Optical Design | Corrected Dall-Kirkham |
Aperture | 17 inch (432 mm) |
Focal Length | 2939 mm (115.71 inch) |
Focal ratio | F/6.8 |
Central Obstruction | 23.7% by surface area; 48.6% of the Primary Mirror Diameter |
Back Focus from Mounting Surface | 10.24 inch (260 mm) |
Back Focus from Racked in Focuser | 7.24 inch (184 mm) |
Weight | 106 lbs (48 kg) |
OTA Length | 42 inch (1067 mm) |
Optical Performance | 6.5 micron rms at 21mm and 9.6 micron at 26mm off-axis |
Upper Cage | Carbon Fiber Truss |
Lower Cage | Carbon Fiber Truss with Carbon Fiber Light Shroud |
Optimal Field of View | 70mm Image Circle |
Diameter | 190 mm (7.48 inch) |
Material | Precision Annealed Pyrex |
Shape | Spherical |
Coating | Enhanced Aluminum - 96% |
Optical Diameter | 17 inch (432 mm) |
Outer Diameter | 17.5 inch (445 mm) |
Shape | Prolate Ellipsoid |
Material | Fused Silica |
Coating | Enhanced Aluminum - 96% |
Diameter | 105 mm (4.13 inch) |
Number of lenses | 2 |
Coating | Broadband AR Coatings (less than .5% reflected from 400 to 700nm) |
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 | 225 lbs (102.1 kg) |
Crate Width | 30 inch (762 mm) |
Crate Height | 37 inch (940 mm) |
Crate Length | 58 inch (1,473 mm) |
INCLUDED ACCESSORIES
Ronchi Spacer (600341 & 600343) | This spacer sits in place of a focuser and is used for setting the primary to secondary spacing. It has an 1-1/4 inner diameter and may be used with 1-1/4 oculars for collimation |
Ronchi Ocular | This ocular is a Ronchi screen used for setting the primary to secondary spacing |
Primary Mirror Cover | The Primary Mirror Cover protects the primary mirror |
Planewave Thumb Drive | Containing all documentation and software for collimation and spacing |
12VDC Power Supply | Provides power for the fans (Not included for European Orders) |
Free Shipping | No |
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