Celestron 80GTL manual Utility Features, Hint

objects are relative to the location of the telescope, they are only valid for that exact location. To save land objects, once again center the desired object in the eyepiece. Scroll down to the "Save Land Obj" command and press ENTER. The display will ask you to enter a number between 1-25 to identify the object. Press ENTER again to save this object to the database.

Enter R.A. - Dec: You can also store a specific set of coordinates for an object just by entering the R.A. and declination for that object. Scroll to the "Enter RA-DEC " command and press ENTER. The display will then ask you to enter first the R.A. and then the declination of the desired object.

GoTo Object: To go to any of the user defined objects stored in the database, scroll down to either GoTo Sky Obj or Goto Land Obj and enter the number of the object you wish to select and press ENTER. NexStar will automatically retrieve and display the coordinates before slewing to the object.

To replace the contents of any of the user defined objects, simply save a new object using one of the existing identification numbers; NexStar will replace the previous user defined object with the current one.

Get RA/DEC - Displays the right ascension and declination for the current position of the telescope.

Get Alt-Az- Displays the relative altitude and azimuth for the current position of the telescope.

Goto R.A/ Dec - Allows you to input a specific R.A. and declination and slew to it.

Goto Alt-Az- Allows you to enter a specific altitude and azimuth position and slew to it.

				MENU
		To store a set of coordinates (R.A./Dec) permanently into the NexStar database,
Helpful		save it as a User Defined Object as described above.
					UTILITIES
Hint
						SETUP TIME-SITE
	Utility Features
						ANTI-BACKLASH
		Scrolling through the MENU options will also provide access to several advanced					AZM POSITIVE
		utility functions such as anti-backlash compensation and slew limits.					AZM NEGATIVE
							ALT POSITIVE
		Setup Time-Site- Allows the user to customize the NexStar display by changing					ALT NEGATIVE
						SLEW LIMITS
		time and location parameters (such as time zone and daylight savings).
							SLEW ALT MAX
		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					SLEW ALT MIN
		eyepiece when the hand control arrow buttons are pressed (especially when changing				DIRECTION BUTTONS
		directions). The NexStar's anti-backlash features allows the user to compensate for
		backlash by inputting a value which quickly	rewinds the motors just enough to					AZM BUTTONS
		eliminate the play between gears. The amount of compensation needed depends on the
								ALT BUTTONS
		slewing rate selected; the slower the slewing rate the longer it will take for the star to				LIGHT CONTROL
		appear to move in the eyepiece. Therefore, the	anti-backlash compensation will have
		to be set higher. You will need to experiment with different values; a value between
		20 and 50 is usually best for most visual observing, whereas a higher value may be					DISPLAY OFF
		necessary for photographic guiding.					DISPLAY ON
		To set the anti-backlash value, scroll down to the anti-backlash option and press					KEY PAD OFF
							KEY PAD ON
		ENTER. Enter a value from 0-100 for both azimuth and altitude directions and press				SELECT MODEL
		ENTER after each one to save these values. NexStar will remember these values and
		use them each time it is turned on until they are changed.

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