The real question is, why was the quarter wave antenna worse, not why
was the CFA so good. A 1/4 monopole can approach 100% efficiency and
can be 3dB up on a dipole when erected properly - in which case any
other single element antenna cannot have any MORE gain.
As Egypt is surrounded by sand, doesn't it look like a ground
conductivity issue destroying the efficiency of the conventional
radiator. As the CFA is less dependant on a ground for termination of
the Reactive fields it could just possibly be better in these
circumstances.
All the CFAs built and tested at higher freqs have never been as good as
the dipoles or similar they were supposed to replace. In fact usually
6dB or more worse
Andy G4JNT
----------
From: M & S[SMTP:[email protected]]
Reply To: [email protected]
Sent: 2000-06-20 14:48
To: [email protected]
Subject: LF: CFA Antenna: miraculous?
Information of interest:
What is different about the CFA? As an example, a CFA only 21 feet
(6.5
m) tall, located at Tanta in the center of Egypt, provides AM
broadcast
service at 1.16 MHz (258 Meters) to millions of people from Cairo
north
to the coast. Certified measurements provide evidence that this small
CFA produces a radiated signal almost 6 dB stronger than the previous
1/4 wavelength vertical broadcast tower which was 211 feet (65 Meters)
tall. To express the performance a different way >> with the tall
tower,
a 100,000 watt transmitter was required for the desired coverage. With
the miniature CFA the same coverage was attained with the transmitter
power reduced to 30,000 watts.
As seen on:
http://www.antennex.com/
73, Mark, F6JSZ
http://perso.club-internet.fr/sovergne
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