Still life on MF and LF

It is some time since I was active on 137kHz and 472kHz WSPR, but there are still stations active I see. I shall return to 472kHz WSPR in the autumn and may even try some tests from this QTH on 137kHz. I do need a better antenna and earth system though. My earth-electrode "antenna" is remarkable, but I know I should be able to increase my ERP considerably with a loop or loaded long-wire. I managed 250km on WSPR with a loop at the old QTH on 137kHz and a vertical loop with similar loop area should be possible I think. I shall probably need help from locals with erection though in my present state. I might change to a 2m big-wheel stack at the same time?