Following the discovery here, I tried to measure the SRCL OLG at Resonance today.  After a couple tries, I was able to get a reasonable measuremet, but didn't find anything obviously off with SRCL at Resonance. Attached plots show the data from the measurement, the first plot is the amplitude and second is the phase, blue traces are a reference from a previous measurement, red is the current measurement. I was hoping to see that the gain or phase margin were close, but the gain margin at 80 hz is about 25 deg and the gain is something like -6 dB. There is a little bit of a bump at 80hz, but I wouldn't guess that that is a problem, given the phase margin.

Two other points, the previous alog pointed to the wrong DTT template, I used the SRCL_OLG_NOISE_3F.xml. And, I also was able to drive harder for this measurement,and had to, it was hard to resolve anything at 80 hz with the excitation in the measurement. The template is set with an amplitude of 30, I drove with an amplitude of 70.

Because we didn't find anything problematic here, Sheila suggested we try measuring at CARM_TO_REFL, and we just happened to have a lockloss. I'll try again in a bit.