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Entry  Wed Nov 18 22:49:06 2020, gautam, Update, ASC, Some thoughts about AS WFS electronics 
    Reply  Sun Nov 22 21:09:37 2020, gautam, Update, ASC, Planned mods for WFS head aLIGO_wfs_v5_40m.pdfTFs.pdfnoise.pdf
       Reply  Wed Nov 25 18:18:41 2020, gautam, Update, ASC, Planned mods for WFS head anodeVsOutput.pngsensitivity.png
          Reply  Sat Nov 28 21:44:53 2020, rana, Update, ASC, Planned mods for WFS head 
          Reply  Thu Dec 10 22:46:57 2020, gautam, Update, ASC, WFS head assembled aLIGO_wfs_v5_40m.pdfTF_meas.pdf
             Reply  Thu Dec 17 15:23:56 2020, gautam, Update, ASC, WFS head characterization oNoise.pdfZ_Hi.pdfZ_Low.pdfIMG_9030.jpgiNoise.pdf
    Reply  Wed Nov 25 18:30:23 2020, gautam, Update, ASC, Some thoughts about AS WFS electronics 
       Reply  Wed Dec 2 23:07:19 2020, gautam, Update, ASC, Electrical LO signal for AS WFS RF_Frequency_Source.pdf
          Reply  Thu Dec 3 11:02:35 2020, rana, Update, Electronics, Electrical LO signal for AS WFS 
          Reply  Thu Dec 3 13:55:52 2020, Koji, Update, ASC, Electrical LO signal for AS WFS 
             Reply  Thu Dec 3 20:38:46 2020, gautam, Update, ASC, Electrical LO signal for AS WFS RF_Frequency_Source.pdfdemodPath.pdfEOMpath.pdf
                Reply  Thu Dec 3 21:14:38 2020, Koji, Update, ASC, Electrical LO signal for AS WFS 
                   Reply  Thu Dec 3 21:44:49 2020, gautam, Update, ASC, Electrical LO signal for AS WFS 
                      Reply  Fri Dec 4 03:02:40 2020, Koji, Update, ASC, Electrical LO signal for AS WFS 
                         Reply  Fri Dec 4 22:41:56 2020, gautam, Update, ASC, Freq Gen Box revamp 
                            Reply  Sat Dec 5 20:44:35 2020, gautam, Update, ASC, Freq Gen Box re-installed 6x
                               Reply  Mon Dec 7 12:38:51 2020, gautam, Update, IOO, IMC loop char OLTFcomparison.pdfdemodMons.pdfOLTFcomparison.pdf
                               Reply  Mon Dec 7 22:54:30 2020, gautam, Update, LSC, Modulation depth measurement modDepth.pdf
                                  Reply  Sat Jan 16 18:59:44 2021, gautam, Update, LSC, Modulation depth measurement PLL.pdfmodDepth.pdfmodProfile.pdfEOMpath_postMod.pdf
Message ID: 15707     Entry time: Fri Dec 4 03:02:40 2020     In reply to: 15706     Reply to this: 15710
Author: Koji 
Type: Update 
Category: ASC 
Subject: Electrical LO signal for AS WFS 

1. That's true. But we are already in that regime with the Var attn at 0dB, aren't we? We can reduce the input to the amp by 1-2dBm sacrificing the EOM out by that amount (we can compensate this for the demo out by removing the 1dB attn).

2. Not 100% sure but one possible explanation is that we wanted to keep the Marconi output large (or as large as possible) to keep the SNR between the signal and the noise of the driver in Marconi. The attenuator is less noisy compared to the driver noise.

3. My guess is that theoretically we were supposed to have 13dBm input and 20dBm output in design. However, the actual input was as such.  We can restore it to the 13dBm input.

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