On Apr 9, 11:05 pm, Owen Duffy wrote:
"K7ITM" wrote groups.com:
...

transduced line voltages and currents. I think it was about ten years
ago in this group that I posted the derivation of the equations to
determine forward and reflected from measurement of voltage and
current at a point on a TEM line, IF you know the impedance of the
line.

Hi Tom,

I guess it is the misconceptions about these things that drive us to write
such stuff.

I drafted an article recently showing what the typical SWR meter samples,
and the use of that information, including treatment of Pf and Pr as stand
alone values. The article is athttp://www.vk1od.net/VSWR/VSWRMeter.htm.

Owen

Hi Owen,

I had a quick look at your article. Though I didn't try to proof-read
it for accuracy, I was reminded that the equations I posted those long
years ago said that if you know the _instantaneous_ voltage and
current at a point on a line, and know its impedance (as a frequency-
independent quantity), the equations apply, and you can resolve that
instantaneous pair of values into forward and reverse. That's
something that's not immediately obvious when people think only about
sine waves.

Cheers,
Tom