Today I adjusted the DHARD gain and asked Ryan to rerun the simulines measurements to see if changing the DHARD gain has any measureable effect on the sensing function. This tests possible L2A2L coupling present in the sensing function.

Based on recent OLGs of the HARD loops, I decided we could probably lower each gain by 3 dB. For DHARD P, this takes the gain from -30 to -18 and DHARD Y from -40 to -24.

We ran one simulines with DHARD P gain lowered and one with DHARD Y gain lowered. These measurements can be compared with this morning usual calibration measurement.

The results seem a bit inconclusive to me. There might be some change in the phase below 10 Hz. First I compare the three sensing measurements, then I take the ratio of each measurement with the "nominal settings" measurement.