On Sun, 6 Jun 2010 14:21:16 -0700 (PDT), Keith Dysart
wrote:

The 100W forward and 50W reflected have no relation to actual powers

From HP Journal V.3n7-8

DIRECTIONAL couplers have been used
widely in wave guide applications for
such purposes as monitoring power, meas
uring reflections, mixing, and for isolation
of signal sources. All of these applications
make use of the property that power flowing
in one direction in the main branch of the
coupler induces a power flow in only one
direction in the auxiliary circuit.

73's
Richard Clark, KB7QHC