Orion ASTROVIEW 9862 - Manual (Page 8)

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tripod so the telescope points north. There is a label bear-
ing a large “N” at the base of the equatorial mount (Figure
8). It should be facing north.
The equatorial mount is now approximately polar-aligned for
casual observing. More precise polar alignment is required for
astrophotography and for use of the manual setting circles.
From this point on in your observing session, you should not
make any further adjustments to the latitude of the mount, nor
should you move the tripod. Doing so will undo the polar align-
ment. The telescope should be moved only about its R.A. and
Dec. axes.
the Polar axis Finder scope
A feature of the AstroView 100 EQ is the polar axis finder
scope housed inside the R.A. axis of the equatorial mount (see
Figure 9). When properly aligned and used, it makes accurate
polar alignment quick and easy to do. Alignment of the polar
finder need only be done once, unless it gets bumped or oth-
erwise shifts its position.
Remove the cover cap from the front opening in the R.A. axis
of the mount (see Figure 6). Look through the polar finder at
a distant object. Focus the polar finder so that the images and
reticle are sharp by rotating the eyepiece end of the finder.
Notice that the reticle pattern consists of a crosshair with a
circle around the middle. On the circumference of this circle
is a tiny circle; this is where Polaris will be placed for accurate
polar alignment once the finder is properly aligned. Alignment
of the polar finder is best done during the day, before going
out into the field at night.
aligning the Polar axis Finder scope
Aligning the polar axis finder scope so that it will accurately
point at the true north pole is a two-step procedure. First, the
polar finder must be rotated in its housing so that the small
circle in which Polaris will be placed in is in the proper initial
position. Next, the polar axis finder must be adjusted so that it
points directly along the mount’s R.A. axis.
We will start by aligning the polar finder rotationally. Refer to
Figure 9.
1. Loosen the large thumbscrew just above the R.A. setting
circle. Rotate the R.A. setting circle until the line above the
“0” on the setting circle lines up with the pointed indicator
that is cast into the mount (located directly below the large
thumbscrew; see Figure 8). Retighten the thumbscrew.
2. Rotate the date circle until the “0” line on the meridian off-
set scale lines up with the time meridian indicator mark.
The meridian offset scale is printed on the inner circumfer-
ence of the date circle, and is labeled “E20” to “W20”. The
time meridian indicator mark is an engraved line on the
exterior of the polar finder’s housing. It is on the “ring” of
the housing that is closest to the date circle.
3. The R.A. setting circle is labeled in hours, from “0” to “23”
(military time). For Northern Hemisphere observers, refer
to the top numbers on the setting circle. Each small line
represents 10 minutes of R.A. The date circle is labeled
from “1” to “12”, with each number representing a month of
the year (“1” is January, “2” is February, etc.). Each small
line represents a two-day increment.
4. Loosen the R.A. lock lever and rotate the mount about the
R.A. axis until the March 1 indicating mark (the long line
between the “2” and the “3”) on the date circle lines up with
the 4 PM mark (the long line above the “16”) on the R.A.
setting circle. You may find it convenient to remove both the
counterweights and the telescope optical tube to do this.
5. Now, loosen the three thumbscrews on the polar finder
housing and rotate the polar finder so the small circle where
Polaris will be centered is located straight down from the
intersection of the crosshairs. Retighten the thumbscrews.
The polar axis finder scope is now properly set in its initial
position. Next, you must align it so that it is exactly parallel to
the mount’s R.A. axis:
6. Look through the polar finder at a distant object (during the
day) and center it in the crosshairs. You may need to adjust
the latitude adjustment T-bolts and the tripod position to do
this.
Figure 8. For polar alignment, position the tripod so that the “N”
label at the base of the mount faces north. The two azimuth fine
adjustment knobs above it are used to make small adjustments to the
mount’s azimuth position.
Azimuth
fine
adjustment
knobs
Tripod
attachment
knob
Figure 9. The polar axis finder scope installed in the right
ascension (R.A.) axis of the mount.
R.A. setting circle
lock thumbscrew
Pointer
R.A. setting circle
Meridian
offset scale
Polar scope
housing
Polar axis
finder scope
Date circle
Ring with
engraved time
meridian indicator
mark
Polar scope
alignment
thumbscrew (3)