PlaneWave CDK20 Telescope (f/6.8)
Starting Price: $39,000.00
Price as Configured: $39,000.00
Price as Configured: $39,000.00
Brand: PlaneWave Instruments / SKU: PW-200104Q
The CDK20 from PlaneWave Instruments is crafted with precision engineering and cutting-edge technology, making it ideal for dedicated astrophotographers and discerning astronomers. With its robust design and advanced features, the CDK20 is well-suited for various advanced observational and scientific applications, consistently delivering high-quality images.
The CDK20 f/6.8 stands out with its impressive specifications and features:
- 20-inch (508 mm) aperture
- 3454 mm focal length
- f/6.8 focal ratio
- 224 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 before the telescope will ship. A shipping quote can be obtained on request.
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Optical System
| Optical Design | Corrected Dall-Kirkham (CDK) |
| Aperture | 20 inch (508 mm) |
| Focal Length | 3454 mm (135.98 inch) for f/6.8 3951 mm (155.55 inch) for f/7.77 |
| Focal ratio | f/6.8 or f/7.77 |
| Central Obstruction | 39% of the primary mirror diameter |
| Back Focus from Mounting Surface | 8.81 inch (224 mm) for the f/6.8 10.61 inch (269.49 mm) for the f/7.77 |
| Weight | 140 lbs (63.5 kg) |
| OTA Length | 47 inch (1,194 mm) |
| | |
| Upper Cage | Carbon fiber truss |
| Lower Cage | Carbon fiber truss and light shroud |
| Optimal Field of View | 52mm image circle |
Secondary Mirror
| Diameter | 191 mm (7.5 inch) |
| Material | Fused silica (quartz) |
| Shape | Spherical |
| Coating | Enhanced aluminum – 96% |
Primary Mirror
| Optical Diameter | 20 inches (508 mm) |
| Outer Diameter | 20.5 inches (521 mm) |
| Shape | Prolate ellipsoid |
| Material | Fused silica (quartz) |
| Coating | Enhanced aluminum – 96% |
Lens Group
| Diameter | 90 mm (3.54 inch) |
| Number of lenses | Two |
| Coating | broadband AR Coatings (less than .5% reflected from 400 to 700nm) |
Standard Features
| CDK Optics | The Corrected Dall-Kirkham design yields a perfectly flat field free from off-axis astigmatism, coma and defocus. |
| 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 blow air inside the back of the telescope. 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. |
| Delta-T Ready | For added dew prevention, the CDK14 is internally wired with polyimide film heater pads and temperature sensor, ready to be controlled with the optional Delta-T controller. |
Shipping
| Crated Shipping Weight | 291 lbs (130 kgs) |
| Crate Width | 33 inches (838 mm) |
| Crate Height | 33 inches (838 mm) |
| Crate Length | 65 inches (1651 mm) |
Includes 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 |
