Dall-Kirkham Optical Tube Assembly 17”

Part#: 170120

Price: $24,000.00

This is a Dall-Kirkham optical design with coatings that are optimized to transmit in infrared or ultra violet wavelengths.  It is diffraction limited across a 20mm image circle at the focal plane.  There are no refractive lens, only reflective components to the design.  For IR application, reflectives coatings are a protected gold which give better than 98% reflectivity from .65 micron (650nm) to 5 micron (5000nm).  This design is ideal for infrared astronomy or LIDAR applications.  UV optimized coatings can also be used at an additional cost.

The DK is available in the three different apertures, 24", 20", 17" and 12.5"


Aperture 17"
Focal Length 2938 mm
Central Obstruction 48% of the Primary Mirror Diameter, 8.27 inch
Back Focus 10.24" from focuser mounting surface, 5.8" from racked in focuser
Weight 106 lbs
OTA Length 37"
Optical Tube Carbon Fiber
Upper Cage Carbon Fiber Truss
Lower Cage Carbon Fiber Truss with Carbon Fiber light shroud
Dimensions Overall Dimensions


Diameter 17.75"
Aperture 20"
Focal ratio f/3
Mounting Laser Collimated and Permanently Fixed
Material Precision Annealed Pyrex
Coating Protected Gold Reflective Coating - 98% (.65-16micron)


Diameter 6.25 inch
Material Precision Annealed Pyrex
Shape Spherical
Coating Protected Gold Reflective Coating - 98% (.65-16micron)

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 conrolled by a computer if the optional Electronic Focus Accessory (EFA Kit) is purchased.


Crate Dimensions:  58" x 30" x 37" Crate Shipping Weight:  225 lbs