Early this afternoon I adjusted the two mirrors before the COMM beatnote PD. i.e. the mirror that steers the beam onto the diode, and the beamsplitter which combines the x arm transmisison with the frequency doubled PSL. This brought the COMM beatnote up from ~ -16 dB to ~ -9 dB.

This could be aligned better by adjusting the mirror which splits the x arm transmission path between the comm and diff paths, but I wasn't sure how good the PR3 alignment really was so for now this is good enough.