SKY-WATCHER S11670 User Manual page 15

The Polar Alignment Finderscope or 'polarscope' gives Northern Hemisphere users a convenient tool for pointing
at the NCP. It has a large circle circumscribing the path of Polaris, with the NCP located at the crosshair, and it
has a smaller circle to indicate the direction of Polaris. However, the Earth rotates and the orientation of the stars
changes, so a method is needed to obtain the correct alignment of Polaris in the polarscope, for the date and
time of your viewing session.
Aligning the polarscope to the mount's polar axis:
This is most easily done by pointing at a terrestrial
target with the RA drive turned off. To allow full rotation
around the RA axis, remove the telescope and the
counterweight, including the rod. Unlock the Dec
clutch and rotate to Dec 0°, then lock the Dec clutch.
Remove the cap from the bottom of the RA axis shaft
and the plug from the top (Fig.k, EQ5 shown here).
At the bottom of the polar shaft is a black, 24-hour
clock dial. The top row of numbers is for Northern
Hemisphere use, the lower for the Southern
Hemisphere. Unlock the setscrew just above it and
rotate the dial until zero is aligned with the indicator
cast into the metal just below the screw. Tighten the
setscrew to lock the dial (Fig.k1).
The silver dial just below it is a calendar dial. The
months are numbered 1-12. The longest lines
separate the months, the middle-length lines are ten
days apart, and the short lines between them are two
days apart.
The black collar holding this silver dial in place, has an
indicator line inscribed on it. The numbers nearest this
collar are marked "E 20 10 0 10 20 W". These will be
explained later, but for now rotate the silver dial until
the middle zero is aligned with the indicator line on the
black collar.
At midnight on November 1, on the Central Meridian of
your local time zone, Polaris is directly above the NCP.
It is therefore directly below when viewed through the
inverted view of the polarscope. This provides a good
way to orient the polarscope in the mount.
Unlock the R.A. clutch and rotate the mount in R.A.
until 'November 1' (long line between 10 and 11) on
the calendar dial is lined up with '0' (midnight) on the
24-hour clock dial, then lock the clutch again (Fig.k2).
Loosen the three polarscope alignment screws.
Look into the polarscope and you will see the Polaris
Location Indicator diagram. Locate a smaller circle
(Polaris written next to it) off on the big circle (Fig.k3).
Turn the polarscope until the little offset circle is at the
bottom and then slide it into the polarscope holder,
lined up with the zero on the clock dial. Insert the
polarscope far enough so that later it will not interfere
with the protective cap.
Dec lock knob
Fig.k
Dec dial
Fig.k1
0
Fig.k2
R.A. lock knob
Setscrew
Indicator
24 hour clock
Date circle
Meridian Offset
Indicator
Polarscope holder
Polarscope
alignment screw
Polarscope
Setscrew
Indicator
Time: 24:00 (midnight)
Date: November 1
Polarscope holder
Polarscope
alignment screw
Polarscope
Fig.k3
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