Meade DS-2090AT-TC Instruction Manual page 15

4.
During
base. The user is then requested to center the stars in the eyepiece and press ENTER.
Two-Star Alignment requires some knowledge of the night sky. AutoStar displays a database
of bright stars and two stars are chosen by the observer from the database for alignment. It is
recommended that you choose stars with which you are familiar the first trying out this method.
One-Star Alignment also requires some knowledge of the night sky. One-Star Alignment is
identical to Easy: Align (see
base of bright stars and only one star is chosen by the observer. The accuracy of One-Star
Alt/Az Alignment, unlike the Two-Star Alignment procedures, depends on how well the observ-
er levels the telescope and how close to North the telescope is pointed when setting the Home
Position (Fig. 16). Because the Two-Star Alignment methods use two stars to align upon, they
are more precise than One-Star Alignment.
Date changes the date used by AutoStar. This function is useful to check events in the past or
Note: The time and
future. For example, set the Date menu for a day three months in the future. Then check the
date information is
"Select Item: Event" menu for the Sunset time on that date. See
kept by a high
precision internal
Time changes the time entered into AutoStar. Setting the correct time is critical for AutoStar to
clock, which is set
properly calculate locations and events. Time may be set to 24-hour mode (military time) by
at the factory and
selecting the "blank" option which follows the "AM" and "PM" options.
held by a long-life
Daylight Saving is used to enable or disable Daylight Savings time.
lithium battery.
Replace the internal
clock's battery with a
Telescope accesses the several options, including:
CR2023 lithium
{
battery. This battery is
located in the battery
{
compartment.
{
The battery is avail-
{
able from Meade,
photographic supply
houses or any place
lithium batteries are
sold.
{
{
{
{
Point the telescope North. Use a compass or the North Star, Polaris as a guide to locating
North.
EASY TWO-STAR ALIGN , AutoStar automatically chooses two bright stars from its data-
EASY (TWO-STAR) ALIGN
NOTE: Daylight Savings Time may be referred to by different names in various areas
of the world. Check local time to verify.
Model: Allows you to select the telescope model connected to AutoStar.
Focal Length: Displays the focal length of the selected telescope.
Az Ratio and Alt Ratio: The Az (Azimuth) ratio and Alt (Altitude) ratio refers to the gears
of the telescope's motors. Do not alter these numbers.
Az Percent: The Az (Azimuth) Percent allows you to change the azimuth backlash, i.e., the
way the Arrow keys move the telescope along the azimuth (horizontal) axis. If you enter a
value near 100, the telescope tube responds more quickly (it responds immediately at
100%) as you hold down an Arrow key and also slews (moves) the tube more quickly. If
you enter a value near 0, it takes longer for the tube to respond as you hold down an Arrow
key and also slews the tube more slowly. Experiment with this option. Try changing the per-
cent value until you get a "feel" for the Arrow keys that is comfortable for you.
Alt Percent: The Alt (Altitude) Percent operates identical to the AZ Percent option (see
above), but allows you to change the altitude backlash, i.e., the way the Arrow keys move
the telescope when moving along the altitude (vertical) axis.
Train Drive: Trains the Altitude and Azimuth motors to locate objects with more precision.
If you are experiencing any problems with pointing accuracy, select the Tarin the Drive
procedure and follow the on-screen instructions, to insure accurate pointing and tracking.
Tracking Rate: Changes the speed at which the telescope tracks targets in the sky.
Sidereal: The default setting for AutoStar; sidereal rate is the standard rate at which
a.
stars move from East to West across the sky due to the rotation of the Earth.
b. Lunar: Choose this option to properly track the Moon over long observing sessions.
c. Custom: Allows entry of user-defined tracking rates.
Reverse L/R: Reverses the functions of the Left and Right Arrow keys (i.e., the Right key
moves the telescope to the left).
Reverse UP/DOWN: Reverses the functions of the Up and Down Arrow keys (i.e., the Up
key moves the telescope down).
, above), except AutoStar displays a data-
15
EVENT MENU , page 24.