Meade LXD 75 Instruction Manual page 59

Meade Instruments Corporation
35-4702-00
CC
FC C
Tested to comply
with FCC Standards
B
FOR HOME OR OFFICE USE
A B
Fig. 51: Mode screws on rear of
Electronic Controller. (1) Mode Screw
A; (2) Mode Screw B.
Definition: Sidereal.
As the Earth rotates
beneath the night sky,
the stars appear to move
from East to West. The
speed at which the stars
move is called the side-
real rate. You can setup
your telescope to move
at the sidereal rate so
that it automatically
tracks the stars and
other objects in the night
sky. The tracking function
automatically keeps an
object more or less cen-
tered in the telescope's
eyepiece.
See pages 17 and 18 for
more information.
MODE Key: Press and hold MODE to place the Electronic Controller into the
Mode function, i.e., to select operation for the Northern or Southern Hemisphere.
See
TRACKING RATES
OUT Key: Use this key to decrease the tracking rate. See
page 60.
IN Key: Use this key to increase the tracking rate. See
60.
Modes of Operation
• When both the A and B screws are in place, the Northern hemisphere polar mode
is selected when power is applied (i.e., the motor drive is activated for operation in
the Earth's Northern Hemisphere). This is the factory default mode.
• Remove mode screw B (2, Fig. 51) to make the Southern Hemisphere polar mode
the automatic default of the Electronic Controller when power is applied (i.e., the
motor drive is activated for operation in the Earth's Southern Hemisphere ).
• Remove mode screw A to disable the tracking function. Select either the Northern
hemisphere polar mode or the Southern Hemisphere polar mode, as described
C
above, to make the tracking function available. See
page 61, for more information.
Note: Removing either A or B screw affects only the telescope's default
mode; you may still make mode changes when desired using the MODE key.
Slew Speeds
The Electronic Controller has four slew speeds that are directly proportional to the
sidereal rate. Press SPEED to change the slew speed (use the Arrow keys to slew the
telescope in the desired direction). Note each slew speed corresponds to one of the
four LED's of the Electronic Controller.
Light 1 (top LED): The fastest speed. Use to move the telescope quickly from one
point in the sky to another.
Light 2: Best for centering an object in the viewfinder.
Light 3: Best for centering an object in the field of a low-to-moderate power eyepiece,
such as the standard SP 26mm.
Light 4: The slowest speed. Use to center an object in the field of view of high-power
eyepieces, such as the optional 6.7mm or 12.4mm.
The four available speeds are:
Light 1 =1200 x sidereal (300 arc-min/sec or 5°/sec)
Light 2 = 32 x sidereal (8 arc-min/sec)
Light 3 = 8 x sidereal (2 arc-min/sec)
Light 4 = 2 x sidereal (0.5 arc-min/sec )
The two slowest speeds (2x and 8x sidereal) can be used for manual tracking of
astronomical objects while observing through the eyepiece.
To move the telescope using the Electronic Controller:
Insert a low-power eyepiece (e.g., SP 26mm) into the eyepiece holder (2, Fig. 1)
1.
and tighten the eyepiece thumbscrew (1, Fig. 1).
2. Tighten the R.A. and Dec. locks (17 and 33, Fig. 1), if necessary.
3. Verify that the On/Off switch (24D, Fig. 1) on the telescope's Computer Control
panel is off.
4. Plug in the Electronic Controller coil cord (4, Fig. 49) to the HBX port (24A, Fig.
1) on the Computer Control panel.
Flip the power switch to ON. The LED (24C, Fig. 1) on the Computer Control
5.
panel lights.. The Speed indicators lights will cycle off and on in sequence.
6. Press any key on the Electronic Controller and the telescope slews momentarily
in the vertical and horizontal directions to test the motors.
, page 60.
TRACKING RATES
, page
TRACKING RATES
CHANGING THE POLAR MODE
,
,
5 9