Celestron CGX Instruction Manual page 20

Use the scroll buttons to select from the following options:
• Lights Control: Independently adjust the brightness of
the number keypad and the LCD
• Scrolling Menu: Adjust how fast words move across the
face of the LCD
• Toggle Bold Font: Change the format of the font
displayed on the LCD from normal to boldface
• Set Contrast: Use the scroll keys to adjust the contrast
of the LCD
• Set Language: Change the displayed language on
the LCD
NOTE: The Set Language feature may also appear the first
time you use your new hand control. You may also initi-
ate it at any time by holding down the Option button (the
Celestron logo) for 10 seconds while powering up the
telescope.
Scope Setup Menu
Setup Time-Site – Allows the user to customize the
telescope's display by changing time and location
parameters (such as time zone and daylight savings)
Anti-backlash – All mechanical gears have a certain
amount of backlash or play between the gears This play
is evident by how long it takes for a star to move in the
eyepiece when the hand control arrow buttons are pressed
(especially when changing directions) The CGX
anti-backlash feature allows the user to compensate for
backlash by inputting a value which quickly rewinds the
motors just enough to eliminate the play between gears
The amount of compensation needed depends on the
slewing rate selected; the slower the slewing rate the longer
it will take for the star to appear to move in the eyepiece
There are two values for each axis, positive and negative:
• Positive is the amount of compensation applied when you
press the button in order to get the gears moving quickly
without a long pause
• Negative is the amount of compensation applied when you
release the button, winding the motors back in the other
direction to resume tracking
Normally, both values should be the same You will need to
experiment with different values (from 0-99); a value between
20 and 50 is usually best for most visual observing, whereas
a higher value may be necessary for photographic guiding
To set the anti-backlash value, scroll down to the anti-backlash
option and press ENTER While viewing an object in the
eyepiece, observe the responsiveness of each of the four
arrow buttons Note which directions you see a pause in the
star movement after the button has been pressed Working
one axis at a time, adjust the backlash settings high enough
20 | ENGLISH
to cause immediate movement without resulting in a
pronounced jump when pressing or releasing the button
Now, enter the same values for both positive and negative
directions If you notice a jump when releasing the button but
setting the values lower results in a pause when pressing
the button, use the higher value for positive, but use the
lower value for negative The telescope will remember these
values and use them each time it is turned on until they are
changed
Filter Limits – When an alignment is complete, the telescope
automatically knows which celestial objects are above the
horizon As a result, when scrolling through the database
lists (or selecting the Tour function), the hand control will
display only those objects that are known to be above the
horizon when you are observing You can customize the
object database by selecting altitude limits that are appropriate
for your location and situation For example, if you are
observing from a mountainous location where the horizon
is partially obscured, you can set your minimum altitude limit
to read +20° This will make sure that the hand control only
displays objects that are higher in altitude than 20°
TIP: If you want to explore the entire object database, set
the maximum altitude limit to 90° and the minimum limit to
–90°. This will display every object in the database lists re-
gardless of whether it is visible in the sky from your location.
Direction Buttons – The direction a star appears to move
in the eyepiece changes depending on which side of the
Meridian the telescope tube is on This can create confusion
especially when guiding on a star when doing astroimaging
To compensate for this, the direction of the drive control keys
can be changed To reverse the button logic of the hand
control, press the MENU button and select Direction
Buttons from the Utilities menu Use the Up/Down arrow
keys (10) to select either the azimuth (right ascension) or
altitude (declination) button direction and press ENTER
Select either positive or negative for both axes and press
ENTER to save Setting the azimuth button direction to
positive will move the telescope in the same direction that
the telescope tracks (i e , towards the west) Setting the
altitude buttons to positive will move the telescope counter-
clockwise along the DECLINATION axis
GoTo Approach – Lets the user define the direction that
the telescope will approach when slewing to an object This
allows the user the ability to minimize the effects of backlash
when slewing from object to object Just like with Direction
Buttons, setting GoTo Approach to positive will make the
telescope approach an object from the same direction
as tracking (west) for azimuth and counterclockwise in dec-
lination Declination GoTo approach will only apply while the
telescope tube is on one side of the Meridian Once the tube
passes over to the other side of the Meridian, the GoTo
approach will need to be reversed