Sudarshan, Kiwamu,

As planned, we disabled the two pcal lines at around 550 Hz this evening (i.e. 534.7 and 540.7 Hz, see alog 19272) which brought some saturation issue the other day (alog 19891). From now on, we will have to use the 325.1 and 331.9 Hz lines (alog 19823) for calibration for the  high frequency part.

Also, we moved the suspension line from 538.1 Hz (alog 19926) to 329.9 Hz so that it is close to the new Pcal lines at around 330 Hz. We chose this frequency based on a prime number, 3299. This frequency should be also good in terms of the continueous wave search according to Jeff's alog 14836.

We tested the new suspension line in full lock, with DARM actuating on ETMY with a low pass ESD filter engaged. As we kind of expected, the suspension line used up a good fraction of the total rms in ESD DAC counts. We decreased the line amplitude by more than a factor of two, which resulted in 1x10⁴ counts in the ESD DAC as of now. This is sort of OK, but commissioners can feel free to disable it if necessary. The attached shows a spectrum of the ESD DAC when it was fully locked with the low pass engaged on ETMY and with the new suspension line injected. As seen in the spectrum, the suspension line is a dominant rms source when the low-pass is engaged. Also a screenshot of the new setting for the suspension line is attached.