Meade RCX400TM instruction manual Which One’s the Alignment Star?

Important Note:

Once the telescope is aligned, only use the Arrow keys to move the tele- scope. Once the telescope has been aligned, do not loosen the telescope locks (13 and 17, Fig. 1a), or move the base manually, or alignment will be lost.

Important Note:

If the objects you have chosen are not in the eyepiece after after alignment, it is also recommended that you

CALIBRATE SENSORS.

This menu allows you to improve your telescope's pointing accuracy to align- ment stars. It calibrates to correct slight mechanical misalignment due to transport, vibration, or aging. It is recommended that calibration be performed once on a new telescope after the user initially assembles it.

When this menu is selected, the telescope slews to Polaris. Autostar II then prompts you to center Polaris and to press ENTER. Autostar II uses the position of Polaris to fine tune the position of North and also detects level for the base of the telescope.

4.Autostar II initializes the Smart Drive if "On" has been previously chosen from both the R.A. and Dec. PEC menus in the "Setup: Telescope" menu (the very first time the system is turned on, the Smart Drive feature will not be enabled). Once "On" is chosen, Autostar remembers the setting until "Off" is chosen again. If "On" has been selected, the R.A. and Dec. motors operate briefly and "Initializing: Smart Drive" displays.

5.A message displays that warns not to look at the Sun. At the end of this message, press the key prompted by Autostar II to signify that the message has been read and understood.

6."Automatic Alignment" displays. Press ENTER. The system now performs the fol- lowing routines (press any Autostar II key to abort Automatic Alignment) :

Caution: As the telescope performs the following operations, it will swing and rotate. Keep a safe distance from the telescope.

a.Finds the home position. Moves the telescope to find the "home" position. When the home position is found, the system knows the limiting positions of the telescope and can avoid tangling cables and over-rotating the telescope.

b.Detects “level” of the base of the telescope; finds tilt and tip. To detect level, Autostar II must calculate "level" at three compass points. See FINDING TRUE LEVEL in the RCX400 INFO box on page 25.

Autostar II also determines the positioning (i.e., tilt and tip) of the optical tube.

c.Finds North. Locates magnetic North, then calculates true North. See

FINDING TRUE NORTH, page 25.

d.Attempts a "GPS Fix." The RCX400's GPS receiver attempts to acquire and sync up with signals from GPS satellites. "Getting GPS Fix" displays. See THE GLOBAL POSITIONING SYSTEM in the RCX400 INFO box on page 25.

After performing these operations, Autostar II now knows:

JThe telescope's limiting positions

JWhere level is for the telescope

JThe location of true North

JThe observing site's location

JThe date and time

e.Star Alignment. Autostar II then chooses two stars to align upon. "Searching...." displays. When the telescope slews (moves) to the first star for alignment, it may not appear in the field of view in the eyepiece. If it is not, look through the viewfinder—in most cases, the star will be visible. Use the Arrow keys to move the telescope (you can change speed at which the telescope moves: see SLEW SPEEDS, page 21 for more information) until the star is vis- ible and centered in the eyepiece. The alignment star should be easily recog- nized and be the brightest star in the area of the sky where the telescope is pointing. Press ENTER. Repeat this procedure for the second star. For more information about alignment stars, see WHICH ONE'S THE ALIGNMENT STAR? below.

RCX400 TIPS

Which One’s the Alignment Star?

If Autostar has chosen an alignment star with which you are unfamiliar, how can you be sure if the star in your eyepiece is really the alignment star?

The rule of thumb is that an alignment star is usually the brightest star in that area of the sky. If you perform a GO TO to an alignment star and you're not sure if you have located the alignment star or it isn't in the eyepiece, look through your viewfinder. When you view an alignment star in the viewfinder, it stands out dra- matically from the rest of the stars in that portion of the sky. The viewfinder will help you locate a star more quickly than the eyepiece, because it has a much wider field of view than the eyepiece. Using Autostar, set the slew speed to 6 or higher and use the Arrow keys to center the alignment star in the viewfinder. If your viewfinder has been aligned with the telescope, the alignment star should now be in the eyepiece. Set the slew speed to 4 or less and center the star in the eyepiece.

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