This afternoon we made an attempt to transition to ETMX ESD in low noise to see what impact it would have on our noise.  We spent most of our commisioning window damping violin modes, so didn't make a lot of progress on this. 

Attached is some text which can be copied and pasted into a guardian terminal to do the transition (read comments).  We were able to transition half way to ETMX by setting the gains equal.  The red trace in the attached screenshot is the OLTF measured with equal gains on the two ETMs, the gold is a reference from before any changes.  Based on this, I think that we should use a gain of 1.5 in L3_LOCK_L to transition to ETMX (ETMY is 1.25) and preserve the UGF.  

The IFO unlocked at the end of this measurement, I am not sure why.