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ID Date Authorup Type Category Subject
  4226   Sat Jan 29 03:13:44 2011 ranaUpdateWienerFilteringImprovement in H1 Wiener FF prediction by using weights and taps

(Jenne, Rana)

Tonight we noticed that there were significant improvements to be had in the predicted DARM Wiener filtering FF performance by using weighting filters and more taps in the FIR filter.

The plots below tell the story:

The first one shows the improvement in the residual (black & blue) by applying a weighting filter. The weight filter tilts the spectrum up at HF and applies and all real pole BP from 10-20 Hz.

The second plot shows the improvement gotten by using 3000 instead of 2000 taps for the Wiener filter. With the larger number of taps we not only get the big improvement at LF, but also some beefy reduction in the higher frequency stack modes and the LOS roll mode.

I'm not sure why we haven't run across this before; the weighting filter was arrived at today by just iterating by hand on the placement of poles and zeros until the trace looked nice.

Jenne is going to run this new filter on the S5-month that we have been using for stationarity testing.

* Some notes:

** this Wiener stuff is faster, by far, on rossa than either megatron or rosalba or my laptop. More than a factor of 3.

*** there is a bug with Macports/Matlab - if you get fftw3 with Macports, it sets itself as the right version to use. This confuses matlab in some cases.

     if you get the error about libfftw3.dylib, whe trying fft in matlab after installing macports, then you can fix it by setting the Matlab lib/ path with the fftw libraries to be ahead of /opt/local/lib in the LD_LIBRARY_PATH in your .cshrc.

Attachment 1: darmweight.png
Attachment 2: darm3000.png
  4252   Fri Feb 4 18:58:19 2011 ranaUpdateComputersTemporarily removed cronjob for rsync.backup


I removed the rsync backup from nodus' crontab temporarily so as to not have multiple backup jobs running.  The job I started from yesterday was still running.  Hopefully the backup will finish by Monday.

The line I removed was:

0 5 * * * /opt/rtcds/caltech/c1/scripts/backup/rsync.backup

Actually, this is not true. Joe actually killed the currently running backup and set it to start tomorrow morning at 6AM. Its taking forever since its not an incremental backup but a new one due to the change in the setup.

  4255   Sun Feb 6 02:29:28 2011 ranaUpdateElectronicsAnalog MFD: longer cable

I swapped over to a 3x longer cable (old 65 ft. Pasternak cable from ancient 40m days). The old one was 6m, the new one is 18.2 m. It was already coiled up so I put it into a tupperware box to shield it somewhat from the HVAC wind.

The noise went down nearly proportional to the length (after I recalibrated the DAQ channel for the ~3x higher phase->voltage gain). With this length, the peak-peak mixer range is 5.5 MHz, so still enough to go an FSR here.


I give credit to the low frequency improvement entirely to Tupperware for their excellent containers. The current noise limit is most likely the SR560.

  4258   Mon Feb 7 21:23:11 2011 ranaConfigurationPSLPSL FSS Temperature Sensor Interface box removed

I noticed that the RMTEMP channel was spiking myteriously when Kiwamu opened the PSL door. We found out that the LEMO connectors would intermittently short to the case and cause ~1 deg steps in the temeprature.

We have removed the case and examined it. Not only were the connections to the box intermittent, there was a cold solder joint inside on an unsecured flying add-on opamp. The whole thing is a giant hack.

PK was the last person to work on this box, but I'm sure that he wouldn't have left it in this state. Must be gremlins.


The LEMO connectors on the front are the ones touching. The LT1021 is the badly soldered part.

  4276   Sat Feb 12 23:22:21 2011 ranaUpdateElectronicsREFL11 Photodiode replaced

375 mW is way too much light. We must never put more than 100 mW on any of these diodes. We don't want to blow up more diodes like we did with the WFS. The InGaAs diodes often show an excess dark noise before they finally let go and completely fail. This one may show excess during the shot noise testing.

We should ensure that the beam paths are engineered so that none of these new detectors ever sees such high light levels.

The DC path should be made to let us see a 10V from the differential EPICS readout when there is 100 mA of photocurrent (i.e. an effective 100 Ohms transimpedance):

0.1 A  * 10 V/A * 5 V/V * 2V/V

The last factor of 2 is from the single to differential conversion.

If we really only get 15 mV from 375 mW, then this diode or the circuit is broken.

  4282   Mon Feb 14 01:19:18 2011 ranaUpdateCDSToday's CDS problems

This is just a listing of  CDS problems I still notice today:

  1. MC2-MCL button was left ON due to BURT failure. This, of course, screws up our Green locking investigations because of the unintended feedback. Please fix the BURT/button issue.

  2. The GCV - FB0 status is RED. I guess this means there's something wrong? Its really a bad idea to have a bunch of whited out or falsely red indicators. No one will ever use these or trust these in the future.
  3. MC1/2/3 Lockins are all white. Also, the MODE switches for the dewhitening are all white.
  4. Is the MC SIDE coil dewhitening filter synced with anything? It doesn't seem to switch anything. Maybe the dewhite indicators at the top right of the SUS screens can be made to show the state of the binary output instead of just the digital filter
  5. MC WFS is all still broken. We need a volunteer to take this on - align beams, replace diodes, fix code/screens.
  4292   Mon Feb 14 21:59:35 2011 ranaUpdateCDSUpdated some DAQ channel names

Although Joe and Kiwamu claim that they have inserted the correct DAQ names for the OPLEVs (e.g. PERROR and YERROR) back in Jan. 11, when I look today, I see that these channels are missing!

I want my PERROR/YERRORs back!


  4293   Mon Feb 14 23:29:04 2011 ranaSummarySUSETMX Fitlers moved around

All of the SUS used to have only 1 filter module for SIDE. They now have 3 filter modules for SIDE just like the other DOFs.

Today I moved the filters around so that the sensor filters are in SDSEN, the servo filters are in SUSSIDE, and the dewhitening for the coil is in SDCOIL.

I noticed along the way that the bounce/roll mode notches for all of the suspensions are still set for the frequencies of the previous suspensions. Suresh has 'volunteered' to find the new frequencies and make the new bandstop filters by looking up the seminal work on this by Dan Busby / Sam Waldman.

  4304   Tue Feb 15 21:45:08 2011 ranaUpdateIOOThe MC TRANS Story

I forgot to elog that last night I touched up the MC2_TRANS QPD setup. I was perplexed by it always going out of alignment so I investigated.

I found that the fork clamp for the steering mirror for the QPD was not tightened. Shame. The beam diameter was equal to the aperture of the QPD and was clipping. Double shame.

I added a lens and tightened the mounts and centered the beam at ~9 PM yesterday. You can see in the attached trend that the measured power went up by ~10%.

Later, there's a big gap where Valera and Steve change out the PMC. You can see that the MC REFL voltage goes from 4.5 V to 5 V (10% increase in the power delivered to the MC).

There's essentially no change in the total transmission - this indicates that although the PMC transmission is now higher by ~10%, the matching to the IMC has been degraded by an equivalent fraction.

Needs some mode matching work.

Attachment 1: a.png
  4309   Wed Feb 16 23:54:34 2011 ranaUpdateCDSToday's CDS problems
  1. ETMX cannot load his filter coefficients. Even if I change the file, the load button doesn't work. I tried changing the lockin filters but they won't load.
  2. The ETMX filter modules appear to have 2048 for some of the modules and 16384 for some of the others. How come the make script doesn't make them all 16384?
  3. There are a bunch of kill/start scripts in the scripts/ directory instead of in the scripts/FE/ directory. Did this get reverted after a new code exchange?
  4. I tried restarting the code using c1startscx, but that doesn't work correctly. It cannot find the burtrb and burtwb files even though they are in the normal path.
  5. Kiwamu was using a bunch of cockamamie filters I found.
  6. I can't get any minute trend data. I tried on rossa, rosalba, and op440m.
MC damp dataviewer diaggui AWG c1lsc c1ioo c1sus c1iscex c1iscey RFM The Dolphins Sim.Plant Frame builder TDS Cabling
  4318   Thu Feb 17 23:11:40 2011 ranaUpdateElectronicsVCO Frequency Noise Measurement with the MFD

This is the 140 ft. MFD measurement of the VCO phase noise. It is open loop and so should be a good measurement. The RMS is 30 Hz integrated down to 2 mHz.

I don't know why this doesn't agree with Suresh's measurements of the same thing which uses the PLL feedback method.

In BLUE, I also plot the frequency noise measured by using a Stanford DS345 30 MHz func. generator. I think that this is actually the noise of the FD (i.e. the SR560 preamp) and not the DS345. Mainly, it just tells you that the PINK VCO noise measurement is a real measurement.

I calibrated it by putting in a 5 kHz_pp triangle wave on the sweep of the DS345 and counting the counts in DV.

Attachment 1: vco.png
  4319   Thu Feb 17 23:41:46 2011 ranaFrogsDAQFrames Directory got the wrong name: Data unreachable

DTT stopped working for recent data. An 'ls' in the frames/full/ directory reveals:

drwxr-xr-x 2 controls controls 258048 Feb  3 12:26 9807
drwxr-xr-x 2 controls controls 258048 Feb  4 16:13 9808
drwxr-xr-x 2 controls controls 262144 Feb  5 19:59 9809
drwxr-xr-x 2 controls controls 258048 Feb  6 23:46 9810
drwxr-xr-x 2 controls controls 258048 Feb  8 03:33 9811
drwxr-xr-x 2 controls controls 262144 Feb  9 07:19 9812
drwxr-xr-x 2 controls controls 253952 Feb 10 11:06 9813
drwxr-xr-x 2 controls controls 266240 Feb 11 14:53 9814
drwxr-xr-x 2 controls controls 266240 Feb 12 18:39 9815
drwxr-xr-x 2 controls controls 266240 Feb 13 22:26 9816
drwxr-xr-x 2 controls controls 262144 Feb 15 02:13 9817
drwxr-xr-x 2 controls controls 253952 Feb 16 05:59 9818
drwxr-xr-x 2 controls controls 241664 Feb 17 09:46 9819
drwxr-xr-x 2 controls controls  28672 Feb 17 12:22 9820
drwxr-xr-x 2 controls controls  32768 Feb 17 15:06 6663
drwxr-xr-x 2 controls controls  73728 Feb 17 23:39 6664
controls@fb /frames/full $ date
Thu Feb 17 23:39:27 PST 2011

  4329   Sat Feb 19 01:58:20 2011 ranaSummaryElectronicsLow Noise BJT Pre-Amp

Frank put his low noise preamp info here.

I suggest that we build these (using Altium) but replace the cheapo transistors with the high class MAT03 matched BJT pair from Analog Devices.

This will allow us to have a pre-amp better matched to the noise of the mixers down to low frequency.

  4333   Mon Feb 21 17:29:57 2011 ranaSummaryIOOMyterious data loss: FB needs investigation

Looks like there was a mysterious loss of data overnight; since there's nothing in the elog I assume that its some kind of terrorism. I'm going to call Rolf to see if he can come in and work all night to help diagnose the issue.


  4363   Sun Feb 27 13:09:56 2011 ranaUpdateGreen Lockingsidebands on beatnote

When Koji and I were massaging the MC, we noticed that the oscillations were at 48.5 kHz. They were pretty huge and are probably what you're seeing on the beat. My guess is that they are the PZT resonances of the PSL 2W NPRO; we need to put a notch in the FSS box - it still has the notch from the old NPRO.

  4375   Thu Mar 3 20:30:03 2011 ranaSummaryPSLPMC Sweeps @ different input power levels to measure the Finesse

Its been well noted in the past that sweeping the PMC at high power leads to a distortion of the transmitted power curve. The explanation for this was coating absorption and thermo-elastic deformation of the front face of the mirrors.

Today, I did several sweeps of the PMC. I turned off its servo and tuned its PZT so that it was nearly resonating. Then I drove the NPRO via the HV driver (gain=15) with 0-150 V (its 1.1 MHz/V) to measure the PMC transmitted light. I adjusted the NPRO pump diode current from 2A on down to see if the curves have a power dependent width.

In the picasa web slideshow:

There are 3 significant differences between this measurement and the one by John linked above: its a new PMC (Rick says its the cleanest one around), the sweep is faster - since I'm using a scope instead of the ADC I feel free to drive the thing by ~70 MHz in one cycle. In principle, we could go faster, but I don't want to get into the region where we excite the PZT resonance. Doing ~100 MHz in ~30 ms should be OK. I think it may be that going this fast avoids some of the thermal distortion problems that John and others have seen in the past. On the next iteration, we should increase the modulation index for the 35.5 MHz sidebands so as to get a higher precision calibration of the sweep's range.

By eye I find that the FWHM from image #4 is 11 ms long. That corresponds to 300 mV on the input to the HV box and 15 V on the PZT and ~16.5 MHz of frequency shift. I think we expect a number more like 4-5 MHz; measurement suspicious.

  4400   Thu Mar 10 14:30:53 2011 ranaUpdateGreen LockingIntensity noise limits the beatnote sensitivity

There are 3 standard techniques to reduce this effect:

1) Stabilize the end laser by sensing the green light coming into the PSL before recombination and feeding back with SR560 (this is the only one that you should try at first).

2) Moving to the center of the MFD fringe via ETM steps.

3) Auto-alignment of the beam to the arm.

  4403   Thu Mar 10 21:45:34 2011 ranaUpdateGreen LockingIntensity stabilization loop using beatnote DC.

Ridiculous and hacky. Digital stabilization removed as well as the old "leave a pile of equipment on a stool" strategy.

We used a a BNC cable to send a pickoff of the beam before the recombination to the end via an SR560.

  4408   Sun Mar 13 04:00:53 2011 ranaUpdateCDSETMY Sim work

I did some work on the ETMY real and Sim.

  1. Set SUS coil gains to have the same quadropole arrangement as the magnets do (-1, 1, 1, -1) so that POS = POS instead of pringle.
  2. Set the Sim Magnet polarities to match this. These are the ETMY_CI filter banks.
  3. Found that the Xycom cable from the ETMY slow controls was unplugged at the Xycom side. This was preventing enabling the ETMY coil driver and so there was no real damping of the suspension going on. I plugged it in and checked that the mirror could now be moved.
  4. The C1SUS_ETMY master screen's BLUE output filter area is now mis-labeled. If you trust the screen you would set it up to drive the suspension incorrectly. This MUST be fixed along with all of the other misleading features of the screen.
  5. ETMY SUSSIDE filter bank had a 2048 Hz sample rate and was making the damping not work correctly. Fixed to 16384 Hz.
  6. 12 Hz, 4th order Cheby low pass added and turned on for the local damping filtering. This is not optimum, but its just there to give us some filtering without introducing some instability via phase lag around 3 Hz.
  7. ETMY OL beam re-aligned on ISCT-EX.
  8. TM Offset buttons not working on the main overview screen.

It seems like there is still a problem with the input whitening filters. I believe the Xycom logic is set such that the analog whitening of the OSEM signals is turned ON only when the FM1 is turned OFF. Joe has got to fix this (and elog it) so that we can damp the suspension correctly. For now, the damping of the ETMY and the SETMY require different servo gains and signs, probably because of this.

  4450   Mon Mar 28 18:13:32 2011 ranaUpdateGreen Lockinga mixer school

Using 2 dBm for a Level 7 mixer is so bogus, that I will dismantle this as soon as I come over.


  4453   Mon Mar 28 22:56:14 2011 ranaUpdatePSLNew PMC Base Riser Design

Its going to need some kind of way to locate the PMC on the top. In the previous design, we had the 3 balls to decouple the body from the base. That design was flawed due to the roughness of the holes in the PMC body.

Also probably need some kind of relief on the bottom. Its possible that it would be OK like this, but I am unsure if the shop can maintain the flatness we want over the whole length and/or the flatness of any given (OLD) optical table over ~8". Its probably not a good idea to have to torque this (aluminum?) to make it conform to the optical table's shape.

  4507   Mon Apr 11 09:49:53 2011 ranaUpdateElectronicsNew Green PD test1

 Ooh. Can you explain the purpose of the resistors which are connected to the (+) inputs? It looks like some real electronics ninjitsu.

  4514   Mon Apr 11 23:35:02 2011 ranaUpdateRF SystemInstalled low pass filters in the demod boards

I am a little concerned about using these low pass filters so close to the band edge. Recall that there is no on-board preamp for the RF input to the mixer.

So, if the input impedance of the filters is not 50 Ohms, we will get some unwanted reflections and sensitivity to cable length.

I think its worth while to check the impedance or S-parameters of these things with the LO activated to find out if we need to remove them or not.

  4537   Sat Apr 16 02:00:14 2011 ranaUpdateLSC11MHz demod board : 90 degree splitter

One way to avoid some of the bad stuff in there is to take the 1 dBm input and amplify it to ~21 dBm before splitting and sending in to the Level 17 mixers.

One way to do this is by using the A3CP6025 from Teledyne-Cougar. Its an SMA connectorized amp which can put out 25 dBm and has a gain of 24 dB. We can just glue it onto the demod boards. Then we can remove the ERA-5 amplifiers and just use the broadband splitter as Kiwamu mentioned.

  4559   Fri Apr 22 10:28:22 2011 ranaUpdateRF SystemRF Source Harmonics
You should be able to resolve the other harmonics by decreasing the IF BW or RBW on the analyzer. Even though
they're OK, its useful to have the final measurement of all of them in some kinds of physical units (like dBm, but
not dBm/Hz or dB or dBcubits).
  4568   Tue Apr 26 01:20:02 2011 ranaUpdateElectronicsPOX_11 debugging

The performance plots for POX_11 in the wiki are horrendous and the schematic is missing.

I opened up the box and found all kinds of horrors. There were multiple tunable parts and a flurry of excess nonsense.

The top 2 worst offenders:

1) The main tunable inductor was busted. I removed it and found that the coil was open. Too much indelicate soldering in its vicinity had melted the wire. Someone had put extra inductors and capacitors around it to make it seem as if the PD was working fine, but the noise performance was off by a factor of ~100.

2) The MAX4107 had a 1.4k series resistor. This make the output go through a 1450/50 voltage division which is not nice for the SNR. I removed it.

I then struggled for awhile to get a sensible response. It turned out that the TEST IN input was not giving me a sensible TF. Jenne and I fired the Jenne laser at it and found that the 11 MHz main resonance is there. In the morning I'll finish this off and post more results. I think its going to end up being fine.

We are going to have to take a careful look at all the RFPDs if this one is any indication...

  4569   Tue Apr 26 22:03:49 2011 ranaUpdateElectronicsPOX_11 debugging

I used the Jenne AM laser to tune up the PD (used to be POX_11 but now is called REFL_11). In addition to the notch at 22 MHz, I have also put in a LC notch at 5*f = 55.3 MHz. The transfer function below shows the RF OUT of the PD v. the drive to the laser. I didn't divide out by the 1811 because its not on the EE bench.



  4576   Wed Apr 27 21:08:08 2011 ranaUpdateLSCAS11

I worked on AS_11 today. Its ready for its noise / optical gain calibrations. I have left it on Suresh's desk.


This was one of the 24.5 MHz Black Box (Ben Abbott) style RFPDs rescued from LLO. The tunable inductor that was installed was too small to get the frequency down to 11 MHz and so I swapped in one of the shielded, ferrite core ones from our '7mm' CoilCraft kit. It had a range of 1.2 - 1.8 uH according to the datasheet.

I wasn't able to simulataneously get the peak at 11.06 MHz and the notch at 59.3 MHz and so I took Koji's advice and tuned the peak best. The plot above shows how the notch is slightly off. I think its not a problem; to get it better we would have to change out the inductor for the "2-omega" notch, but I was too lazy. The thinking is that its more important to have the gain be symmetric around the signal readout frequency so as to not imbalance the audio sidebands.

Since this one is going to be AS_11, we think that the 22 MHz signal will be tiny: the transmission of the 11 MHz sidebands to the dark port is small. If we later want to put in a 22 MHz notch anyway, there is space to do this via the 'active notch' pads around the MAX4107.

For the above plot, I used the Jenne laser. The DC output of the PD was ~30 mV (~0.6 mA). The RF drive to the laser was -10 dBm: no saturations. I have calibrated out the cable responses, but not using the 1811 setup, so the absolute calibration has yet to be done.

Also, it needs some new stickers. It would be handy if someone can figure out how to get some sheets of stickers that we can put into the printer. Then we can laser printer all of the data onto the stickers and stick them to the RFPD box.

  4589   Fri Apr 29 13:58:36 2011 ranaUpdateLSCY arm locked : details


 * Farfalla, a lab laptop, seems out of network.

 If you look at the real host table instead of the misleading host table in the wiki, you will see that someone has deleted Farfalla from there. She needs to be re-added.

  4620   Tue May 3 18:46:06 2011 ranaUpdateIOOMC Locking not working

I found that the MC autolocker was OFF. Kiwamu says he turned it off because its slow. Suresh says that he has some feelings that maybe something is wrong. I'll let them describe what they know about the MC in an elog.

I checked the trend of the MC and PMC transmissions for the past 30 days:


Looks like the alignment has been drifitng. PMC was corrected recently by Koji, but the alignment of the input beam to the MC or the MC itself has to be fixed. Has someone been twiddling the MC SUS alignment biases??

Attachment 1: Untitled.png
  4647   Thu May 5 18:38:01 2011 ranaSummaryCDSSub-system TRAMP adjustments

I think that the gain ramping time (_TRAMP) should be set to 1 second for all filter modules by default. We don't want them to switch instantaneously except in a few special cases.

So Jamie and I wrote a script (in scripts/general/) which sets all of these fields to 1 for a given system. The name of the system is an argument to the script. e.g.

>  setTRAMP LSC 1

The idea is that we set it once and then from then on, its captured by the autoBURT. Of course, we have to run this script each time we add new filter modules to a model.

  4661   Sun May 8 17:29:01 2011 ranaUpdateIOOMC beam spot centering

It seems like the best option would be to make the MCASS just adjust the SUS biases and center the beams on the suspended optics. Is this not possible somehow?

  4662   Sun May 8 22:59:40 2011 ranaUpdatePSLPSL reference cavity temperature box modifications

I looked at the PSL temperature box. It started out as D980400-B-C. Then it was revised by Peter King as per the LHO mods E020247.

There are some more things to do to it to make it useful for us:

  1. R3, 4, 7, 8, 12, & 13 should be changed from 1k to 0 Ohms, I think. I cannot figure out their purpose.
  2. All resistors should be made metal-film. Right now, its kind of a mish-mash.
  3. The active filter U6B has a corner frequency of ~50 Hz. This seems not useful for keeping the 4116 DAC noise out of the temperature. We should lower this to ~30 mHz to take advantage of the stability of the LT1021 which was put in.

** Frank reminds me that we don't use the TIdal or VME external inputs anymore since we moved to the EPICS/Perl PID control. So all we have to do is make sure these inputs are hardware disabled/disconnected.

  4672   Mon May 9 20:30:20 2011 ranaUpdatePSLPSL reference cavity temperature box modifications

I re-installed the box (@ ~8:15) after reflowing some of the solder joints. I will observe it over night and then remove the 1K resistors. Attached is a 8 hour minute-trend.

Attachment 1: Untitled.png
  4681   Tue May 10 20:57:05 2011 ranaUpdatePSLPSL reference cavity temperature box modifications : after 24 hours still OK


I re-installed the box (@ ~8:15) after reflowing some of the solder joints. I will observe it over night and then remove the 1K resistors. Attached is a 8 hour minute-trend.

 I compared this 24 hour trend with the one from this day exactly one year ago. Seems the same, so now I can make the resistor change.

Attachment 1: Untitled.png
  4693   Wed May 11 21:58:30 2011 ranaUpdateSUSETMX_OPLEV : He-Ne replaced



I found that a He-Ne laser which has been used for ETMX_OPLEV was NOT giving the light.

Since I didn't find the switch key for it I have no idea if the laser is simply off or dead.

 The dead laser was replaced by new JDSU 1104P of  2.6mW. The return beam is big ~5 mm diameter of 0.3 mW,  1400 counts

 Whenever replacing any Oplev laser, please also put into the ELOG when it was installed so that we have an electronic record of the laser lifetime.

  4702   Thu May 12 10:27:02 2011 ranaUpdateRF Systeminstallation of RF splitters in Demod boards


Rana also advised that we must use the boards which have the piggy-back amplifiers on those signals which are most useful.  We referred to Alberto's thesis and chose POY55 (MICH and SRCL), REFL11(PRCL)  and AS55 (DARM) as the most useful signals.  We currently have these amps on AS11, REFL11 and AS55.  We need to convert either AS11 or REFL11 into a POY55.  Since we need to troubleshoot REFL11, I thought we might as well modify that and in the process also fix its Q output.  So I renamed AS11 as REFL11 and will convert the old REFL11 into POY55 tomorrow. 

 I think we should leave them as is; the AS11 was made by taking into account the SB levels at the AS port and should not become REFL11. We should instead convert one of the old 25 or 33 MHz diodes into a POY55.

  4705   Thu May 12 22:54:20 2011 ranaUpdateDAQInput Beam Naming change (no more IP)

 We decided to rename the Input Beam channels (while keeping temporary backwards compatible aliases) as:


  4707   Thu May 12 23:41:47 2011 ranaUpdateCDSMEDM Snapshots not working

Looks like 2 different MEDM Snapshot functiions (at least) are broken.

The regular update of the screens here as well as the usual "Update Snapshot" and view "previous snapshot" button on all of the auto-generated screens.

Also, how do we add the snapshot button to the custom made screens?

  4718   Sun May 15 03:58:19 2011 ranaUpdateCDSdiagonalization of MC input matrix

There has been some input matrix diagonalization in the past by Yuta and Kiwamu, but I find the automation to be not totally satisfactory.

It would be better if we could automatically fit the data to find the Suspended optic eigenfrequencies and then use that to get the matrix. So I wrote a peak fitter to get the matrix.

It gets the data from mafalda with NDS2, then it makes the PSDs, and then starts with some initial guesses (based on looking at the plots) and them uses fminsearch to get the peak frequencies and Q's.

Using the output of this, we can use Yuta's method and take the passive transfer functions with the free swing data (from April 30, so we got do do it quick) to get the input matrix.


Doing the SUS input matrix is nice for having good damping (as long as we remember to include SIDE), but my motivation is to produce a good null stream from the 4 face sensors so that we can estimate the sensor noises at all times.

Attachment 1: mc1.png
  4725   Mon May 16 11:14:36 2011 ranaUpdateIOOwiring diagram for IP-POS

Just FYI, the 3113 is a 12-bit ADC, so we won't get very good resolution out of these. We should get one of those purple boxes.

Also, I corresponded some with Dave Barker. The 40m Wiki at LHO is down because of disk errors. He's working on it and will let us know. But suggests that we move it to Caltech since he'll turn the box off at the end of the year.

Mon May 16 13:57:49 2011    Wiki is back up.

  4743   Wed May 18 22:11:31 2011 ranaConfigurationLSCNew digital lockin added to LSC model/screen


 This is OK....but, the input matrix should come from the same place as the regular input matrix: i.e. it should be just another row like CARM, DARM, etc. rather than have its own screen.

Also, I think a nice mod to all the matrices would be if the ORANGE triangle was only visible when there's a signal flowing through it.

  4745   Thu May 19 00:22:21 2011 ranaUpdateelogRestarted, Italian-style


Aka, from a hotel in Pisa.

 Restarted Thu May 19 00:21:49 2011 to recover from Jenne's Italian terrorism.

  4746   Thu May 19 00:23:44 2011 ranaUpdateCDSdiagonalization of MC input matrix

 I've moved all of my SOS peak fitting stuff into the scripts area so that Leo can make it better:


findPeaks.m gets the data and makes the fitted spectra that I put in the previous entry.

findMatrix.m is the barely started script that ought to take the TF data and output the matrix to the MEDM screen.

  4786   Mon Jun 6 02:09:39 2011 ranaUpdateElectronicsPOY11 Rework Nearly Complete

I've finished tuning POY11 and it is now sitting on top of the analyzer waiting for Koji to test its noise.


  1. R2 has been switched from a 50 -> 110 Ohm R and a (29 Ohm | 47 pF) in parallel to it. This makes the gain of the MAX4107 be ~20 above 100 MHz and ~5 around 11 MHz. The high gain at high frequency makes it stable (squashes the 200 MHz oscillation) and the low gain at low frequency is to prevent saturation (the raw 11 MHz transimpedance is too high).
  2. There are two notches: 22.12 MHz and 55.3 MHz.
  3. The TEST IN input has been disabled since it wasn't useful.
  4. 107 Ohms inserted into between the U11 output and the TSENSE feedthrough. This is to prevent oscillations when driving the long Dsub cable. This needs to be done on all Gold Box RFPDs.
  5. R4 -> 50 Ohms.
  6. Had trouble tuning this to get the resonance at 11.06 MHz. This turned out to be the parallel inductance coming from L3 (previously 1.45 uH) whereas we needed a total inductance of ~1.6 uH. So I changed L3 to 33 uH to get it to be negligible compared to 1.7 uH at 11 MHz. This needs to be considered for all the 11 MHz diodes.


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  4791   Mon Jun 6 22:41:22 2011 ranaUpdateSUSSwitching problem in SUS models

Some weeks ago, Joe, Jamie, and I reworked the ETMY controls.

Today we found that the model rebuilds and BURT restores have conspired to put the SUS damping into a bad state.

1) The FM1 files in the XXSEN modules should switch the analog shadow sensor whitening. I found today that, at least on ETMY and ETMX, they do nothing. This needs to be fixed before we can use the suspensions.

2) I found all of the 3:30 and cts2um buttons OFF AGAIN. There's something certainly wrong with the way the models are being built or BURTed. All of our suspension tuning work is being lost as a consequence. We (Joe and Jamie) need to learn to use CONLOG and check that the system is not in a nonsense state after rebuilds. Just because the monitors have lights and the MEDM values are fluctuating doesn't mean that "ITS WORKING". As a rule, when someone says "it seems to work", that basically means that they have no idea if anything is working.

3) We need a way to test that the CDS system is working...

Attachment 1: a.pdf
  4796   Wed Jun 8 22:48:09 2011 ranaUpdateCamerasITM camera lenses changed

I focused these lenses so that we could get a clean image of the mirrors and the OSEMs.

Our goal is to have an image where the optic diameter almost fills the entire monitor. We want the focus to be adjusted for the YAG beam (which is almost the same as focusing for the OSEMs). This will NOT produce a nice image of the cage using visible light, but that is just fine.

When Justin Garofoli was here he found a nice lens combo that did the job, so if anyone can find his old email or elog, lets just go back to that.

For now, we do not need a camera/lens system to focus very tightly on the center of the optic.

  4803   Fri Jun 10 12:02:10 2011 ranaUpdateCDSSecond trends only go back 12 days


While answering a quick question by Kiwamu, I noticed we only had second trends going back to 99050000 GPS time, May 27th 2011. 

Trends (I thought) were intended to be kept forever, and certainly longer than full data, which currently goes back several months.

Jamie will need to look into this.

 Our concept is to keep second trends for 1-2 months and minute trends forever. The scheme that Alan had worked out many years ago had it such that we could look back to 1998 and that the minute trends would be backed up somehow.

If its not working, we need to get Alan's help to recover the previous configuration.

  4830   Fri Jun 17 00:17:26 2011 ranaConfigurationElectronics2 RFPDs sent to LLO

Koji and I found 2 RFPD boxes to send to LLO. We've put them onto Steve's desk to be overnighted to Valera.

One of them is our old 21.5 MHz gold box RFPD from the FSS (which we don't use). The other one is a 2mm gold box one which was previously tuned for 66 MHz.


They shipped out on Friday

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  4843   Mon Jun 20 17:58:00 2011 ranaUpdateCDSGateway program killed

There was a rogue, undocumented, gateway process running on NODUS since ~4 PM. This guy was broadcasting channels back into the Martian and causing lockups in the IOO controls. I did a kill -9 on its process.

Someone will pay for this.

ELOG V3.1.3-