I have closed down on 6m and 10m WSPR and have been on 630m (472kHz) WSPR for about an hour with 5mW ERP and no preamp using the earth-electrode "antenna". Best DX on RX is DH5RAE (995km). For the second night in a row GW0EZY (251km) has spotted my 5mW ERP WSPR.
UPDATE 1946z: We definitely need a few new stations on 472kHz WSPR. I am rapidly exhausting stations "in range".