Meade LX200 Instruction Manual page 18

side of the keypad. Altazimuth coordinate readings
can still be displayed in the coordinates mode (see
MODE 2, page 22). Refer to QUICK START (page 9)
for the LAND menu option, for full operating
procedures. You will also find that the addition of the
Meade #928 45-Degree Erect Image Prism or the
Meade #924 Porro Prism instead of the standard
supplied star diagonal prism, will give the normal
right-side-up and left-to-right views that you are
accustomed to when using a spotting scope.
3. SMART: The SMART menu file controls the Smart Drive
and allows you to train almost all of the periodic error from
the Right Ascension drive worm gear (errors induced by
tiny gear imperfections that tend to slightly speed up or
slow down the drive tracking speed, that occur in a regular
8 minute pattern, or for every rotation of the worm) for
greatly enhancing the tracking characteristics or the
amount of East and West drift of your LX200. This greatly
simplifies guiding during astrophotography. The menu
also has provisions for correcting Declination drift. Smart
Drive will retain the training given to the R/A drive, even
after the telescope is turned off. There is of course a way
to erase any training given to it at your command.
The SMART menu has five options. They are; LEARN,
UPDATE, ERASE, DEC LEARN, and DEC CORRECT. To
use the Smart Drive, the LX200 must be mounted with the
optional equatorial wedge (see APPENDIX A, page 25),
equipped with an illuminated reticle eyepiece*, and used
in the POLAR align menu selection. Be sure to train the
Smart Drive in the 60.1 Hz Quartz setting that the LX200
will be automatically set at power up. Thereafter, you can
adjust this setting in the TIMER/ FREQ mode and still
enjoy the periodic error correction.
Once a polar alignment has been completed, your LX200
will point to a bright star overhead that will be near the
Celestial Equator. This will be a good star to train the
Smart Drive on. You can of course, move to another star
just as long as you are near 0 degrees in declination and
more or less overhead in Right Ascension. Now is good
time to set the brightness and/ or the pulse rate (see THE
LX200 KEYPAD HAND CONTROLLER, page 14) of the
illuminated reticle on the guide star and practice guiding
for a few minutes.
To actually begin training the Smart Drive, move the LCD
arrow to LEARN by using the PREV or NEXT key and
press ENTER. There will be numbers that will appear next
to the LEARN display, that will begin counting down to
zero. The highest number that can appear is 240. The
period of the worm is eight minutes and the number
represents a sector of the worm wheel which will change
to the next lower digit every two seconds. As the keypad
display approaches sector 5, an alarm will alert you that
training is about to commence. At this point try to keep the
star on the same location of the crosshair during the eight
minute training sequence by pressing the N, S, E, and W
keys. After eight minutes, the training is over and Smart
Drive will play back the drive corrections automatically,
dramatically improving the R.A. drive tracking.
If you wish to further refine the accuracy, move the LCD
arrow to UPDATE and press ENTER and follow the same
instructions as above. This can be done in UPDATE as
many times as you wish. With each training the Smart
Drive will average your training sequences.
If you find that you have made a mistake in training (e.g.
pushed E instead of W when you should have), you can
eliminate the memory by moving the LCD arrow to
ERASE and press ENTER.
A star that drifts consistently North or South during
guiding, can also be corrected for. Move the LCD arrow to
DEC LEARN and press ENTER. Begin making drive
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corrections immediately by pressing any of the direction
(N, S, E, W) keys to keep the star on the crosshair of the
guiding eyepiece. It is suggested that you train in DEC
LEARN for at least half of your intended exposure time for
an astrophoto. The longer that you train, the more
accurate the DEC LEARN will be. Once the desired time
is finished, press ENTER and the training will cease. The
Smart Drive will then determine how many key pushes
that you gave in N and S and choose the direction based
from which direction received more commands. It then
averages the time between key pushes in the chosen
direction. In this way, the Smart Drive can correct for
Declination drift (should your polar alignment be slightly
off), or will allow you to more precisely guide on non-
stellar objects, such as comets, asteroids, etc.
To play back your DEC LEARN training, move the LCD
arrow to DEC CORRECT and press ENTER. To halt the
play back press ENTER again. To erase the DEC LEARN
training, either move the LCD arrow back to DEC LEARN
and press ENTER twice or turn the LX200 off.
12/24 HR: The 12/24 HR menu selection of the
4.
TELESCOPE file simply toggles between a 12 and 24
hour display of local time in the time mode.
To toggle between 12 and 24 hours displays, move the
arrow to 12/24HR and press ENTER. To return to the
original setting, press ENTER again.
5. HELP: The HELP menu selection of the TELESCOPE file
is an electronic mini-manual that will briefly describe the
function of each command key on the LX200 keypad.
To use this menu, move the arrow with the PREV or
NEXT key to HELP and press ENTER. To read the lines
of text, use the PREV and NEXT keys. To exit, press
MODE.
6. REVERSE N/S: The REVERSE N/S menu selection of
the TELESCOPE file reverses the direction of the
telescope in North and South movements (e.g., when you
press the N key the scope will move South or down
instead of North or up). This is especially useful during
some guiding applications in imaging and observing.
To use the REVERSE N/S menu, move the arrow to
REVERSE N/S and press ENTER. If you wish to return
the direction commands to the original setting, press
ENTER again.
7. REVERSE E/W: The REVERSE E/W menu selection of
the TELESCOPE file reverses the direction of the
telescope in East and West movements (e.g., when you
press the W key, the telescope will move East instead of
West).
To use the REVERSE E/W menu, move the arrow to
REVERSE E/W and press ENTER. If you wish to return
the direction commands to the original setting, press
ENTER again.
BALANCE: When adding optional equipment to the
8.
LX200, like a heavy camera, it is often necessary to
rebalance the telescope using the Meade #1404 Tube
Balance Weight Systems.
Selecting option #8 from the TELESCOPE menu moves
the LX200 telescope rapidly up and down in Declination.
This provides an easy way to determine when the
telescope is balanced
(Remember, loosening the Dec. lock to check the balance
will cause the LX200 to lose alignment.)
When the telescope is out of balance, the LX200 will draw
more current when slewing in the "heavy" direction and
the Dec. motor will sound different.
After selecting option #8, watch the Ammeter and listen to
the Declination motor to determine when the LX200 is
balanced.
in the Declination axis.