4.6kms with earth electrode "antenna" and 250mW on 136kHz

Today I tried some more experiments with my 20m spaced earth electrode "antenna" and small QRP beacon TX on 136kHz. I switched over to QRSS3 and  used the FT817, E-field probe and PC with Spectran to see where copy stopped. 1.5km from home and solid copy on QRSS3 when holding the E-field probe box as high as possible above the car roof. Then I drove on to a spot 4.6km from home and copy was again achieved, albeit not as strongly.  I'm certainly getting a signal radiated beyond the near field.  I'd like to check "antenna" directionality by looking for signal levels with the QRSS3 beacon at all compass points some 4-5kms away from the QTH.

In the meantime, if anyone near Burwell, Cambs wants to look for the QRSS3 signal near 136.93kHz I'll leave it running until about 8pm tonight when I have to switch off as my grandson is sleeping in the shack bedroom. Any reports would be amazing.