TLDR: H1 is back to observing as of 05:47 UTC after an extended period of corrective maintenance.

[ISC] Sheila and I went out to ISCT1 to fix the COMM beatnote alignment and were able to increase it from -22 dBm to 0 dBm (all just by turning the yaw knob on the far beamsplitter which combines COMM and DIFF). Once we came back, I started the locking sequence. After a round of CHECK_MICH_FRINGES, PRMI locked instantly and ASC did its job, making the POP buildups as good as I've seen them tonight. DRMI locked quickly afterwards, and we continued locking without issue. NLN reached at 05:03 UTC.

Once locked, I noticed some SDF differences on the PRM, PR2, and PR3 models related to A2L gains. Trending them back and conferring with Sheila, these should have been accepted yesterday after Sheila's work in alog77988, so I accepted them. Trends and SDF accepting screenshots in attachments 1 and 2.

[CAL] There were also some SDF diffs on the CALCS and SUSETMX models, which were expected following alog78008; these were accepted and screenshots are in attachments 3 and 4.

[SQZ] To finish off the activities before observing this evening, Sheila and Naoki pointed out that SQZ performance was poor. I started by running SCAN_ALIGNMENT_FDS and SCAN_SQZANG with SQZ_MANAGER, but high frequency noise didn't seem to be any better. Naoki suggested setting the SQZ angle to 160 and running SCAN_SQZANG again, thinking the optimum angle was outside of the range done by the first scan. He was right, and after the second scan the angle settled at 202 and DARM looks much better. I accepted the SDF diffs for ZM4 and ZM6 alignment sliders, screenshot is attachment 5.