Specifications - Orion 9931 Instruction Manual

scope. Never use regular glass cleaner or cleaning fluid
designed for eyeglasses. Always apply the fluid to the tissue,
never directly on the optics. Gently wipe the lens, taking care
not to rub too hard. Use lots of tissue on larger lenses. DO
NOT take eyepieces apart for cleaning!
Cleaning First-Surface Mirrors
Cleaning is seldom needed (perhaps once a year) and best
done only when definitely needed. Covering your telescope
will prevent the mirrors from getting dirty. Improper cleaning
can scratch mirror coatings, so don't be too eager to do so.
Small specks of dust or flecks of paint have virtually no affect
on performance, so do not clean your mirror too often. It is too
much trouble for little gain!
The primary mirror and secondary mirror of your telescope
are front-surface aluminized and then overcoated with hard
silicon monoxide, which prevents the aluminum from oxidiz-
ing. These coatings normally last through many, many years
of use before requiring recoating (which is easily done).
The diagonal mirror is more likely to require cleaning, since it
is right up near the eyepiece. It should be cleaned by blowing
dust off first, then wiping gently with cleaning tissue damp-
ened with lens fluid. Be extra gentle when cleaning first-surface
mirrors; be especially careful not to rub grit over the surface.
Very tiny, barely visible "sleeks" are not unusual and don't
affect performance. A sleek will only be visible when looking
from an angle at the mirror, while a scratch will be visible all
the time.
A primary mirror does not need to be spotless to function
properly. The light-gathering surface of the mirror vastly
exceeds the surface area of dust particles that may accumu-
late. When you notice dust particles on the surface of the
mirror, they may be blown off using a blower bulb. However,
there will come a time when the primary mirror will need to be
cleaned; this should be done with care.
Distilled water can be used to cleanse the mirror. Over a sink,
rinse the mirror cell assembly with the distilled water. Hold the
mirror cell assembly at a steep angle so the water will run off
the surface of the mirror. If necessary, dirt and grease smudg-
es can be removed with a wet cotton ball. Use one cotton ball
for every wipe of the mirror.
For a really dirty mirror, or every three to five years, a more
thorough cleaning of the mirror can be undertaken. The mirror
must be separated from the mirror cell assembly: remove the
safety tape wrapping and carefully cut the silicone glue which
holds the mirror to the particle board baking plate. Take extra
precautions not to scratch the mirror during this step.
Fill a dish tub or sink with a gallon of distilled water, add 10
drops of Ivory liquid soap or lens cleaning solution that is safe
10
for multi-coated eyepieces. Soak the mirror, aluminized side
up, for about 10 minutes. Then, with the mirror still under
water, use a cotton ball and gently wipe the mirror. Wipe in
one direction only, and after each wipe discard the cotton ball
and use a fresh one for the next wipe. After the mirror is clean,
rinse with distilled water. Hold the mirror at a steep angle and
use a blower bulb to help the water droplets drain from the
surface; a cotton ball can be used to soak up some of the
excess water. Air dry.
Once dry, clean any remaining silicone from both the back of the
mirror and the particle board backing plate. Use silicone glue (clear
silicone caulking works well) to reattach the mirror to the backing
plate. The mirror cell assembly is now ready to be reinstalled.
With very little maintenance, your Orion Deep Space Explorer
will provide years of viewing pleasure.
Enjoy the view!

9. Specifications

6" DSE
Primary mirror focal length: 1200mm
Primary mirror diameter: 6 inches
Focal ratio: f/8
Weight: 33 lbs. (base 18 lbs., tube assembly 15 lbs.)
Tube length: 50 inches
Power with standard 25mm eyepiece (1.25"): 48x
8" DSE
Primary mirror focal length: 1200mm
Primary mirror diameter: 8 inches
Focal ratio: f/6
Weight: 41 lbs. (base 21 lbs., tube assembly 20 lbs.)
Tube length: 51 inches
Power with standard 25mm eyepiece (1.25"): 48x
10" DSE
Primary mirror focal length: 1140mm
Primary mirror diameter: 10 inches
Focal ratio: f/4.5
Weight: 68 lbs. (base 30 lbs., tube assembly 38 lbs.)
Tube length: 50 inches
Power with standard 25mm eyepiece (1.25"): 46x