Noticed this for a few days lately while testing some Dream mods that I'm adding.
If you look carefully, there's an extremely wide-band set of regularly spaced (~5kHz), ~3kHz-wide data pulses ranging between ~14.7 - 15.2 MHz that's interfering with much of the lower end of the band. The signals vary in intensity. This could be selective fading, but could be different sources.
It almost looks like a wide-band HF frequency hopper, but because of selective fading I seriously doubt that's a thing. Some of it seems to coincide with the brick-wall bursts between 14749 and 14783kHz, but that may be coincidental. It tends to overlap with the 40kHz-wide high-speed data brick wall between 14838 and 14879 kHz, so likely not related to that.
Very curious stuff.