Support Astromart! | Log In | Help
Astronomy NewsTelescope ClassifiedsTelescope AuctionsTelescope Articles & ArticlesTelescope Articles & ReviewsTelescope and Astronomy ForumsAstronomy Events Calendar
View Categories
Browse By Location
Place A New Ad
Display Preferences
Search Classifieds

User Name:


Save Login
New to Astromart?
Register an account...

Terms of Service
Privacy Policy
Help & FAQ
Astronomy Links
User Profiles
Top Users List
RSS Feeds

Home > Classifieds > Astromart Classifieds > Telescope - Reflectors > Classified #198536

Wanted: Boo Hoo! 4.25" Optical Craftsmen mirror wanted

Please Log In to view the details for this classified ad.
Don't have an Astromart account? Click here to create one

Well we've all heard about good companies turning out bad mirrors and it looks like Mom & I got bad luck or taken for a ride when she got this one for me in Xmas 1965. Should OC's founder Dick Nelson be roasting in hell? I don't know, but let all commercial vendors know, little boys grow up and some time, maybe a long time, there is a day of reckoning!

My rehab project has hit a snag because the 4.25" f/10 parabolic primary shows strong astigmatism and undercorrection. The astigmatism is particularly bad, and is symptomatically classic: oval out of focus star images, intra-focus axis at 90 degress to extra-focus axis, it's really awful.

I'm very likely to pop for a new one, they're not expensive, but most f/10s are spherical and OC at least in theory was parabolizing its 4.25s. I'm willing to give an OC 4.25 one more try for authenticity's sake. So if you have a small OC in the closet and would like to cut loose of it to restore the good name of Dick Nelson etc. please do drop me a line. I'm not really interested in the other 4.25s of the era as they were mostly spherical and sphericals are available today cheap. I would be needing a mirror that has at least enough coating to swing a star test as I'm not willing to recoat without checking for gross deformities.

I need the mirror and mirror only, I have a mount and tube.

thank you,
Greg Nowell

ps. My other scope is a c14, please don't think I'm starving for aperture!

Back to Listing

All times are in (GMT-8:00) Pacific Standard Time Zone  
Astronomy News | Telecope Classifieds | Telescope Auctions | Telescope Reviews | Telescopes | Telescope and Astronomy Forums | My Account | Help | RSS