Defocused star images. Misaligned 1, 2, Aligned

Follow these steps for collimation of the optical system:

The only adjustments possible, or necessary, on the RCX400 models is performed with the AutoStar handbox. No adjustment screws are necessary (or provided), as with tra- ditional telescopes. A high-powered eyepiece, such as a 9mm eyepiece, or a 9mm eyepiece with a 2x barlow, is required for collimation. A good rule of thumb to follow is to select the highest power eyepiece you will use with your telescope, and double it (a 2x barlow is ideal for doubling). See Fig. 42a below, to see images of an aligned and misaligned image.

a.Select the “Collimation” option in the Setup/Telescope menu. Once this option is selected, you will be able to use Autostar’s Arrow keys to adjust the image of the star you have selected.

b.While looking through the eyepiece, Use Autostar II's Arrow keys at the slowest slew speed, begin to move the defocused center ring so that the rings become more concentric. You will most likely need to press more than one Arrow key.

c.You will notice that the star image will move across the field of view of the eye- piece. If while using the Arrow key, the defocused star image moves out of the eyepiece field, press MODE to temporarily leave the collimation menu.

d.When you have left the “Collimation” menu, use the Arrow keys to bring the image back to the center of the eyepiece field.

e.Press ENTER to select the “Collimation” option again.

f.Use the Arrow keys to continue to adjust the image until it becomes concentric. If the image moves out of the eyepiece field, perform steps c through e as many times as necessary.

g.Carefully examine the concentricity of the diffraction rings. Always double check the image in the center of the field of the eyepiece. The star point should appear as a small central dot (commonly referred to as an “Airy disc”) with a diffraction ring surrounding it. You now have the best alignment of the optics possible with this telescope.

Set Default and Restore Default Options: The factory has collimated your telescope and saved the settings in the Restore Default option. You may retain this setting and recall it if the telescope needs collimation. Or you may overwrite this setting using the Set Default option after performing precise collimation and recall it again when need- ed with the Restore Default option.

			1	2	3
			Fig. 42a: Defocused star images. Misaligned (1, 2), Aligned (3).
			Align (Squaring) the OTA: If you are using a non-RCX telescope or if you have
			changed your RCX collimation or mounting significantly from the factory defaults, you
			must align the OTA. When you select this menu, Autostar will ask you to center two
			stars in the telescope that are on opposite sides of the sky.
			Once you have centered them, the telescope will slew back to the first star. You will
			then be asked to center the star using the OTA align bolt. These are two bolts, with
	OTA Alignment
	Bolts		one in the center of the other. Using a 9/16 flat wrench, loosen the center bolt and hold
			this one so it doesn't move. Then place 13/16 open ended or combination spanner
			wrenches on the outer bolt. Turn the outer bolt until the star is centered. When cen-


Fig. 42b: The OTA align bolt.			tered, tighten just the center bolt. This will hold the bolts securely in that position.
Fig. 42b: The OTA align bolt.
			Note that there is a bolts on either side of the OTA align bolt (Fig. 42b). These bolts
			must be loosened during the procedure and tightened afterward.
		Looking at or near the Sun will cause irreversible damage to your eye. Do not point this telescope at or near the				29
		Sun. Do not look through the telescope as it is moving.

Follow these steps for collimation of the optical system:

Fig. 42a: Defocused star images. Misaligned (1, 2), Aligned (3).

Fig. 42b: The OTA align bolt.