Meade LXD 75 instruction manual Procedure #2 To correct for elevation misalignment, Position a

Fig. 45: Position A.

Fig. 46: Position B.

Fig. 47: Cradle adjustment screws.

Important Note: The image will appear right-side-up, but reversed left-for- right, in the eyepiece of a refractor telescope. The image will appear upside-down, but correct left-for-right, in the eyepiece of a Schmidt- Newtonian telescope, if the eyepiece extends horizontally from the tube, as described in Step #3.

5.Loosen the R.A. Lock (Tip: Make sure you do not accidentally loosen the Dec. Lock. If you do, restart the procedure beginning at Step #2). Rotate the telescope 180° in the R.A. axis ONLY, until the optical tube is in position B. See Fig. 46. Note the position of your target in the eyepiece.

6.Using the Autostar Up and Down Arrow keys ONLY, move the optical tube in Dec. axis until your target is HALFWAY back to the center of the eyepiece.

7.Rotate the telescope 180° in the R.A. axis ONLY, to return the optical tube to posi- tion A. Verify that your target is in the same location in the eyepiece vertically as in the previous step (that is, it is not higher or lower or absent from the eyepiece). Ignore side-to-side misalignment (that is, if it has moved to the right or left).

8.Repeat steps 6 and 7, if necessary, alternating positions A and B, until the hori- zontal object is in the same vertical location in the eyepiece in both positions.

9.The Dec. optical axis is now calibrated to be at 90 degrees. For Procedure #2, DO NOT adjust the declination of the optical tube, either manually or with the hand- box.

Procedure #2: To correct for elevation misalignment

After performing the attitude correction, select an object that is at a very great distance (at least a mile away) to approximate infinity. Ideally, the object should be unique, with several identifiable objects to the left and right of it.

1.Rotate the mount about the R.A. axis only and move the optical tube to position A.

2.WITHOUT moving the declination axis from its position determined in the previ- ous alignment, adjust the legs, latitude, and azimuth of the tripod to center the object in the eyepiece.

Procedure #2: Step 2 Step 4 Step 5 Step 6

3.Rotate the telescope 180° in the R.A. axis ONLY, until optical tube is in position B.

4.Observe the position of the object in the eyepiece. Assuming that the declination was properly set in the previous procedure, the object should have moved only horizontally (that is, side-to-side) from its original position. It may be out of the eyepiece altogether.

5.Using the adjustment mechanism on the bottom of the cradle (Fig. 47), move the reference object approximately half the distance towards the center of the eye- piece.

To adjust the cradle screws, use the supplied hex key to loosen the two outside screws. Then adjust the position of the object by tightening or loosening the cen- ter screw. Perform this adjustment on both sets of screws. When finished, retight- en the outer screws.

Before moving the optical tube, note the location that the telescope is centered on relative to the reference object. Depending on the telescope type and acces- sories in use, you may need to move the optical tube opposite to the direction that appears in the eyepiece. The best way to be sure is to move the optical tube (using the cradle screws) a little, and verify that the correct direction was moved through the eyepiece.

6.WITHOUT moving the declination axis from its position determined in the previ- ous alignment, and WITHOUT adjusting the cradle position further, adjust the legs, latitude, and azimuth of the tripod to center the object in the eyepiece again.

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