Bushnell 78-8831, 78-8846 Telescope User Manual


 
6
DETAILED ASSEMBLY
No tools are required for assembly of your telescope.
Remove all components from the carton and identify all components. It is a good idea to lay all the parts out in front of you
before assembly. Since your telescope is a precision optical system the parts require careful handlingparticularly the onboard
computer, telescope, eyepieces, and various accessory lenses.
SET UP TRIPOD AND ACCESSORY TRAY
1. Stand Northstar Computerized Star Locator Assembly and attached tripod legs in
the upright position. Spread tripod legs to a comfortable distance.
2. Fold down the accessory tray braces and place the Quick Release Accessory
Tray on top of braces. (See Quick Assembly Diagram)
3. Turn accessory tray until it snaps into place.
4. Adjust tripod leg height to suit by opening tripod leg lever and extending tripod legs
to desired height. Clamp Tripod Leg lever closed when complete.
ATTACH TELESCOPE TUBE
1. Locate Main Telescope Tube.
2. Remove Telescope Tube Thumb Nuts from side of Telescope Tube.
(See Quick Assembly Diagram)
3. Position Main Telescope Tube Attachment Bolts through Telescope Tube Bracket at the top of the Northstar
Computerized Star Locator Assembly. Make sure the telescope is pointing in the correct direction. (Logo on
telescope tube should be right-side up.)
4. Reattach Telescope Tube Thumb Nuts to Main Telescope Tube Attachment Bolts once Main Telescope Tube and
Northstar Computerized Star Locator Assembly are assembled together.
ATTACH FINAL TELESCOPE ACCESSORIES
1. Locate Red Dot Finderscope.
For Reflector Telescopes: Remove Finderscope attachment nuts from Main Telescope Tube. Place Finderscope
Assembly over Finderscope Attachment Bolts and reattach Finderscope thumb nuts to Finderscope Mount Bolts.
NOTE: The large end of the finderscope should face the open end of telescope tube.
2. Attach Low Power Eyepiece.
For Reflector Telescope Models: Insert lowest power eyepiece in the focusing mechanism by backing out
eyepiece set screw and inserting eyepiece fully.
3. Tighten all set screws to secure accessories.
4. Remove Objective Dust Cover exposing entire diameter of open end of telescope.
SELECTING AN EYEPIECE
You should always start viewing with the lowest power eyepiece, which in this case is the 20 mm lens. Note: the base power
of each eyepiece is determined by the focal length of the telescope objective lens. A formula can be used to determine the
power of each eyepiece: telescope OBJECTIVE lens focal length divided by EYEPIECE focal length = MAGNIFICATION (e.g.
Using the 20 mm lens, a sample calculation could look like this: 750 mm / 20 = 38x or 38 power. Telescope models will
vary in focal length.)
Included with this telescope is a Barlow lens. Barlow lenses are used to double or triple the power of your telescope. Place
your Barlow between the focusing tube and the eyepiece. Using the example above, your 3x Barlow lens would give you a
total power of 114x or 114 power. (38 x 3 = 114x or 114 power). The magnification calculation would look like this: 750
mm /20mm = 38 power. 38 power x 3=114 power.