J. Garcia, J. Kissel

Today while trying to troubleshoot the FMY Damping Loops, a strange high-frequency noise was evident in the time-series signals via a dataviewer session.  A spectra of the H2:SUS-FMY_OSEMINF_*_OUT_DQ channels reveals a strange 75Hz peak in only the F1, F2, and F3 channels.  The added mystery is the fact that these channels share a physical cable with the *FMY_OSEMINF_SD_OUT channel.  We assume this is purely electronic noise arising from one of the boxes in the racks and not due to physical motion. This may also explain the added jitter in the OSEM input signals indicated by the dial indicators on the medms.  Attached is a power spectra of the *FMY_M1_OSEMINF_*_OUT_DQ and *ITMY_M0_OSEMINF_*_OUT_DQ channels with the 75Hz peak not apparent in the ITMY channels.  Investigations to ensue.

This peak is also not evident in the *ITMY_L1_OSEMINF_*, *ITMY_L2_OSEMINF_*, or *ITMY_R0_OSEMINF_*_OUT_DQ channels.  Plots for L1, L2, and R0 attached in the second pdf.