Cecil Moore wrote:
x
a1=10----|
|----s21(a1)=5 toward the load
s11(a1)=5----|

For those of you who are unfamiliar with the way s-parameter
voltages are normalized, here are the *actual measured*
voltages at the impedance discontinuity at t=0 + delta-t.
All three voltages can easily be seen on an o'scope a
short time after t=0. During the buildup to steady-
state Vref1 goes from 50V to 0V. How that is possible
without interaction is the question for ac6xg.

x
Vfor1=70.7V----|
|----120.7V=Vfor2 toward the load
Vref1=50V----|
rho1-- | --tau2(Vref2)=0

The corresponding equation used by RF engineers is:

Vref1 = rho1(Vfor1) + tau2(Vref2)

In this t=0 case, Vref2=0, so

Vref1 = rho1(Vfor1) at t=0
--
73, Cecil http://www.w5dxp.com