Correction:

Roy Lewallen wrote:

This isn't quite correct. A standing wave is the result of isn't the sum
of traveling waves. It's a description of the envelope of the current
distribution that sum produces. . .

It should read:

This isn't quite correct. A standing wave isn't the sum of traveling
waves. It's a description of the envelope of the current distribution
that sum produces. . .

Roy Lewallen, W7EL

Roy Lewallen wrote:
This isn't quite correct. A standing wave isn't the sum of traveling
waves. It's a description of the envelope of the current distribution
that sum produces. . .

Look at this standing wave:

http://www.chemmybear.com/standing.html

The equation for that standing wave is:

Ex = E*e^j(wt-Bz) + E'*e^j(wt+Bz) [see quote below]

At one time in the cycle, the standing wave equals zero
all up and down the line.

A STANDING WAVE *IS* THE SUM OF TRAVELING WAVES.

On page 285 of "Fields and Waves in Modern Radio",
2nd edition, by Ramo and Whinnery, it gives the
equations for the forward wave, the reflected wave,
and the standing wave. Begin quote:
--------------------------------------------------
Incident Wave --- E*e^j(wt-Bz)

Reflected Wave --- -E*e^j(wt+Bz)

If Ex = 0 at z = 0 for all values of time, E' = -E.

[Standing Wave equation]
Ex = E*e^j(wt-Bz) + E'*e^j(wt+Bz) = -2jE*sin(Bz e^jwt)

[Standing wave envelope equation on page 42]
V = -2jV1*sin(Bz)

End quote:
--------------------------------------------------
The standing wave equation is simply the sum of the
traveling wave equations.
--
73, Cecil http://www.w5dxp.com