Meade 114EQ-AR instruction manual Primary Mirror Adjustments, Star Testing the Collimation

Meade114EQAR 3/28/07 9:52 AM Page 20

must be unthreaded slightly to the point of where you can tilt the diagonal

18holder from side-to-side by grasping the diagonal holder with your hand and

tilt until you see the primary mirror become as centered in the reflection of the diagonal mirror as possible. Once you are at the best position, thread in the 3 Phillips-head diagonal tilt screws to lock the rotational position. Then, if necessary, make adjustments to these 3 Phillips-head screws to refine the tilt-angle of the diagonal mirror until the entire primary mirror can be seen centered within the diagonal mirror reflecting. When the diagonal mirror is correctly aligned, it will look like Fig. 14 (Note: The primary mirror is shown out

of alignment).

C. PRIMARY MIRROR ADJUSTMENTS

If the diagonal mirror (1, Fig. 16) and the reflection of the primary mirror (2, Fig. 16) appear centered within the drawtube (3, Fig. 16), but the reflection of your eye and the reflection of the diagonal mirror (4, Fig. 16) appear off center, you will need to adjust the primary mirror tilt Phillips-head screws of

the primary mirror cell (3, Fig. 13). These primary tilt screws are located behind the primary mirror, at the lower end of the main tube. To adjust the primary mirror tilt screws, first unscrew several turns, the 3 hex-head primary mirror cell locking screws (2, Fig. 13) that are next to each primary mirror tilt Phillips-head screw. Then by trial- and-error, turn the primary mirror tilt Phillips-head screws (3, Fig. 13) until you develop a feel for which way to turn each screw to center the reflection of your eye. Once centered, as in Fig. 14, turn the 3 hex- head primary mirror cell locking screws (2, Fig. 13) to relock the tilt-angle adjustment.

D. STAR TESTING THE COLLIMATION

With the collimation performed, you will want to test the accuracy of the alignment on a star. Use the 25mm eyepiece and point the telescope at a moderately bright (second or third magnitude) star, then center the star image in the telescope's field-of-view. With the star centered follow the method below:

•Bring the star image slowly out of focus until one or more rings are visible around the central disc. If the collimation was

performed correctly, the central star disk and rings will be concentric circles, with a dark spot dead center within the out-of- focus star disk (this is the shadow of the secondary mirror), as shown in Fig. 17C. (An improperly aligned telescope will reveal elongated circles (Fig. 17A), with an off-center dark shadow.)

•If the out-of-focus star disk appears elongated (Fig. 17A), you will need to adjust the primary mirror Phillips-head tilt screws of the primary mirror cell (3, Fig. 13)

•To adjust the primary mirror tilt screws (3, Fig. 13), first unscrew several turns the 3 hex-head primary mirror cell locking screws (2, Fig. 13), to allow free turning movement of the tilt knobs.

•Using the flexible cable controls move the telescope until the star image is at the edge of the field-of-view in the eyepiece, as in Fig. 17B.

•As you make adjustments to the primary mirror tilt screws (3, Fig. 13), you will notice that the out-of-focus star disk

Looking at or near the Sun will cause irreversable damage to your eye. Do not point this telescope at or near the Sun. Do not look through the telescope as it is moving.