472kHz WSPR

We are now approaching the DX season on 472kHz. Last autumn, I used my homebrew transverter and was regularly spotted in Norway despite using 10mW ERP WSPR and my earth-electrode "antenna" in the ground. The transverter puts out about 12W into 50 ohms, but the "antenna" is quite inefficient. 

When I left the band earlier in the year, I think there was a break in the connection to the "antenna" which I need to mend.

See https://sites.google.com/site/g3xbmqrp3/mflf/472wspr

See also https://sites.google.com/site/g3xbmqrp3/mflf/472khz_tvtr