Since we are frequently running out of range on the end station VCOs, when there is high wind, we switched the drive of the fiber AOM back to the IMC VCO. This was the original scheme. It has the disadvantage that the end station green locking now depends on the IMC to be locked. On the other hand, this is probably not a big deal, when working with the fully locked interferometer.
Kiwamu, Sheila,
We found that we had to lock ALS DIFF and COMM sequentially with this change, instead of in parallel as we have been doing. This morning we found that we could not transition the tidal to common with this change, so we reverted it so we are again using the fixed frequency RF source for the fiber AOM. We labeled both of the cables as well, so that next time the wind picks up we can put this back. We will probably not need high bandwidth common tidal with this modification, so we can try turning this bandwidth down and leaving off the IMC F offset, then later engaging it with a slow ramp.