Orion 9005, 120ST EQ User Manual

INSTRUCTION MANUAL

Orion®

AstroView

#9005 Equatorial Refracting Telescope

™

120ST EQ

Providing Exceptional Consumer Optical Products Since 1975

Customer Support [phone]
E-mail: [e-mail]

Corporate Offices [phone]

89 Hangar Way, Watsonville, CA 95076

IN 155 Rev. B 02/09

Tube rings
Objective lens cell
Dew cap/lens shade

Declination lock lever

Large counterweight

Small counterweight

Counterweight lock knobs
Counterweight shaft

“Toe saver”

Tripod leg

Accessory tray attachment point

Finder scope

Finder bracket

Focus knob

Eyepiece

Star diagonal

Right Ascension slow-motion control

Declination slow-motion control

Right Ascension lock lever

Polar axis finder scope

Latitude adjustment T-bolts

Accessory tray bracket
Accessory tray

Leg lock knob

Figure 1. The AstroView 120ST EQ Refractor

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Congratulations on your purchase of a quality Orion telescope! Your new AstroView 120ST EQ Refractor

is designed for high-resolution viewing of astronomical objects. With its precision optics and equatorial
mount, you’ll be able to locate and enjoy hundreds of fascinating celestial denizens, including the plan­ets, Moon, and a variety of deep-sky galaxies, nebulas, and star clusters.

If you have never owned a telescope, we are pleased to welcome you to amateur astronomy. Take some
time to familiarize yourself with the night sky. Learn to recognize the patterns of stars in the major con­stellations; a star wheel, or planisphere, available from Orion or from your local telescope shop, will
greatly help. With a little practice, a little patience, and a reasonably dark sky away from city lights, you’ll
find your telescope to be a never-ending source of wonder, exploration, and relaxation.

These instructions will help you set up, properly use and care for your telescope. Please read them over
thoroughly before getting started.

Table of Contents

1. Parts List .............................................................................................................................. 3

2. Assembly ............................................................................................................................. 4

3. Balancing the Telescope ...................................................................................................... 6

4. Aligning the Finder Scope ................................................................................................... 7

5. Setting Up and Using the Equatorial Mount ........................................................................ 7

6. Using Your Telescope–Astronomical Observing .................................................................. 11

7. Astrophotography ................................................................................................................. 14

8. Terrestrial Viewing ................................................................................................................ 15

9. Care and Maintenance ........................................................................................................ 15

10. Specifications ....................................................................................................................... 16

1. Parts List

Qty. Description

1 Optical tube assembly

1 German-type equatorial mount

1 Large counterweight

1 Small counterweight

1 Counterweight shaft

3 Tripod Legs with mounting hardware

1 Accessory tray with mounting hardware

1 Accessory tray bracket

2 Slow-motion control cables

1 Polar axis finder scope

1 Plastic cover for polar axis finder scope

2 Optical tube mounting rings

1 6x30 achromatic crosshair finder scope

1 Finder scope bracket with O-ring

1 Mirror star diagonal (1.25")

1 25mm (40x) Plössl eyepiece (1.25")

1 10mm (100x) Plössl eyepiece (1.25")

1 Dust cap

4 Assembly Tools (2 wrenches, Phillips screwdriver,
flat-head screwdriver key)

WARNING: Never look directly at the Sun

through your telescope or its finder scope—
even for an instant—without a professionally
made solar filter that completely covers the front
of the instrument, or permanent eye damage
could result. Young children should use this
telescope only with adult supervision.

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2. Assembly

Carefully open all of the boxes in the shipping container. Make
sure all the parts listed in Section 1 are present. Save the
boxes and packaging material. In the unlikely event that you
need to return the telescope, you must use the original packag­ing.

Assembling the telescope for the first time should take about
30 minutes. No tools are needed, other than the ones pro­vided. All bolts should be tightened securely to eliminate
flexing and wobbling, but be careful not to over-tighten or the
threads may strip. Refer to Figure 1 during the assembly pro­cess.

During assembly (and anytime, for that matter), DO NOT
touch the surfaces of the telescope objective lens or the
lenses of the finder scope or eyepieces with your fingers. The
optical surfaces have delicate coatings on them that can eas­ily be damaged if touched inappropriately. NEVER remove
any lens assembly from its housing for any reason, or the
product warranty and return policy will be voided.

1. Lay the equatorial mount on its side. Attach the tripod legs
one at a time to the mount using the bolts installed in the
tops of the tripod legs. Remove the bolt from the leg, line
up the holes in the top of the leg with the holes in the base
of the mount, and reinstall the bolt so it passes through
the leg and the mount. Tighten the wingnuts only finger­tight, for now. Note that the accessory tray bracket
attachment point on each leg should face inward.

2. Tighten the leg lock knobs at the base of the tripod legs.
For now, keep the legs at their shortest (fully retracted)
length; you can extend them to a more desirable length
later, after the scope is completely assembled.

3. With the tripod legs now attached to the equatorial mount,
stand the tripod upright (be careful!) and spread the legs
apart enough to connect each end of the accessory tray
bracket to the attachment point on each leg. Use the
screw that comes installed in each attachment point to do
this. First remove the screw using the supplied screw­driver, then line up one of the ends of the bracket with the
attachment point and reinstall the screw. Make sure the
smooth side of the accessory tray bracket faces up.

4. Now, with the accessory tray bracket attached, spread the
tripod legs apart as far as they will go, until the bracket is
taut. Attach the accessory tray to the brackets with the
three wingnut-head screws already installed in the tray.
Push the screws up through the holes in the bracket, then
thread them into the holes in the tray.

5. Next, tighten the wingnuts at the top of the tripod legs, so
the legs are securely fastened to the equatorial mount.
Use the larger wrench and your fingers to do this.

6. Orient the equatorial mount as it appears in Figure 1, at a
latitude of about 40°, i.e., so the pointer next to the latitude
scale (located directly above the Orion logo on one side of
the mount) is pointing to the line at “40.” To do this, loosen
one of the latitude adjusting T-bolts and then tighten the
other latitude adjusting T-bolt until the pointer and the “40”

Figure 2: To adjust the latitude angle of the equatorial mount, loosen
one of the two latitude adjustment T-bolts, then tighten the other.

line up (Figure 2). The declination (Dec.) and right ascen­sion (R.A.) axes many need re-positioning (rotation) as
well. Be sure to loosen the RA and Dec. lock levers before
doing this. Retighten them once the equatorial mount is
properly oriented.

7. Thread the counterweight shaft into the equatorial mount
at the base of the declination axis until tight. Make sure
the casting at the top of the bar is threaded clockwise as
far as it will go before attaching the shaft.

8. Remove the knurled “toe saver” retaining screw on the
bottom of the counterweight shaft and slide both counter­weights onto the shaft. Make sure the counterweight lock
knobs are adequately loosened so the metal pin inside the
counterweight is recessed enough to allow the counter­weight shaft to pass through the hole. Position the
counterweights about halfway up the shaft and tighten the
lock knobs. Replace the toe saver on the end of the bar. It
prevents the counterweights from falling on your foot if the
lock knobs happen to come loose.

9. Attach the two tube rings to the equatorial head using the
bolts that come installed in the rings. Remove the bolts, then
push them, with the washers still attached, up through the
holes in the tube ring mounting plate (on the top of the equa­torial mount) and rethread them into the bottom of the tube
rings. Tighten the bolts securely with the smaller wrench.
Open the tube rings by loosening the knurled ring clamps.

10. Lay the telescope optical tube in the tube rings at about the
midpoint of the tube’s length. Rotate the tube in the rings
so the focus knobs are on the underside of the telescope.
Close the rings over the tube and tighten the knurled ring
clamps finger-tight to secure the telescope in position.

11. Now attach the two slow-motion cables to the R.A. and Dec.
worm gear shafts of the equatorial mount by positioning the
small screw on the end of the cable over the indented slot

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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 ten­sioner 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 dove­tail 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.

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
the entire housing from the mount to locate the O-ring and
reseat it. This is done by rotating the entire housing coun­terclockwise. Once the polar axis finder scope is in the
housing, tighten the three thumbscrews. These thumb­screws 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.

Objective
lens cell

Lock ring

Spring-loaded tensioner

Dovetail base

Figure 3. The 6x30 finder scope and bracket.

Date circle

Ring with engraved
time meridian indi­cator mark

Polar scope
alignment
thumbscrew (3)

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

R.A. setting circle

offset scale

Polar scope

finder scope

Black nylon

alignment

thumbscrews

Eyepiece

Pointer

Meridian

housing

Polar axis

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