Alexa, Sheila, others

This morning we had a difficult time realinging, for reasons that aren't all clear.  (It seems like this should be easier than it normaly is.)

A few things that happened:

ITMX ISI was not isolating, did someone do this on purpose? Jim brought it back up for us.

The M0 Lock filter gains were reset to 1 again, so that the loop gains for the intial arm alingment were wrong again.  Arnaud figured out that guargian is doing this, and is working on a solution.  Beware, anyone who sets gains in SUS lock filters, they will get overwritten with the sus guardian as is.

After we got the arm cavity alingment back and stable, I had to realing the beat note on ISCT1.  I was able to realing it just by using an IR card and saw 27.4mV pp coming out of the PD, so this seems good enough for now.

Some numbers:

SHG shutter closed: -42dBm reported by PFD RF readback, about 1mV pp noise on the RF mon of the PFD.

Shutter open and beam aligned by eye: -34dBm reported by PFD RF readback, 27.4mV pp out of the PD, and about 2.5 mV pp on RF mon of the PFD.