thomas.shaffer@LIGO.ORG - posted 11:10, Tuesday 26 March 2019 - last comment - 11:49, Wednesday 27 March 2019(47883)
Started HIGH_FREQ_LINES Grd with new starting freq
Pep Covas, T. Shaffer
Started the HIGH_FREQ_LINES Guardian node to sweep H1:CAL-PCALX_PACALOSC1_OSC_FREQ from starting frequency to 2000Hz by 500Hz steps. The steps will happen every 12 hours, but it will wait until we are not locked to change the frequency, so it could be longer than the 12.
Line amp = 35000
Starting freq = 5950.0Hz
Step size = 500Hz
We unmonitored H1:CAL-PCALX_PCALOSC1_OSC_FREQ in SDF.
J. Kissel, P. Covas
We found that the PCALX saturated, so we turned off the line at 5950.0 Hz, then turned off the optical follower servo and then reenabled it. Then we turned up the line around 0:18 UTC. We saw the non-linearity (down-conversion) seen previously in O2 is still there, which produces a line at 86 Hz, as can be seen in the attached plot. At 0:24:45 the frequency of the line was changed to 3 kHz.
We have seen that the line had been reverted back to ~6kHz. At 18:47 UTC we have changed it to 3001.3 Hz