[Jenne, Sheila]

We spent much of the evening trying to find a better combination of QPDs to use for the SOFT error signals, since SOFT is what is moving, and pulling down our recycling gain.

In the past, we have chosen combinations that are insensitive to TransMon pitch and yaw, so that we don't put TransMon motion back into our arms. 

One of the things we tried tonight was to instead chose a combination for SOFT that was insensitive to HARD. Unfortunately, our HARD and SOFT modes are very nearly degenerate in the QPDs, so that turns out to have been a poor idea.  We were able to close the loops around this combination (before we realized that it wasn't going to be great), and I moved the SOFT offsets around to recover our power recycling gain.  In the screenshot, you can see that when we increased the PSL power, we lost recycling gain.  Then, it comes back. (Also shown is my stray click on the PSL guardian screen where I accidentally requested more than 50W. We kept lock during that adventure).

We tried once to create a combination that is maximally sensitive to SOFT (which will also be very sensitive to HARD).  We engaged the pitch loops with this combo, and lost recycling gain, and then lost lock.  So, more work to be done here.

We're still not sure what is the best combo to use - there are more things in this department to try out.