- Locked for four and a half hours during Daniel dinner, lost lock due to small earthquake right as I returned.
- Lockloss right after ENGAGE_SOFT_LOOPS.
-- On second lock, stepped through the state, had trouble with CHARD P/Y ringing up when engaging FM1 (+30dB). Caught by disengaging FM1s and instead increasing CHARD P gain from 2 to 20 and CHARD Y gain from 2.5 to 25. Had to reduce both gains to 15 to get arms to settle.
-- Lost lock when switching on SRC1 P/Y FM1s (-20 dB) and ramping SRC2 P/Y gains from 100 to 15 causing a 0.6 Hz ringup. Seem like a CHARD/DHARD Pitch ringup triggers by lowered SRC gains.
-- Next time was able to proceed through ENGAGE_SOFT_LOOPS by hand with no problems. Not clear what was different between these two locks.
- Got to NOMINAL_LOW_NOISE for about 15 minutes. The lock was particularly ratty, POP18 and PRG were oscillating periodically at about 0.5 Hz, and the IX EX saturation audio alarms kept sounding. Seems to have been an oscillation in the pitch loops, CSOFT and SRC1 look most guilty.
- Lost lock stepping through ENGAGE_SOFT_LOOPS on CHARD P/Y again.
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FOM is from 4 hour lock earlier. Calibration is a by-hand matching of the PCAL lines to DARM. Scattering seems to have been reduced from what we've seen last week.