Thanks John. I use Spectrum Lab, and also run WSJTx on a laptop with Windows 10. Receiver tuned to 13,553.900 (USB)
Spectrum lab provides a lot of great features, apart from the obvious seen in these captures. One thing I played with, but conditions at the time precluded useful observations, was to use the "plotter" function to record propagation during the day. This is quite easy to set up, and I was able to configure a plot of signal - noise for a couple of beacon frequencies. Noise was measured from an average "power" in a thin sliver of band with no signals. Signal was measured from whatever peak strength was seen in a thin sliver containing a beacon. I believe there was a write up in Lowdown by an experimentor using VLF signals, tracked in a similar way, to reveal SID events.
Ed
I've yet to pursue the idea further, but general current conditions may yield more interesting results.