filiberto.clara@LIGO.ORG - posted 14:05, Wednesday 21 February 2018 - last comment - 17:48, Wednesday 21 February 2018(40642)
ITMY UIM
While closing out the recently replaced SUS ITMY R0 RT OSEM (alog 40634), found short on UIM chain. Short is on cable SUS_ITMY_16, pin 5, cathode side of LED for UIM UR.
Sheila and Kissel have confirmed that this UIM UR LED is not used (and would be a much larger scope to fix). So, we have opted to save this fix for a future fix. Attached shows the spectrum of all of the L1 and L2 stage OSEMs for ITMY - you can see the elevated noise on the black L1 UR trace.