Following on from the Monday Log, thought it prudent to look closer at the V1 sensor.  Plot one of that alog suggested the V1 and possibly the H1 sensors were outliers.

The first attachment here shows high and low gain responses during quiet ground motion times.  You'd expect the signals to be the same unless the GM is different.  All sensors show differences at lower frequencies with V1 starting to diverge at 150 mHz.  Below about 70mHz, the other two vertical traces diverge while the horizontal stays similar to as low as 40mHz.

The second attachment shows all High Gain responses between quiet and large EQ times.  On this plot, the before noted problem of the V1 sensor is not presenting itself, that is, all the vertical signals look similar well below 10mHz.  Does this suggest the V1 low gain signal path has issues?  Otherwise, why would not all the vertical sensors reflect the same GM condition...?