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4.3
Aligning the Polar Axis Scope to the R.A.
Axis
Before using the polar scope for polar alignment, the polar
scope itself must be aligned to the mount's R.A. axis. The reticle
of the polar axis finder scope has a tiny star map printed on it
that makes precise polar alignment quick and easy (Figure 21).
At the center of the reticle is a cross, which you'll use in the pro-
cedure below to align the polar scope to the R.A. axis.
1.
Loosen the Dec. clutch wheel and rotate the optical tube
about the declination axis until you have a clear view
through the polar axis finder scope (Figure 22). Then
retighten the Dec. clutch.
2.
Look through the polar scope at a distant object (during
the day) or at Polaris (at night) and center it on the cross
in the middle of the reticle. You may need to adjust the
latitude jackscrew and azimuth adjustment knobs of the
mount and the tripod position to do this. Focus the polar
scope by rotating its eyepiece.
3.
Rotate the mount 180° about the R.A. axis. It may
be convenient to remove the optical tube and
counterweights before doing this. If the object remains
centered on the center cross of the reticle after the
rotation, then the polar scope is properly aligned to the
R.A. axis and no adjustment is needed.
4.
If the target deviated from the cross, then use a 1.5mm
Allen wrench to adjust the three small Allen screws on
the polar scope (Figure 23a) to move the target half
the distance back to the cross (Figure 23b). Then you
will re-center the object on the cross as in step 2 using
the mount's azimuth adjustment knobs and the latitude
jackscrew.
5.
Repeat steps 2 to 4 until the object stays centered on the
cross of the reticle when rotating the mount on the R.A.
axis.
Note:
• When adjusting the Allen screws, loosen one screw
only ¼ of a turn, and then tighten the other two.
• Do not over tighten the Allen screws as it might damage
the reticle plate in the polar scope.
• Do not loosen one screw completely or loosen more
than one screw at a time, or the reticle plate in the polar
scope will be disengaged and further adjustment is
impossible.
• If the reticle plate does disengage, remove the
polar scope's eyepiece by turning the knurled ring
counterclockwise and engage the reticle plate again.
4.4
Polar Alignment Using the Polar Scope
1.
Set up the Atlas Pro mount. It is recommended to load
the mount with the counterweights and telescope (in that
order!) and level the mount prior to polar alignment.
12
Figure 21. The reticle of the polar axis scope shows the positions
of the Big Dipper and Cassiopeia relative to Polaris and the north
celestial pole (NCP). For southern hemisphere users, four stars of
the constellation Octans are depicted.
Opening in
declination
shaft
Figure 22. To view through the polar scope, rotate the Dec. axis
of the mount until the opening in the Dec. shaft lines up with the
opening in the mount housing.
2.
Move the tripod so the telescope tube and right
ascension axis point roughly at Polaris (for Northern
Hemisphere) or toward the four dim stars (approx
magnitude 5 or 6) of Octans (for Southern Hemisphere).
You may need to adjust the altitude and azimuth
adjustments to accomplish this.
3.
Loosen the Dec. clutch wheel and rotate the optical tube
about the declination axis until you have a clear view
through the polar axis finder scope (Figure 22). Then
retighten the Dec. clutch
.
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