Do you want to learn how to perform the periodic error correction procedure?
See PERIODIC ERROR COR-
RECTION, page 39.
Tip:
If the "ENTER to Sync" feature is accessed by mis- take (holding the ENTER key for more than 2 sec- onds), press MODE to return to the previous screen.
■Mount Lower Limit: Allows you enter a percentage that sets a lower limit as to how far the optical tube can swing downward during a programmed slew. (Note that it does not prevent you from performing a manual slew past this limit.) This is useful when you have a large optical tube (12" model) or have a dewshield attached to the telescope— you can prevent it from striking the telescope base.
■Train Drive: All telescopes have a certain amount of "backlash" (looseness in the interplay of gears). This menu allows you to compensate for the backlash in the the Altitude and Azimuth motors— which helps locate objects with more precision.
If you are experiencing any problems with pointing accuracy, follow the procedure described in APPENDIX D: TRAINING THE DRIVE, page 59, to insure accurate pointing and tracking. Also see CALIBRATE SENSORS, below.
■Calibrate Sensors: This menu allows you to improve your telescope's pointing accuracy to alignment stars. It calibrates to correct slight mechanical misalign- ment due to transport, vibration, or aging. It is recommended that calibration be performed once on a new telescope after the user initially assembles it.
When this menu is selected, the telescope slews to Polaris. Autostar II then prompts you to center Polaris and to press ENTER. Autostar II uses the position of Polaris to fine tune the position of North and also detects level for the base of the telescope.
■Tracking Rate: Changes the speed at which the telescope tracks targets in the sky.
a.Sidereal: The default setting for Autostar II; sidereal rate is the standard rate at which stars move from East to West across the sky due to the rotation of the Earth.
b.Lunar: Choose this option to properly track the Moon over long observing sessions.
c.Custom: Allows entry of
■Guiding Rate: Allows you to change the base slew speed, 1x. Enter a percent- age of the speed (either more or less than 100%) and press ENTER. This func- tion may be useful in guiding the telescope during CCD and
■Reverse L/R: Reverses the functions of the Left and Right Arrow keys for con- trolling the telescope's motioni(.e., the Right key moves the telescope to the left).
■Reverse U/D: Reverses the functions of the Up and Down Arrow keys for con- trolling the telescope's motioni(.e., the Up key moves the telescope down).
■Home Sensors: Turns off or on the True North and True Level sensors, if pre- ferred, for Easy,
■Dec. PEC: Allows you to perform periodic error correction on the Dec. drive worm gear. Must be performed with a
■R.A. PEC: Allows you to perform periodic error correction on the R.A. drive worm gear. Must be performed with a
■High Precision: If High Precision is turned on, when looking for a faint celestial object (e.g., a nebula or galaxy), Autostar II first slews to a nearby bright star and displays "ENTER to Sync." Center the star in the eyepiece, then press ENTER. At that point the telescope has a high precision alignment to that part of the sky and it then slews to the object that was originally requested.
Targets: Switches between Astronomical targets and Terrestrial targets. If "Astronomical" is selected, the telescope tracking motor is activated and any object you observe will remain centered in the eyepiece. If "Terrestrial" is selected, the track- ing motor is turned off. See TO TRACK AN OBJECT AUTOMATICALLY, page 18.
Site provides access to several options including:
■Select: Displays the currently selected observing site. Use the Scroll keys to cycle through all available sites (see ADD below). Press ENTER when the site
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