On Wed, 06 Sep 2006 07:36:13 GMT, Owen Duffy wrote:

I have plotted theoretical forward and reflected power for a detailed
model of RG58C/U at 100MHz with a severely mismatched load to
illustrate the underlying thing that is being measured by a
reflectometer.

The plots are at http://www.vk1od.net/lost/NN7K.htm .

Comments?

Hi Owen,

Interpretative comment - You state here "theoretical" plots of a
model. At the reference you state "indicated forward power, reflected
power." To me this implies data taken, not generated from a model's
formula - but my interpretation may be a stretch.

Data source comment - However, you go to rather elaborate lengths to
specify a load of 2+0.5j (sic) and a line of 50.36571-j0.17872. What
was the point of injecting reactances here if you simply wish to
illustrate the degradation of SWR with feedline loss? They add to the
implication of data taken, not generated - except for 5 place
resolution at 100 MHz which is (excuse me) absurd.

Elaboration of the implications of interpretation and data source
comment - Further implying this was data taken at the bench is the
declaration "THE REFLECTOMETER IS NOT CALIBRATED FOR THE LINE Zo."
Again, my presumption circuits peg on that one because the reactances
are so easily removed from emphatic concern if you are in control of
the "virtual" workspace.

Informational comment - What is supposed to be the total length of
line? Was it matched at its input, or simply fed by a transmitter?

Picky comment - Graph font sizes are a squint too small.

Last, really picky comment - Your copyright notice at the bottom is
off by a year.

73's
Richard Clark, KB7QHC