No working green WFS with centering yet.

1. WFSB segment 3 demod signal is a factor of 10 weaker than the others when the beam is centered.

Giving the WFS centering servo a YAW offset (+0.4 in YAW so the beam stays at -0.4) would recover the balance. But at that point we're already almost railing MCL PZT.

2. Difference between good alignment (H1:ALS-C_TRY_A_LF_OUT_DQ=870-900) and not-terrible (smaller than 800) is big on WFS centering.

We made the centering servo work when the alignment is not that bad, but later when I manually aligned the arm, the servo started railing.

So, one of the problems seems to be that we don't have much range for MCL PZT mirror.

The screenshot shows the demod phase setting and RF WFS error signal, and you can see that the WFSB seg3 signal is very small. The reason why WFSB spectra look washed out is because the WFS centering kept railing during the measurement (sorry).

Next step would be to go to the end station, manually releave the PZTs, and repeat the measurements. I'll leave the centering servo disabled for now.