We are baffled by our apparently low OMC transmission (alog 64240).

To check the health of the OMC, I looked at an April single bounce 50 W OMC scan and fit a Lorentzian to the +45_00 peak.
I found the HWHM to be 0.338 MHz.

We looked up the FSR of the OMC to be 265 MHz: DCC T1000276

The finesse of the OMC in April was 395, which is around 2% lower than the 400 measured by Koji when installed.  Definitely not enough to account for our "low OMC transmission".