Thread the two provided
threaded attachment
knobs through the mounting slots into the ETX base.
Tighten to a firm feel only. Do
not
overtighten or damage
to the threads may occur.
The
ETX Astro Telescope can be used for land or celestial
observing.
To track celestial objects, polar alignment is
required, along with the motor drive system of the ETX. (See
the
Motor Drive section of the ETX instruction manual.)
POLAR ALIGNMENT
Polar alignment is the process of lining up the telescope’s polar
axis with the North Celestial Pole (or South Celestial Pole if
observing from the southern hemisphere).
With a polar aligned ETX, tracking celestial objects is possible
simply by turning on the drive motor in the base of the telescope.
The motor counteracts Earth’s rotation, keeping objects in the
field of view. Also, with a polar aligned telescope, the
and R.A. setting circles may be used to locate faint objects
directly from their
coordinates.
Fig. 3. (left)
The ETX Astro Telescope on
for
land
The
ETX, ready for
1 .
Polar Alignment Procedures
Make sure the ETX is
attached to the tripod, as described
above In this
sheet, with
lock knob (10) and
the
lock lever (11)
locked
Step (a) below
IS
to pointing the telescope’s polar
due north (or due south for observers in the southern
hemisphere). Step (b)
IS
to
the telescope’s
angle equal to the latitude angle of your
location.
a.
On top of one of the
legs, locate the letter
This represents the north leg of the
up
the
telescope-and-tripod and
the tripod
lea marked
points due north. For observers the
southern hemisphere (e.g.,
the lea marked
should
due south.
b.
Determine the latitude of your observing
by
checking a road map, atlas, or refer to pages 12-13 of the
ETX manual. To set the latitude of the tripod to your
location, loosen the latitude lock knob
Fig. 1. Turn the fine latitude adjustment knob
Fig. 1,
clockwise or counterclockwise until the latitude pointer
Indicates the correct latitude on the latitude scale
Fig. 1.
It may be necessary to loosen the lock nut on the fine
latitude adjustment knob
Fig. 1, to allow enough
movement of the mount to achieve the latitude of your
location. Once the
latitude has been set, tighten
the lock nut until it is flush
the mount.
the
latitude lock knob
Fig. as well.
.
Note:
The fine azimuth adjustment knobs
Fig. which
move the telescope horizontally without moving the tripod itself,
may be used to
the alignment procedure.
Note:
By following the procedures listed above, the ETX
telescope is polar aligned for most celestial observing
applications. See Figure 3. Approximate polar alignment is
sufficient in the great majority of these applications. Do
not
allow a time-consuming effort at precise polar alignment to
interfere wifh your basic enjoyment of the telescope, as such
precise alignment is, in general, not
Using the North Star, Polaris, to find North aids in the polar
alignment procedure. Polaris can be found in relation to the Big
Dipper by projecting a line from the so-called “pointer stars” of
the Big Dipper. For southern hemisphere alignment, locate
south by using the faint star Sigma
(the South Star)
Cassiopeia
Fig. 4: Locating Polaris.
2.
Using a Polar Aligned Telescope
Once the telescope is polar aligned, the ETX motor drive will
keep a celestial object in the field of view of the telescope.
a.
b.
C.
d.
e.
3.
To center a celestial object within a polar aligned
telescope, unlock the
and R.A. lock levers of the
telescope (see
the Locating Astronomical Objects section
of the ETX instruction manual).
Do not move the tripod or
adjust the latitude angle when centering an object in the
telescope, as this will destroy the polar alignment.
Once a celestial object has been centered in the
telescope, lock the
and R.A. lock levers.
Locate the On/Off switch on the bottom of the ETX drive
base and turn on the motor drive.
The motor drive will
keep the celestial object within the telescope’s field of
view.
Note:
Depending on the accuracy of the alignment
procedure, it may be necessary to use the R.A. and
Slow Motion Controls to make minor adjustments to keep
the celestial object in the field of view.
The motor drive disengages when the R.A. and
lock
levers are unlocked and re-engages when the lock levers
are locked, making it possible for the motor drive to remain
on during the entire observing session.
At the end of an observing session, remember to turn off
the motor drive.
Terrestrial Use of the Field Tripod
In land viewing applications, the three legs of the Field Tripod
may be
an arbitrary orientation. The telescope
mounting, however, should be placed in a horizontal positron:
(Fig.
by turning the fine latitude adjustment knob
to read
unlocking and
the latitude lock
1, to accomplish this adjustment. The
motor drive
should be turned off
applications.
Use the
telescope’s R.A. and
slow-motion controls for fine motion in
horizontal and vertical.
If you have any questions regarding the use of the ETX Field
Tripod,
p l e a s e c a l l M e a d e C u s t o m e r S e r v i c e a t
(949)