Orion 9738 instruction manual Balancing the Telescope, Inserting the Eyepiece

Models: 9738

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Figure 3b. Pullback on the tensioner and slide the finder scope into its bracket until the O-ring is seated in the bracket ring.

Inserting the Eyepiece

Loosen the thumbscrew on the 1.25" adapter (Figure 4) and remove the small dust cap. Insert the 25mm eyepiece into the focuser and secure it with the thumbscrew.

Your telescope is now completely assembled and should appear as shown in Figure 1.

1.25"

 

2" eyepiece

eyepiece

adapter

adapter

 

 

Focus lock thumbscrew

Focus knobs

Collimation screw pair (3)

Figure 4. The 2" focuser of the SkyView Pro 8 EQ.

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 5a). That’s the point at which the shaft remains horizontal even when you let go with both hands (Figure 5b).

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 5c).

6.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 5d)

7.Retighten the tube ring clamps.

The telescope is now balanced on both axes. When you loos- en 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.

 

a.

b.

c.

d.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Orion 9738 instruction manual Balancing the Telescope, Inserting the Eyepiece