Meade LXD 75-Series instruction manual Method #4 Smart Drive Training Periodic Error Correction

The telescope first moves 180° on the Dec. axis and then rotates 180° on the R.A. axis. Autostar displays "Slewing....".

When the telescope has completed the 180° slew, the telescope will be under the mount instead of over it. The counterweight shaft is now pointed upwards and the cradle adjustment screws (Fig. 47) are easily accessible.

7.Autostar again prompts you to center the landmark you have chosen in the eyepiece. Use the Arrow keys to center the object and then press ENTER.

8.The telescope moves again on the R.A. axis. Use the cradle screw adjustment mechanism on the bottom of the cradle to center the landmark in the eyepiece.

To adjust the cradle screws, use the supplied hex key to loosen the two outside screws. Then adjust the position of the landmark by tightening or loosening the center screw. Perform this adjustment on both sets of screws. When finished, retighten the outer screws. The axis is now aligned.

Note: This procedure maximizes the pointing accuracy of the telescope provid- ed the telescope is always placed on the mount in the same fashion. A mark made on the mount under the saddle will ensure this alignment is maintained.

Method #4: Smart Drive Training (Periodic Error Correction)

If you wish to improve the gear performance on your telescope, first, perform the train the drive procedure (see page 20). Then use the Periodic Error Correction (PEC) Train menu option to remove the slight perturbations from center that occur due to the mechanical nature of a telescope. To perform this procedure, you need to use a high- power reticle, such as the 9mm reticle (see OPTIONAL ACCESSORIES, page 37).

Important Note: In order for the Smart Mount training to operate and be updated properly, you must “park” the telescope (see PARK SCOPE, page 28).

PEC Train Menu Option

To perform the procedure on the R.A. axis, pick a bright star in the South that has min- imal movement and is about 30° above the horizon (Note: If in the Southern hemi- sphere, pick a star in the North that is about 30° above the horizon).

Important Note: The Train option overwrites any previous PEC data.

1.Select "PEC Train" from the Smart Drive menu (in the "Setup: Telescope" menu) and press ENTER.

2.Look through the reticle. Use the Arrow keys to keep the star centered in the reticle cross-hairs. Autostar displays a count of the 150 positions of the worm gear. When the count reaches 150, one cycle is complete. A full cycle takes about 12 minutes.

3.Press MODE to exit.

PEC Update Menu Option

PEC Update does not overwrite the data, but updates the training using information gathered from both the last and the current training sessions. Press the MODE key to exit from this option. If you wish to further refine your training, select this menu again and repeat the procedure.

PEC Erase Menu Option

Select this option to erase all PEC training data.

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