This evening, in the on-going program to evaluate noise produced by the HVAC, I shut down just the 5 operating CS turbines, in AH1,2,3. The figure shows the range increase (about 4 Mpc), DARM spectra (decrease between 20 and 200 Hz), and vibration spectra.

Start shutting down: 1:00 UTC Nov 9

Start  turning on: 1:10

Start shutting down: 1:20

Start turning on: 1:30