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Message ID: 1870     Entry time: Fri Aug 18 21:22:26 2017
Author: Craig, awade 
Type: DailyProgress 
Category: NoiseBudget 
Subject: 2017 Aug 18 Trans Beatnote Spectra 

Here is our first trans spectrum in Vrms/rtHz.  We haven't had time to fully calibrate the PLL actuation to get the spectrum into Hz/rtHz, that will come tomorrow.

The beatnote is around 100 MHz.  We demodulated the beatnote with a PLL, using the Marconi as local oscillator with a 800 kHz FM modulation range.

The North cavity temperature voltage was set to 10.6 V by me at around noon today, and the beatnote frequency is just now settling down, still drifting by a little but not so bad as earlier where we had to retune the Marconi carrier frequency every five minutes.

Ocassionally the South path will start ringing at the PZT starts railing.  I turned the common and fast gains way down so this doesn't happen so much, this had a marked effect on this spectrum.  Further investigation is needed for why the South path is ringing, Andrew suspects our negative power supply is not outputting any current, which could make the PZT suseptible to railing somehow.

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20170818MarconiSettings.jpg
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