Meade 2045 Operating Instructions Manual page 14

4" schmidt-cassegrain telescope
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4.
Tighten the screw or screws in the same direction as the darker shadow is off-center and loosen the
other screw or screws. Continue this process until the defocused image is brought back to the center of
the telescopic field. If, after following these steps, the secondary mirror shadow is still off-center in the
out-of-focus star image, repeat procedures until the shadow is exactly centered.
5.
Now proceed to a higher power (e.g. 9mm) eyepiece and repeat steps 3 and 4. Any lack of
concentricity at this point will require only extremely slight adjustments of the 3 set screws.
6.
As a final check on collimation, examine the star focus image in-focus with a fairly high power (9mm or
shorter focal length) eyepiece, under good seeing conditions. The starpoint should appear as a small
central dot (the so called "Airy disc") with one diffraction ring surrounding it. Make very small adjustments
of the 3 set screws, if necessary, to center the Airy disc in the diffraction ring. With this final adjustment
performed, the telescope is collimated.
Fig. 5: Summary of the Collimation Procedure
(a) Note if the darker shadow is decentered, as shown, inside the lighter circles; (b) use the telescope's
controls to move the image to the edge of the field in the same direction as the darker shadow is off
center; (c) tighten and/or loosen, as appropriate, the secondary housing's 3 collimation set screws to
bring the image back to the center of the field; repeat (a) and (b), if necessary.
The Meade Model 2045 has been designed and manufactured for years of trouble free operation and
repairs should rarely be necessary. If a problem does occur, first write or call our Customer Service
Department. Do not return the telescope for servicing until you have communicated with us in this way,
since the great majority of problems can be handled without return of the telescope to us. When
telephoning or writing, please explain in detail the exact nature of the problem so that we may offer a
prompt remedial procedure. Be sure to include your full name, address and phone number.
1 A

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