Anyone have any idea what this noise is?

This noise comes and goes at my location. It repeates every 5 seconds and goes from below 1 Mhz to 14 MHz.  Sometimes modulation becomes very complext with waterfall looking like a 4 leaf clover. I am close to Ft Bragg army base so it might be military.

Sometimes waterfall looks like a christmas tree.  It will bother me for days and then its gone for a week or two.