30" Troubleshooting
These tips are meant for general kinds of problems. If the solution(s)
given here fail to help, please call the appropriate person in Observing
Support.
- Problem:
You've gone below the horizon limit. The buzzer is buzzing and the telescope
won't move.
- Possible Solution:
Hold down the Horizon Limit Override button on the main telescope console while moving the
telescope back above the limit using the handpaddle. Before you push a
movement button, be certain you will be moving the telescope in the proper
direction (UP from the horizon). Moving the telescope lower than horizontal
can cause the telescope mirror to move in its cell and cause alignment
problems.
- Problem:
You can't find your object!
- Possible Solution:
If there has been a power outage of more than a few seconds, the RA dial may be
set incorrectly. It only tracks the sky when there is AC power to the building
(the telescope itself does not need to be on). To reset the RA dial, first move the telescope to the meridian if it is not already there. Then look at
the clock on the handpaddle and get the LST. Using the allen wrench
at the center of the HA dial, put the wrench into the RA dial and turn the wrench until the RA matches the LST. Then point to a star near the zenith bright enough for easy
identification and do a final tweak to the RA dial after centering the object
in your field. Store the allen wrench back in the HA dial. Do NOT adjust
the Dec dial. It should always be all right. If the LST is not available on
the handpaddle, go to one of the Suns in the control room. Type 'cosmo' in
an unused xterm window. Then type 'p sun' or 'p moon' (or point to something
that is up at the time). The LST will be given along with the coordinates.
- Problem:
Your image seems to be getting the wrong amount of light.
- Possible Solution:
One possibility is that the dome is partially blocking your object. Another
is that you are not using the filter you think you are. If you have done an
abort or CTRL-C while in ICE or if you have restarted IRAF or ICE, the filter
wheel must be manually checked (if you're not sure which one you're on) and
re-homed. It also occasionally happens that the filter wheel does not move
completely into its proper seated location. If this happens, it will need to
be put into its proper location and re-homed.
- Problem:
Telescope tracking seems poor.
- Possible Solution:
The tracking values for the 30" given by Point are NOT correct. The nominal
value for the 30" track motor is 14.955 arcsec/sec rather than 15.000. See
the tracking charts on the main 30"/PFC page for more information.
