Richard Clark wrote in message . ..


It leaves open the question as to how does one know whether two
things with the same units are the same (or not); a much more
challenging problem, I suspect.

...Keith


You will note that this bears no relation to ohms being different,
because as you observed with the horsepower example, it is simply
flipping through translations until you hit the units you want.

73's
Richard Clark, KB7QHC


I don't think anyone here is arguing that a wave traveling
through a transmission line is the same as an EM wave traveling
through free-space.

But as Richard has shown, the units are always the same, as they
should be. Just like a meter is still a meter, whether it is in
torque or work.

But it tells you something about what you are measuring, and the
clue is that the E field is defined by the voltage potential field,
and the H field by amps (turns).

And if the permittivity (impedance) of the material surrounding
an antenna will affect it's input impedance, i think it's something to
consider.


Slick

Dr. Slick wrote:
"And if the permittivity (impedance) of the material surrounding an
antenna will affect its input impedance, I think it is something to
consider."

The permittivity surrounding our antennas rarely changes and is the same
for nearly all antennas.

My dictionary says of permittivity: "See Dielectric Constant".

Velocity can be affected by dielectric constant as is seen in
solid-dielectric coax. Fortunately, the dielectric constant of the
environment our antennas operate in is nearly constant.

Were matching antennas to 377 ohms significant, it would manifest itself
in the century of experience of using many antennas of many differing
types.

Best regards, Richard Harrison, KB5WZI