Szczepan Bialek wrote:
Totally wrong. The power lines and receiver antennas must have ground
connection.
"The wire antennas used with crystal receivers are monopole antennas which
develop their output voltage with respect to ground. They require a return
circuit connected to ground (earth) so that the current from the antenna,
after passing through the receiver, can flow into the ground. The ground
wire is attached to a radiator, a water pipe, or a metal stake driven into
the ground.[4"

Do you think that monopole antennas are the only existing antennas?
It seems you do.

However, that is not true. A dipole antenna does not need a ground
connection as the output voltage is not with respect to ground, but
between the two terminals.