Orion 120ST EQ, 9005 instruction manual First unthread the two black nylon thumbscrews

on the worm gear shaft. Then tighten the screw.

12.To place the finder scope in the finder scope bracket

(Figure 3), first 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 groove 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 that does not have the alignment

thumbscrews while pulling the chrome, spring-loaded ten-

sioner on the bracket with your fingers. Push the finder

scope through the bracket until the O-ring seats just inside

the front opening of the bracket cylinder. Now, release the

tensioner and tighten the two black nylon thumbscrews a

couple of turns each to secure the finder scope in place.

13.Insert the base of the finder scope bracket into the dove-

tail slot on the top of the focuser. Lock the bracket into

position by tightening the knurled thumbscrew on the

dovetail slot.

14.Remove the cover cap on the end of the focuser. Insert the

chrome barrel of the star diagonal into the focuser and

secure with the thumbscrew on the drawtube.

Objective	Black nylon
lens cell		alignment
Lock ring	thumbscrews
			Eyepiece
Spring-loaded tensioner
Dovetail base

Figure 3. The 6x30 finder scope and bracket.

15.Then insert an eyepiece into the star diagonal and secure

it in place with the thumbscrews on the diagonal. (Always

loosen the thumbscrews before rotating or removing the

diagonal or an eyepiece.)

16.Install the polar axis finder scope into its housing inside

the R.A. axis of the equatorial mount (Figure 4). First

loosen the three thumbscrews on the housing, which is

located at the rear of the R.A. axis. Insert the front end of

the polar finder (the end without the eyeguard) into the

housing so only about 1" of the polar finder extends from

the back of the housing. Do this slowly and with a twisting

motion to prevent the internal O-ring from becoming

unseated. If it does become unseated, you can remove

Date circle

Ring with engraved time meridian indi- cator mark

Polar scope alignment thumbscrew (3)

Pointer

R.A. setting circle

Meridian offset scale

Polar scope housing

Polar axis finder scope

the entire housing from the mount to locate the O-ring and

reseat it. This is done by rotating the entire housing coun-

terclockwise. Once the polar axis finder scope is in the

housing, tighten the three thumbscrews. These thumb-

screws will be used later to align the finder with the

mount’s R.A. axis.

17.Remove the objective lens dust cover.

The AstroView 120ST is now assembled and should appear as pictured in Figure 1.

Figure 4. The polar axis finder scope installed in the right ascension (R.A.) axis of the mount.

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