I'd never thought of that. I suppose it applies to any situation where the
feeder is electrically short, and the majority of the current is less than it
would be when matched. I presume that the moral is that formulas only really
work when the feeder is electrically long enough for you to be concerned about
what the losses might be.
--

Conversely, for a very short line closed on 5 ohm (instead of 500 ohm), the
extra loss caused by SWR would be higher than that shown on the ARRL graph
(apart from the fact that, when attenuation is so low, the extra attenuation is
generally not of much interest, nor it can be read on the ARRL chart).

Evidently the ARRL chart shows some average between the two cases. On the other
hand they probably had no better way to synthetically illustrate a concept
without giving too many details.

73

Tony I0JX