2. Using the HOME Alignment Routine: Using the HOME
alignment routine requires only two steps (assuming the
SEThas been performed). First, before turning off power
to the telescope, park the telescope by selecting PARK
from the HOME menu. This will position the telescope to
a known position, which the telescope remembers even
when the power is off. Turn off the power.
When turning the power back on, perform the FIND from
the HOME menu. The telescope looks for the HOME
sensors in both axes. When it finds them, it is ready for
operation. As in the SETroutine, the telescope searches
only 30° sections of the gears. If you forgot to PARK the
telescope, or if it has been manually moved in R.A.
and/or Dec., then perform step 2 in Setting the HOME
Point before performing FIND home.
d. 12/24 HR: The 12/24 HR menu selection of the
TELESCOPE file toggles between a 12- and 24-hour display
of local time in the Time mode.
To toggle between 12- and 24-hour displays, move the
arrow to 12/24HR and press ENTER. To return to the
original setting, press ENTER again.
e. HELP: The HELP menu selection of the TELESCOPE file is
an electronic mini-manual that briefly describes 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.
f. REVERSE N/S: The REVERSE N/S menu selection of the
TELESCOPE file reverses the direction of the telescope in
North and South movements (when you press the N key, the
telescope moves 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. To return the direction
commands to the original setting, press ENTER again.
g. REVERSE E/W: The REVERSE E/W menu selection of the
TELESCOPE file reverses the direction of the telescope in
East and West movements (when you press the W key, the
telescope moves East instead of West).
To use the REVERSE E/W menu, move the arrow to
REVERSE E/W and press ENTER. To return the direction
commands to the original setting, press ENTER again.
h. BALANCE: When adding optional equipment, like a heavy
camera, to the LX200, 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 Dec.
This provides an easy way to determine when the telescope
is balanced in the Dec. axis (loosening the Dec. lock to
check the balance will cause the LX200 to lose alignment.)
When the telescope is out of balance, the LX200 draws
more current while slewing in the heavy direction and the
Dec. motor will sound different. After selecting option #8,
watch the ammeter and listen to the Dec. motor to determine
when the LX200 is balanced.
i. HI-PRECISION: The High-Precision Pointing feature of LX200
allows for very precise pointing of the telescope. With the
unique LX200 SYNC command, 0.3 arc-sec resolution
encoders, and high-speed DC servo motors, you can now
place objects in the telescope’s field of view with one arc-
minute or better pointing accuracy. This makes critical image-
placement applications, such as CCD imaging, possible.
Normal telescope pointing accuracy is better than five arc-
minutes when you perform a casual alignment. This is more
than accurate enough for most observing applications. (A
casual alignment is one that uses the UNKNOWN SITE or
one that is done without the use of a reticle eyepiece to
center the alignment stars exactly.) This type of alignment
puts objects into the field of view of most eyepieces and is
more than adequate for almost any visual observing
application.
A critical alignment improves the pointing accuracy of the
telescope to two arc-minutes or better. This type of alignment
requires accurate SITE information, time, date, proper
selection of the two alignment stars, and a reticle eyepiece to
center the alignment stars exactly. These steps generally
require only a few extra seconds, yet they substantially
improve the telescope’s positioning. Critical alignment
provides telescope positioning suitable for all but the most
demanding pointing applications—including CCD imaging
with larger-chip cameras, like the Meade Pictor 416 and
Pictor 1616 CCD cameras.
The HI-PRECISION feature increases the pointing accuracy
of the LX200 to one arc-minute or better; it also requires the
critical alignment described above. This yields the best
pointing accuracy possible, placing objects into the active
area of the even the smallest CCD cameras.
For most applications, the HI-PRECISION feature is not
required to get maximum enjoyment out of the telescope. For
an evening of simple visual observations, the casual
alignment is sufficient. Do not let pointing precision
overshadow the fun of observing the night sky.
The HI-PRECISION POINTING mode requires the critical
alignment, described above, to maximize the telescope’s
pointing ability. The LX200 default condition is with HI-
PRECISION disabled. To activate this mode, select the HI-
PRECISION option from the TELESCOPE menu (option #9).
When selected, HI-PRECISION change to upper case
letters.
When HI-PRECISION is active, the LX200 automatically
does the following when a GO TO is initiated.
1.
HP will search the alignment star database and find
the three closest stars to the object (or position)
entered. This process takes about 10 seconds; the
keypad shows Display 26:
Display 26
2.
The telescope slews to the nearest alignment
star. These are all bright stars (brighter than third
magnitude); they are far enough apart to ensure
that there will only be one in the field of view. The
keypad display shows Display 27:
Display 27
Using a reticle eyepiece, center the star in the field of
view. (Or center the star on the CCD chip if using a
CCD camera.) Press GO TO when the star is
centered.
NOTE: If this star is not in the field of view or if it is obstructed
by a land object, the other two stars are available. Use the
PREV and NEXT keys to cycle through the three closest stars.
3.
The telescope slews to the selected object or position.
HI-PRECISION
Searching. . .
Center STAR XXX
then press GO TO
