On 06/12/2014 09:59 AM, Wimpie wrote:

When the source impedance doesn't match the coupler reference impedance,
the forward power reading on the coupler can be more than the net power
supplied by the source. This is due to multiple reflections. VSWR
readings do not depend on source impedance.

Hello, and I think it would be more accurate to state that the
definition of load VSWR ("SWR") is source impedance agnostic but it is
always referenced to some value, say 50 or 75 ohms. If the load VSWR is
being calculated from incident and reflected readings from a mismatched
directional WM (which is just a directional coupler with terminations
and an indicator(s))then errors will occur, as has been pointed out
already. Sincerely, and 73s from N4GGO,

--
J. B. Wood e-mail: