Ian Jackson wrote:
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).

Or you could use a ferrite antenna with a coupling coil wound to
match the impedance.

Oh, wait, that would be a coil wound around a ferrite bar with no
ground connection whatsoever and no place for jumping electrons.

Good Lord, could it possibly work with no jumping electrons and no
ground?

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

Yes, some early microwave receivers were in essence crystal sets until
the components became available to build the stages necessary for a
superheterodyne receiver.

Most of the simple Gunn diode based door openers are also basically crystal
set receivers.

Where do electrons jump from in a horn antenna?