Strange data (?) signal on 6860 kHz

[WA4FHY]

I usually park on 6925 kHz if I'm not doing anything else; one afternoon last year,
just before Thanksgiving, I started seeing a strong carrier on 6860 kHz. It was of
interest because it was much stronger than any other signals in that part of the band -
 see screenshot below (I hope!). The signal would come on near local sunrise, NOT fade
in but as if someone flipped a switch; it was of more or less stable strength until around
sunset when it would go away just as it appeared in the morning - as if someone
flipped a switch off. One day I decided to see if it was a real signal: 1) fired up the trusty
ol' R-70 and yes, it was there, 2) I logged onto several remote SDRs, from the Northeast to
Point Reyes, with a stop at the Northern Utah SDR - it could be received on all of them. 




Shortly after the first of this year, I noticed a change - I could see what looked like modulation
that seemed to be near random bursts of data. See image below. Also, it did not show up
as regular as in the past.


More recently, it has changed again - the carrier is gone, only the random data bursts
show up! See image below.


This has my curiosity; I have no idea what this is. Any thoughts on this anyone???

10may21 - Looks like the same, or similar, station is using 6885 kHz this morning.

19sep21 - This, or similar, station is now sometimes on 6860 kHz, 6885 kHz, or 6988 kHz
                 Seems to change with time of day. Also, "data bursts" are not as wide as originally seen