Meade Instruments 50 AZ-T - Manual (Page 9)

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circles with the Celestial Pole at the center. By lining up the
telescope's polar axis with the North Celestial Pole (or South
Celestial Pole if observing from the Earth's Southern
Hemisphere), celestial objects may be followed (tracked) by
moving the telescope about one axis, the polar axis.
Polar alignment consists of the following two operations:
1. Aligning the telescope with the celestial pole:
a. Identify the tripod leg designated as the "North Leg"
(3), Fig. 11, (the leg that is parallel to the Polar Housing
(2), Fig. 11, when viewed from above).
b. Set the mount on level ground with this "North Leg"
pointing North.
2. Tilt the telescope tube towards Polaris, so that the polar
axis (1), Fig. 11, in now roughly aligned with the North
Celestial Pole.
Note: Polaris, the North Star, lies close to, but not exactly on the
North Celestial Pole. Aligning the telescope with Polaris will be
adequate for visual observing and photography of the Moon and
planets. Polaris can be found in relation to the Big Dipper by
projecting a line from the so-called "pointer stars" of the Big
Dipper, as shown in Fig. 12.
How to Locate Objects in the Night Sky
Now that your telescope is fully assembled and polar aligned,
you are ready to begin observations.
Note that although the above assembly and polar alignment
procedures may seem quite tedious — particularly if the
Starfinder is your first serious telescope — in fact, assembly and
polar alignment will quickly become routine. Once set, the
latitude angle of the pier need never be changed, unless moving
your observing site a considerable distance in latitude, perhaps
150 miles or more.
For the beginning amateur astronomer, the simplest method of
locating objects in the night sky — and an excellent way to learn
how to operate your telescope — is to look at a celestial object
that can be clearly seen with your own eyes.
Find the desired object in the viewfinder, center the object in the
viewfinder's crosshairs, then observe through the main
telescope's eyepiece and adjust the focus knob until the image
is clear and sharp. With the motor drive turned on, observe how
the telescope tracks, or follows, the object as it arcs across the
sky. Turn the motor drive off for a few seconds, and note how
rapidly the objects move through the field of view.
The position of celestial objects changes over the course of the
year, so obtaining a star chart — such as the Meade Star
Charts, available from your Meade dealer — or referring to the
monthly star charts presented in astronomy magazines, such as
Sky & Telescope and Astronomy will be helpful.
With these aids and with a little experience at the controls of the
Starfinder, you will soon be exploring the surface of the Moon,
the planets of our Solar System and the incredible assortment
of star clusters, galaxies, and nebulae that lie beyond.
The Motor Drive
The DC drive system on your Starfinder telescope can be
operated from either an internal battery pack or an external 12
volt source (such as a car battery). Directions for installing the
batteries are on page 5. To use the motor drive, follow this
procedure:
1. With the telescope polar aligned as described above, turn
the motor drive on with the On switch located on the Control
Panel. See Fig. 2.
2. After switching the motor drive on, allow one minute for the
drive to take up any internal gear-backlash.
3. Now, as the telescope moves from object to object, the
motor drive will automatically track, or follow the object, fully
compensating for the effects of the earth's rotation.
Southern Hemisphere Operations. Tracking is normally in a
westerly direction (for the northern hemisphere) but can be
changed by installing the southern hemisphere jumper as
follows:
1. On the Drive Motor Housing (18), Fig. 1, loosen the set
screw and remove the Set Collar (3), Fig. 14.
2. Loosen the set screw and remove the R. A. Setting Circle
(2), Fig. 14.
3. Remove the three Phillips head screws (5), Fig. 14,
attaching the dust cover (1), Fig. 14, to the back plate of the
Drive Motor Housing.
4. Remove the dust cover carefully. The circuit board is
attached to the inside of the dust cover, with wires leading to
the drive motor.
5. On the circuit board, locate 2 "L"-shaped prongs extending
from the board. One prong should have the jumper (a small,
plastic, black square with two openings, side by side)
attached.
Fig. 13: Setting Circles. (1) R.A Setting Circle; (2) D e c l i n a t i o n
Setting Circle.
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1
Fig. 12: Locating Polaris.
With these two steps accomplished, the telescope is sufficiently
well polar aligned for all visual observing purposes, as well as
for photography of the Moon and planets.
Calibrating the Declination Circle: When the telescope is polar
aligned for the first time, take a moment to check the calibration
of the Declination setting circle (8), Fig. 1, using the following
steps:
1. Center Polaris in the telescope's field of view.
2. Use the hex wrench provided to loosen the Declination
setting circle (2), Fig. 13. With your finger, turn the setting
circle until the dial reads 89.2° — the Declination of Polaris;
then re-tighten the hex screw without moving the circle. The
Declination setting circles are now calibrated.