After the unsuccessful search for the AS_C signal today (see 41962 and comments), I wanted to get some of the DRMI alignment better.  This will help us be sure that, when we go into HAM6, we're working with a roughly okay beam. 

I started with a place that I knew from last week that I could lock PRX.  While locked in PRX, I dithered PRM in length and rotated the RF phase of REFL_9 and REFL_45 until the PRCL signal was all in the I-phase.  This took REFL 45 from an old value of -13 deg to a new value of -53 deg.  This took REFL 9 from an old value of -90 deg to a new value of -30 deg.  Net -40 deg for RF45, and +60 deg for RF9.

The only mirror (out of PR2, PR3, BS, ITMX) whose alignment was different from the single-bounce alignment was PR2.  So, I noted my PRX-locked value for PR2, and went back to the single-bounce value.  I walked PR2 toward my PRX slider values, while moving SR2 and SR3 to keep beam on AS_A and AS_B.  In the end I was able to lock PRX while still seeing beam at the AS port.  I then misaligned the PRM and aligned the SRM, giving me an SRX configuration.  I did a very rough alignment of SRM until I saw SRX fringes.  I then misaligned SRM, and ITMX, and realigned ITMY.  I moved ITMY around until I saw beam on the AS WFS again (since we don't have an AS camera yet).  Once I realigned ITMX, I had some weak MICH fringes.  I tweaked up the alignment of ITMY, and now have pretty good MICH fringes. 

Depending on what we decide in the morning meeting, I may work more on locking and aligning DRMI, although the beam we have should be good enough to see signal on AS_C, certainly within picomotor range.  Since we're seeing beam at AS_AIR, we can't actually be all that far off......