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a.
Figure 31. Collimating the optics.
look like this.
(b)
With the collimation cap in place, if the optics are out of alignment, the view might look something like this.
Here, the secondary mirror is centered under the focuser, but it needs to be adjusted (tilted) so that the entire primary
(c)
mirror is visible.
(d)
The secondary mirror is correctly aligned, but the primary mirror still needs adjustment. When the primary
mirror is correctly aligned, the "dot" will be centered, as in
puter screen. It will usually take approximately 30 sec-
onds for the new firmware to load into the hand controller.
It may take significantly longer if a serial-to-USB adapter
is employed on your computer.
6.
When the download is complete, the Firmware Loader
will display "Update Complete."
The firmware in the computerized GoTo hand controller has
now been updated. You can click on the "HC Version" button to
confirm the new version number of the firmware (and possibly
the database, but the hardware version will not change with
internet updates).
NOTE: If the error message "Can not connect to a
SynScan hand control" appears on your computer, check
all cable connections. Also, try closing all other computer
programs that might be attempting to use the COM port.
NOTE: If the error message "Firmware update failed..."
appears on your computer, remove the power plug from
the hand controller, and then reconnect it. Now, repeat
the firmware update procedure.
By default, the data communication rate between the GoTo
hand controller and the computer is 115kbps. The RS-232 port
on some PCs may not support this high data transfer rate. If
the firmware update procedure fails after a few tries, try reduc-
ing the data transfer rate by pressing the SETUP button on
the hand controller. This will reduce the data transfer rate to
9.6kbps. The controller's LCD screen will show "Lo" in the lower
right hand corner to indicate the lower transfer rate setting. The
firmware update procedure remains the same except it will take
much longer for the firmware to load into the hand controller.
24
(XX12g
only)
(a)
When the mirrors are properly aligned, the view down the focuser drawtube should
.
(e)
b.
d.
9. Collimating the
Optical System
To get the sharpest images, your telescope's optical sys-
tem must be in precise alignment. The process of aligning
the primary and secondary mirrors with each other and with
the mechanical axis of the telescope is called collimating.
Collimating is relatively easy to do and can be done in day-
light or at night.
Because the primary mirror is shipped separately from the
optical tube, the telescope's optics must be collimated before
it can be used. Most of the adjustments will be to the tilt of the
primary mirror, as the secondary mirror has been pre-aligned
at the factory. It is also good idea to check the collimation
(optical alignment) of your telescope before each observing
session and make any necessary adjustments.
To check collimation, remove the eyepiece and look down the
focuser drawtube. You should see the secondary mirror cen-
tered in the drawtube, as well as the reflection of the primary
mirror centered in the secondary mirror, and the reflection of
the secondary mirror (and your eye) centered in the reflection
of the primary mirror, as depicted in Figure 31a. If anything
is off-center, as in Figure 31b, proceed with the following col-
limation procedure.
The Collimation Cap and Mirror Center Mark
Your XXg comes with a collimation cap. This is a simple cap
that fits on the focuser drawtube like a dust cap, but has a hole
in the center and a reflective inner surface. The cap helps cen-
ter your eye so that collimating is easier to perform. Figures
31b-e assume you have the collimation cap in place.
c.
e.
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