Radials For EFHW Verticals

Whilst reading the book "Low Band DX'ing" by ON4UN, I came across a section which called me to doubt what I had previously said about 1/2 wave end fed antennas. I decided to do a test to see if I could prove or disprove what was written in the book. I do wonder if the radials could still be coupling & having some effect on the "without radials" test, even though they were not physically connected? I'm not too sure about that one. The Amateur Radio UK channel is run by UK radio amateur M0GQC (James). As the channel name would suggest, the channel focuses primarily on amateur radio within the UK!!!