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Note: If your telescope does not begin tracking when you activate the motor drive (you should hearing a "whirring"
sound), check the configuration of the "mode screws" on the back of the Electronic Controller. See "Modes of
Operation" in your telescope's operating instructions for more information.
Caution: Do not move the tripod or adjust the latitude setting while observing, or the mounting alignment will be lost.
Note: The telescope's motor drive disengages when the Horizontal and the Vertical lock levers are unlocked and
re-engages when the levers are relocked.
3.
At the end of an observing session, remember to turn off the motor drive.
Altazimuth (Alt/Az) Mount
Ideal for both terrestrial applications and also for astronomical observation with Autostar. Altazimuth (alt/az) mounting (from
"altitude" meaning vertical and "azimuth" meaning horizontal) permits movement of the telescope tube in both the vertical
(altitude) and the horizontal (azimuth) directions.
To mount your telescope in the alt/az mode:
1.
Loosen the latitude control latch (4, Fig. 1) and lift up the tilt-plate (2, Fig. 1) so that you can easily access the underside of
the plate. Relock the latitude control latch, so the assembly doesn't slip while you are attaching the telescope. (See Fig. 1.)
2.
ETX-70AT model: Line up the two mounting holes of your telescope over the attachment knobs (5, Fig. 3). Thread the
attachment knobs into the base of the telescope. Tighten to a firm feel only.
ETX-90EC, ETX-105EC, and ETX-125 models with Autostar: Line up the mounting hole on the base of the telescope
marked "High Latitude Leg" with the attachment knob that is closest to the latitude control bar (see Fig. 2). Line up the
other mounting hole with the attachment knob at the bottom of the tilt-plate. Thread both attachment knobs into the base
of the telescope. Tighten to a firm feel only. (See Fig. 3.)
3.
Unlock the latitude control latch (4, Fig. 4) and lower the tilt-plate until it is level (push the tilt-plate down until it stops; this
is the level position). Lock the latitude control latch. (See Fig. 6.)
Using an Alt/Az Mounted telescope
The telescope is now altazimuth mounted on the #884 Tripod. Motions of the telescope may be effected in either horizontal or
vertical directions. ETX telescopes equipped with an Autostar hand controller (standard equipment with the ETX-70AT:
optionally available for the ETX-90EC, ETX-105EC, and ETX-125EC) may be used in the altazimuth mode, and the Autostar
hand controller directs the telescope to track astronomical objects in both vertical and horizontal directions, simultaneously.
Note that in the case of altazimuth mounting, the orientation of the tripod is irrelevant: the tripod may be placed on the ground
with tripod legs pointing in arbitrary directions. For information on the use of your ETX telescope equipped with an Autostar
hand controller, consult your telescope's operating instructions.
Fig. 6: Altazimuth Alignment.
Note that the tilt-plate is
level.
North
Celestial
+
Pole
Fig. 7: Example of Polar Alignment.
Note that the face of the tilt-plate
points North.
-3-
North
+
Celestial
Pole
Fig. 8: Example of Polar Alignment.
Note that the face of the tilt-plate
points North.
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