ORION TELESCOPES & BINOCULARS SKYVIEW PRO 6LT EQ 9872, Instruction Manual

10. Open the tube rings by loosening their clamps and lay the

telescope optical tube in the rings at about the midpoint of
the tube’s length. Rotate the tube so that the focuser is at
a convenient height for viewing. Close the tube rings and
re-tighten the tube ring clamps.

Installing the Finder Scope

To place the finder scope (Figure 3a) in the finder scope brack-
et, unthread the two black nylon thumbscrews until the screw
ends are flush with the inside diameter of the bracket. Place the
O-ring that comes on the base of the bracket over the body of
the finder scope until it seats into the slot on the middle of the
finder scope. Slide the eyepiece end (narrow end) of the finder
scope into the end of the bracket’s cylinder opposite the align-
ment thumbscrews while pulling the chrome, spring-loaded
tensioner on the bracket with your fingers (Figure 3b). Push the
finder scope through the bracket until the O-ring seats just
inside the front opening of the bracket cylinder. Release the
tensioner and tighten the two black nylon thumbscrews a cou-
ple of turns each to secure the finder scope in place. Insert the
base of the finder scope bracket into the dovetail holder on the
top of the focuser. Lock the bracket into position by tightening
the knurled thumbscrew on the dovetail holder.

Inserting the Eyepiece

Loosen the thumbscrews on the focuser and remove the
small dust cap. 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.

4. 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 right ascension (R.A.) axis, then the declination
(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 right ascension axis. Rotate it until the counter-
weight 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 4a). That’s the point at which the
shaft remains horizontal even when you let go with both
hands (Figure 4b).

3. Retighten the counterweight lock knobs. The telescope is

now balanced on the right ascension axis.

4. To balance the telescope on the declination axis, first tight-

en the R.A. lock lever, with the counterweight shaft still in
the horizontal 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. 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 4c).

6. Position the telescope so that the optical tube is horizon-

tal. Let go with both hands. If the optical tube does not
move then you have properly balanced the telescope with
respect to the declination axis (Figure 4d). If the optical
tube does move, then you must adjust the position of the
optical tube in the tube rings until it does balance in the
declination axis.

The telescope is now balanced on both axes. 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.

5. Using Your Telescope

Focusing the Telescope

With the 25mm eyepiece inserted in the focuser, loosen the
R.A. and Dec. lock levers and move the telescope so the front
(open) end is pointing in the general direction of an object at
least 1/4-mile away. Now, with your fingers, slowly rotate one
of the focusing knobs until the object comes into sharp focus.
Go a little bit beyond sharp focus until the image just starts to
blur again, then reverse the rotation of the knob, just to make
sure you’ve hit the exact focus point.

Figure 4. 

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 counterweights 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 knob released, loosen the tube ring lock clamps a few turns ands
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.

5

a.

b.

c.

d.