Andy wrote:
"So the above told us zip about the question Reg asked. Roy answered the
question correctly and you haven`t even attempted it."

I assumed the definition of "field strength" correctly answered Reg`s
question and his descrepancy lay elswhere.

Field strength of an electromagnetic wave is expressed in microvolts per
meter. It is defined as the number of microvolts which would be induced
in a properly placed piece of wire one meter long.

If a field strength of one microvolt per meter does not induce one
microvolt into a piece of wire one meter long, why not? I`ve been
looking for an explanation and found a possible answer in Figure 2-9-1
on page 31 of Kraus` 3rd edition of "Antennas".

The possible explanation is called the "effective height" in meters of
an antenna. It is a "factor", which when multiplied by the microvolts
per meter of the field strength, gives the volts induced in the antenna
at its terminals.

According to Kraus` figure, h is a function of current distribution in
the antenna. The text says that for a dipole 0.1 lambda long, h = 0.5X
the length of the antenna. Reg did not specify a frequency or wavelength
for his antenna, as I recall, and he did specify a ground mounted
vertical whip 1 m long for his receiving antenna.

For a dipole 0.5 lambda long, Kraus gives (h) as 0.64X the length of the
antenna.

For all I know, there is a vertical antenna length in terms of
wavelength for which h=1. If so, the volts between the antenna base and
the ground directly under it would numerically exactly equal the
microvolts per meter of the field strength. All we need to do is pick
the right frequency. The applicable Formula is (1) on page 30.

I suspect that in most cases, h is determined experimentally.

I regret I`ve not had a copy of Kraus nearly as long as I`ve had a copy
of Terman. I`m still using an edition I`ve had for 58 years. It shows
lots of wear and tear.

Best regards, Richard Harrison, KB5WZI