Appendix a - technical specifications – Celestron NexStar HC User Manual
Page 39
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Appendix A - Technical Specifications
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Design Maksutov-Cassegrain
Catadioptric
Aperture
4 inches (102mm)
Focal Length
52 inches (1325mm)
F/ratio of the Optical System
13
Primary Mirror: Diameter
Coatings
102mm
Multi-layer coating process
Secondary Mirror Spot Size
Secondary Obstruction
1.25"
34.4% by diameter; 11% by area
Corrector Plate: Material
Coatings
BK-7 Optical Glass
A-R Coatings both sides
Highest Useful Magnification
240x ( ~ 6mm eyepiece)
Lowest Useful Magnification (7mm exit pupil)
15x ( ~ 80mm eyepiece)
Resolution: Rayleigh Criterion
Dawes Limit
1.36 arc seconds
1.14 arc seconds
Photographic Resolution
140 lines/mm
Light Gathering Power
212x unaided eye
Near Focus standard eyepiece or camera
~ 20 feet
Field of View: Standard Eyepiece
: 35mm Camera
1.0º
1.51º x 1.04º
Linear Field of View (at 1000 yds)
52.5 feet
Magnification: Standard Eyepiece
: Camera
55x
27x
Optical Tube Length
13.5 inches
Weight of Telescope
11 Lbs.
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Input Voltage
Maximum
Minimum
12 V DC Nominal
18 V DC Max.
8 V DC Min.
Batteries Required
8 AA Alkaline
Power Supply Requirements
12 VDC-750 mA (Tip positive)
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Motor: Type
Resolution
DC Servo motors with encoders, both axes
.26 arc sec
Slew speeds
Nine slew speeds: 4º /sec, 2º /sec, 1º/sec, .5/sec, 32x, 16x, 8x, 4x, 2x
Hand Control
Double line, 16 character Liquid Crystal Display
19 fiber optic backlit LED buttons
Fork Arm
Cast aluminum, with integrated hand control receptacle
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Software Precision
16 bit, 20 arc sec. calculations
Ports
RS-232 communication port on hand control
Tracking Rates
Sidereal, Solar, Lunar and King
Tracking Modes
Alt-Az, EQ North & EQ South
Alignment Procedures
AutoAlign (2-star alignment)
Database
25 user defined programmable object.
Enhanced information on over 100 objects
Total Object Database
4,033