Also, the line noise changed.
K1:LSC-AS_PDA1_RF17_Q_ERR_DQ
K1:OMC-TRANS_DC_SUM_OUT_DQ
K1:PEM-VOLT_OMC_RACK_DC_PM18_OUT_DQ
K1:PEM-VOLT_OMC_CHAMBER_GND_OUT_DQ
The characteristic shape around 2-3 Hz may come from interferometer, and when changed to DC control, it also appeared in DC and GND monitors.
(But there are similar structures in many PDAs)
(And several peaks between 10-50 Hz may be appeared by DC lock)
(And OMC chamber GND is dirty...)
