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Entry  Thu May 23 15:45:48 2019, anchal, DailyProgress, FSS, Oscillations in North FSS Mixer Channel and power NorthCavFSSOsc.pdf
    Reply  Thu May 23 15:56:22 2019, awade, DailyProgress, FSS, Oscillations in North FSS Mixer Channel and power 
Message ID: 2350     Entry time: Thu May 23 15:45:48 2019     Reply to this: 2351
Author: anchal 
Type: DailyProgress 
Category: FSS 
Subject: Oscillations in North FSS Mixer Channel and power 

After the vacuum can is heated, I aligned the north cavity again today to about 60% mode matching. however, I'm seeing a weird oscillation in the mixer channel of FSS board which is very big (5 Vpp) and is happening alongside a large power fluctuation in transmitted light. See attached plot from oscilloscope of reflected DC level and the micer channel from FSS. The repition rate of the oscillations make this a 7.35 kHz noise. I have never seen this before. Further, these oscillations are completely unaffected from chaning COM gain or the Fast gain in the FSS path. Comments required.

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Attachment 1: NorthCavFSSOsc.pdf  108 kB  Uploaded Thu May 23 16:50:23 2019  | Hide | Hide all
NorthCavFSSOsc.pdf
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