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Entry  Mon Jan 24 18:13:20 2011, Zach, Electronics, GYRO, PDH servo basic_design.png
    Reply  Tue Jan 25 00:05:57 2011, Koji, Electronics, GYRO, PDH servo 
       Reply  Tue Jan 25 01:30:01 2011, Zach, Electronics, GYRO, PDH servo PDH2.pdf
          Reply  Tue Jan 25 01:39:00 2011, Koji, Electronics, GYRO, PDH servo 
             Reply  Tue Jan 25 02:09:16 2011, Zach, Electronics, GYRO, PDH servo 
                Reply  Tue Jan 25 02:18:17 2011, Koji, Electronics, GYRO, PDH servo 
                   Reply  Wed Jan 26 01:20:10 2011, Zach, Electronics, GYRO, PDH servo PDH2.pdf
                      Reply  Wed Jan 26 06:20:03 2011, Koji, Electronics, GYRO, PDH servo 
                         Reply  Wed Jan 26 12:42:36 2011, Zach, Electronics, GYRO, PDH servo 
                            Reply  Wed Jan 26 18:10:37 2011, rana, Electronics, GYRO, PDH servo 
                               Reply  Wed Jan 26 19:47:42 2011, Zach, Electronics, GYRO, PDH servo PDH2.pdf
                                  Reply  Wed Jan 26 20:01:31 2011, Zach, Electronics, GYRO, PDH servo 
Message ID: 1262     Entry time: Tue Jan 25 00:05:57 2011     In reply to: 1261     Reply to this: 1263
Author: Koji 
Type: Electronics 
Category: GYRO 
Subject: PDH servo 

1. I don't like the logarithmic variable gain. I like the dial on the box which indicates the number proportional to the gain. This means that the variable gain stage is to be an inverting amplifier with the potentiometer in the feedback path. I recommend it as far as AD829 does not get screwed up by the stray reactances of the potentiometer.

2. Let's put buffered test points before and after the excitation input. These test points should be connected to the panel connector. There should be a manual (or remote?) switch that disconnect the exc input such that we can avoid the noise injection through it.

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