26
3. Look into the eyepiece. Move the telescope about the R.A.
axis using the R.A. direction buttons on the hand controller
while carefully observing the movement of the star.
4. Keep moving the telescope about the R.A. axis back and
forth to keep the star within the eyepiece field of view.
Rotate the eyepiece in the focuser (or diagonal) until
the movement of the star becomes parallel to one of the
illuminated crosshairs
(Figure 5a)
. This crosshair will
represent R.A. movement in the course of this procedure,
and the perpendicular crosshair will represent Dec.
movement. Tighten the set screws to secure the eyepiece
in position.
5. Point the telescope North and set the latitude scale to
your local latitude using the altitude adjustment knobs on
your mount. Alternatively, place Polaris in the polar axis
finder scope if your polar axis finder scope is accurately
aligned with the mount.
6. Loosen the R.A. clutch and rotate the telescope about the
R.A. axis until the counterweight shaft is parallel to the
ground, i.e., horizontal (as shown in
Figure 6a
).
7. Using the Dec. direction buttons on the hand controller,
adjust the telescope in Dec. so Polaris lies on the R.A.
crosshairs of the illuminated reticle eyepiece
(Figure 5b).
8. Without moving the R.A. axis, adjust the azimuth
adjustment knobs on the mount to place Polaris in the
center of the eyepiece field of view. Adjustment in Dec.
axis using the hand controller may be necessary.
9. Rotate the R.A. axis 180 degrees
(Figure 6b)
. The
counterweight shaft should be leveled and pointed to the
other side of the mount. If Polaris can be placed at the
center of the eyepiece by rotating the Dec. axis only, it
means the cone error is small and no further adjustment
is needed; otherwise, continue with the following steps.
10. Rotate the Dec. axis to bring Polaris as close as possible
to the center of the finder scope or the telescope’s
eyepiece.
11. Carefully nudge the telescope in a HORIZONTAL motion
while observing the movement of Polaris in the eyepiece
field of view
(Figure 7).
Determine which – left or right
– direction brings Polaris closer to the center of the
eyepiece. This will reveal the direction in which you should
adjust the telescope on the saddle or the mounting bar to
reduce the cone error.
12. Use a shim (or other method) on the proper side of the
saddle or mounting bar to raise the telescope slightly.
Look into the eyepiece while applying the shim, if possible.
Reduce the distance between Polaris and the center of
the eyepiece by HALF (not all the way!).
13. Repeat Steps 8 and 9 to check whether the cone error is
now acceptable. Repeat Steps 10, 11, and 12 if necessary
until Polaris remains in the center of the eyepiece field of
view, or moves slightly around the center, when the mount
is rotated about the R.A. axis.
Note:
This adjustment can be done in the daytime by
targeting a distant, small object – at least ¼ mile away
– instead of Polaris.
Appendix D: SynScan
Self-Diagnosis
The SynScan hand controller contains a built-in self-diagnosis
program. To run a full test, you first need to make a “Loop-Test
Plug” by referring to
Appendix E
and the following instructions:
• Short the pin-2 (TX_RS232C) and pin-5 (RX_RS232C) of an
RJ-12 plug.
Here are the diagnosis steps:
1. Insert the two “Loop-Test Plugs” into the corresponding
ports of the SynScan hand controller.
2. Press the “2” and “5” keys simultaneously and power on
the hand controller.
3. The hand controller will display “SynScan B.I.T.” for a short
time.
4. The LCD screen will go black and then clear for a while for
the purpose of checking the LCD display.
5. If there is any problem with the RS-232C function of the
serial port (the RJ-12 outlet) or there is no Loop-Test
Plug connected to the serial port, the screen will display
“COM1 ERROR.” Press ENTER to continue.
6. If there is any problem with the hand controller port or
there is no Loop-Test Plug inserted in that port (the RJ-45
outlet), the screen will display “COM2 ERROR”. Press
ENTER to continue.
7. If everything is fine, the test will proceed to Step 8;
Otherwise, the SynScan hand controller will show
“EEPROM ERROR” or “Flash ERROR.” Press ENTER to
continue in that case.
8. Check keypad and other features:
• The screen will display “Key=” in the top row. If a key is
pressed, the name of the key will be displayed.
• The power voltage will be displayed on the bottom row
of the screen.
