A further analysis of the mysteriously disappearing 92Hz bump in DARM has been done. Attached are Figures 1,2, & 3 which show spectrograms of DARM, MICH & PERCL respectively. There is clearly a decrease in noise around 92Hz in all of them. Figure 4 looks at the accelerometeters around the PR tower before and after the disappearing bump. There is a line at 92Hz in the PR accelerometers that has disappeared. Lastly figure 5 is a spectrogram of the SPRB_LINK_ACC which was used to pinpoint the time the line disappeared to 14:19:49UTC ±1s (1184595607). Correlated in time to some VAC switch offs (38736).

It is also worth noting there appears to be 6 drifting lines in PERCL (3 pairs of lines all drifting in the same way), the clearest lines are Figure 3 around 115Hz. By eye these do not seem correlated to any F7 temperature sensors and are drifting significantly over a day. These lines can be very faintly seen in LSC_DARM. Is this an issue with aliasing even though we don't see mirror images? There is also some change around 80Hz in Figure 1 (LSC_DARM) that is not yet well understood.