I've noticed when the band is up 50.315 has a carrier that is very strong at times but never any audio. Also I'm getting a similar one at 54.310 but they don't seem to be linked.
50.313 mHz is Amateur Radio FT8 modulation USB data. Depending on your receiver and mode it may sound like carriers w/o modulation... and be observed on 50.315.
Glad it helped. Yes, it has some coverage. I wonder what the power output is. As I type this it's still there when nothing else is. It's like some guy has an FT8 setup connected to a KW amp or something.
It’s not coming from a single station. Multiple ham stations transmit simultaneously for 15 seconds, then receive for 15. 6 Meter propagation has been very good lately so you are receiving even more stations than normal. You can demodulate the transmissions with WSJT-X software by K1JT. And join in the communications with a ham license.
Sometimes I leave WSJT running on 50.313 in the background. Great indicator of the band being open. I'm seeing hams in Mexico & Canada this evening from Oklahoma.