Meade RCX400TM Mounting and Focusing the Viewfinder for the First Time, Aligning the Viewfinder

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Fig. 21: Viewfinder bracket assembly: Slide the track (23) into the mounting slot (22). Tighten the thumbscrews (24) to secure.

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Fig.22: 8x50 Viewfinder tube: Objective lens (25), eyepiece/focuser (26) and locking ring (27).

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Fig. 23: Viewfinder adjustment screws (28).

Fig. 24a & 24b: Jupiter; examples of the right amount of magnification and too much magnification.

2.Insert eyepiece: Remove the UltraWide 24mm eyepiece from its container and slide it in the diagonal mirror. Tighten the thumbscrew (Fig. 20) located on the diagonal mirror to a firm feel only.

3.Remove dust cover: Remove the dust cover (18, Fig. 1a) from the optical tube assembly by gently prying it off.

Mounting and Focusing the Viewfinder for the First Time

The first time you mount and focus the viewfinder, follow the these steps:

1.Slide the track on the bottom of the viewfinder bracket into the slot in the viewfind- er mounting assembly. See Fig. 21. To secure the viewfinder to the mounting assembly, tighten the two thumbscrews to a firm feel only.

2.Slide the viewfinder tube (see Fig. 22) into the viewfinder bracket. Loosely tight- en the adjustment screws (see Fig. 23). You will use the adjustment screws to align the viewfinder (see the next section below).

2.Look through the viewfinder. Rotate the eyepiece/focuser until you sharply focus the crosshairs.

3.Loosen (rotate clockwise) the objective lens locking ring.

4.Rotate the objective lens until you sharply focus on an object located at infinity.

5.Tighten the locking ring.

6.You may now rotate the eyepiece to focus on objects.

Aligning the Viewfinder

To align the viewfinder, perform steps 1 through 4 during the daytime; perform step 5 at night.

1.If you have not already done so, insert the UltraWide 24mm eyepiece into the diagonal mirror.

2.Unlock the R.A. (13, Fig. 1a) and Dec. (17, Fig. 1a) locks so that the telescope moves freely on both axes.

3.Point the telescope at some well-defined and stationary land object at least 200 yards distant, such as the top of a telephone pole or street sign. Center the object in the telescope eyepiece. Re-tighten the R.A. and Dec. locks.

4.Look through the viewfinder eyepiece and loosen or tighten, as appropriate, one or more of the viewfinder adjustment screws (see Fig. 23) until the viewfinder crosshairs are precisely centered on the object you previously centered in the tel- escope eyepiece.

5.Check this alignment on a celestial object, such as the Moon or a bright star, and make any necessary refinements, using the method outlined in steps 2 through 4.

Note: Seeing conditions vary widely from night-to-night and site-to-site. Turbulence in the air, even on an apparently clear night, can distort images. If an image appears fuzzy and ill-defined, back off to a lower power eyepiece for a more well-resolved image (see Fig. 24a and 24b).

RCX400 TIPS

Too Much Power?

Can you ever have too much power? If the type of power you’re referring to is eyepiece magnification, yes, you can! The most common mistake of the begin- ning observer is to “overpower” a telescope by using high magnifications which the telescope’s aperture and atmospheric conditions cannot reasonably support. Keep in mind that a smaller, but bright and well-resolved image is far superior to one that is larger, but dim and poorly resolved (see Figs. 24a and 24b). Powers above 400X should be employed only under the steadiest atmospheric condi- tions.

Autostar II can calculate the best eyepiece for you to use. Try out the “Eyepiece Calc” feature in the Utilities menu.

Most observers should have three or four additional eyepieces to achieve the full range of reasonable magnifications possible with the RCX400 telescopes. See OPTIONAL ACCESSORIES, pages 48 - 50.

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