On Fri, 9 Dec 2005 00:16:31 +0000 (UTC), "Reg Edwards"
wrote:

Sorry, I forgot "per metre".

I should have said -

"According to the text books, the field strength from 1 Kw at 1
kilometre = 300 millivolts per metre."

For an isotropic radiator, is it correct to calculate the power flux
density at 1Km at 1000/(4*pi*1000**2), and to find the field strength
from FS in V.m = (power flux density * 120*pi)**0.5? That gives
173mV/m. It would be 245mV/m if the power were radiated uniformly in
hemisphere.

300mV/m is conditional on the power radiated in a hemisphere and from
an antenna with directivity (field proportion to the cosine of the
angle of elevation).

Does that make sense?

Owen
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