"Szczepan Bialek" wrote in message
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"Dave" wrote
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"Szczepan Bialek" wrote in message
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"Dave Platt" wrote
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In article ,
Jeff Liebermann wrote:

I forgot to connect my comments to the original question. Sorry(tm).
You're correct. There's no way to get a good isotropic radiator
pattern with a simple vertical radiator. However, you can still get
fairly close if you make the antenna sufficiently small relative to
the operating wavelength. As the physical antenna size approaches a
point radiator, the pattern starts to look rather spherical.

The difference in pattern between a half-wavelength dipole,
and an infinitesimally-short dipole (i.e. one whose length
approaches a point source) is actually quite small.

A dipole is always the two monopoles and never a point source. Only
monopole is a point source.
S*

there is no such thing as a monopole antenna. unless you have discovered
the magnetic monopole somewhere?

Chris wrote: "Monopole antennas are developed from dipoles by substituting
one of the
elements, often using a 'reflection' of the remaining element in a ground
plane. Their characteristics are different from those of the parent
dipole
because of this substitution but they still have the same kind of
axially-symmetric radiation pattern, with linear polarisation and no
radiation in the direction of the end of the monopole."

Is he right?

different context... "Monopole" antennas as he is describing are a specific
type of antennas that are otherwise described as 'verticals', 'ground
plane', or several other terms.. all of which actually are dipoles in the
context that they have 2 poles, not that they look like a 'half wave dipole'
which is a special case of a dipole. In his context it refers to a vertical
with some real size greater than zero. in your context the 'monopole is a
point source' means you think that a point source is a monopole which is
impossible since a monopole(meaning single pole) can't radiate. His
description is a bit simplified, but otherwise reasonable for a "Monopole"
antenna, but you must always remember there are 2 poles even in a "Monopole"
antenna... just one of them is the ground screen or radials.