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Home > Classifieds > Astromart Classifieds > Telescope - Reflectors > Classified #232089

For Sale: 20" Ritchey-Chrétien for < 20K

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Brand new, 500 cm, F8.2 Ritchey-Chrétien for sale. Manufactured by Advanced Optical. 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 by Oldham Optical. 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. 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 $19,995. 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.

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