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Old March 5th 04, 08:18 AM
Richard Harrison
 
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Art, KB9MZ wrote:
"Well that is news to me. I never consider the matching circuit as part
of an antenna, but only a required band aid."

Art only recently changed his mind it seems. A year or so ago he was
arguing that the tuned T-matched arrangement he claimed to have invented
added gain from its radiation to that of his dipole. I said ,
"impossible because radiation from a small loop is directed in the plane
of the loop." So Art hates me.

More recently we discussed current distribution on short loaded vertical
antennas and if current had to be the same at both ends of a loading
coil. It doesn`t. Yuri presented in evidence Fig 9-22 from page 9-15 of
the 2nd edition of ON4UN`s "Low-Band DXing". Art shows disdain for
experts and books, so he may have paid no attention or quickly forgot.

One of the six examples in ON4UN`s figure is a continuously loaded
radiator. No doubt, no matter how feeble it is, the radiation emanates
from the loading coil which comprises the entire antenna.

Richard Clark was showing that the choice of series resonant or parallel
resonant as a model may be based on application or impedance.

A parallel resonant circuit exhibits high impedance. It is used for high
isolation as a trap, and as a phase inverter for a collinear as in the
self-resonant coil from Kraus presented by Cecil. A parallel resonant
circuit is also used to match end-fed 1/2-waves and similar high
impedance antennas. Many cheap small radios just connect the high
impedance antenna to to the hot end of the tank circuit.

The J-pole drives an end-fed 1/2-wave antenna from a short-circuited
1/4-wave stub. The stub is equivalent to a parallel resonant circuit and
exhibits a high impedance at its open-circuit end. This was another of
Richard Clark`s examples.

I regret Art fails to see the relevance of much of the accurate
information offered.

Best regards, Richard Harrison, KB5WZI