In message , Szczepan
Bialek writes



"The wire antennas used with crystal receivers are monopole antennas

The words "almost always, almost every time, almost invariably and
almost without exception" are missing.

As crystal receivers are normally used at low frequencies (long and
medium wave), the obvious antenna to use is an end-fed long wire
monopole. This, of course, requires a ground.

However, in principle, you could use a (probably large) dipole, provided
you modified/designed the circuit of the receiver so that it would take
a balanced input (which would probably also be low impedance).

I'm pretty sure that some of the early radar receiving systems used
essentially a dipole antenna feeding a crystal receiver.





--
Ian