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Entry  Mon Jun 3 16:46:31 2019, gautam, Update, IOO, IMC not locking PCdrive_RMS.png
    Reply  Tue Jun 4 10:56:31 2019, gautam, Update, IOO, IMC diagnostics IMCdiag.pdf
       Reply  Thu Jun 6 22:11:53 2019, Koji, Update, IOO, IMC diagnostics 
          Reply  Thu Jun 13 18:01:18 2019, aaron, Update, IOO, IMC diagnostics 
             Reply  Fri Jun 14 13:10:00 2019, aaron, Update, IOO, IMC diagnostics 
                Reply  Mon Jun 17 12:37:16 2019, aaron, Update, IOO, IMC diagnostics 
                   Reply  Tue Jun 18 20:35:07 2019, aaron, Update, IOO, IMC diagnostics 
                      Reply  Wed Jun 19 19:12:51 2019, aaron, Update, IOO, IMC diagnostics PMC_Error_Spectrum.pdfPDH_signal.pdfPDH_signal_full.pdf
                         Reply  Mon Jun 24 15:49:05 2019, aaron, Update, IOO, IMC diagnostics sweep_config_updated.png
                            Reply  Tue Jul 2 19:36:18 2019, aaron, Update, IOO, IMC diagnostics PDH_error.pdfPMC_Error_Spectrum.pdf
          Reply  Fri Jun 21 19:36:26 2019, Koji, Update, IOO, IMC diagnostics IMC_error.pdf
             Reply  Sun Jun 23 08:09:53 2019, gautam, Update, IOO, NPRO diagnostics consolidatedOscopeScreenCaps.pdfRINcomp.pdfPLL_OLTF.pdfPLLnoise.pdf
                Reply  Sun Jun 23 09:36:32 2019, gautam, Update, IOO, IMC is locking normally again PMCdiag.pdf
                   Reply  Sun Jun 23 14:43:14 2019, Koji, Update, IOO, IMC is locking normally again 
                   Reply  Mon Jun 24 08:12:10 2019, gautam, Update, IOO, IMC is locking normally again IMCdutycycle.png
                      Reply  Mon Jun 24 11:48:35 2019, gautam, Update, IOO, IMC in-loop error spectra and OLTF IMCfreqNoise.pdfIMC_OLTF.pdfIMC_CMboard.jpg
Message ID: 14681     Entry time: Tue Jun 18 20:35:07 2019     In reply to: 14677     Reply to this: 14683
Author: aaron 
Type: Update 
Category: IOO 
Subject: IMC diagnostics 

I made a script (/users/aaron/40m/GPIB/tds_dump.py) that grabs data from a Tektronix scope and packages into a pickled dict with the following structure:

  1. ch1
    1. times ("ts")
    2. values ("vals")
    3. channel info ("info")
  2. ch2
    1. ""
  3. etc

I made a python notebook that does the following:

  1. Grab the data from the pickle above
  2. Fit a triangle wave to the drive signal
  3. Determine the (change in Volts) / second from the triangle wave, as well as define the times of a single sweep of the PDH error signal
  4. Trim the error signal data to contain the PDH signal from the carrier and two sidebands only (the original trace was for three periods).
  5. Fit the functional form of the PDH signal to the trimmed error signal. 
    1. The sideband frequency is fixed at 35.5 MHz, and the scaling of Volts-to-Hz is left free, so this fit gives the calibration of IF volts to Hz.
  6. Grab the spectra (already saved from the Agilent with the netgpib scripts) and apply this V-to-Hz scaling
  7. Plot the spectra

The fit in step (5) is still looking quite bad, despite the fitted values being close to the expected. Since we really just want a calibrated spectrum, I'll instead fit a line to the linear portion of the PDH error signal for the carrier and both sidebands, then determine the scaling from that.

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