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Entry  Thu Nov 9 00:20:02 2017, Craig, DailyProgress, PLL, PLL OLGTFs with different Frequency Modulation Levels 7x
    Reply  Thu Nov 9 10:55:45 2017, awade, DailyProgress, PLL, PLL OLGTFs with different Frequency Modulation Levels 
Message ID: 1975     Entry time: Thu Nov 9 00:20:02 2017     Reply to this: 1976
Author: Craig 
Type: DailyProgress 
Category: PLL 
Subject: PLL OLGTFs with different Frequency Modulation Levels 

With the help of the PLL autolocker, I retook the OLG of the PLL with a frequency modulation level of 10 kHz and 3 kHz. 

I did this because we have new beatnote spectra in the can at both levels of frequency modulation and we would like to calibrate and add to the noise budget.  The new spectra are in the ctn_labdata/ git repo under ./cit_ctnlab/ctn_labdata/data/20171108_TransBeatnoteSpectrum/

I calculated this PLL OLG the same way I did so previously through the SR560 preamp.  This result is plot 2.

I wasn't convinced this was right, so I did it again my calculating the PLL OLG from the mixer error signal through some OUT1/EXC = G/(1 + G) math.  This result is plot 1.

The results matched up pretty well:

The 3 kHz FM Deviation PLL OLG had a UGF of ~2.3 kHz in both plots 1 and 2.

The 10 kHz FM Deviation PLL OLG had a UGF of ~5 kHz in plot 1, and ~4.3 kHz in plot 2.

I was doubtful because this is so much less than our previous PLL OLG UGF, which was ~30 kHz at 10 kHz FM Devn.  The preamp gain is down to 100 from 200, but not clear otherwise why the PLL UGF is down 6 times as opposed to just 2 times...

With this in hand we should be able to easily calibrate the low-actuator noise spectra we took earlier today.

Attachment 1: OLG_from_PLL_OUT1_over_EXC_FM10kHz_08-11-2017_225218_JustBode.pdf  149 kB  | Hide | Hide all
OLG_from_PLL_OUT1_over_EXC_FM10kHz_08-11-2017_225218_JustBode.pdf
Attachment 2: OLG_from_PLL_OUT1_over_EXC_FM10kHz_08-11-2017_225218.tgz  59 kB
Attachment 3: OLG_from_PLL_CTRL_over_EXC_FM10kHz_08-11-2017_235017_JustBode.pdf  151 kB  | Hide | Hide all
OLG_from_PLL_CTRL_over_EXC_FM10kHz_08-11-2017_235017_JustBode.pdf
Attachment 4: OLG_from_PLL_CTRL_over_EXC_FM10kHz_08-11-2017_235017.tgz  59 kB
Attachment 5: PLL_SR560.jpg  1.702 MB  | Hide | Hide all
PLL_SR560.jpg
Attachment 6: PLL_Marconi.jpg  1.777 MB  | Hide | Hide all
PLL_Marconi.jpg
Attachment 7: PLL_Agilent.jpg  2.062 MB  | Hide | Hide all
PLL_Agilent.jpg
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