5
1. Keeping one hand on the telescope optical tube, loosen
the R.A. lock knob. The telescope should now be able to
rotate freely about the R.A. axis. Rotate it until the coun-
terweight shaft is parallel to the ground (i.e., horizontal).
2. Now loosen the counterweight lock knob and slide the
weight along the shaft until it exactly counterbalances the
telescope. That’s the point at which the shaft remains
horizontal even when you let go with both hands.
3. Retighten the counterweight lock knob. The telescope is
now balanced on the R.A. axis.
4. To balance the telescope on the Dec. axis, first tighten the
R.A. lock knob, with the counterweight shaft still in the
horizontal position.
5. With one hand on the telescope optical tube, loosen the
Dec. lock knob. The telescope should now be able to
rotate freely about the Dec. axis. Loosen the tube ring lock
knob two or three turns, until you can slide the telescope
tube forward and back inside the ring (this can be aided by
using a slight twisting motion on the optical tube while you
push or pull on it).
6. Position the telescope so that it remains horizontal when
you carefully let go with both hands. This is the balance
point for the Dec. axis.
7. Retighten the tube ring lock knob.
The telescope is now balanced on both axes. Hereafter, when
you loosen the lock knobs on the axes and manually point the
telescope, it should move without resistance and not drift from
where you point it.
4. aligning the Finder scope
A finder scope has a wide field of view to facilitate the location
of objects for subsequent viewing through the main tele-
scope, which has a much narrower field of view. The finder
scope and the main telescope must be aligned so they point
to exactly the same spot in the sky.
Alignment is easiest to do in daylight hours. First, insert the
lowest-power (longest focal length) eyepiece into the star
diagonal. Then loosen the R.A. and Dec. lock knobs so the
telescope can be moved freely.
Point the main telescope at a discrete object such as the top
of a telephone pole or a street sign that is at least 200 yards
away. Move the telescope so the target object appears in the
very center of the field of view when you look into the eye-
piece. Now tighten the R.A. and Dec. lock knobs. If the object
moved off center when you tightened the lock knobs, use the
slow-motion control knobs to re-center it in the field of view.
Now look through the finder scope. Is the object centered in
the finder scope’s field of view, i.e., on the crosshairs? If not,
hopefully it will be visible somewhere in the field of view, so
that only fine adjustment of the finder scope alignment screws
will be needed to center it on the crosshairs. Otherwise you’ll
have to make coarser adjustments to the alignment screws to
redirect the aim of the finder scope.
The two spring-tensioned alignment screws on the finder
scope bracket make alignment of the finder scope very easy.
You don’t need to adjust them, only the other four alignment
screws. By loosening one alignment screw and tightening
another, you change the line of sight of the finder scope.
Once the target object is centered on the crosshairs of the
finder scope, look again in the main telescope’s eyepiece and
see if it is still centered there as well. If it isn’t, repeat the
entire process, making sure not to move the main telescope
while adjusting the alignment of the finder scope.
Check the alignment by pointing the main telescope at anoth-
er object and centering it in the finder scope. Then look
through the main telescope eyepiece and see if the object is
centered. If it is, your job is done. If it isn’t, make the neces-
sary adjustments to the finder scope’s alignment screws until
the object is centered in both instruments.
Note that the image seen through the finder scope appears
upside-down. This is normal for astronomical finder scopes.
5. setting up and using
the Equatorial Mount
When you look at the night sky, you have no doubt noticed
that the stars appear to move slowly from east to west over
time. That apparent motion is caused by the Earth’s rotation
(from west to east). An equatorial mount is designed to com-
pensate for that motion, allowing you to easily keep
astronomical objects from drifting out of the telescope’s field
of view when you’re observing them.
The equatorial mount enables you to follow, or track, objects
by slowly rotating the telescope on its right ascension axis,
using only the R.A. slow-motion cable. But first the mount
must be aligned with the Earth’s rotational axis.
For Northern Hemisphere observers, this is achieved by sim-
ply pointing the mount’s R.A. axis at the North Star, or Polaris.
It lies within 1° of the north celestial pole (NCP), which is an
extension of the Earth’s rotational axis out into space. Stars in
the Northern Hemisphere appear to revolve around Polaris.
To find Polaris in the sky, look north and locate the pattern of
the Big Dipper (Figure 2 see pg. 10). The two stars at the end
of the “bowl” of the Big Dipper point right to Polaris.
Observers in the Southern Hemisphere aren’t so fortunate to
have a bright star so near the south celestial pole (SCP). The
star Sigma Octantis lies about 1° from the SCP, but it is
barely visible with the naked eye (magnitude 5.5). Consult a
star atlas or other reference book for instructions on polar-
aligning your telescope in the Southern Hemisphere.
Polar alignment
For general visual observation, an approximate polar align-
ment is sufficient. This must be done at night, when Polaris is
visible.
1. Level the equatorial mount by adjusting the length of the
three tripod legs accordingly.