We are wondering what noise is limiting our trans beatnote measurements.  We suspect the FSS is particularly noisy, so we are taking PZT fastout spectra, calibrating it, and putting it on the noisebudget.

When I did so I ended up with a spectrum which was two orders of magnitude too great.  I am not sure what is going on.  Maybe the EOM path is working to cancel most of the PZT noise? 

Bokeh version of the noisebudget.

Some stats:

Both path's FSS UGF ~ 120 kHz.

South Error Signal RMS ~ 160 mV  (read off of oscilloscope)

North Error Signal RMS ~ 60 mV  (read off of oscilloscope)

South PZT Vrms to Hz Calibration: 6.55 MHz/Vrms (done to check whether we were crazy for posting this spectrum in the first place)

Issues:

South Test 2 Excitation digital button doesn't work.  The acromag doesn't seem to be responding for that particular button, even though the Ramp Engage and Test 1 Excitation buttons work.