Dan it is wise to remember that Richard "cherry picks" statements from
assorted books and disregards the chapter heading and what is discussed in
that chapter. He only looks for a statement that suits his present state of
mind and suggests authority and ignores the underlying subject of the
thread. In that same chapter it is discussed how the losses mount up as you
move away from the resonant point and shows where the losses could amount to
5dB no less. There is a proviso
in that the antenna books that I have precede the one that he is refering to
so there may be some evidence that somebody has pushed the envelope beyond
Maxwell and others.
I think the actual chapter refers to broadband antennas rather than those of
a narrow bandwidth so it is always advisably to check so called "book
quotes" rather than accept what people interprete what is relavent in their
own minds.
Regards
Art


"Dan Richardson @mendolink.com" ChangeThisToCallSign wrote in message
...
Let me try this one more time. You had posted earlier and I commented
on this:

"A receiving antenna must be resonant to enable full acceptance of
available energy, and it must be matched to avoid re-radiation of more
than 50% of the energy it is able to grab."

I commented on the first portion of your statement (above). My only
point is that it makes no difference if an antenna's is resonate or
not in determining how much energy it grabs.

That's it, nothing more.

73
Danny, K6MHE


On Mon, 23 Feb 2004 13:43:55 -0600 (CST),
(Richard Harrison) wrote:

Dan Richardson wrote:
"The fact is resonance or not is not the determining factor."

Resonance of the antenna system is the determining factor in the
performance of a standing-wave antenna.

This is an amateur group, so you may check the "ARRL Antenna Book". My
19th edition has resonant antennas on page 9-2.

Fig 2 is a series RLC circuit representation of the typical
standing-wave antenna.

Ohm`s law should be noncontroversial (I=E/Z).
To maximize I with a given voltage, Z must be minimized. Z in the series
circuit is the phasor sum of R and X.

R has probably been established firmly in an antenna by its construction
and placement but we can tune the antenna system to make it resonant so
that we eliminate X to get maximum current into the antenna and to
thereby get maximum performance out of the antenna.

Best regards, Richard Harrison, KB5WZI