17
is pointed. You may press the scroll buttons to switch between
the different coordinate options.
Set Slew Limits: Allows you to set slewing limits of the GoTo
base’s altitude axis, to prevent the optical tube from colliding
with the base. When you press ENTER in the Set Slew Limits
submenu, you may enable or disable the slew angular limita-
tions in altitude. If you enable the slew limit setting, the hand
control will prompt you to edit the upper and the lower altitu-
dinal limitations in degrees. You may use the numeric keys to
edit the number and use the RIGHT and LEFT keys to move
the cursor. The slew limit range is dependent on the mount
and the optical tube installed on the mount.
Re-align Encoder: The SkyQuest XTg GoTo base uses
two encoders on each axis to track its position for GoTo and
Autotracking functionality. One encoder is coupled to the axis
shaft and the other is coupled to the motor shaft for each axis.
This dual encoder design allows you to move the telescope
by hand or electronically via the hand controller’s directional
buttons without losing its alignment. However, accuracy may
be diminished when the telescope is moved by hand. The fol-
lowing procedure can be used to recover pointing accuracy.
1. Browse to the Re-align Encoder submenu under SETUP
menu list, and then press ENTER. The hand control will
display “Re-align Encoder, press ENTER”.
2. Press ENTER, then the hand control will show the two
alignment stars that were centered in the last star-align-
ment procedure.
3. Use the scroll keys to select one of the previous align-
ment stars or select another star to recalibrate the axis
encoders. Then press ENTER to confirm.
4. After selecting the star as the reference star to recalibrate
the axis encoders, the telescope will slew to the select-
ed reference star. When the telescope stops slewing, it
should be pointing somewhere close to the reference
star. Use the directional keys to center the reference star
in the field of view of the illuminated Plossl crosshair eye-
piece, and then press ENTER to confirm.
5. The hand control will prompt “Re-align Encoder complet-
ed.” on the LCD screen. Press ENTER to confirm and
finish the Re-align Encoder procedure.
Handset Setting – This submenu allows adjustments of the
brightness of the LCD backlight, the LCD contrast, the bright-
ness of the LED button lights, and the beeper volume of the
hand controller. Press the RIGHT or LEFT directional key to
increase or decrease the values.
Factory Setting: Allows hand controller to be reset to the fac-
tory default setting. Note that this will not delete PAE settings
or User Defined objects.
Figure 26. The
SkyQuest optical tube
properly set up for
collimation. Note the white
paper placed across from
the focuser, and the level
angle of the optical tube.
Ideally, the telescope
should be pointing at a
white wall. (IntelliScope
model shown.)
Figure 27. To center the secondary mirror under the focuser,
hold the mirror holder in place with one hand while adjusting the
center bolt with a Phillips screwdriver. Do not touch the mirror’s
surface!
Figure 28. Adjust the tilt of the secondary mirror by loosening or
tightening the three alignment set screws with a 2mm hex key.