Orion Argonaut 6 9068, Argonaut 6"" Maksutov-Newtonian, 9068, 21481 Instruction Manual

IN 104 Rev.B 0199

Providing Exceptional Consumer Optical Products Since 1975

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

Corporate Offices [phone]
P.O. Box 1815, Santa Cruz, CA 95061

INSTRUCTION MANUAL

Orion

®

Argonaut

™

6"

Maksutov-Newtonian

#9068 Optical Tube Assembly

#21481 With GP-DX Equatorial Mount

2

1. Parts List

Qty. Description
1 Optical tube assembly
1 10x50 finder scope
1 Finder scope bracket
2 Tube mounting rings
1 Standard mounting plate
1 Dust cover
If you purchased the #21481 package, the following items

should also be included (in one or more additional boxes):
1 GP-DX equatorial mount
1 Aluminum tripod
1 Dovetail mounting plate
1 Extra 8.1-lb. counterweight
2 6mmx1 socket head cap screws

2. Unpacking and Assembly

Exercise care when unpacking the shipping box(es). We rec­ommend keeping the original shipping box and packing
materials; in the event the telescope needs to be shipped to
another location or returned to Orion for warranty repair, hav­ing the proper shipping container will help ensure that your
telescope will survive the journey intact.

The only assembly required for the Argonaut 6" optical tube is
to attach the finder scope bracket (the finder scope comes
already installed in the bracket. Locate the mounting block
adjacent to the telescope’s focuser. Line up the tab on the bot­tom of the finder bracket base with the slot on the mounting
block. Thread the thumbscrew on the base of the bracket into
the threaded hole on the mounting block until tight. Make sure
the finder scope is positioned in the bracket so the wide (objec­tive) end points toward the front of the telescope; you may have
to remove the finder scope from the bracket and turn it around.
Do so by first loosening all the nylon adjustment screws.

If you have purchased the package with the GP-DX mount,
refer to the instructions that come with the mount in order to
assemble it. Before the telescope can be attached to the GP­DX mount, the optical tube will need to be connected to the
dovetail mounting plate. First, remove the standard mounting
plate that is already attached to the tube rings. Use a 5mm
Allen wrench to unthread the four socket head cap screws.
Locate the two 6mmx1 socket head cap screws that are
included with the package. These are not the screws that
come taped to the dovetail mounting plate; those screws
have no purpose here, and may be discarded. Attach the
dovetail mounting plate to the tube rings with the 6mmx1
screws. Of the three holes on the bottom of each tube mount­ing ring, use the one that is in the center. You will need to
position the tube rings slightly closer to each other in order to
achieve the hole spacing on the dovetail bracket. This is done
by loosening the tube ring lock knob on the side of the ring,

C

ongratulations on purchasing an Orion telescope!

The Argonaut 6" Maksutov-Newtonian is a preci­sion instrument designed for high-performance astronomical observation. With its Maksutov-Newtonian
optical system expertly crafted in Russia, you’ll enjoy exquisite views of countless celestial objects.
These instructions will help you properly use and care for your telescope. Please read them over thor­oughly before getting started.

Table of Contents

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

2. Unpacking and Assembly....................................................................................................... 3

3. The Optics .............................................................................................................................. 4

4. Using the Telescope ............................................................................................................... 5

5. Care and Maintenance........................................................................................................... 6

6. Specifications.......................................................................................................................... 6

7. Suggested Accessories.......................................................................................................... 6

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.

3

and then moving the ring down the telescope optical tube
until properly positioned. Retighten the tube ring lock knob
when done. Attach the dovetail mounting plate so that the
smooth, flat side of it faces the telescope optical tube.

Now that the dovetail mounting plate is attached to the tube
rings, the optical tube fits into the dovetail slot on the head of
the GP-DX mount. Make sure both included counterweights
are placed on the counterweight shaft; both weights are nec­essary to properly balance the load. Secure the optical tube
in place with the dovetail tube plate lock screw. Also tighten
the knurled metal safety screw. Refer to the manual that
comes with the GP-DX mount for instructions on how to bal­ance and properly use the mount.

3. The Optics

The Maksutov-Newtonian optical design yields exquisite,
refractor-like images yet has a much more compact optical
tube than an equivalent 6" refractor. It employs a spherical
primary mirror. A spherical mirror of this aperture would, by
itself, yield an unacceptable degree of spherical aberration,
so the design incorporates a deeply concave “corrector” lens,
often called a “meniscus,” at the front of the scope. This lens,
at the center of which the secondary mirror holder is mount­ed, provides sufficient correction to render a sharp,
undistorted image. The diameter of the central obstruction
has also been minimized to further increase image contrast.

The purplish tint of the meniscus is caused by multi-layer
coatings that have been applied to the surfaces of the glass
to enhance light transmission and image contrast.

Collimation

Collimation is the process of adjusting the optical compo­nents of a telescope so they are perfectly aligned with each
other. Your telescope’s optics were aligned at the
factory, and should not need much adjustment unless the
telescope was roughly handled during shipment. You will
never need to adjust the positioning of the front corrector
lens; only the primary and secondary mirrors. Accurate align­ment is important to insure the peak performance of your
telescope, so it should be checked occasionally. Collimation
of the mirrors is easy to do and should be done in daylight.

To check the collimation, remove the eyepiece and look
straight down the focuser drawtube. Turn the focus knob until
the drawtube is in its most recessed position, and hold your
eye just above the end of the drawtube. Make sure you are
looking straight down the focuser, or your adjustments will not
be correct. You should see the secondary mirror centered in
the drawtube, the reflection of the primary mirror centered in
the secondary mirror, and the reflection of the secondary mir­ror centered in the reflection of the primary mirror (behind the
reflection of the primary mirror’s central black circle), as in
Figure 1D, page 7. If anything is off-center, follow the
collimation procedure below.

Use a Collimation Tool

To aid in centering your line of sight down the focuser draw­tube, and in centering the mirror reflections during collimation,
it is very helpful to use a precision collimating tool containing
crosshairs, such as the Orion Collimating Eyepiece #3640.
We highly recommend you purchase one.

Aligning the Secondary Mirror

With the eyepiece removed, look straight down the open
focuser drawtube at the secondary (diagonal) mirror. It helps
to adjust the secondary mirror in a brightly lit room with the
telescope pointed toward a bright surface, such as white
paper or a wall. Ignoring the reflections, the secondary mirror
itself should be centered in the field of view. If it isn’t, it must
be returned to Orion Telescopes to be adjusted, as this can­not be corrected by the user. This has been checked during
assembly at the factory, so there should not be a problem.

If the entire primary mirror reflection is not visible in the sec­ondary mirror (as it is not in Figure 1B), you will need to adjust
the tilt of the secondary mirror. This is done by alternately
loosening one of the three alignment screws visible in the
center of the corrector lens a turn or two and tightening anoth­er one. You will need a flat-head screwdriver to do this. (Do
not adjust the central Phillips-head screw!) The goal is to cen­ter the primary mirror reflection in the secondary mirror, as
depicted in Figure 1C. Don’t worry that the reflection of the
secondary mirror (the smallest circle, with your eye reflected
in it) is off-center behind the reflection of the primary’s central
black circle (as also is the case in Figure 1C); you will fix that
in the next step.

Adjusting the Primary Mirror

The final adjustment is made to the primary mirror. It will need
adjustment if, as in Figure 1C, the secondary mirror is cen­tered under the focuser and the reflection of the primary
mirror is centered in the secondary mirror, but the small
reflection of the secondary mirror (with your eye inside) is off­center behind the reflection of the black circle in the center of
the primary. The tilt of the primary mirror is adjusted with the
three sets of collimation screws on the back end of the opti­cal tube (bottom of the mirror cell). The collimation screws
can be turned with Allen-head wrenches.

Each set of collimation screws works together to adjust the
tilt. The smaller screw pushes the mirror cell forward, while
the larger screw pulls the mirror cell back. One must be loos­ened and the other tightened by the same amount to adjust
the tilt. Try tightening and loosening one set of collimation
screws one turn. Look into the focuser and see if the sec­ondary mirror reflection has moved closer to the center of the
primary mirror reflection. Repeat this process on the other
two sets of collimation screws, if necessary. It will take a little
trial and error to get a feel for how to tilt the mirror in this way
to center the reflection. (It helps to have two people for pri­mary mirror collimation, one to look in the focuser while the
other adjusts the collimation screws.)

The view through the Collimating Eyepiece should now
resemble Figure 1D. The secondary mirror is centered in the
focuser; the reflection of the primary mirror is centered in the