136kHz using the earth electrode "antenna"

This evening I was able to copy G3XIZ on 136.5kHz CW at 559 using my deaf (at 136kHz) FT817 fed from my 20m base earth electrode "antenna" used on VLF. I've made a recording and emailed it to Chris who is 46km away from me. Later this year I hope to transmit QRSS or CW on 136kHz, but the antenna needs some thought as I don't have much space.