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Entry  Wed May 19 22:40:19 2010, Dmass, Electronics, Doubling, Oddness with my box Plotted17.pdfMZVoltsLowAvg.pdf
    Reply  Wed May 19 23:33:18 2010, Dmass, Electronics, Doubling, Oddness with my box 
       Reply  Thu May 20 00:41:51 2010, Koji, Electronics, Doubling, Oddness with my box 
          Reply  Thu May 20 21:43:01 2010, Dmass, Electronics, Doubling, Oddness with my box 
             Reply  Fri May 21 17:42:29 2010, Dmass, Electronics, Doubling, The Box Itself MZ_Electronics.pdfMZBoxGoodPic.png
                Reply  Fri Jun 4 13:46:26 2010, Dmass, Electronics, Doubling, The Box Itself 
Message ID: 780     Entry time: Wed May 19 22:40:19 2010     Reply to this: 781
Author: Dmass 
Type: Electronics 
Category: Doubling 
Subject: Oddness with my box 

I noticed some funny behavior I couldn't explain.

  • I take my Green PD inputs off on my box, and replace them with 50 Ohm terminators
  • I look at the difference signal downstream
  • This difference signal noise level changes by almost two orders of magnitude depending on whether or not I have the IR PDs blocked.
  • This seems WRONG
  • I think the green voltage noise level shown for with the IR PDs illuminated is higher than the level measured at around the same setup.

So it seems

  • The green difference noise is lowest when I have no light on the IR PDs and 50 ohm terminators on the green inputs.
  • The green difference noise is highest with terminators on the inputs and light on the IR PDs
  • The green phase noise is between these two levels when we measure it...
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