Roy Lewallen wrote:

Reg is correct. Even a very short structure, much shorter than a
wavelength, acts like a transmission line. A short structure just acts
like a short transmission line. It's just that if it's short, there are
simpler ways to analyze it which will get us essentially the same
answer. But we can use full blown transmission line analysis on any
structure if we choose, and should get the correct answer.

Seems that you agree that the distributed network model works for
all common problems. That makes sense since the distributed network
model is a superset of the lumped-circuit model.

Using Dr. Corum's rule that models should be switched at 15 degrees,
15 degrees of a 450 ohm transmission line will transform 50+j0 ohms
to 54+j120 ohms. The difference in 50 ohm SWR is 7:1 Vs 1:1. That
seems like a pretty large error to me just to be able to stick
with the lumped-circuit model.
--
73, Cecil http://www.qsl.net/w5dxp