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ID Date Author Type Category Subject Text Attachments
  15803   Thu Feb 11 11:10:05 2021 AnchalSummaryBHDSatellite Amplifier Very Low frequency noise After modificationsHere is a proper measurement for PD transimpedance
amplifier circuit in the Satellite amplifier
box D1002818 S2100029. The input from rear
 AfterChangesSpectrum_AC.zipD1002818_S2100029_OutputNoiseSpecAfterChanges.pdfD1002818_S2100029_InputRefCurrentNoiseSpecAfterChanges.pdfD1002818_S2100029_InputRefDispNoiseSpecAfterChanges.pdf 
  15802   Wed Feb 10 21:14:03 2021 gautamUpdateElectronicsProduction version of the HV coil driver testedSummary:

I did what I consider to be a comprehensive
set of tests on the production version of
 inputDiffRecTF.pdfLVnoises.pdftotalNoise.pdftimeDomainTests.pdf 
  15801   Wed Feb 10 17:18:03 2021 KojiSummaryBHDSatellite Amplifier Output Offset measurementsTesting the satellite amp i.e. 
PD driver
- To test the noise of the PD transimpedance
  
  15800   Wed Feb 10 15:25:45 2021 gautamSummaryBHDSatellite Amplifier Output Offset measurementsWhy not just do this test with the dummy
suspension box and CDS system? I think Rich's
claim was that the intrinsic LED RIN was
  
  15799   Wed Feb 10 15:07:50 2021 AnchalSummaryBHDSatellite Amplifier Output Offset measurementsI measured the output DC voltage of the
satellite amplifier box at PDMon port when
the PDA input was shorted
  
  15798   Wed Feb 10 14:14:58 2021 gautamUpdateElectronicsCustom cables receivedWe received the custom cables to test the
new suspension electronics. They are under
my desk. So we are ready.
 satWiring.pdf 
  15797   Wed Feb 10 11:45:59 2021 AnchalSummaryBHDSatellite Amplifier Very Low frequency noise After modificationsAs suggested, I wrapped the satellite amplifier
box D10028128 S2100029 in blanket and foam
and took very low frequency spectrum starting
 6x 
  15796   Thu Feb 4 15:14:55 2021 YehonathanUpdateBHDSOS assemblyI gathered all the components I could find
from the SOS towers and the cleanroom and
put it all on the table next to the flow
 20210204_144007.jpg 
  15795   Wed Feb 3 21:28:02 2021 gautamUpdateCDSCDS crash and CDS/IFO recoveryI am just reporting my experience - this
may be a new failure mode but I don't
think so. In the new RTCDS, the ntp server
  
  15794   Wed Feb 3 18:53:31 2021 KojiUpdateCDSCDS crash and CDS/IFO recoveryReally!? I didn't reboot the machines
between "sudo date" and "rtcds
start c1x0*". I tried rtcds. If it didn't
  
  15793   Wed Feb 3 16:27:19 2021 AnchalSummaryBHDSatellite Amplifier Transfer Functions and noise After modificationsI have made modifications recommended in
this doc.
The changes made are:
 D1002818_S2100029_TFAfterChanges.pdfD1002818_S2100029_OutputNoiseSpecAfterChanges.pdfD1002818_S2100029_InputRefferedNoiseSpecAfterChanges.pdfD1002812_S2100029_After_Modifications_Feb3.jpgAfterChanges.zip 
  15792   Wed Feb 3 15:24:52 2021 gautamUpdateCDSCDS crash and CDS/IFO recoveryDidn't get a chance to comment during the
meeting - This was almost certainly
a coincidence. I have never had to do
  
  15791   Tue Feb 2 23:29:35 2021 KojiUpdateCDSCDS crash and CDS/IFO recoveryI worked around the racks and the feedthru
flanges this afternoon and evening. This
inevitably crashed c1lsc real-time process.
  
  15790   Tue Feb 2 18:24:54 2021 KojiUpdateBHDSOS assemblyYou can remove the components of the optical
table enclosure (black ones) and use the
optical table as your working area too.
  
  15788   Tue Feb 2 17:09:17 2021 yehonathanUpdateBHDSOS assemblyI set up a working area on the table next
to the south flow bench (see attachment).
I also brought in a rolling table for some
 20210202_165501.jpg20210202_162452.jpg 
  15787   Tue Feb 2 11:57:46 2021 AnchalSummaryBHDHAM-A Coil Driver measurements After modifications TF and Noise S2100028I have made the modifications on the other
board D1100687 S2100028 as well. The measurements
were taken as mentioned in 40m/15784.
 D1100687_S2100028_After_Modifications_Feb01_2021.jpgD1100117_S2100028_TF.pdfD1100117_S2100028_Voltage_Noise_Spectrum.pdfD1100117_S2100028_Current_Noise_Spectrum.pdfAfterChanges.zip 
  15786   Mon Feb 1 12:30:21 2021 gautamUpdateElectronicsMore careful characterizationSummary:


Swapping out the KEPCO
HV supplies (linear) I was using for a pair
 HVPS.pdfHV_testckt.pdftotalNoise.pdf 
  15785   Fri Jan 29 17:57:17 2021 AnchalHowToCDSAcromag wiring investigationI found a
white paper  from Acromag which
discusses how to read differential signal
 GeneralLabWiringDiffWith2Wires.pdfGeneralLabWiringDiffWith3Wires.pdfDiffReadResistorbtwnINandRTN.pdf 
  15784   Fri Jan 29 15:39:30 2021 AnchalSummaryBHDHAM-A Coil Driver measurements After modifications TF and Noise S2100027I fitted zeros and poles in the measured
transfer function of D1100687 S2100027 and
got zeros at 130 Hz and 234 Hz and poles
 D1100687_S2100027_After_Modifications_Jan28.jpgD1100117_S2100027_TF.pdfD1100117_S2100027_Voltage_Noise_Spectrum.pdfD1100117_S2100027_Current_Noise_Spectrum.pdfAfterChanges.zip 
  15783   Thu Jan 28 22:34:21 2021 gautamUpdateSUSDe-whiteningSummary:


We will need de-whitening
filters for the BHD relay optics in order
 DACnoiseModels.pdfactuationRange.pdfdeWhiteTFs.pdfdispNoiseModels.pdf 
  15782   Thu Jan 28 21:44:45 2021 gautamSummaryBHDHAM-A Coil Driver measurements After modificationsLooks fine to me visually but the verdict
can only be made once the z:p locations are quantitatively confirmed,
and the noise tests pass. It would be interesting
  
  15781   Thu Jan 28 18:04:55 2021 AnchalSummaryBHDHAM-A Coil Driver measurements After modificationsI did the recommended
modifications on of the boards with serial
number S2100028. These included:
 D1100117_S2100027_TF.pdfAfterChanges.zip 
  15780   Thu Jan 28 12:53:14 2021 AnchalSummaryBHDHAM-A Coil Driver measurements before modificationsI took some steps to reduce the coupling
of 60 Hz harmonics in noise measurement.
The box was transferred to the floor instead
 D1100117_S2100027_Current_Noise_Spectrum.pdfD1100117_S2100027_Voltage_Noise_Spectrum.pdfD1100117_S2100028_Current_Noise_Spectrum.pdfD1100117_S2100028_Voltage_Noise_Spectrum.pdfSpectrumMeasurement.zip 
  15779   Tue Jan 26 15:37:25 2021 AnchalHowToCDSAcromag wiring investigationHere I present few wiring diagrams when
using Acromag to avoid noisy behavior and
ground loops.
 GeneralLabWiring.pdfGeneralLabWiring2.pdfGeneralLabWiring3.pdf 
  15778   Tue Jan 26 12:59:51 2021 AnchalHowToCDSAcromag wiring investigationTaking inspiration from SR785 on how it
reads differential signal, I figured that
acromag too always need a way to return current
 TestingDifferentialSignalWithFloatingRTNwrtIN-.pdf 
  15777   Tue Jan 26 10:58:30 2021 gautamUpdateSUSMC2 tickler stuck onFor whatever reason, the autolocker didn't
turn the tickle off for several
hours. Seems to work okay now. The linked
  
  15776   Mon Jan 25 18:18:04 2021 AnchalSummaryBHDSatellite Amplifier Transfer Functions and noise 

I took transfer function and noise
measurement of satellite amplifier box's
 D1002818_S2100029_TFandNoiseSpectrum.pdfD1002818_Testing.zip 
  15775   Wed Jan 20 19:12:16 2021 gautamUpdateCDSSLwebview fixedAfter fixing multiple issues, the model
webviews are updating, should be done
by tomorrow. It should be obvious from the
  
  15774   Wed Jan 20 18:07:09 2021 AnchalSummaryBHDHAM-A Coil Driver measurements before modificationsI have taken transfer functions and noise
measurements of the two HAM-A coil driver
boxes D1100687 #S2100027 and #S2100028. All
 7x 
  15773   Wed Jan 20 10:13:06 2021 gautamUpdateElectronicsHV Power supply bypassingSummary:

Installing 10uF bypass capacitors
on the High
 bypassCaps.pdfIMG_9079.jpgIMG_9078.jpgHVampNoise_driven_chassis.pdfprintCoilCurrents.pdf 
  15772   Tue Jan 19 15:43:24 2021 gautamConfigurationCDSUpdated CDS upgrade planNot sure if 1Y1 can accommodate both c1sus2
and c1bhd as well as the various electronics
chassis that will have to be installed. There
  
  15771   Tue Jan 19 14:05:25 2021 JonConfigurationCDSUpdated CDS upgrade planI've produced updated diagrams of the
CDS layout, taking the comments in 15476 into
 40m_CDS_Network_-_Planned.pdf40m_CDS_Network_-_Current.pdf 
  15770   Tue Jan 19 13:19:24 2021 JonUpdateCDSExpansion chassis from LHOIndeed T1800302 is
the document I was alluding to, but I completely
missed the statement about >3 GHz speed.
  
  15769   Sat Jan 16 18:59:44 2021 gautamUpdateLSCModulation depth measurementI decided to analyze the data I took in
December more carefully to see if there are
any clues about the weird LSC sensing.
 PLL.pdfmodDepth.pdfmodProfile.pdfEOMpath_postMod.pdf 
  15768   Fri Jan 15 17:04:45 2021 gautamUpdateLSCMessed up LSC sensingI want to lock the PRFPMI again (to commission
AS WFS). Have had some
success - but in doing characterization,
 PRFPMI_Jan12sensMat.pdfPRMI3f_ALS_Jan11_largeOffsetsensMat.pdf 
  15767   Fri Jan 15 16:54:57 2021 gautamUpdateCDSExpansion chassis from LHOCan you please provide a link to this "list
of boards"? The only document I can
find is T1800302.
 Screenshot_2021-01-15_17-00-06.png 
  15766   Fri Jan 15 15:06:42 2021 JonUpdateCDSExpansion chassis from LHOKoji asked me assemble a detailed breakdown
of the parts received from LHO, which I do
based on the high-res photos
  
  15765   Thu Jan 14 12:32:28 2021 gautamUpdateCDSRogue master may be doing something good?I think the "Rogue
Master" setting on the RFM network
may be doing some good. 5 mins, ago, all
 Screenshot_2021-01-14_12-35-52.png 
  15764   Thu Jan 14 12:19:43 2021 JonUpdateCDSExpansion chassis from LHOThat's fine, we didn't actually
request those. We bought and already have
in hand new PCIe x4 cables for the chassis-host
  
  15763   Thu Jan 14 11:46:20 2021 gautamUpdateCDSExpansion chassis from LHOI picked the boxes up this morning. The
inventory per Fil's email looks accurate.
Some comments:
  
  15762   Wed Jan 13 16:09:29 2021 AnchalHowToCDSAcromag wiring investigationI'm working on a better wiring diagram
that takes into account multiple power supplies,
how their GND is passed forward to the circuits
 SimpleTestsStriptoolImages.pdf 
  15761   Tue Jan 12 11:42:38 2021 gautamHowToCDSAcromag wiring investigationThanks for the systematic effort.


Can you please post some
time domain plots (ndscope perferably or
  
  15760   Tue Jan 12 08:21:47 2021 anchalHowToCDSAcromag wiring investigationI used an Acromag XT1221 in CTN to play
around with different wiring and see what
works.  Following are my findings:
 SingleEndedNonFloatingWiring.pdfSingleEndedFloatingWiring.pdfDifferentialSignalWiring.pdf 
  15759   Mon Jan 11 19:10:10 2021 ranaUpdateBHDMonte Carlo loop coupling Simulations
looking better, but the CARM plot
still looks weird.
you should
plot from 0.01 - 10,000 Hz
All
  
  15758   Mon Jan 11 16:11:51 2021 YehonathanUpdateBHDMonte Carlo loop coupling SimulationsI dived into the alog to make the OLTFs
in the MC_controls example more realistic.
I was mainly inspired by these entries:
 MC_LANCE_OLTFs.pdf 
  15756   Fri Jan 8 20:01:11 2021 gautamUpdateALSNoisy ALSI did this test today. The excess
noise around 100 Hz doesn't show up in
the green beat.
 ALSX_IR_green.pdf 
  15755   Thu Jan 7 23:25:19 2021 KojiUpdateALSNoisy ALSIf the sensing noise level of the end PDH
degraded for some reason, it'd make the
out of loop stability worse without making
  
  15754   Thu Jan 7 21:16:22 2021 gautamUpdateALSNoisy ALSI thought about it, but wouldn't that
show up at the AUX PDH error point? Or because
the loop gain is so high there we wouldn't
  
  15753   Thu Jan 7 20:07:27 2021 KojiUpdateALSNoisy ALSHow about resurrecting the PSL table green
beat for the X arm to see if the non-fiber
setup shows the same level of the freq noise
  
  15752   Thu Jan 7 19:16:11 2021 gautamUpdateALSNoisy ALSI'm also wondering why the error monitors
for the X and Y loops report such wildly
different spectra for the suppressed frequency
 ALS_ERR_MON.pdfAUXnoise.pdf 
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