Rick, Michael

After switching to the final RF sources for the PMC and FE EOM yesterday we needed to tune the PMC servo. After adjusting the phase through the delay box and the gain through the MEDM screen we found a good configuration with 20 11/16ths ns of delay and -4 dB of gain. This gave a UGF of about 6 kHz. However, there was some structure peaking around 80 kHz on the transfer function which gave us a low gain margin of 2 dB. We decreased the servo gain to -6 dB to increase the gain margin to 4 dB. We now have a UGF of about 4 kHz with 70 degrees of phase margin. I've attached a plot of the transfer function with a gain of -6 dB.