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Mirror identification

Started by brewtes, 07/05/2018 02:40AM
Posted 07/05/2018 02:40AM Opening Post
Help! I bought a Cassegrain mirror set mounted in a Cave  Astrola mirror cell and secondary spider. They are not Cave mirrors I think, the only ID on them is the number C12-2. This is a 12.5" f16 Cassegrain or Dall Kirkham but I can't identify the mirrors any further. Any help appreciated. Jim
Posted 07/05/2018 03:04AM #1
Hi. James!

I don't know how convenient this would be for you, but if you can form a good prime-focus axial image using the PM alone, then the configuration would be Classical Cass. On the other hand, if that image is LOADED with spherical aberration... then it would most likely be a Dahl.

There is another possibility... Ritchey... but that seems unlikely, given the probable vintage of the OTA.  Tom

29-inch Dob in a dome
36-inch upgrade soon
LUNT 80/80 solar scope
FLI 6803 cam
APM 100mm APO Binos
JMI RB-16 Night Vision Binos
Zeiss 20x60 IS binos
Posted 07/05/2018 04:35AM #2
I'll take a guess and suggest it may be a vintage coulter DK optics set. I believe Cave would have a serial number on his optics whereas Coulter likely did not. I had an observing buddy who had a set from Coulter and he wasn't thrilled with its performance, hard to collimate and a large secondary, here's an old Coulter ad for them:
https://www.google.com/search?q=coulter+optical+catalogue&sa=N&biw=1920&bih=876&tbm=isch&source=iu&ictx=1&fir=XWvfWtszEzBLMM%253A%252C3wxHFeyUKwJejM%252C_&usg=__84zi6_VojfoWYZRdRphfbnjAqi4%3D&ved=0ahUKEwjN9ozpj4fcAhVwHzQIHUoBB1c4ChD1AQhPMAs#imgrc=HS1U3OsCKuGJEM:
Posted 07/05/2018 02:03PM #3
I think you are right! I was told once they may be made by coulter. That helps. Thanks!
Posted 07/05/2018 02:08PM #4
Thanks Tom, I will try your test right away!
Posted 07/06/2018 01:54AM #5
James,
When you figure it out, please post a review if you get it up and running...