An old wireless con trick

[Doodlebug]

There have been con tricks ever since humans starting acquiring things of value. The interesting question is how did he fake the improved performance.

Maybe he converted the earth socket to an aerial socket with big attenuation, plug a wire aerial in for poor reception then the capacitor in the right aerial socket for good reception. Fiddling about on the back no one would have noticed. Or he had a secret high value R in the wire aerial, or even O/C 6 inches in from socket.
I do remember though folk handing over 1/2 a crown (2/6) to buy.