"Cecil Moore" wrote
...
Szczepan Bia³ek wrote:
In nature not separate transverse and longitudinal waves.

Longitudinal waves require a medium. For many years,
empty space was considered to be empty. We now know
that "empty" space is not empty and has a structure
that teems with quantum particles, i.e. the "aether"
actually exists although not in the conventional
matter form that was earlier assumed.

Sound waves propagate in conventionall matter form (gas, liquid, solid).
They always have the two components (transverse and longitudinal). In
practice is the full analogy acoustic waves - electric waves.
It is not easy to to describe the aether. But it exists in common term "eter
waves". The ether waves are artifically produced and for this reason we know
more about them. To produce them we do not need to know if they are electric
or EM.
After some time will be clear which vision (Ampere or Heaviside) is in
agreement with practice,

I wanted to know if radio people observe the frequency doubling when
receiving signals from a dipole.

Frequency doubling can occur in non-linear systems.
Every powered transistor stage has a certain degree
of non-linearity. A passive antenna system is usually
linear.

You are saying about frequency changing. Are many ways to decrease a
frequency and a few to increase. Doubling is a special case of increasing.
In the Luxembourg effect no frequency doubling in above sense. All antenas
radiate in complex way. It is also obvious that it radiate from different
parts. That radiation from different parts may be not in phase at the
receiver. They may be in the opposite phase (like for dipoles). Here is the
key. Opposite phase means also the two pulses in one cycle. Each receiver
has its own resonant frequency. In the result long waves were received as
medium waves with the twice more frequency. There were no doubling in your
understanding.
S*