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Old July 23rd 06, 06:24 AM posted to rec.radio.amateur.antenna
Reg Edwards Reg Edwards is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 167
Default Length & number of radials


"Walter Maxwell" wrote
The graphs reporting BLE's measurements are pretty conclusive. In

addition, the
BLE paper is the basis on which the FCC set the requirements for

the
ground
systems on all AM BC stations since 1939


==========================================

My point is that when there is a sufficient number of radials of

sufficient
length to approach a nearly-perfect ground, the ground

characteristics beneath
the radials are irrelevant within the area they cover in determining

the
terminal impedance and efficiency of the radiator. Therefore, the

different gr
ound characteristics that prevail as the frequency increases above

3.5 MHz are
also irrelevant.
Walt, W2DU

============================================

Dear Walt,

At risk of upsetting a great number of patriotic USA citizens, all BLE
hero-worshippers, I admit to having speed-read BLE's lengthy paper
some years back. Their conclusion, that with a sufficiant number and
length of radials the ground characteristics are irrelevant, is so
glaringly apparent they could have stayed in their offices and saved a
great deal of expense and copper wire. I am reminded of John Cleese's
remark "They must have had first-class honors degrees in stating the
bleeding obvious".

Because BL&E omitted to measure ground conductivity and permittivity
on the site their conclusion amounted to making a virtue out of a vice
and Marzipan the Magician's magic number of 120 came into existence.
Their sponsors should have made them go back to finish the job.

In the absence of any other information at the time, the fact of
irrelevance was of interest to LF and MF broadcasters with money to
burn, but it was, and still is, of no use to radio amateurs, confined
to the HF bands with limited purses, small back yards and XYL's to
keep happy.

My small program Radial_3 has been singled out and I have been accused
of disagreeing in a disruptive, almost criminal manner with BL&E's
conclusions. This is patently untrue! The program has nothing to do
with BL&E except that it deals with a similar subject in terms
appropriate to amateurs and draws its own independent conclusions.

Your absence caused a little worry. Glad to hear you were only
working.
----
Reg.