During one of Fabrice's final measurements on our Unit#1 Assy, it was noticed that the V2 GS13 appeared to have a gain of 2 lower than everyone else. We wanted to check this out. Today, the Seismic Team finished moving all the GS13's from Unit#1 to Unit#2. Today, I ran power spectra looking at the GS13's in various states. [See attached plots] Meas UL: This was with Unit #2 Locked. Here V2 looks to be ok (if anything it seems bigger than everyone else (in contrast to the Meas LL below). Meas LL: This was an old measurement from a locked Unit #1. Here may be the gain of 2 less on the V2 GS13. Meas UR: Here Unit#2 was UNLOCKED. Everything looks normal here. All the H's look similar and the V's look similar. Meas LR: The H2/V2 cable was swapped with the H3/V3 cable (Unit#2 is locked). Nobody looks glaringly different on this plot. The DTT data taken for this measurement is available for your perusal here: /opt/svncommon/seisvn/seismic/HAM-ISI/X1/Data/unit_2/dtt/20100729_geo_V2check.xml