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Zeiss Telescope Tune Up?

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#1 RobTeeter


    Vendor (Teeter's Telescopes)

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Posted 01 April 2021 - 12:15 PM

Hey guys,


New to this forum, but not new to CN.  A friend sent me his Carl Zeiss Jena 80mm refractor to have a look at and see if I could clean the objective and adjust the three eyepieces in the turret so their individual helical focusing assemblies move smoother. I've worked on many various telescopes before but this one is a different bird. The objective lens appears to be dirty on the inside (of course!).  Is there any advice out there for getting to the inside of the objective?  I see no screws to remove the that part of the assembly so am wondering if I have to go in through the front by removing the lenses by removing the retaining rings (hmmm, I don't really relish that task).  As for the eyepieces, I don't see an obvious way to separate them from their helical focusing mechanisms...


Anyone have experience working with this model Zeiss?


Pictures attached.


Thanks much!

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#2 astrokeith


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Posted 01 April 2021 - 01:05 PM

Try unscrewing the main tube at the joint ring that is about 50mm back from the front.

I would expect the next conical section to unscrew from the roof prism section.


There is usually a screw thread joint at every major interface.


(I'm using binocular disassembly process here!)

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#3 Terra Nova

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Posted 01 April 2021 - 01:07 PM

That’s a nice old Zeiss spotter! Does the brass objective cell unscrew? It looks like it might. That would give you direct access to the innermost surface.

#4 starman876


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Posted 01 April 2021 - 01:34 PM

A strap wrench or two would help with this task.

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#5 GreyDay



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Posted 01 April 2021 - 05:32 PM

I'd try splitting it at the first joint (50mm back from the cell) take a look at the rear of the cell to see if it can be unscrewed. If it can, i'd leave the glass in the cell and clean it that way.


One thing i find intriguing with this scope is.... how does the Turret work while attatched to a terrestrial adapter when the EP's are at 90 degrees on top and at the rear?


I've seen turrets with EP's 90 degrees to the ota like Zeiss/Unitron with no terrestrial adapter because they have a built in prism, I've also seen spotters that use terrestrial adapters but their EP's line up parallel to the ota (like a Baader Q turret), so how does this work with EP's both parallel and at 90 degrees through a terestrial adapter? could anyone explain how it works?


EDIT:  Answered my own question, It's the wrong turret fitted to the scopeor is it the camera angle?, also the brass bit at the end is part of the sliding dewshield where the missing cap has worn the paint, a quick internet search turned up these images:


zeiss 80
zeiss 80 2

Edited by GreyDay, 01 April 2021 - 06:19 PM.

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