Notes specific to each run

July 2001

• off-centre rings used for locking cryostats
• observers present: NGD, KK, MRM, AJR

September 2001

• off-centre rings used for locking cryostats
• observers present: NGD, KK, MRM, AJR

March 2002

• lock-down screws with locking nuts on cryostats
• braces on cryostats helped stabilise against flexure but were suspected of making galvanic contact, see next item
• variable read noise on EEV13 - fault reported - could not be diagnosed
• observers present: MA, NGD, AJR

October 2002

• ING staff has installed new(?) electrical isolaters under the CCD controllers
• tested Marconi CCD, which showed pattern noise just like EEV13, leading to the replacement of the right arm camera power supply, which solved the problem! (EEV13 used in run)
• observers present: DC, NGD, KK, HRM, AJR

February/March 2003

• Removed grating unit from PN.S and inserted plastic spacers (nylon screw heads) and extra springs in order to increase stability of gratings and prevent "clunk". Took spacings back out after third night in case they were causing focus problems (see below).
• Used Marconi CCD on PNSR for first three nights, and couldn't seem to get the instrument into good focus, so switched to EEV13 and the problem seemed to be solved.
• General focus issues discovered: filter tilt may marginally affect focus; filter change definitely does?; vertical spot sizes should be checked as well as horizontal (because of half-moon shapes).
• Elevated read noise began in PNSR after 6th night, so power supply changed to one labelled "Use with PN.S" (which should have been used in the first place?!)
• observers present: NGD, HRM, NRN, AJR

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