Stefan Wolfe wrote:
Since you are using ladder line (assuming you use a suitable gauge for the
power transmitted), the dielectric and resistive losses losses are
insignificant even at relatively high SWR. I doubt it matters much whether
your feedline is 100 feet or 320 feet; most relected power will still get
transmitted out and not be absorbed as heat.

And at some extreme impedances (accompanied by extreme
SWRs) losses mount in the tuner and balun if not in the
transmission line. I have a rule of thumb to keep the
ladder-line SWR below 25:1 which probably fits with
your "relatively high SWR" statement.
--
73, Cecil http://www.w5dxp.com