Earlier this evening, I tried hand-tuning the a2l coefficients for PRM and SRM. Just as I was finishing and trying to see if I actually did anything good, the RF45 went crazy, so we'll have to wait for a future lock to really start looking at coherences, etc.
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PRM Pit
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Dither M3 at 20.125 Hz, 8 counts.
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Change M3 P2L gain from 0 to +1.1 to minimize the peak in PRCL.
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No discernible change in the peak height in DARM.
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Using P2L gain of +0.5 was better for minimizing the peak in DARM, but not for minimizing the peak in PRCL.
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PRM Yaw
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Dither M3 at 20.125 Hz, 20 counts.
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Change M3 Y2L gain from 0 to +0.87 to minimize peak in PRCL.
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This makes the peak in DARM worse! Why?
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SRM Pit
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Dither M3 at 20.125 Hz, 10 counts.
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Change M3 P2L gain from 0 to -1.0.
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Minimizes peak height in SRCL.
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Drastically reduces peak height in DARM.
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SRM Yaw
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Dither M3 at 20.125 Hz, 10 counts.
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Change M3 P2L gain from 0 to -1.2.
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Minimizes peak height in SRCL.
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Drastically reduces peak height in DARM.
After this, I ran A2L for the test masses. Then RF45 went bad. So, I'll come back to this tomorrow.