40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Mon Jul 7 21:36:33 2014, Jenne, rana, Update, PSL, PMC local oscillator is going wonky PMC_LO_failing.pdf
    Reply  Mon Jul 7 22:18:26 2014, Koji, Update, PSL, PMC local oscillator is going wonky 
       Reply  Tue Jul 8 15:28:32 2014, Koji, Update, PSL, PMC local oscillator is going wonky 
          Reply  Wed Jul 9 00:47:22 2014, Koji, Update, PSL, PMC local oscillator is going wonky 
             Reply  Wed Jul 9 11:41:12 2014, Koushik, Update, PSL, PMC local oscillator is going wonky 
                Reply  Wed Jul 9 19:53:34 2014, rana, Update, PSL, PMC LO monitor trend (5 years) LODET.png
                   Reply  Thu Jul 10 01:02:13 2014, rana, Update, PSL, more PMC science PMCloCal.pdf
          Reply  Wed Jul 9 00:59:09 2014, rana, Update, PSL, PMC local oscillator is going wonky PMC_RFslider.pdf
Message ID: 10159     Entry time: Wed Jul 9 00:47:22 2014     In reply to: 10153     Reply to this: 10162
Author: Koji 
Type: Update 
Category: PSL 
Subject: PMC local oscillator is going wonky 

Koushik replaced an ERA-5 in the PC path. We put the module back to the rack and found no change.
The epics LO level monitor monitor is still fluctuating from 6~11dBm. We need more thorough investigation
by tracing the signals everywhere on the board.

Despite the poor situation of the modulation, PMC was locking (~9PM). Rana suspect that the PMC demodulation
phase was not correctly adjusted long time. 

Koushik has the measured power levels and the photos of the board. I'll ask him to report on them.

ELOG V3.1.3-