stefan.ballmer@LIGO.ORG - posted 16:48, Friday 14 August 2015 - last comment - 18:10, Friday 14 August 2015(20539)
Comparison of pre- and post-EOM driver oscillator RIN
Daniel, Stefan Puzzled by Evan's elog on the still persisting broadband noise (alog 20524), we hooked up the pre-EOM driver 45MHz RIN monitor again (plot 1) - Interestingly, the out-of-loop RIN monitor is still coherent with the pre-EOM driver input (just 38 dB lower), although there is a sign flip below ~2.5kHz (plot 2 shows the transfer function).
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Robert, Daniel, Stefan Installed cable from PSL rack to EOM driver test excitation. This will allow us to measure the (driven) 45MHz oscillator RIN transfer function once the winds die down. We hooked the drive up to EXTRA_AO_2, and verified the drive works. We can measure the TF during the next lock. (Work permit 5434)