"J.B. Wood" napisal w wiadomosci
...
On 06/13/2012 06:11 PM, garyr wrote:
This site http://www.frontiernet.net/~jadale/Loop.htm states that: "A
properly designed Loop primarily responds to the magnetic component of
the
radio wave. Note that noise resides primarily in the electrical
component..."
Hello, and a loop (dipole) antenna doesn't "respond" to just the magnetic
(electric) component of a propagating electromagnetic wave. A (receiving)
loop or dipole antenna intercepts the incoming electromagnetic (EM) wave.
Last time I checked an EM wave had both electric and magnetic components.
Just because an orientation of an axis of the antenna resulting in maximum
signal strength is parallel to the electric or magnetic component of an EM
wave doesn't mean that it's responding to just that component.
I wish hams and others would quit trying to redefine electromagnetic
theory. Hams have designed and constructed novel and practical antennas
over the years but their explanations about how they work are often just
plain wrong. Sincerely, and 73s from N4GGO,
The explanations are wrong because the radio waves are simply the electric
waves or the electron waves.
From this point of view the next is obvious;
"Since the directional response of small loop antennas includes a sharp null
in the direction normal to the plane of the loop, they are used in radio
direction finding at longer wavelengths. The loop is thus rotated to find
the direction of the null."
" Although a similar argument may seem to apply to signals received in that
plane, that voltages generated by an impinging radio wave would cancel along
the loop, this is not quite true due to the phase difference between the
arrival of the wave at the near side and far side of the loop."
From:
http://en.wikipedia.org/wiki/Loop_antenna
S*