I did a tilt decoupling-like measurement on ETMY ISI, driving in Z with a low pass filter (rolling off at ~200 mHz), all the isolation loops engaged, and all the blends swith to Start, I looked at the Z and RZ seismometer signals on St1 and St2 (results shown in dashed lines on the attached plot). I then switched the same drive signal to the ETMY HEPI, and again looked at the seismometers (solid lines on the same plot). I don't know what to make of it, but the RZ coupling is clearly different between driving on the ISI versus the same drive on HEPI. And it only shows up in the GS-13s.  Huh. Template is in the H1 BSC-ISI svn, in the /Misc/Tilt Decoupling folder with the name Z_to_RZ_w_hepi.xml.

I've restored all settings on the ISI, so blends should be back to the new nominal for commissioners tonight.