ORION TELESCOPES & BINOCULARS Observer 70mm EQ 9802 Instruction Manual

IN 096 Rev. A 0898

Providing Exceptional Consumer Optical Products Since 1975

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INSTRUCTION MANUAL

Orion

®

Observer

™

70mm EQ

#9802 Equatorial Refracting Telescope

Tube rings

Tube ring clamps

Finder scope

Finder scope bracket

Finder scope alignment

screws (3)

Focuser drawtube

Eyepiece

Star diagonal

Focus knob

Declination slow-motion control

Declination lock knob

Latitude lock knob (hidden)

Latitude scale

Right ascension setting circle

Right ascension

slow-motion control

Tripod leg

Leg lock thumbscrew

Objective lens
Dew shield
Tube ring mounting bolt
Declination setting circle

Right ascension lock knob (hidden)
Counterweight shaft

Counterweight
Counterweight lock knob

Retaining washer and screw
Azimuth lock knob (hidden)
Tripod leg attachment bolt

Accessary tray bracket
Accessory tray

2

Figure 1. Observer 70 EQ Parts Diagram

3

C

ongratulations on your purchase of a quality Orion telescope.

Your new Observer 70 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 before, we would like 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 and 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.......................................................................................................4

4. Aligning the Finder Scope .................................................................................................... 5

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

6. Using the Telescope—Astronomical Viewing ....................................................................... 6

7. Terrestrial Viewing ................................................................................................................ 9

8. Care and Maintenance......................................................................................................... 9

9. Specifications........................................................................................................................ 9

10. Suggested Accessories ........................................................................................................9

1. Parts List

Qty. Description
1 Optical tube assembly
1 German-type equatorial mount
2 Slow-motion control cables
1 5x crosshair finder scope
1 Finder scope bracket
1 Counterweight
1 Counterweight shaft
1 25mm (36x) Kellner eyepiece (1.25")
1 90° mirror star diagonal
1 Tripod accessory tray
3 Tripod legs
3 Accessory tray screws with wing nuts and washers
1 Objective lens cap

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. Be sure to also cover
the front of the finder scope with aluminum
foil or another opaque material to prevent
physical damage to the internal
components of the scope itself as well as to
your eye. Young children should use this
telescope only with adult supervision.

4

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 during the warranty period,
you must use the original packaging.

Assembling the telescope should take only about 15 minutes.
Be careful not to overtighten screws and bolts or the threads
may strip.

During assembly (and anytime, for that matter), DO NOT
touch any of the lenses of the telescope, finder scope, or eye­pieces, or the mirror of the diagonal, with your fingers. The
optical surfaces have delicate coatings on them that can 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 base of the mount by sliding the tripod
leg bolt into the hole in the mount and lightly tightening the
wing nut finger-tight. (Use the screwdriver tool provided
on the head of the bolt while tightening the wing nut.) Note
that the hinged accessory tray bracket on each leg should
face inward.

2. Thread the three thumbscrews into the lower leg joints.
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 equatorial mount attached, stand the tripod upright
and spread the legs apart enough to attach the accessory
tray to the three hinged tray brackets on the legs. The
brackets should be positioned underneath the tray. Use the
three small accessory tray screws and wing nuts and wash­ers provided. Do not tighten the wing nuts yet.

4. Now, with the accessory tray attached but not tightened,
spread the tripod legs apart as far as they will go, until the
accessory tray brackets are taut. Then tighten the wing
nuts of the accessory tray screws.

5. Next, tighten the wing nuts of the tripod leg bolts at the
base of the equatorial mount.

6. Orient the equatorial mount as it appears in Figure 1, with
the latitude scale set at about a 40° angle. Tighten the lat­itude adjustment knob, the declination (Dec.) and right
ascension (R.A.) lock knobs, and the azimuth lock knob all
finger-tight.

7. Slide the counterweight on to the counterweight shaft.
Make sure that the screw that holds the retaining washer
at the bottom end of the shaft is tightened. This washer
will prevent the counterweight from slipping off the shaft
and possibly onto your foot if the counterweight lock knob
should come loose! Now, with the counterweight lock
knob loose, hold the counterweight in one hand and the
thread the shaft into the equatorial mount (base of decli­nation axis) with the other hand. When it is threaded all
the way in, position the counterweight about halfway up
the shaft and tighten the counterweight lock knob.

8. Remove the tube rings from the telescope tube. Attach the
ring to the equatorial head with the two hex-head bolts
provided. Then lay the telescope tube in the (open) tube
rings, with the rings about midway along the tube’s length,
as in Figure 1. (Note that the Dec. slow-motion shaft,
where the Dec. slow-motion control cable attaches,
should be pointing back toward the eyepiece end of the
telescope. If it isn’t, remove the telescope optical tube,
loosen the Dec. lock knob, and rotate the equatorial head
180° on the Dec. axis.) Now close the tube rings over the
optical tube and tighten the tube ring clamps finger-tight to
secure the telescope.

9. Now attach the two slow-motion cables to the R.A. and
Dec. slow-motion shafts of the equatorial mount by posi­tioning the setscrew on the end of the cable over the
indented slot on the shaft, then tightening the setscrew.

10.Attach the finder scope bracket to the optical tube over the
two pre-installed bolts located near the focuser. It doesn’t
matter whether the slanted bracket stem slants forward or
backward; choose whichever orientation you like. Secure
the bracket in place with the two round thumbscrews. Do
not loosen the two small hex nuts at the base of the bolts,
as they keep them from falling into the optical tube.

11.Install the finder scope in the bracket. To do this, first
unscrew the three alignment screws a few turns so they
don’t hinder insertion of the finder scope. The larger,
objective lens of the finder scope should face the same
direction as the objective lens of the main telescope. Then
lightly tighten the three alignment screws until the finder
scope is held securely.

12.Insert the chrome barrel of the star diagonal into the
focuser drawtube and secure with the thumbscrew on the
focuser drawtube.

13.Then insert the eyepiece into the star diagonal and secure
it in place with the thumbscrew on the diagonal. (Always
loosen the thumbscrews before rotating or removing the
diagonal or an eyepiece.)

3. Balancing the Telescope

To insure smooth movement of the telescope on both axes of
the equatorial mount, it is imperative that the optical tube be
properly balanced. We will first balance the telescope on the
R.A. axis, then on the Dec. axis.

1. Keeping one hand on the telescope optical tube, loosen
the R.A. lock knob. 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 the counterweight lock knob and slide the
weight along the shaft until it exactly counterbalances the
telescope. That’s the point at which the shaft remains hor­izontal even when you let go with both hands.

3. Retighten the counterweight lock knob. The telescope is
now balanced on the R.A. axis.