cav1_set1.mat - Initial narrowband measurement on cavity 1, pretty close
cav2_set1.mat - Cavity 2 about 6.25 kHz low
cav2_set2.mat - Moved tuner C by -1270 degrees
cav2_set3.mat - Span to 400 kHz
cav1_set2.mat - Span to 400 kHz

Cavity 1:
        G: 0.3391
    sigma: 1.7959e+05
       wr: 3.1395e+09
        x: [0.3391 1.7959e+05 3.1395e+09 9.7266e-07 -86.1302]
      tau: 9.7266e-07
      phi: 105.1059
        Q: 1.7482e+04

Cavity 2:
        G: 0.4263
    sigma: 1.8873e+05
       wr: 3.1395e+09
        x: [0.4263 1.8873e+05 3.1395e+09 9.8095e-07 -105.3276]
      tau: 9.8095e-07
      phi: 85.1756
        Q: 1.6635e+04

Moved attenuation around to raise the maximum probe signal level and to
adjust the loop gain for at least unity at nominal high voltage
