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:

Password:

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

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

Home > Classifieds > Astromart Classifieds > Telescope - Reflectors > Classified #208964

For Sale: 20 inch Ritchey-Chrétien

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

Brand new, 500 cm, F8.2 Ritchey-Chrétien for sale. Manufactured by Advanced Optical (see web site). The OTA, mount and drive are included. Specifications: Construction is of very heavy gauge machined aluminum castings (185kg). It can be disassembled easily with simple tools for transportation. Comes with a 2” Crayford electro focuser. It includes a fan cooled power supply (input: 110 VAC Output: 24 VDC) which provides power for CPU, positioners and encoders. The CPU drive units and the stepper motors run in micro step mode through Swiss planetary gearboxes to the anti-slip rim drives (25/1 ratio). The encoders are high resolution and made in the USA. Includes a full set of balance weights. Optics: The optics are of Ritchey-Chrétien Cassegrain type, manufactured from B.K. optical glass. Mirror sets are to an accuracy of 1/8 wavelength. High grade aluminum and silica coatings are used on both primary and secondary mirrors. The optics alone are worth nearly 20K and manufactured by Oldham Optical (see web site). Primary mirror 500 mm made from low expansion borosilicate. The primary mirror is mounted in a fully machined multi contact - floating cell. Substantial cooling air flow is afforded along with quick release fittings. The secondary mirror is 185mm. Primary (Dia / Focal length / Ratio): 500 / 1375 / f 2.75 Secondary (Dia / Radius / Ratio): 185 / 1283 / f 8.2 Combined focal length: 4100mm. Resolution (Daw's criteria): 0.25 Arc Seconds. A 7x 50 achromatic finder scope, a 25 mm eye lens, and a tool kit will be supplied. I’m asking $21,000. If you are serious about astronomy, you'll never find a better deal. Check OGS, RC, Parallax, or APM for their prices of a 20" Ritchey-Chrétien. Serious inquires only please.
 

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