500kHz (600m) Activity is increasing slowly as more stations in more countries get active. Once your Antenna efficiency RX or TX reaches a certain level the circle of possible contacts expands. The number of of stations logged quickly get to a level and new ones are slow to come in.
I am pleased to have a report overnight from the POLICE, well the call always looks like that and makes it memorable, I think, let me try, PA0LCE, yes that's right at 423Km and -33dB on WSPR so right on the edge of de-code-ability.
There are several more bridges to cross. Local stations at 5 to 6 Km and 15 Km who report, no see, although there may have been an odd 30 seconds of good signal at 6Km the other night, not enough QRSS to be sure. These local distances intrigue me.