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Entry  Fri Feb 19 13:38:26 2021, gautam, Update, LSC, PRFPMI 
    Reply  Fri Feb 19 18:22:42 2021, rana, Update, LSC, PRFPMI sensiing matrix woes 
Message ID: 15827     Entry time: Fri Feb 19 18:22:42 2021     In reply to: 15822
Author: rana 
Type: Update 
Category: LSC 
Subject: PRFPMI sensiing matrix woes 

I would:

  1. look at the free swingin michelson. Should be able tu null that siggnal in all ports to define the Q phase.
  2. If things are weird, put an RF signal nto the demod board mhich is offset from the LO by ~100 Hz and verify the demod/whitening chain is kosher.
  3. Lock PRMI and drive lines > 200 Hz. If PRC/MICH are not orthogonal, then there may be a mis tuning of RF SB wavelength and cavity lengths.
  4. IF PRMI is sort of healthy, we could be having a weird SB resonance in the arms.
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