30
3. Secondary mirror-holder adjustments: If the secondary mirror (1, Fig. 31) is centered in the
focuser drawtube (2, Fig. 31), but the primary mirror is only partially visible in the reflection (3,
Fig. 31), the three “+” (Phillips head) secondary mirror-tilt screws (2, Fig. 27) should be slight-
ly unthreaded to the point where the secondary mirror-holder (3, Fig. 27) can rotate about its
axis parallel to the main tube. Grasp the secondary mirror-holder (avoid touching the mirror sur-
face!) with your hand and rotate it until, looking through the drawtube, you can see the primary
mirror centered as well as possible in the reflection of the secondary mirror. With the rotation
of the secondary mirror-holder at this best-possible position, thread in the three Phillips head
screws (2, Fig. 27) to lock the rotational position. Then, if necessary, make adjustments to
these three Phillips head screws to refine the tilt-angle of the secondary mirror, until the entire
primary mirror can be seen centered within the secondary mirror’s reflection. With the second-
ary mirror thus aligned the image through the drawtube appears as in Fig. 32.
4. Primary mirror adjustments: If the secondary mirror (1, Fig. 32) and the reflection of the pri-
mary mirror (2, Fig. 32) appear centered within the drawtube (3, Fig. 32), but the reflection of
your eye and the reflection of the secondary mirror (4, Fig. 32) appear off-center, then the pri-
mary mirror tilt requires adjusting, using the Phillips head screws of the primary mirror cell (3,
Fig. 28). These primary mirror-tilt screws are located behind the primary mirror, at the lower end
of the main tube. See Fig. 28. Before adjusting the primary mirror-tilt screws, first unscrew by
several turns (use either a hex wrench or pliers) the three hex-head primary mirror lock screws
(2, Fig. 25) which are also located on the rear surface of the primary mirror cell and which alter-
nate around the cell’s circumference with the three Phillips head screws. Then by trial and error
turn the primary mirror Phillips head tilt screws (3, Fig. 28) until you develop a feel for which
way to turn each screw to center the reflection of your eye in the drawtube. (An assistant is
helpful in this operation.) With your eye centered as shown in Fig. 29, turn the three hex head
primary mirror lock screws (2, Fig. 28) to re-lock the tilt-angle of the primary mirror.
The telescope’s optical system is now aligned, or collimated. This collimation should be re-
checked from time to time, with small adjustments (per steps 1, 2, and/or 3, above) effected as
required to keep the optics well-aligned.
Specifications
DS-114AT
Optical design......................................................................................Reflector
Clear aperture ....................................................................................114mm
Focal length ........................................................................................910mm
Focal ratio ........................................................................................f/8
Resolving power..................................................................................1.0 arc secs
Max power ..........................................................................................325X
Mounting..............................................................................................Single-arm, motorized Alt-Az
Alignment ..........................................................................................Altazimuth
Slew Speeds ......................................................................................1x sidereal to 5.5°/sec in 9 increments
Tripod ..................................................................................................Aluminum, full-length; adjustable w/accessory tray
Optical Tube Dimensions ....................................................................5.5" x 34"
Batteries (user-supplied) ....................................................................10 x AA
Autostar
Processor ............................................................................................68HC11, 8MHz
Flash Memory ....................................................................................512KB, reloadable
Keypad ................................................................................................10 key alphanumeric
Display ................................................................................................2 line, 16 character LCD
Backlight..............................................................................................Red LED
RS-232 ................................................................................................Optional
Coil Cord ............................................................................................24"
Database ............................................................................................more than 1400 objects
Length..................................................................................................5.60" (14.2cm)
Width (LCD end)..................................................................................3.08" (78cm)
Width (Connector end)........................................................................2.10" (53.5cm)
Depth ..................................................................................................0.93" (23.5cm)
Autostar net weight..............................................................................0.35 lbs (0.169kg)
