ASTRO-PHYSICS 900 Manual

MODEL 900 PARTS LIST
1 Polar axis assembly (right ascension-R.A.) with stepper drive
1 Declination (Dec.) axis assembly with stepper drive
1 Pier top adapter with six (6) 5/16-18 x 5/8" button head screws with washers
(These will be attached to your pier post if you ordered one)
1 Stainless counterweight shaft with washer stop and black plastic knob (knob has 5/16 thread)
1 Dual axis quartz micro-drive control box
1 "Y" connector cable
1 D.C. Power cord (cigarette lighter adapter on one end)
1 Hex key set
1 Piece of Velcro (to attach hand controller to surface of your choice)
1 Polar Axis Telescope Adapter
In order to fully assemble your mount, you will need the following items separately sold: mounting plate, pier,
counterweights, and portable rechargeable battery pack. Several sizes and types are available for your selection.
Many of these items will be discussed throughout these instructions.
Several additional options will help to enhance your observing experience: Polar alignment scope, JMI computerized
digital setting circles, and Santa Barbara Instrument Group ST-4 or ST-6 CCD Imaging camera/autoguider, trays for
your pier and 12 volt rechargeable battery.
INTRODUCTION
We recommend that you familiarize yourself with the
assembly and basic operation of the mount indoors.
The temperature will be comfortable, the mosquitos at
bay, and you'll have enough light to see the illustrations
and read the manual. Please take particular note of
counterbalancing, use of the clutches and operation of
the hand controller.
WHY POLAR ALIGN?
If you were to take a long exposure photograph with
Polaris (often called the North Star) in the center of the
field, you would discover that all stars seem to revolve
around Polaris. This effect is due to the rotation of the
earth on its axis. Motor driven equatorial mounts were
designed to compensate for the earth's rotation by
moving the telescope at the same rate and opposite to
the earth's rotation. When the polar axis of the
telescope is pointed at the celestial pole (polar aligned)
as shown in the diagram to the right, the mount will
follow (track) the motions of the sun, moon, planets,
and stars. As a result, the object that you are
observing will appear motionless as you observe
through the eyepiece or take astrophotos.
For visual observation, a rough sighting of Polaris
through the hole in the polar axis is fine. However if
astrophotography is your goal, accurate polar
alignment is critical.
ASTRO-PHYSICS
MODEL 900 GERMAN EQUATORIAL WITH
DUAL AXIS QUARTZ MICRO-DRIVE (900QMD)
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