H1 struggled last night/this morning--H1 was down close to 6hrs (NOTE: µseism is elevated).
Since there hadn't been an alignment, thought this would do the trick since one hadn't been run a few hours into relocking. Unfortunately, DRMI & PRMI didn't look great post-IA. CHECK MICH FRINGES helped. Then continued with locking with various locklosses. During locking I happened to notice a RETURN of the SRC noise during OFFLOAD_DRMI_ASC (noted: alog83080, alog82997). This is post-SRC2_Pitch gain reduction a couple days ago (alog83092, alog83078).
This noise issue definitely looks ugly and continues to exhibit SRM/SR2 Saturations heard via Verbal and for the one for this current lock it eventually calmed down on its own after a few minutes (this was around 1732utc). While waiting for H1 to get to OBSERVING, looked to see if we if there were other instances of this noise returning (atleast for the last 1.5 days). Here were the times when it occurred with the lower SRC2_P gain of 40 for ISC_LOCK state -111 (w/ notes for each one; also see attachments):
- 1732utc: About 90-sec, LARGE noise, no action taken, and H1 survived and made it to NLN
- 1652utc: About 40-sec, LARGE noise, caused a LOCKLOSS
- 902utc: About 40-sec, small noise
- feb28 1413utc: About 30-sec, very small, but observable
- feb28 725utc: About 30-sec, very small, but observable
Perhaps it's getting worse? Also only had the one lockloss from looking at these for the last 1.5 days.
