Celestron C11 User manual

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C11 & CGE PRO
The C11 is our second largest Schmidt Cassegrain telescope and suitable for mobile use. Every time
one likes to use it, one has to put it up again from scratch. The purpose of this article is to describe
the details of this process.
Scattered pieces
To protect the sensitive electronics from humidity and other harsh weather conditions they are stored
in the lab course room. The remaining mechanical parts stay in the dome, so that one does not need
to carry them around.
Stored in the dome:
the tripod1.
the tube (C11)2.
counterweights + bar3.
Stored in lab course room:
the CGE PROs electronic box1.
the CGE PRO mount2.
a box containing all 1.4″ eyepieces and the corresponding filters3.
sun filters4.
Setup
The CGE PRO is a parallactic mount, which has to be adjusted to point to the northern celestial1.
pole. Therefore, the tripod (see figure 1) should be positioned accordingly. To do so, it is usually
sufficient to point the tripod leg with the carrier for the hand terminal to the south.
Now put the electronic box on the tripod (see figure 2) and fix it with three bolts (see figure 3).2.
Place the mechanics of the CGE PRO (see figure 4) on the electronic box and fix it again with3.
three bolts (see figure 5). Due to the heavy weight of the mechanics, this step should be
performed by two people.
Screw the counterweight bar into the mechanics and place the counterweights on it (see4.
figure 6). When you fasten the screws on them, they are hold in place.
Connect the electronic box to the engines of the mount. The cables (see figure 7) go in the5.
ports on the side of the electronic box (figure 8). The cables have different lengths. The short
one connects electronic box with the right-ascension axis, while the longer one is for the
declination axis (see figure 9). The cables only fit in one position.
Now plug the energy supply (see figure 10) and the hand terminal (see figure 11) into the6.
corresponding ports (see figure 12).
The attachment of the tube should also be performed by two people. One inserts the dovetail7.
into the clamp of the mount (see figure 13 and figure 14) and holds it in place. The other one

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tightens the screws (see figure 15).
Remove the cover from the tube (figure 16) and add, if needed, the sun filter (see figure 17).8.
Now you can attach an eyepiece, a camera, or a spectrograph to the tube. To use 2″ oculars or9.
one of the other instruments you need to exchange the 1.4″ adapter at the end of the tube by a
2″ adapter from the storage container.
Often a focal reducer is already attached to the telescope. It can be easily removed, if you don't10.
want to use it.
Before using the telescope you have to tare the rotation axes. First lose the bolts fixing the11.
right-ascension axis, until you can freely move the telescope around this axis. Now adjust the
position of the counterweights such that there is no movement along this axis anymore. Tighten
the bolts again and repeat this procedure for the declination axis. As there are no
counterweights for this axis, one has to shift the tube along the clamp to tare the declination
axis. Again this should be done by two people.
Done! (figure 18)12.
Fig. 1: CGE PRO tripod
Fig. 2: Tripod with the
electronic box (the red circle
indicates one of the bolts that
needs to be fastened)
Fig. 3: One of the bolts
Fig. 4: Mechanics of the CGE
PRO
Fig. 5: CGE PRO mounted on
the electronic box and the
tripod (the red circles indicate
two of the bolts that need to
be fastened)
Fig. 6: CGE PRO with the
counterweights on the bar

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Fig. 7: Cables for the
connection of the electronic
box with the engines
Fig. 8: Electronic box with
ports for the cables
Fig. 9: CGE PRO with the cable
attached
Fig. 10: Mobile power supply
and the cable reel
Fig. 11: Hand terminal
Fig. 12: Ports for the power
supply (left) and the hand
terminal (right) at the
electronic box

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Fig. 13: Dove tail on the tube
Fig. 14: CGE PRO clamp on the
mount
Fig. 15: Attachment of the C11
at the CGE PRO
Fig. 16: Tube with the cover Fig. 17: Tube with the sun
filter
Fig. 18: Telescope build up
completely
Start-up
The CGE PRO can simply switched on and off via the On/Off switch at the electronic box. In contrast
to the OST, the CGE PRO does not require any shutdown procedure. It simply can be switched off.
After the boot of the mount, it is almost always required to create a new alignment. The following
possibilities exist:
Two Star Align
One Star Align
Solar System Align
Quick-Align
Last Alignment
Re-Alignment
Unfortunately, the handling of the hand terminal of the CGE PRO is not as intuitive as the one of the
OST. However, after a short settling in period even an inexperienced user can safely handle this
mount.

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Alignment
Usually it is required to create a new alignment after each start of the mount. If we want to use the
telescope more than one night in a row, we have the opportunity to put the mount into a hibernation
mode (see below) that allows to disconnect the mount from the power supply and at the same time to
conserve the alignment. If the mount is used at a fixed position, one also can use a previously saved
alignment.
General procedure:
switch on the mount1.
press ENTERto start the alignment procedure2.
press ENTER to allow the mount to move to the initial position (the co-called switch position)3.
enter the date4.
enter the time5.
select Daylight Savings time or Standard time6.
select the time zone (+1)7.
select the alignment method8.
In addition to the above settings one also has to set the location after a reset of the mount to the
default settings. This can be done by selecting a location from a list of known locations or by entering
the latitude and the longitude.
Solar System Alignment
The Solar System Alignment is useful especially for solar observations, since one can directly use the
Sun to create the alignment. While the precision of the Solar System Alignment is lower than what
one can achieve with an alignment procedure that is based on several stars, it is usually sufficient for
solar observations. Before the Sun can be used as an alignment star, it is required to allow the
telescope to actually move to the Sun because this in blocked by default for security reasons. This can
be done via UTILITIES → SUN MENU → ENTER. Apart from the points mentioned above, the Solar
System Alignment requires the following steps:
select Solar System Align (with the ↑ and ↓ buttons and not with the NSWO buttons)1.
select Sun in the menu and confirm it with ENTER ⇒ subsequently the telescope is moving the2.
estimated position of the Sun
search for the Sun and center the Sun in the eyepiece (Do not use the finderscope as3.
suggested by the software, since we do not have a solar filter for the finderscope!)
confirm with ENTER4.
press ALIGN ⇒ Finished!5.
Two-Star Alignment
The Two-Star Alignment and it refinement with additional stars is the default procedure to build a new
alignment for night observations. Besides the points mentioned above the following steps are
necessary:
select Two Star Align from the menu → subsequently, the telescope suggests bright stars that1.

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are above the horizon
select and confirm the first calibration star with ENTER2.
center the star in the eyepiece (the finderscope is often not very helpful, since it is most of the3.
time not well aligned with tube)
confirm with ENTER4.
press ALIGN → afterwards the telescope suggests the second alignment star5.
select and confirm the second calibration star with ENTER6.
center also this star in the eyepiece (in case it is not possible to find this star, one can select a7.
new star by pressing UNDO)
confirm with ENTER8.
press ALIGN → subsequently, the alignment can be improved with additional stars (3 are9.
recommended, 6 are possible)
press UNDO to complete the alignment10.
Hibernation
The hibernation mode offers the possibility to use the telescope several nights in a row, while
switching off the power supply during the day. It ensures that the alignment will be conserved.
However during hibernation, it is not allowed to move the telescope at all. The following steps are
necessary to put the telescope into hibernation:
press the MENU button1.
select HILBERNATE from the UTILITES menu2.
move the telescope to the desired park position3.
switch off the telescope4.
disconnect the power supply and arrange for weatherproof cover (Important: do not move the5.
telescope anymore!)
Wake up:
reconnect the power supply1.
switch on the telescope2.
confirm Wake up with ENTER3.
confirm the time and the location4.
The telescope is ready for the next observation!5.
Troubleshooting
Known error sources and their solutions can be found here.
Additional documentation
More details on the CGE PRO and the C11 can be found in the corresponding manuals in the lab
course room.

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