Reports until 04:30, Tuesday 11 October 2016
H1 ISC
terra.hardwick@LIGO.ORG - posted 04:30, Tuesday 11 October 2016 (30399)
PI Mode2 Open Loop Transfer Function Continued

Follow up to alog 30294

I've re-measured the open loop transfer function of Mode2 a few times after decreasing gain and tweaking phase to try to move towards stability. Halving damping gain halves loop gain (31 --> 16) but neither changing damping phase (+/- 30 deg) or phase picked up from bandpass (30 deg --> 0 deg) changes overall loop phase; all still leave us with ~160 deg phase differential. 

Images attached to this report