Cecil Moore wrote:
If one adds the two equations (samples) the reflected
terms drop out and the result is a voltage proportional
to the forward wave.

If one subtracts the two equations (samples) the
forward terms drop out and the result is a voltage
proportional to the reflected wave.

Continuing: The phase of the standing-wave current
in a 1/4WL stub is constant from feedpoint to tip.
However, two directional couplers, one placed at the
1/3 point and the other placed at the 2/3 point
would allow one to see the 30 degree phase shift in
the traveling-waves at the points before diode
rectification takes place.
--
73, Cecil http://www.w5dxp.com