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"Unbranded" Circle T 60/700

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#1 Klepler

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Posted 09 January 2019 - 02:15 PM

Dears

recently I found an old, small, unbranded refractor. What attracted me to this scope was that the tube and accesorries are almost entirely metallic (only a tube cap, and a finder focuser are plastic). It came with a lot of accesorries: a prism diagonal, a finder with achromatic and coated lens (unfortunately chipped a bit - not shown), two .965 eyepieces (H9 and H5.5), an interesting, green "MOON" filter and a pretty sturdy fork mount (but surprisingly, without a "shaft" to precisely control the elevation).

 

The label has a Circle T mark, but nothing more... I assume years ago this scope was something like an initial scope for beginners. But in fact it looks to me like a quite nice instrument.

 

I have no experience with vintage, "classic" scopes. Please, tell me more about it :)

 

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#2 DMala

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Posted 09 January 2019 - 04:20 PM

I only have direct experience with early Towa telescopes, which are quite good to excellent. This is a later model (early 70s maybe?) and based on opinions read on this forum I would guess that the lenses may be of acceptable to medium quality, while the tripod may be a bit flimsy. The finder and eyepieces may also be really entry level. But I am sure it may still offer some good stargazing fun if you enjoy using old telescopes
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#3 Tenacious

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Posted 09 January 2019 - 07:23 PM

Welcome to Cloudy Nights.

 

Everything is relative.  When assembled correctly, your scope will far outperform Galileo's telescopes in about every category.  I say this because it appears that your objective has been disassembled in the first photo (an element appears to be laying to the right).  Here is the first link I found detailing the correct order and orientation of the achromat's elements.  Having an element flipped sharply degrades the performance of your objective.  A Google search will probably turn up more info with better illustrations.

 

I started with Newtonian reflectors.  My first view of Jupiter through a humble but good 60mm f/15 refractor just a few years ago re-ignited my interest.   I couldn't believe the comparative fidelity of the image.  The Moon, planets and double stars became fun targets, especially when it was inconvenient to set-up a larger scope.

 

It's all about how much fun you can have with the scope under the sky.


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#4 Klepler

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Posted 10 January 2019 - 04:06 AM

Hi,

thanks for your comments. Indeed, I like this scope and I am going to have as much fun of it as possible. Eventually, "vintage" scopes can be found cheap, so they are good for education/rehealsal project.

 

What You can see on the picture next to the dew shield is a plastic, front cap smile.gif I have unscrewed the dew shield and whole lens cell assembly from the tube just to see what's happened inside. BTW the lens is in pristine condition, there are no scratches, no traces of previous cleaning or grease from fingers, just a bit of dust.

 

The mount is virtually unusable without that metal shaft, or rod, to control angle of elevation. Screws deform the tube but don't support it safely enough. So for a now it is basically an azimuth mount only smile.gif I "have to" adapt something by myself, or find another mount.

 

What's more complicated for me, is that one (smaller) EP came with its retaining ring loosened, and one (field?) lens tilted. It seems the eyepiece is a basic Huyghenian design, but for me that small lens is bi-concave. For a now I put it back in random direction, and it appears to be working...

 

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Edited by Klepler, 10 January 2019 - 04:09 AM.

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#5 Chuck Hards

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Posted 10 January 2019 - 08:35 AM

The only real limitation with this scope is the stock eyepieces that came with it.  You will get much better low and medium-power views with 1.25" eyepieces.  You would need to purchase a hybrid diagonal to use them, fortunately they are not expensive.



#6 Tenacious

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Posted 10 January 2019 - 09:26 AM

I can check my parts drawer.  I probably have one of those adjustable rod assemblies for holding altitude. 



#7 Chuck Hards

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Posted 10 January 2019 - 10:00 AM

I think Bill Vorce at Telescope Warehouse sells them as well, if you come up empty handed.  They come with the entire yoke assembly but it's still a very inexpensive part.



#8 Chuck Hards

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Posted 10 January 2019 - 10:03 AM

Yep, here it is:

 

LINK



#9 Klepler

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Posted 10 January 2019 - 11:32 AM

Perfectly agreed about modern EPs, but I would like to play with vintage ones too. Old EPs are stylish smile.gif

 

I should find a rod adjuster around me, from a "department store class" scope or sth like that. Also, I've got a plastic adapter for 1.25''. Thanks for your attention, but I live at the other site of the globe, probably laugh.gif


Edited by Klepler, 10 January 2019 - 11:34 AM.


#10 John Rose

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Posted 10 January 2019 - 06:16 PM

The scope may not have come with the altitude adjustment shaft.  If it did there should be a threaded hole on the optical tube just forward of the focuser, just out of sight in the photograph. There will also be a mounting hole on the right side fork arm  below the mounting screw.

 

In the past there were a number of vendors who sourced good quality .965 eyepieces at decent prices. Kellners,  Orthoscopics and Plossels. Orion, Celestron and University Optics come to mind. These do show up occasionally on the used market. They were often the same lenses as in their 1.25" eyepieces.

 

John



#11 Bomber Bob

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Posted 10 January 2019 - 09:56 PM

Welcome to The Classics!

 

You have a mid-1970s Towa.  Optics of the scope & eyepieces should be good.  The mount & tripod will be shaky, and limit the magnification - and probably your patience.

 

My 1978 Towa 80mm F15 had an excellent lens.  The eyepieces were usable, but upgrading to 1.25" Meade Research Grade Orthoscopics gave me 1000s of hours of very fine views.

 

I prefer to use simple .965" eyepieces rather than a hybrid diagonal -- optical quality is often questionable.  If you don't find decent Erfles / Kellners / Orthoscopics in our CN Classifieds, check eBay.  I got my first vintage 1980s spectros Plossl on that site from a seller in Germany.



#12 Klepler

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Posted 13 January 2019 - 12:12 PM

Hi, thanks for Your responses. It is nice to get to know what do you have got. To be honest, I bought it being curious about its eyepieces and right angle prism diagonal - something you don't see often anymore. The prism and lenses in eyepieces seem to be coated. And I am sure it will be at least decent and perfectly usable traveller :)

 

Indeed, there is no mounting hole on the fork arm, nor an attachment for an adjusting rod on the scope tube. On something like a local craigslist I found another scope that has a "proper" adjusting rod for scopes of that era, I guess:

 

https://apollo-irela...mage;s=1000x700

 

But I am not going for that, I am just going to attach a dovetail of some sort, and use the scope with a photo tripod. BTW is that "Edu Science" scope a "better" brand than mine? I asked for a photo of the label, and it is also 60/700, but a circle "R".



#13 roscoe

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Posted 13 January 2019 - 12:44 PM

Nope, yours is about guaranteed to have both a better objective lens and a better focuser than the edu-sci.

 

John and BB's advice is right on the money..... hold out for better .965's, perhaps including a better diagonal. 

 

If you watch the classifieds for a week or two, likely an equatorial mount on wood legs will appear.  The camera tripod will be perfect for checking it out and some moon-views, but unless you have a fancy 'fluid-head' one, it'll be challenging to keep an object in sight at higher power.


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#14 Klepler

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Posted 14 January 2019 - 06:11 PM

I am going to start a restoration of this scope. Not a big thing, just to clean the optics and remove aged grime from the tube.

But I can't unscrew retainig ring holding the lens in the cell. I want to do this, because there are tiny, shiny metal particles between elements of the doublet clearly visible. The retaining ring is not overtight, because you can hear and feel a gentle rattling when shaking the cell, but a bit too much to my taste.

What can I do to manage with it? And also, if putting optical elements back to its cells/tubings, what can I do to prevent small dust particles going into EPs or between doublet elements? Any suggestions are hereby welcome smile.gif

 

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Edited by Klepler, 14 January 2019 - 06:14 PM.



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