Telescope Reversal
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The telescope can be operated from its nominal position (on the East
side of the pier) or it can be moved to the West side of the pier.
This procedure is called reversing the telescope. There are two ways
of reversing the telescope, from the floor and from the pier. The
former is mentioned here mainly for completeness but it is not
to be attempted by any observers other than Staff Astronomers. This
manual page will describe how one reverses the telescope via the pier
ship's wheel controls. While reversing from the pier it is possible
that one will only have to move the telescope in RA. The technique
mentioned here will include RA and Dec.
- When it is necessary to reverse the telescope one starts out by
moving the telescope to the Southeast side of the pier with the floor
at its upper limit. Lock the telescope in RA, but leave the
declination unlocked. While one can move the telescope completely
from the pier it is generally easier to do this move from the
floor. It is also easier and safer to turn on the dome lights, if that
is not possible due to the desired target object (e.g. object is dim),
then have a helper keep a red light on the end of the telescope during
the reversal procedure.
- At the ship's wheels the first thing one does is lock the HA
wheel by turning the center wheel clockwise (Figure 1). Once the HA
wheel is locked, unclamp the HA clamp while keeping one hand on the HA
wheel.
- Near the north end of the pier is a gear (Figure 2) that is then
moved into place by a hand crank (Figure 3). Once it is in place
(Figure 4) the observer will need to move to the ship's wheels (Figure
1).
- Begin to slowly move the telescope over to the West side of the
pier using coordinated movements of the wheels. Keep your eye on the
end of the telescope to make sure you don't crash it into the floor.
Continue moving the telescope until the counter weights (Figure 5) are
no longer above the telescope. Move the telescope a little further
West and you are done moving it from the ship wheels.
- Lock the HA clamp, unlock the ship's wheel, and put the
declination gear in the out position. Then go back to the telescope
on the floor and move it to the target.
- To park the telescope or move it back to the East side of the
pier, repeat the above procedure except move the telescope in the
opposite direction (West to East, instead of East to West).
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Figure 1: Pier ship's wheels and RA clamp.
Figure 2: Declination gear in the out position
Figure 3: Declination gear handle
Figure 4: Declination gear in.
Figure 5: Counter Weights
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Last modified: Wed Jun 30 11:37:59 PDT 2010