It occurs to me I might be able to do a whole lot better than actual
measurements. I should be able to simulate a power meter in the SWCadIII
Spice simulator, and do a transient analysis. This will let me go from RF to
DC out. They also have models for lossless and lossy transmission lines,
which should make it possible to see how steady state is reached from
turning the source on at T=0.

Tam/WB2TT