changed the frequency noise readout to the cable-delay version to see how it works.
As the loss of the cable is very large and the signal from the photodetector not very strong i had to add some amplifiers for signal conditioning (see figure below).
Data is acquired with channel C3:PSL-FSS_FREQCOUNT in replacement for the frequency counter. Started taking data around 11/2/4 4:16:30 UTC.
Will do final calibration tomorrow. First test gave signal from mixer changes from peak-to-peak for about 600kHz (+/-10%) in frequency change.