Mitch, Corey, Hugo,

Quick TFs were taken in the morning. They shown 1/2 gains on L4C-V1 and GS13-V2. The other main issue was the presence of a high-Q resonnance at 237Hz, on the Actuator-H1--to--GS13-H1 TF.

• The 1/2 gains were quickly corrected by adjusting the electrical connections on X1-SEI electronics rack, and on the in-air cable extensions. These connections probably got loose when work was performed on the rack, last Friday.  
   
• The resonnance seen at 237Hz on Actuator-H1--to--GS13-H1 TF is something we were chasing for about a week now. We first suspected that the stack of big masses set on top of the optical table, to payload the ISI, were somehow resonating (as we saw it in the past). We tried different configurations for those top masses, without much success (see SEI log #59). 
  Further inspection revealed un-torqued bolts on the outter walls between corner 2 and 3. Having them torqued improved the TFs in terms of HF noise, but did not remove the unwanted high-Q resonance. 
  Today's investigation revealed untorqued bolts at the base of GS13-H1. The quick transfer funcions taken after torquing those bolts, showed that the unwanted resonance was gone. The boundary conditions at the pod's base are now constraining enough to prevent it from moving independently from the ISI.

Transfer Functions measurements are running overnight.