Reports until 15:23, Monday 21 December 2015
H1 ISC (DetChar)
evan.hall@LIGO.ORG - posted 15:23, Monday 21 December 2015 - last comment - 16:36, Monday 21 December 2015(24365)
45 MHz glitching again

45 MHz stabilization started gitching circa 23:15:00 Z.

This was accompanied by a drop of a few percent in AS90.

Nothing is visible in the spare amplitude demod on the ISC rack (23567). Noise appears stationary with an rms of a few millivolts, meaning the RAN of this glitch at the ISC rack (not including the EOM driver chain) is less than a few parts in 105.

Comments related to this report
jim.warner@LIGO.ORG - 15:29, Monday 21 December 2015 (24366)

Things are continuing to degrade. We have dropped out of observing and Evan has gone out onto the LVEA floor to poke at some of the electronics.

evan.hall@LIGO.ORG - 16:36, Monday 21 December 2015 (24369)

Daniel, Jenne, Evan

The 45 MHz jump appeared in AS90 and ASC dc sum.

AS90Q increased in amplitude, while AS90I decreased in amplitude, indicating a phase shift of the 45 MHz. The drop in ASC dc sum means that there was also an amplitude shift.

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