Regarding your 6” f/5 achromat with cell – looking at it from the front it does look like a Jaegers due to the 6 air-spacing tabs, each 45 degrees apart around the circumference. I cannot tell clearly from the side view of the cell if it indeed is a Jaegers cell. Looks like there is felt or something on one side of the relatively centrally located lip/ridge.
I have a Jaegers 6” f/5 that I assembled back in 1978/79 from new parts obtained from Jaegers – achromat and cell, 7” o.d. tube, 7” o.d. dewshield with a black wrinkle finish, Jaegers focuser with a better than 2 inch drawtube, adapter for the focuser to neck down to 2 inches and a second adapter to neck down to 1.25”. When built I mounted the scope on a Meade equatorial mount using Meade rings.
As built the tube length was sized long enough to allow me to use the 38 mm 2 inch plus Erfle eyepiece, described as a Kodachrome viewer that Jaegers sold. As stated the diameter of the focuser drawtube and the eyepiece diameter were bigger than 2 inches. This combo yielded a huge field of close to 4 degrees. Due to the length of the tube necessary for use with the big eyepiece straight thru I could not rack in far enough to achieve focus with 1.25” eyepieces even with a diagonal with the only exception being to use a 2x barlow too. Later Novak introduced what I believe may have been the first 2” diagonal utilizing a galvanized fence right angle fitting and an appropriately sized Newtonian secondary mirror. Kind of crude looking but it worked well. An adapter was machined for the Jaegers 38 mm Erfle eyepiece to allow it's use in the 2" diagonal. This allowed me to cut down the tube length (1st overhaul) which then allowed me to use more 1.25” eyepieces with the scope. As some eyepieces would still not come into focus due to the telescope tube still being too long, the scope went thru it’s 2nd overhaul/modification back in about 1992. At that time I also replaced the crude wooden discs that served as internal baffles. They were replaced with Thousand Oaks filter cells which had pretty much the correct O.D. to fit the 7” tube’s I.D. One was fine as is given correct internal placement. The second one was stopped down further using a sheet of plastic properly fitted and painted.
The original Jaegers focuser was eventually replaced with one of the early focusers from AstroPhysics. That focuser was modified with handles as shown. With the 2nd overhaul I also opted to fit the telescope with a longer dewshield using a new length of tubing available from Hastings. The telescope aluminum tube length is now 20.5 inches from where the tube butts up against the lip/stop on the objective cell to where it meets the focuser.
I have done some photography using this scope and in spite of the fact that it is a 6” f/5 achromat, the false color is not too bothersome. Using a Lumicon Deep Sky Filter the blue haloes disappear almost completely. See comparison of picture of the North American Nebula with and without this filter.
Edited by BarrySimon615, 04 February 2021 - 12:14 PM.