The 66 Hz was a bad choice since Hrec uses this frequency band to estimate the SNR of several lines, even at 71.5 Hz, instead of the adjacent bins as in the past. With the wrong line SNR, Hrec was not recomputing the optical gains and producing a wrong h(t) and BNS range.

It took us a while to remember/discover this feature.

All NCal lines have been moved to near 36 Hz, restoring the proper behavior of Hrec.