"Reg Edwards" wrote in message
...
But the situation is even worse than that! The so-called SWR meter cannot
even tell you the all-important sign of the deviation - just that a
deviation in some unknown direction exists.
Reg, G4FGQ

Reg,

Actually the information we need is there, but not displayed. For RL R0,
the magnitude of the voltage sample is greater than the current sample. For
RLR0, the magnitude of the current sample is greater. For a 50 Ohm meter,
the two samples are, of course, equal for the case where R0=50 Ohms. To
display this information in common meters would be difficult, because the
voltage sample is with respect to ground, but the current sample appears as
a floating differential signal, with the voltage sample as a common mode
signal.

All of this is simple to do in simulation, because I can use opamps with
1000V common mode range, and arbitrarily wide bandwidth.

Tam/WB2TT