Marc, Shalika, Michael

We looked a bit at SHG transfer function using the new spectrum analyser (Source -> Perturb IN, Ch1 -> EPS2 Out, Ch2 -> EPS1 Out). Just a quick check using FFT with white noise injection showed that the gain of the loop is somewhat lower than before. The frequency response Ch2/Ch1 in the reference level is flat at 20 dB until 10 kHz, but now we drop off fairly fast at about 100 Hz. Switches are set to NON INV, 1/F3, DIF OFF, SIGN -