"Richard Fry" wrote
...
On Sep 10, 5:35 am, Szczepan Bia³ek wrote:
And you tell us that radiation from monopoles antennas is polarised.
_____________

S*, you might want to conduct a simple and practical test of your
belief for yourself, to learn whether or not it is true.

A great many/almost all MW, AM broadcast stations use an antenna
system comprised of one or more vertical monopoles.

So you know what is the directivity and phasing.

Such vertical-only polarisation greatly reduces the propagation loss for
the ground
wave, and so increases the ground wave coverage area -- whether or not
a MW station has a directional radiation pattern in the horizontal
plane.

Two vertical monopoles not in phase are like one horizontal dipole. In phase
are like two sources.

Such was scientifically investigated and scientifically proven many
decades ago. This reality is _very_ important to the commercial
success of AM broadcast stations.

Most compact, and inexpensive MW AM broadcast receivers use an
integrated, ferrite core "loopstick" receive antenna.

When such receivers are oriented with their control legends and
displays aligned in the horizontal plane, as when the bottom/back of
the receiver is sitting on a table, they respond most efficiently to
vertically-polarised electromagnetic waves.

When the two sources work the receiver must be propery "algned" (physically
oriented).

THE TEST:

Using such an AM receiver and physical setup, tune to a moderately-
powered, omnidirectional MW broadcast station located at least 20 km
away from your receive location. Then rotate the receiver 360 degrees
around its vertical axis.

With no co-channel signals, you will find that the received signal-to-
noise ratio for that station goes through two, distinct nulls
corresponding to the physical orientations of its receive antenna that
are 180 degrees apart, and along a line of sight from your receive
location to the location of the transmit antenna.

This result demonstrates that such radiation is (vertically)
polarised.

If two sources work, interference take place. Equipments are "polarised" not
waves.

I have not possibility to "conduct any simple and practical test". In the
other topic you wrote: "Only thing is that my plots are based on 1/2-wave
antennas." If it means that you have possbilities to measure a directional
radiation pattern then do such:

The TEST:
1. Measure the pattern for a declared frequency,
2. Measure the pattern for the doubled frequency,

Tell us the findings.
Already I have proposed it to Wim. Now I am proposed it to all of You.
S*


RF