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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: 10172     Entry time: Thu Jul 10 01:02:13 2014     In reply to: 10167
Author: rana 
Type: Update 
Category: PSL 
Subject: more PMC science 

Increased gain and SNR in PMC LO monitor circuit.

  1. R20: 499 -> 50k Ohms (increases gain by 100)
  2. Used Marconi to drive the LO input and readout C1:PSL-PMC_LODET
  3. Fit this function and loaded it into the psl.db file. The old Kalmus way used LOGE, but I wanted to use log10, so I did. The sensor is only useful in a narrow band. Since the signal is so low at low levels, I just fit to the highest 4 points because I was too lazy to do proper weighting. Do as I say, not as I do.

Plot with data and fit attached.

** N.B.: in order to update the calibration without rebooting, I used the following command: z write C1:PSL-PMC_LOCALC.CALC "2.235*LOG(B)+12.265". This allows us to update EPICS CALC records without rebooting the IOC.

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PMCloCal.pdf
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