Back on 472kHz

I have decided to go back onto 472kHz WSPR TX (and RX) with the 15m baseline earth-electrode antenna. Already I am getting spots from the usual UK local and semi-local (101km) stations. I shall leave the system running through the night in the hope of increasing the total number of unique spots of my signals to greater than 22.  On RX I think I need a preamp with the earth-electrode antenna as signals are weaker than with the PAR antenna "in the air".