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Reports until 18:36, Monday 29 September 2014
H1 ISC
keita.kawabe@LIGO.ORG - posted 18:36, Monday 29 September 2014 - last comment - 15:44, Wednesday 01 October 2014(14209)
EY WFS RF whitening nonsense (again)

Summary:

Some whitening settings for EY green WFSA  I3, Q3 and WFSB Q2 channel don't work. It's probably the whitening chassis itself as the whitening request and the readback agree with each other.

For now I'm leaving both of the chassis in place as there are some usable settings, but note that these guys have a history of many troubles due to chassis and crappy cablings (1215912138, 12127).

Details 1:

For WFSA I3 and WFSB Q2, the measured whitening gain doesn't match the request and the readback (attached).

You can see that in both cases one of four stages (+3dB, +6dB, +12dB and +24dB) is failing. It's the 12dB gain stage for WFSA I3 and the 6dB stage for WFSB Q2.

These were measured injecting 20mVpp signal at 100Hz using a function generator and a breakout board.

Details 2:

For WFSA Q3, the third whitening filter doesn't turn on.

For now:

I set the gain to +27dB and turned all filters off.

Images attached to this report
Comments related to this report
keita.kawabe@LIGO.ORG - 08:36, Wednesday 01 October 2014 (14241)
It still might be the cable, so we'll check the cable using bio tester.
keita.kawabe@LIGO.ORG - 15:44, Wednesday 01 October 2014 (14255)

Update: It was crappy connector shell.

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=14243

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