Walter Maxwell wrote:
There is
no radiation from any portion of the line, because the fields developed by the
currents flowing in opposite directions in the two conductors oppose and cancel
each other throughout the entire length of the line. Therefore, no portion of
the feed line becomes part of the antenna."

Hi Walt, I agree with what you said and here is an addition.
A graphic on my web page shows why the G5RV is decently
matched by coax on 75m and 40m as well as 20m.

http://www.qsl.net/w5dxp/G5RV.HTM

The 1/2WL of 300 ohm series section is what the antenna
needs to repeat the resonant feedpoint impedance on 20m.
I still don't know why Mr. Varney installed the 1/2WL
300 ohm section for 20m operation. Why not 100% coax?

The 1/4WL of 300 ohm series section is close to what
the antenna needs to transform the 40m feedpoint impedance
to a nearly pure low resistive value. This can be seen
on the Smith Chart.

The 1/8WL of 300 ohm series section is close to what
the antenna needs to transform the 75m feedpoint impedance
to a nearly pure low resistive value. This can also be
seen on the Smith Chart.

The 0.88WL of 300 ohm series section is close to what
the antenna needs to transform the 12m feedpoint impedance
to a purely low resistive value. I didn't bother showing
this one because it goes more than once around the Smith
Chart.
--
73, Cecil http://www.w5dxp.com