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Old May 15th 06, 03:15 PM posted to rec.radio.amateur.antenna
Tom Donaly
 
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Default FIGHT! FIGHT! FIGHT!

Cecil Moore wrote:
Tom Donaly wrote:

What is a "sinusoidal magnitude function," Cecil?



Y = sin(X)

The magnitude 'Y' is equal to the sine of an angle,
'X', in degrees.

Wouldn't you agree with me that it is ridiculously
ignorant to assert that the magnitude 'Y' has nothing
to do with the phase angle 'X', i.e. that there's no
"phase information in the ... magnitude".


Actually, I don't think it's "ridiculously ignorant" at
all. If all you have is the value of current at one point,
you can't possibly tell anything about the phase. You need
to compare it to something - itself even - somewhere or sometime else in
order to have an idea of phase. Here's what I mean: suppose I have a
piece of wire of unknown length, excited by an unknown frequency, and
picking a random point on the wire I measure 1.73 amps. What is the
phase? You're trying to square the circle and hear the sound of one
hand clapping at one and the same time, Cecil. Of course, in your
case, you know the length of the wire, the frequency of the wave and
its wavelength, and you think you know the current distribution
on the wire (a half wavelength dipole) so you don't need anything
but a ruler to find what you're looking for. Of course, you have to
decide what you mean by the term "phase." Try not to get a permanent
headache thinking about it.
73,
Tom Donaly, KA6RUH