much material can be removed from a structure yet still support its steady-state load.The trick is knowing when to stop!Some excessive reductions leave no safety margin.Such an analysis was likely never done by Coulter since the emphasis was lowest cost.Doing the cutouts would also have added labor and tool expense plus increased production time,all which push up product prices.


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#1940 BigC

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Posted 05 February 2016 - 04:40 AM

http://www.ebay.com/...#item2ca826a5cf




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