10
will allow you to view through the mount with the polar axis
finder scope.
3. Remove the cap on the front of the equatorial mount (Figure
8). Focus the polar finder by rotating the eyepiece. Now,
sight Polaris in the polar axis finder scope. If you have fol
lowed the approximate polar alignment procedure accurate-
ly, Polaris will probably be within the field of view. If not,
move the tripod left-to-right, and adjust the latitude up-and
down (using the latitude adjustment L-bolts) until Polaris is
somewhere within the field of view of the polar axis finder
scope.
4. Shine a red flashlight down the front end of the polar finder
to illuminate the reticle within the field of view. Make sure
the flashlight shines in at an angle, so as not to block the
polar finder’s field of view. It may be helpful to have a friend
hold the flashlight while you look through the polar finder.
Note the constellation Cassiopeia and the Big Dipper in the
reticle. They do not appear in scale, but they indicate the
general positions of Cassiopeia and the Big Dipper relative
to the north celestial pole (which is indicated by the cross
at the center of the reticle). Rotate the reticle so the con-
stellations depicted match their current orientation in they
sky when viewed with the naked eye. To do this, release the
R.A. lock lever and rotate the main telescope about the
R.A. axis until the reticle is oriented with sky. For larger opti-
cal tubes, you may need to remove the tube from the mount
to prevent it from bumping into the tripod. Once the reticle
is correctly oriented, use the right ascension lock lever to
secure the mount's position.
5. Now use the azimuth adjustment knobs (Figure 10) and the
latitude adjustment L-bolts (Figure 8) on the mount to posi-
tion the star Polaris inside the tiny circle marked “Polaris”
on the finder’s reticle. You must first loosen the knob under
neath the equatorial mount on the center support shaft to
use the azimuth adjustment knobs. Once Polaris is proper-
ly positioned within the reticle, you are precisely polar
aligned. Retighten the knob underneath the equatorial
mount.
From this point on in your observing session, you should not
make any further adjustments in the azimuth or the latitude
of the mount, nor should you move the tripod. Doing so will
undo the polar alignment. The telescope should be moved
only about its right ascension and declination axes.
additional note regarding Focusing the Polar
axis Finder scope
The polar axis finder scope is normally focused by simply
rotating the eyepiece focus ring. However, if after adjusting
the focus ring you find that the image of the reticle is sharp,
but the stars are out of focus, then you must adjust the focus
of the polar axis finder's objective lens. To do this, first remove
the polar axis finder from the mount. Look through the polar
axis finder at a star (at night) or distant object at least 1/4 mile
away (during daylight). Use the eyepiece focus ring to bring
the reticle into sharp focus. Now, loosen the focus lock ring
(Figure 11a) and thread the entire objective end of the finder
inwards or outwards until images appear sharp. Re-tighten
the focus lock ring. Once the polar axis finder's objective lens
is focused, it should not need to be adjusted again.
use of the right ascension and Declination
slow‑Motion control Knobs
The right ascension (R.A.) and declination (Dec.) slow-motion
control knobs allow fine adjustment of the telescope’s posi-
tion to center objects within the field of view. Before you can
use the knobs, you must manually “slew” the mount to point
the telescope in the vicinity of the desired target. Do this
by loosening the R.A. and Dec. lock levers and moving the
telescope about the mount’s right ascension and declination
axes. Once the telescope is pointed close to the object to be
viewed, retighten both lock levers.
Note: If you have an optional motor drive attached, you
will need to loosen the manual clutch on the R.A. (and
Dec. for dual-axis drives) worm gear shaft before using
the slow-motion control knob.
The object should now be visible somewhere in the tele-
scope’s finder scope. If it isn’t, use the slow-motion knobs to
scan the surrounding area of sky. When the object is visible in
the finder scope, use the slow-motion knobs to center it. Now,
look in the telescope’s eyepiece. If the finder scope is prop-
erly aligned, the object should be visible somewhere in the
field of view. Once the object is visible in the eyepiece, use
the slow-motion knobs to center it in the field of view.
tracking celestial objects
When you observe a celestial object through the telescope,
you’ll see it drift slowly across the field of view. To keep it in
the field, if your equatorial mount is polar aligned, just turn
the R.A. slow-motion control knob clockwise. The Dec. slow-
motion control knob is not needed for tracking. Objects will
Figure 12.
The optical tube must be at a 90° angle to the right
ascension axis in order to view through the polar axis finder.
