U¿ytkownik "Richard Fry" napisa³ w wiadomo¶ci
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On Sep 11, 2:39 am, Szczepan Bia³ek wrote:
If two sources work, interference take place. Equipments
are "polarised" not waves.
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The net, far-field radiation of two vertical monopoles in a
directional array driven by one transmitter using a power dividing
network is vertically polarised -- because both monopole sources are
vertically polarised.

This type of array is commonly used in commercial AM broadcasting, and
its characteristics (including its polarisation) have been accurately
known for many decades.

Most hams know that a vertical antenna creates a radio wave with vertical
polarization and a horizontal antenna creates a horizontally.

The both antennas (transmitter and receiver) should be aligned. You wrote:
"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, "

It means that the waves are horizontaly polarized. Next you wrote"

"they respond most efficiently to vertically-polarised electromagnetic
waves." I assume that it is a small mistake.
The following is known for many decades:

One mast is omnidirectional. The two are directional like a horizontal
dipole. For this reason "This type of array is commonly used in commercial
AM broadcasting".

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

Some clarification is necessary. The doubled frequency should be set on a
receiving/measuring device.
Each mast radiate omidirectionally. The radiation of the array of the two
interfere. Also in some places it may be received as the doubled frequency.
S*