ClassicRestore / Repair

Clyde Bone’s Tele Vue-140 Re-Built!

Yes, the above scope *is* a Tele Vue: this 700mm, f/5, “TeleVue-140″ scope debuted in 1996 and incorporated our patented 4-element Nagler-Petzval layout in a 5.5”-class Rich Field refractor. To this day the Tele Vue-140 is the largest diameter, fastest focal ratio, Nagler-Petzval refractor we’ve ever made.

Tom does a collimation check on the TV-140 before the rebuild.

We must admit, this “oldie” does look “stubby” without the threaded-on dew shield. Comparing this 24-year old classic to our current production scopes, you can see how far things have evolved at Tele Vue as well as what has remained over the years. A front-on view of the TV-140 with the dew shield removed reveals an enormous amount of objective glass held by a thin aluminum lens cell which slips inside the 6″ diameter tube. Our modern lens cells on all but the Tele Vue-60 slip over the outside of the main tube providing more mass in the cell itself.   For such a large objective, today we would’ve made the front lens cell from stainless steel, as we do in the NP127is, in order to provide a thermal expansion characteristic closer to glass.  In a nod to the age of digital imaging, we’ve also implemented dual-speed focusing and no-sag, dual lock knob drawtubes on all our 2″ and larger focusers. The single lock screw, 1:1 ratio, 2″ focuser with its chrome-plated drawtube on the TV-140 looks quaint in comparison to our current focuser, but still works wonderfully for visual observing where the eye can accommodate for slight de-focus.

Then there are the things that haven’t changed: by 1996 we’d settled on the five-hole focuser knob design and ivory colored powder-coated tube which have become hallmark looks for our scopes. In addition, like all our scopes, this scope doesn’t incur the extra size and weight penalty of traditional baffles in the tube to block stray light. Instead, ultra-flat black flocking provides a countless number of tiny “baffles” to confuse stray light and keep it from degrading contrast. Plus, the Nagler-Petzval optical layout continues to be found on our larger scopes.
Our notion of a “rebuild” includes cleaning up cosmetic blemishes.
This particular Tele Vue-140 was #3 in production and was owned by Clyde Bone. He used it as the “eyepiece” on his home-built 30″ Mersenne telescope. The Mersenne is a large telescope that at first glance looks like a Dobsonian, but the light path feeds out of the altitude axis as parallel rays and you observe from a seated position with your feet firmly on the ground. Ted Hume, is now caretaker to Clyde’s scopes and wrote a guest post on  Clyde Bone and His Two Unusual Mersenne Telescopes! for our blog.
Other companies might be tepid on disassembling a discontinued 24-year-old scope from their line: it is no problem for us.
It was Ted who sent the TV-140 to us. Even given extensive use, it was obviously cared for and in very good shape. There was no need for a full “restoration” that would have required any type of refinishing or searching for NOS parts. Nope, this was a “simple” tear-down and rebuild.
Verifying front doublet spacer symmetry.
Our rebuild process starts and ends with the details. Upon unpacking, all parts and accessories, from the custom case to any hex key sent to us, are noted. Then our master scope tech evaluates the condition and collimation of the scope before any work is done. Any concerns are conveyed to the customer to avoid “surprises” on their end.
Clyde Bones’s TV-140 front lens cell and glass being inspected and cleaned.
Now the scope is fully disassembled. This includes the front and rear doublets on either end of the main tube, focuser housing, drawtube, pinion cap, and pinion.
TV-140 rear lens cell and glass from the back of the tube.
Everything, particularly the optics, is examined and cleaned. Then the scope is reassembled for final collimation check and testing.
Did you observe, sketch or image with Tele Vue gear? We’ll like your social media post on that if you tag it #televue and the gear used. Example:
#televue #tv140 #ethos #saturn
Do you want your Tele Vue images re-posted on Tele Vue Optics’ Social Media accounts? Use this hashtag for consideration:

This old scope was built down the road at our former Suffern, NY location. So we decided to give it a tour of the “new” building in Chester, NY. Below we set it up in the kitchen and aimed it at an artificial star field and planetary image chart we often use at Star Parties during the day.
TV-140 rebuilt: Note Al Nagler’s fresh signature on the scope tube. Our Star Party test target is on the cabinet in back. Yeah, the Starbeam looks silly reversed but who knew we’d be taking pictures for the blog?  Image by Jon Betancourt.
Employing a 21mm  Ethos eyepiece, we imaged our test chart using a FoneMate and smartphone camera.
Tele Vue TV-140 with 21mm Ethos eyepiece and FoneMate smartphone adapter took this image of our Star Party target. Image by Jon Betancourt with Samsung – Galaxy Note 9.
The scope has been returned to Ted, who reports it’s in “perfect condition.”  Originally intended to be sold with Clyde’s 30″ Mersenne, unfortunately the scope sits unsold.  Without a place to store the scope, Ted has reluctantly and sadly decided to sell its parts, including the Tele Vue-140.  If you are interested in acquiring a rare, and in this case storied, Tele Vue-140, contact Ted at
More Info

Latest TVO News