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Reports until 21:04, Friday 02 September 2016
H1 ISC
sheila.dwyer@LIGO.ORG - posted 21:04, Friday 02 September 2016 (29477)
reshaping CSOFT pitch, other locking today

Overall message:

More about CSOFT PIT:

We were using a control filter that had a pair of complex zero compensating the 0.4 Hz resonance, which meant we had very little gain to supress the instability using ASC.  I changed this to a single real zero, which gives us 20 dB gain at the instability frequency. The filter comparison is attached, and a measurement taken at 2 Watts.  In the green measurement I had made a msitake in the filter at 1.5 Hz, the red measurement is with this fixed and the phase should be unchanged from the old design at these frequencies.

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Displaying report 1-1 of 1.