Thanks for responding. What's odd is that the signal spans the entirety of the 19 and 20 bands (in this example) and stays on for very long periods, often until those bands lose propagation. At first, I thought it might be some sort of "new" ionosonde technology, but why for just two segments of the spectrum? The other question is, what the heck kind of device is transmitting simultaneously on all those frequencies without causing QRM to existing frequencies. None of the hams or SW broadcasters seem to be affected. At least none of the ones I listened to while monitoring the pulses. Very odd.