Orion ASTROVIEW 9827 - Manual (Page 5)

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top of the focuser. Lock the bracket into position by tightening
the knurled thumbscrew on the dovetail slot.
inserting the Eyepiece
Loosen the thumbscrews on the eyepiece holder and remove
the small dust cap. Then insert the 25mm eyepiece into the
focuser and secure it with the thumbscrews.
Your telescope is now completely assembled and should
appear as shown in Figure 1.
Balancing the telescope
To ensure smooth movement of the telescope on both axes
of the equatorial mount, it is imperative that the optical tube
is properly balanced. We will first balance the telescope with
respect to the R.A. axis, then the Dec. axis.
1. Keeping one hand on the telescope optical tube, loosen
the R.A. lock lever. Make sure the Dec. lock lever is locked, for
now. The telescope should now be able to rotate freely about
the R.A. axis. Rotate it until the counterweight shaft is parallel
to the ground (i.e., horizontal).
2. Now loosen both counterweight lock knobs and slide the
weights along the shaft until they exactly counterbalance the
telescope (Figure 3a). That’s the point at which the shaft remains
horizontal even when you let go with both hands (Figure 3b).
3. Retighten the counterweight lock knobs. 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 lever, with the counterweight shaft still in the hori-
zontal position.
5. With one hand on the telescope optical tube, loosen the Dec.
lock lever. The telescope should now be able to rotate freely
about the Dec. axis.
6. Loosen the tube ring clamps a few turns, until you can slide
the telescope tube forward and back inside the rings. (this can
be aided by using a slight twisting motion on the optical tube
while you push or pull on it). (Figure 3c).
7. Position the telescope in the mounting rings so it remains
horizontal when you carefully let go with both hands. This is
the balance point for the optical tube with respect to the Dec.
axis (Figure 3d).
8. Retighten the tube ring clamps.
The telescope is now balanced on both axes. Now when you
loosen the lock lever on one or both axes and manually point
the telescope, it should move without resistance and should
not drift from where you point it.
3. using Your telescope
Focusing the telescope
You should now try to familiarize yourself with focusing the
telescope. First, insert the 25mm eyepiece in the focuser and
point the telescope in the general direction of an object at
least a 1/4 mile away. With your fingers, slowly rotate one of
the focus knobs until the object comes into sharp focus. Go
a little bit beyond sharp focus until the object starts to blur
again, then reverse the direction of the knob, just to make
sure you’ve hit the exact focus point.
NOTE: The image in the telescope will appear rotated 180°
(upside-down and reversed left-to-right). This is normal
for astronomical scopes. The finder scope view will also
be rotated 180°. (see Figure 4)
If you have trouble focusing, rotate the focus knob so the draw-
tube is in as far as it will go. Now look through the eyepiece
while slowly rotating the focusing knob in the opposite direc-
tion. You should soon see the point at which focus is reached.
You will have to re-adjust the focus when aiming at subjects of
varying distances, or after changing eyepieces.
Viewing with Eyeglasses
If you wear eyeglasses, you may able to keep them on while
you observe, if the eyepiece has enough “eye relief” to allow
you to see the whole field of view. You can try this by looking
through the eyepiece first with your glasses on, and then with
them off, and see if the glasses restrict the view to only a
portion of the full field. If they do, you can easily observe with
your glasses off by just re-focusing the telescope the needed
amount. If you suffer from severe astigmatism, however, you
may find images noticeably sharper with your glasses on.
Figure 3a, b, c, d: Proper operation of the equatorial mount requires
that the telescope tube be balanced on both the R.A. and Dec. axes.
(a) With the R.A. lock lever released, slide the counterweight along
the counterweight shaft until it just counterbalances the tube. (b)
When you let go with both hands, the-tube should not drift up or
down. (c) With the Dec. lock lever released, loosen the tube ting
clamps a few turns and slide the telescope forward or back in the
tube rings. (d) when the tube is balanced about the Dec. axis, it will
not move when you let go.
Figure 3a Figure 3b Figure 3c Figure 3d