Meade RCX400TM instruction manual Equatorial Wedge, Declination Setting Circle

Fig. 50: Declination Setting Circle.

Fig. 51: Section of Right Ascension Setting Circle.

Using setting circles requires a developed technique. When using the circles for the first time, try hopping from one bright star (the calibration star) to another bright star of known coordinates. Practice moving the telescope from one easy-to-find object to another. In this way, the precision required for accurate object location becomes evi- dent.

Note You may also enter an object's R.A. and Dec. coordinates using the "User: Objects" option of Autostar II's Object menu. Autostar II then auto- matically slews the telescope to the entered coordinates.

Note that the R.A. circle is double-indexed (i.e., there are two series of numbers run- ning in opposite directions around the circumference of the R.A. circle). The upper series of numbers (increasing counterclockwise) applies to observers located in the Earth’s Northern Hemisphere; the lower series of numbers (increasing clockwise) applies to observers located in the Earth’s Southern Hemisphere.

To use the setting circles to locate an object not easily found by direct visual observation:

With the telescope aligned to the Celestial Pole, first look up the celestial coordinates (R.A. and Dec.) of the object in a star atlas. Then loosen the R.A. lock and move the telescope to read the correct R.A. of the desired object; lock the R.A. lock onto the coordinate. Next, move the telescope in Declination to read the correct Declination of the object. If the procedure has been followed carefully, and if the telescope was well- aligned with the pole, the desired object should now be in the telescopic field of a low- power eyepiece.

If you do not immediately see the object you are seeking, try searching the adjacent sky area. Keep in mind that, with the 24mm eyepiece, the field of view of the RCX400 is about 0.75°. Because of its much wider field, the viewfinder may be of significant assistance in locating and centering objects, after the setting circles have been used to locate the approximate position of the object.

Pinpoint application of the setting circles requires that the telescope be precisely aligned with the pole. See PRECISE POLAR ALIGNMENTS, page 60.

Equatorial Wedge

An optional equatorial RCX superwedge is required for equatorial (polar) alignment. See Fig. 54.

The equatorial wedge permits use in an astronomical, or “equatorial,” mode. The wedge fits onto the field tripod. Equatorial alignment allows you to take longer expo- sure photographs with your RCX400.

See the instruction sheet supplied with the wedge for installation and setup information.

Note: For almost all astronomical observing requirements, approximate set- tings of the telescope’s latitude and polar axis are acceptable. Do not allow undue attention to precise polar alignment of the telescope to interfere with your basic enjoyment of the instrument.

Note: The Meade equatorial wedge is designed solely for use in conjunction with your Meade tripod. The wedge should never be used without the tripod (e.g., by placing the wedge alone on a table top and then mounting the tele- scope on the wedge—the wedge may become seriously unbalanced, to the point where the telescope may actually tip over.

Included features:

JAttachment of the wedge to the tripod by means of only one manual knob.

JQuick azimuth adjustment by loosening the manual knob.

JBubble level for rapid tripod/wedge leveling.

JEtched latitude scale for fast adjustment of the latitude angle.

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