Today, we measured the violin modes of the new monolithic ETMy with the goal to determine what contributed to the large-ish pitch offset we were seeing. Nothing egregious was found from violin modes themselves, so we decided to attempt to fix the pitch by re-stress-relieving the stock welded to the horns. This technique has been done before, once here at LHO and once at LLO with success. This time around, we went from ~5mRad differential pitch to ~500 uRad differential pitch. Now, if only we could get a factor of 10 improvement in other aspects of LIGO in the course of a day. . .
See final alignment numbers at this alog.