16 replies to this topic

[MerylB]

I’m looking to gather information on a telescope that was my late fathers. It is a Questar that has been kept in its case. I also have a Linholf tripod that he used with it. Any help is appreciated. 

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[Wisconsin Steve]

Deja vu!

 

Nice scope. 1972 Duplex with Cervit mirror and Broad Band coatings.

Edited by sgorton99, 05 July 2019 - 08:12 PM.

[JamesMStephens]

2-CV-DP-5214-BB-AC tells you everything you need to know, but I can only decode some of it.  

 

CV: Cervit primary mirror

DP: Duplex model (scope separates from mount fork)

BB: Broadband coatings

AC: AC clock drive

 

The 5214 tells you when it was made.  There's probably someone on here who can decode it, but Questar will tell you.

 

Jim

[MerylB]

Thanks for the information. I know very little about telescopes. It’s a steep learning curve! 

[jupiter122]

Surprised that no one has told you what a get this appears to be, depending on the condition of the scope. 3.5” Questars of that vintage can fetch well over $2000 on used sites like CN, and the tripod and mount look quite solid.

Good luck.

Tim

[cbwerner]

Indeed. The tripod looks to be over the top solid!

[Optics Patent]

The Linhof has the essential central post that elevates with a crank. This is the key to comfortable observing. Aim, and then adjust the height to the perfect height. Relaxed neck and back. Sells in the $500 range.  Agree on the $2000 estimate for the scope with adjustment for condition and extras.  Search “How to sell a Questar telescope on the internet” if going that direction. 

 

I’ve never seen an inscribed serial number with “AC”. Interesting. 

[munirocks]

If you have any interest in nature or astronomy then you should keep it not sell it. It has special attributes that you will learn to appreciate the more you use it, and it's a great legacy to remember your dad by.

 

Just learn a few things at a time, and have fun with it.

Very briefly, look up info on these main areas:

1) The knobs on the control box at the back of the scope. These affect the image that you see through the eyepiece (magnification, focus). Certain combinations won't give you any image, and you need to re-focus when changing between certain combinations. And remember to take off the lens cap. 

 

2) The knobs on the side of the fork arms and on the base. These point the scope up-down and right-left. One of the side knobs locks the up-down motion -- best to put this into the unlocked position and leave it there.

 

3) The big dials on the side and base are called "setting circles", and you can use these to help find objects in the sky when doing astronomy. 

[Optics Patent]

You might visit questarzone.com and check out the introduction video if you want to learn more about the scope.

[munirocks]

I wonder if the "AC" was added later during a factory modification - possibly replacing a battery-based PowerGuide system with an AC motor drive system? It is underlined - does that mean anything?

Edited by munirocks, 08 July 2019 - 07:42 AM.

[Wisconsin Steve]

I certainly could be wrong, but it appears the interest on this Q may have waned...

[JamesMStephens]

I certainly could be wrong, but it appears the interest on this Q may have waned...

 

I certainly could be wrong, but it appears the interest on this Q may have waned...

What else is left to say?

[MerylB]

The AC is not underlined. I appreciate everyone’s help. I know much more than when I started!

[Terra Nova]

Rather than selling it, I hope you keep it and use in in the memory of your dad. Perhaps it will become a family heirloom, handed down, used, enjoyed, and storied about for several generations. That would be a fine testament! They truly are wonderful, heirloom-worthy instruments. 

[Gregory Gross]

In addition to #2-CV-DP-5214-BB-AC that is discussed in this thread, there's another example listed on both eBay and the seller's own website with S/Ns F-1254-CV-AC and 3-DP-5382. The Field Model OTA in that listing also has that "AC" indication.

 

Have a close look at the focus knob in the photo of the control box that appears in that sales listing. You'll see an additional knob positioned at a 90-degree angle to the focus rod.

 

With the help of Jim Perkins, I learned that "AC" stands for "Autocollimator," a special applications instrument that Questar sold in the 1970s. Jim also mentioned to me that, in units with "AC" in their serial number, Questar made some internal baffle modifications and added that additional locking knob for preventing focus shift.

 

For more on autocollimators in general, visit the Wikipedia article on that topic. Questar also ran ads for their autocollimator in Scientific American -- see this page on my website for those ads.

[98105dude]

Interesting!

[RichA]

Thanks for the information. I know very little about telescopes. It’s a steep learning curve! 

It's top of the line, it's Duplex which means the tube can be demounted from the mounting and the telescope used on a standard camera tripod for bird watching, whatever, it has a low-expansion mirror material and it has special coatings on the optics which increases the amount of light it gathers.