Celestron CGX-L Equatorial Mount and Tripod CGX-L Manual 5 Languages - Page 19

HINT: In order to minimize the affect of gear backlash on pointing accuracy, the settings for Button Direction should ideally match the settings for GoTo Approach. By default, using the up and right direction buttons to center alignment stars will automatically eliminate much of the backlash in the gears. If you change the GoTo approach of your telescope, it is not necessary to change the Button Direction as well. Simply take notice of the direction the telescope moves when completing its final GoTo approach. If the telescope approaches its alignment star from the west (negative azimuth) and clockwise (negative altitude) then make sure that the buttons used to center the alignment stars also move the telescope in the same directions. Autoguide Rate - Allows the user to set an autoguide rate as a percentage of sidereal rate. This is helpful when calibrating your telescope to a CCD autoguider for long exposure astroimaging. Meridian - This feature instructs the mount on how to respond when it is slewing to objects that are accessible from both sides of the Meridian. The Meridian feature allows the telescope tube to remain on a desired side of the mount when slewing, and continue to track according to the R.A. slew limits the user has set. See R.A. Limits below. The Meridian feature allows for four choices: • Favor Current - Allows the mount to favor whatever side of the mount that it is currently on when slewing to objects close to the Meridian. For example, if your R.A. slew limits are set to allow the mount to track 10° past the meridian, then the telescope will continue to stay on its current side of the Meridian when slewing to objects that are as far as 10° beyond your Meridian. • Favor West - If the target object is accessible from both sides of the mount, selecting "Favor West" instructs the mount to point to the object as if it were on the west side of the meridian. The optical tube will then be positioned on the east side of the mount and pointing west. • Favor East - If the target object is accessible from both sides of the mount, selecting "Favor East" instructs the mount to point to the object as if it were on the east side of the meridian. The optical tube will then be positioned on the west side of the mount and pointing east. • Disable - This is the default setting, which instructs the mount to always swing around to the other side of the pier as required to view objects on the opposite side of the Meridian. However, once at the desired object, the mount will continue to track past the Meridian according to the R.A. slew limits that have been set. • DEC Index - This is the declination index error value that is stored when calibration stars are added after your initial star alignment. • R.A. Index - This is the R.A. index error value set when Utilities/Calibrate Mount/R.A. Switch is carried out. R.A. Limits - Sets the limits that the telescope can slew or track in Right Ascension (R.A.) before stopping. The slew limits are represented in degrees and by default set to 0°, being the position of the telescope when the counterweight bar is extended out horizontally. However, the slew limits can be customized depending on your needs. For example, if you are using CCD imaging equipment that has cables that are not long enough to move with the telescope as it slews across the sky, you can adjust the slew limit on the side of the mount that is restricted by the cables, and command the mount the stop slewing before it reaches this point. Or if you are taking an image of an object that has just crossed the Meridian, you can set the limit to allow the mount to continue tracking in the same direction past the Meridian without the need to "flip" the telescope around to the opposite side of the mount (see Meridian feature above). Using the first example above, the user could slew the telescope in R.A. (azimuth) until it reaches the point that the cables are extended to their maximum. Then by displaying the telescope's azimuth in this position (by looking at Get Axis Position under the Utilities menu) you can determine the telescope's azimuth at its most extended position. Enter this azimuth reading for either the maximum or minimum azimuth slew limit to ensure that the telescope will not slew beyond this point. The telescope slew limits can be set to automatically stop anywhere between 40° above level to 20° below level. To set the R.A. slew limit select the following: • R.A. East Limit - Enter a number between +40° to -20° to define the slew limit when the tube is on the east side of the mount. • R.A. West Limit - Enter a number between +40° to -20° to define the slew limit when the tube is on the west side of the mount. • Disable Limits - This disables any pre-defined values that have been entered and allows the mount to track the maximum amount pass the Meridian (i.e., -20° on both sides) Mount Settings - Once the mount settings have been calibrated (see Utilities section below) the values are stored and displayed in the hand control. It is not recommended that the calibration values be changed. However each setting can be changed if necessary to improve the performance of the telescope. • Cone Value - This is the cone error value set when Utilities/Calibrate Mount/DEC Switch - Cone is carried out. ENGLISH | 19