Sheila, Stefan

We changed the biases on ETMY ESD and EX ESD.  We were able to reduce the amplitude of the 60 Hz line by a factor of about 10 by setting the EY bias to it's positive rail, but this didn't change the broadband noise or any other peaks in DARM.  We also reduced the EX bias to 60% of the range, but this didn't change the noise. 

The attached screenshot shows the upconversion around the 60Hz line, which has prominent peaks at around 0.45Hz.  (Our microseism is low tonight, 0.1 um/sec rms) There isn't this kind of upconversion of the suspension motion on other lines in DARM,