J. Kissel, R. Savage

After Rick and I conversed about the systems level compromises in play (see LHO:69175) when placing the newer 410.2 Hz PCALX line near the 410.3 Hz PCALY line for comparisons like that in LHO:69290, we agree to push forward with the plans discussed in LHO:69175:
    (1) Move the PCALX 410.2 Hz PCALXY comparison line further away from the pre-existing PCALY 410.3 Hz TDCF line. Joe, for entirely different reasons, recommends 0.5 Hz separation instead of 0.1 Hz. THIS ALOG

        The new frequency is H1:CAL-PCALX_PCALOSC2_OSC_FREQ = 409.8 Hz.
     
    (2) Update the "DARM Model transfer function values at calibration line frequencies" EPICs records for the PCALX 410.2 Hz line, NOT YET DONE, SEE BELOW
    (3) Revert all DEMOD the band-passes to have a pass band that's +/- 0.1 Hz wide (what we had in O3)      DONE ALREADY, and now for 410.3 Hz: see LHO:69265 and THIS ALOG
    (4) Revert all DEMOD I & Q low passes to a 10 second time constant, or 0.1 Hz corner frequency           DONE ALREADY, and now for 410.3 Hz: see LHO:69265 and THIS ALOG
    (5) Change COH_STRIDE back to 10 seconds to match the low pass, and Change the BUFFER_SIZE back to 13.0 in order to preserve the rolling average of 2 minutes. DONE ALREADY, and now for 410.3 Hz: see LHO:69265 and THIS ALOG

I've also modified the three band-pass filters in the SIG banks of the special segregated PCALX DEMOD for the PCALXY comparison (i.e. H1:CAL-CS_TDEP_PCAL_X_COMPARE_PCAL_DEMOD_SIG, _EXT_DEMOD_SIG, _ERR_DEMOD_SIG). These had had a pass pand with of 0.01 Hz, so I've created a new band pass for 409.8, butter("BandPass",6,409.79,409.81). It lives in FM1, and I've copied the old band for 410.2 Hz pass over to FM2.

In order to have *all* of our ducks in a row with the line move, we still need to do:
    (2) Update the "DARM Model transfer function values at calibration line frequencies" EPICs records for the PCALX 410.2 Hz line,
but that also means we need to do a step not listed above
    (0) Update the pydarm_H1.ini file to reflect that the pcalx comparison line is now at 409.8 Hz, and
    (6) Let the GDS team know that there's a calibration line frequency change and they need to update the GDS line subtraction pipeline.

This line frequency change is in play as of 2023-05-04 00:20 UTC.
Stay tuned!

Here's the latest list of calibration lines:
Freq (Hz)   Actuator               Purpose                      Channel that defines Freq             Since O3
15.6        ETMX UIM (L1) SUS      \kappa_UIM excitation        H1:SUS-ETMY_L1_CAL_LINE_FREQ          Amplitude Change on Apr 2023 (LHO:68289)
16.4        ETMX PUM (L2) SUS      \kappa_PUM excitation        H1:SUS-ETMY_L2_CAL_LINE_FREQ          Amplitude Change on Apr 2023 (LHO:68289)
17.1        PCALY                  actuator kappa reference     H1:CAL-PCALY_PCALOSC1_OSC_FREQ        Amplitude Change on Apr 2023 (LHO:68289)
17.6        ETMX TST (L3) SUS      \kappa_TST excitation        H1:SUS-ETMY_L3_CAL_LINE_FREQ          Amplitude Change on Apr 2023 (LHO:68289)
33.43       PCALX                  Systematic error lines       H1:CAL-PCALX_PCALOSC4_OSC_FREQ        New since Jul 2022 (LHO:64214, LHO:66268)
53.67         |                        |                        H1:CAL-PCALX_PCALOSC5_OSC_FREQ        Frequency Change on Apr 2023 (LHO:68289)
77.73         |                        |                        H1:CAL-PCALX_PCALOSC6_OSC_FREQ        New since Jul 2022 (LHO:64214, LHO:66268)
102.13        |                        |                        H1:CAL-PCALX_PCALOSC7_OSC_FREQ           |
283.91        V                        V                        H1:CAL-PCALX_PCALOSC8_OSC_FREQ           V
409.8       PCALX                  PCALXY comparison            H1:CAL-PCALX_PCALOSC2_OSC_FREQ        New since Jan 2023, Frequency Change THIS ALOG
410.3       PCALY                  f_cc and kappa_C             H1:CAL-PCALY_PCALOSC2_OSC_FREQ        No Change
1083.7      PCALY                  f_cc and kappa_C monitor     H1:CAL-PCALY_PCALOSC3_OSC_FREQ        No Change
n*500+1.3   PCALX                  Systematic error lines       H1:CAL-PCALX_PCALOSC1_OSC_FREQ        No Change (n=[2,3,4,5,6,7,8])