Return to 472kHz WSPR

At about 1920z I gave up on 6m and returned to MF for the evening and overnight. My best DX spot was from G3WCB (101km). at -20dB S/N.   I am again using 5mW ERP from the short baseline earth electrode "antenna". Within just a few minutes on 472kHz WSPR  I am getting results whereas nearly a day on 6m drew a total blank.