The noise reported earlier in log 24789 looks like another case of RF 45 problems that were not picked up by the monitor.

The first attachment is a spectrogram of DARM showing the burst of noise then a moving comb of lines. We've seen the RF 45 trouble manifest this way before - see log 23269.  Looking carefully at the monitor channel (second plot), one of the lines does appear there, though the burst of noise does not. POP_A_9Q does a good job of witnessing the problem (third plot).