Rana pointed out some rookie mistakes in the filter banks for the QPD centering in HAM6 (AS WFS and OMC QPDs).  We changed the DC3_P,Y loop and the OMC ASC loops to fix the following:

• The filter to provide 1/f loop shaping, a 1.4:1000, has been changed to match the observed resonance frequency of the HTTS and also to lower the high-frequency pole.  The ASC model runs at 2048Hz, and a pole nearly at the Nyquist frequency is Bad News.  The OMC model runs at 16384Hz, so the first implementation of these filters wasn't a problem, but anyways it doesn't make sense to have a rolloff frequency that high.  The filters have been changed to 1.6:300 for yaw, and 1.75:300 for pitch.  The resonance frequencies were taken from the Phase3a HTTS TF measurements.
• The integrator was changed to use the measured resonance values for the frequency of the zero.
• The oddly-named ELF100 was replaced by a cheby1 low-pass at 7Hz.  An elliptic bandpass at around 400Hz was removed.  Also, there's a +12dB gain step in front of the integrator for those times when you need, well, 4x more.

A comparison of the old and new filters is attached; the old version is in blue.  We lose phase at 1-10Hz but it shouldn't be a problem for these simple loops.  The DC4_P,Y filters still need to be changed, but the DRMI is under guardian control and sometimes the loops are turning on, so I'll wait for a quiet moment to fix them.  (Also the guardian filter settings are all wrong.)  Need to remember to add a 60Hz comb to these loops, too.