Thanks to Tom for the comments and additions.

. . .

[I've lost track of who said this:]

The "Magic" of an electrical halfwave transmission line is at a
precise frequency, the reflection of the load to the transmistter is
equal to the characteristic impedance of the transmission line
irregardless of what impedance it is terminated with.


[Roy:]

This is true only of a lossless line. If the load impedance isn't far
from the line's characteristic impedance (i.e., the line's SWR is low),
a small amount of loss won't make much difference. However, if the line
SWR is high, even a small amount of loss can make a major change in the
impedance seen at the line's input. The effect is to skew the impedance
toward the line's Z0.


[Tom:]

The piece that Roy quoted is so outrageous that I can easily believe he
didn't read it right, but I've re-read it several times, and it keeps
coming out the same: the "magical" halfwave line does NOT reflect an
impedance to the source (transmitter) equal to the LINE impedance as
the quoted section says, but it reflects the LOAD impedance (altered by
line loss as Roy says).
. . .

Wow, I certainly read that (top quote) too quickly. Tom is absolutely
right, as written it's very wrong, and I misread it. I retract my
statement about it's being "true only of a lossless line" -- of course
it's not true at all, but works as Tom says.

Roy Lewallen, W7EL