Loading Coils; was : Vincent antenna
Tom Donaly wrote:
Gene Fuller wrote:
Cecil Moore wrote:
Take I = K1*cos(x)*cos(wt), a standing-wave equation.
Let t be any fixed value. cos(x) is an amplitude value
and does NOT vary with time. Therefore, the phase of the
standing-wave signal is constant at any particular time
and does NOT depend upon position along the wire or coil.
Now take I = K2*cos(x+wt), a traveling-wave equation.
Let t be any fixed value. The length dimension 'x'
has an effect on phase, i.e. the phase of of the
signal indeed does depend upon BOTH position AND time.
Cecil,
I know what you are trying to say, but you got the message screwed up.
If 't' is fixed, then the equations are essentially the same with
regard to 'x'. That is typical; a snapshot in time does not say much
about the wave behavior.
73,
Gene
W4SZ
It's generally cos(kx), but maybe Cecil is using a wave where k = 1,
that is, the wavelength is 2*Pi.
73,
Tom Donaly, KA6RUH
Tom,
Sure, that too.
I think one of the reasons this subject keeps coming back again, and not
only from Cecil, is that phase is deceptively simple and very easy to
misuse. A year or so ago I counted up at least 5 or 6 different meanings
of "phase" in routine use on RRAA. Lewis Carroll would feel right at
home here.
73,
Gene
W4SZ
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