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Thu Apr 28 15:23:11 2016, ericq, Update, LSC, Green PDH demod lowpass
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Thu Apr 28 18:53:05 2016, rana, Update, LSC, Green PDH demod lowpass
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Fri Apr 29 16:13:36 2016, ericq, Update, LSC, Green PDH demod lowpass  
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Fri May 6 16:42:12 2016, ericq, Update, LSC, Green PDH demod lowpass 
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Fri May 6 19:08:52 2016, rana, Update, LSC, Green PDH demod lowpass
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Sat May 7 09:40:40 2016, ericq, Update, LSC, Green PDH demod lowpass
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Sun May 8 08:39:21 2016, rana, Update, LSC, Green PDH demod lowpass
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Message ID: 12113
Entry time: Sun May 8 08:39:21 2016
In reply to: 12112
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Author: |
rana |
Type: |
Update |
Category: |
LSC |
Subject: |
Green PDH demod lowpass |
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Indeed. This is why the LSC PDs have a 2f notch in addition to the 1f resonance. In recent versions, we also put a 2f notch in the feedback of the preamp which comes after the diode but before the mixer. The overall 1f to 2f ratio that we get is in the 50-60 dB region. I don't think we have to go that far with this thing; having a double LC already seems like it should be pretty good, or we could have a single LC bandpass with a 2f notch all in one Pomona box. |