Earth-electrode antenna on 40m

This evening I have been trying my stealth antenna (20m separated earth-electrodes, wire in the grass!) on 40m again and getting plenty of WSPR spots. I did try to match it on 160m earlier but couldn't get it below about 3:1 using the Elecraft T1 auto-ATU. Spots from 6 countries in an hour (LA, DL, F, EI, GM, G) with strongest reports from Cornwall (-3dB S/N) which is in the line of the wires/loop.

WSPR spots received using 20m spaced earth-electrode antenna with NOTHING in the air.
 

Earlier today I had a visit from Ted G4NUA, so I showed him my 137kHz antenna, "Where is it?" he said. Exactly - the wire runs back to the house from the far earth rod IN the grass and it is all but invisible!