"Cecil Moore" wrote in message
...
dansawyeror wrote:
The combination of cable and antenna presents something other then R = 50
ohms 0 reactance and the the transmission line see discontinuities. The
result is it radiates.
If the currents are balanced, a 50 ohm transmission line seeing
something other than a 50 ohm load does NOT cause it to radiate.
If a 50 ohm unbalanced transmission line sees a 50 ohm balanced
load and common-mode currents flow on the outside of the coax,
it will usually result in radiation from the feedline. Simply
knowing the magnitude of the feedpoint impedance doesn't tell us
anything about feedline radiation.
--
73, Cecil http://www.qsl.net/w5dxp
Even grossly mismatched open wire transmission line does not radiate
significantly. For example a 66 ft length of 3" spaced, open wire line,
shorted at one end, radiates only 4 - 5% of the input power. 95% is
dissipated in the conductor losses.
73,
Frank