Roy Lewallen wrote:
Now I replace the 50 ohm one wavelength line with a 300 ohm one
wavelength line. For 100 watts delivered to the load, the forward power
on the line is 204 watts and the reverse power is 104 watts. All that
reverse power could do a lot of damage, then?

Probably not at that power level but try this:

Let's say the power handling limit for the 300 ohm line is
1000 watts under matched line conditions. We are delivering
1000 watts to the 50 ohm load. The forward power on the 300
ohm line is 2040 watts and the reverse power on the 300 ohm
line is 1040 watts.

Yes indeed, the reflected power can cause the 300 ohm line
to burn up which is the point Richard Fry was trying to make.
--
73, Cecil http://www.w5dxp.com