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Coronado CaK 90 rebuilt and upgraded includes CaH filter also Sold!

Price - $4,900.00

Ad Number: 129789

Posted: 22 Feb 2018

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Because of unforeseen circumstances, I am reluctantly offering for sale my rebuilt Coronado CaK 90 scope. From what I have heard, only 6 of these were made
I am the second owner of this one. I purchased it several years ago from solar guru Gary Palmer.It was the first one of this model manufactured by Coronado. When I got it, it had some rust problems, so it has been completely refitted and upgraded with not only tighter-spec CaK filters, but also an optional CaH filter.
The original internal filter used in the scope has been replaced and upgraded with an Omega full-aperture piece that goes ahead of the objective. I also added an internal UV-IR cut filter and a violet filter mid-tube to further cut unwanted wavelengths and minimize internal reflections.
The stock Coronado CaK diagonal retains the original “cold mirror,” and I'm including both a Baader double-stack CaK filter and an Omega CaH filter, giving two operating wavelengths out of one scope.
I also experimented with using the scope as a daylight refractor, and found its main lens was not well-color corrected for white-light, so I replaced it with a Meade 90mm f/8.8 achromat from a DS-90 scope (This maintained the stock f/8.8 focal ratio) Sorry – I do NOT have the original lens any more.
One of the three large knurled bolts that screw the two halves of the clamshell together is missing, but it still works just fine with two of the three. There are some additional threaded holes on the sides of the clamshell because at one time I had it mounted in a different yoke.

Any questions, please ask. NOTE: SALE IS FINAL – NO RETURNS OR “TRIAL PERIODS” ACCEPTED. If you buy it, it’s yours to keep.
This is a large, heavy scope. I will charge a flat shipping fee in CONUS of $75 for UPS ground.

Price: $4900 + $75 flat-rate shipping in CONUS


  • Condition excellent
  • Location Marcellus NY 13108

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