PlaneWave CDK20 Telescope (f/7.77)

Starting Price: $39,000.00
Price as Configured: $39,000.00
Brand: PlaneWave Instruments / SKU: PW-200127Q
The CDK20 f/7.77 from PlaneWave Instruments stands as a pinnacle of engineering excellence, tailored for serious astrophotographers and astronomers who demand precision and performance. With its advanced technology and high-quality design, the CDK20 f/7.77 delivers outstanding images for a wide range of advanced observational and scientific applications.

The CDK20 f/7.77 is characterized by its exceptional specifications and features:
  • 20-inch (508 mm) aperture
  • 3951 mm focal length
  • f/7.77 focal ratio
  • 269.49 mm back focus from mounting surface
  • Perfectly flat field across the entire 52mm image circle
  • No off-axis coma or astigmatism
  • Rock-solid fused silica mirrors with low thermal expansion
  • Lightweight and rigid carbon fiber optical tube assembly
NOTE: Shipping cost will be determined after the order is made and must be paid for before the mount will ship. A shipping quote can be obtained on request.
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**NOTE – 200166 adapter is also compatible with CDK17 that have 8.81″ back focus.   CDK17 with 10.24″ back focus will use the 125166 focal reducer. See instruction manual for details.

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This is lens group is designed to convert a CDK20 f/6.8 to f/7.77. The original lens group is unscrewed from the backplate of the optical tube and replaced with the new lens group.

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Price as Configured: $39,000.00

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Optical System

Aperture 20 inch (508 mm)
Focal Length 3951 mm (155.55 inch)
Focal ratio f/7.77
Central Obstruction 39% of the Primary Mirror Diameter
Back Focus from mounting surface 10.7 inch (271.98 mm)
Weight 140 lbs (63.5 kg)
OTA Length 47 inch (1,194 mm)
Upper Cage Carbon fiber truss
Lower Cage Carbon fiber truss with carbon fiber light shroud
Optimal Field of View 52mm image circle

Secondary Mirror

Diameter 7.5 inch (191mm)
Material Fused silica (quartz)
Shape Spherical
Coating Enhanced Aluminum – 96%

Primary Mirror

Optical Diameter 20 inch (508 mm)
Outer Diameter 20.5 inch (521 mm)
Shape Prolate ellipsoid
Material Fused silica (quartz)
Coating Enhanced aluminum – 96%

Lens Group

Diameter 90 mm (3.54 inch)
Number of lenses 2
Coating Broadband AR Coatings (less than .5% reflected from 400 to 700nm)
Optical Diameter 20 inch (508 mm)

Standard Features

Carbon Fiber Truss Design Minimizes thermal expansion which causes focus shift with changes in temperature
Dovetail Expansion Joint Allows for the difference in thermal expansion between carbon fiber and aluminum. The expansion joint allows the aluminum dovetail expand and contract without stressing the carbon fiber lower truss
Cooling Fans Three cooling fans ejecting air from the back of the telescope and four fans blowing across the boundary layer of the mirror surface. This helps the telescope to reach thermal equilibrium quickly. The fans are controlled by a computer if the optional Electronic Focus Accessory (EFA Kit) is purchased.

Shipping

Crated Shipping Weight 291 lbs (132.0 kg)
Crate Width 33 inch (838 mm)
Crate Height 33 inch (838 mm)
Crate Length 65 inch (1,651 mm)

Included Accessories

Primary Mirror Cover To protect the primary mirror
PlaneWave Thumb Drive Contains software and instructions for collimation and spacing the primary to secondary mirror
12VDC Power Supply Provides power for the fans