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Old March 12th 06, 11:16 AM posted to rec.radio.amateur.antenna
Roy Lewallen
 
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Default Radiation Resistance

C = 160 * pi^2 ~ 1579.

This is exactly 4 times the radiation resistance of a short dipole with
linear current distribution (i.e., one without a top hat), since the
average current is twice the amount for the same radiated power.

Of course, this assumes an infinitely thin wire. Any real wire will have
a higher radiation resistance than this.

Roy Lewallen, W7EL

Reg Edwards wrote:
I am not trolling.

What I want to know is the radiation resistance, referred to the base,
of a short vertical wire above a perfect ground, the current in the
wire being assumed uniformly distributed.

The radiation resistance at the base is in the form of -

C * Square( Length / Lambda )

where Length is the physical length or height of the wire and Lambda
is the free-space wavelength.

What is the value of the constant C ?

Thank you.
----
Reg.