[Yuhang, Matteo, Eleonora]

On Tue 3/12 morning we found the FC has difficulties to acquire the lock and to keep it, while in the past months lock was very robust and easy to get.

After some investigation (and having tweeked the gain of ramepeato) we found the input power was reduced from 12 mW to 9 mW, due to temperature change of SHG.

The day before the air conditiong was switched from summer to winter mode by Yuhang.

The injected power was put back to 12mW and the gains were tuned to get UGF ~ 15 kHz.  (See pic 1 and 2). Anyway it seems a loop oscillation happened from time to time and error signal looks noisier than usual. It was quite late and we coudn't keep investingating any longer. We haven't been in TAMA yesterday and today because of F2F.  Will check the situation tomorrow.