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Old December 15th 06, 05:54 AM posted to rec.radio.amateur.antenna
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Default A request for guidance from academics

On 14 Dec 2006 21:04:08 -0800, "art" wrote:

All in all the array represents a band pass filter where effort is made
for constant gain across a band of frequencies


Hi Art,

D.E. Isbell did this 46 years ago.

which is a different
requirement from the Yagi


It has been used for TV antennas for lo those same 46 years and to any
casual view looks like a Yagi.

where amateurs
are only interested in gain without due referance to constancy across
the frequency span
or with regard to the corresponding beam width


Isbell got that too. It was, afterall, everyone's goal and he got:
1. More gain;
2. Better match;
3. More bandwidth;
than 5 un-optimized wires hanging in the air.

Isbell understood Gaus, Maxwell, McGuffey, and the rest and never
appealed to bundles to explain his design (which really bore no more
relation to his antenna than explaining why a car works in terms of
how zippo lighters create a flame).

D.E. Isbell's antenna is included free as an example with every copy
of EZNEC. It contains 5 wires and exhibits:
1. 10% BW
2. 10 dBi gain
3. a serviceable match

Isbell wrote the design up, submitted it to his peers, a jury passed
on his work, it was published, it was patented (3210767) and it has
stood the test of time.

Isbell also explained how to achieve different:
1. Gains;
2. Matches;
3. Bandwidths;
in terms that others could actually build working models.

In regard to this last, I am sure amateur publications offer simple
formula to achieve these goals too.

However, if all one has to read is a book about fields, Isbell's
invention may come as a surprise. Ramo and the boys don't really talk
all that much about "antennas," so citing them as authorities on the
subject makes as much sense as crediting Jane Goodall for the Theory
of Evolution.

73's
Richard Clark, KB7QHC
 
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