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Cecil Moore[_2_] · September 4th 08, 01:34 PM posted to rec.radio.amateur.antenna

wrote:
Cecil, if a transmission line operated in the way you think, it would
be radiating fields all along its length transmitting RF all along the
length of the line.

False! This is easy to visualize and prove. Given a 1/2WL
folded dipole fed with 300 ohm balanced line:

1. Do the out-of-phase differential transmission line
currents radiate? Ideally - NO!, because the fields
from the two wires engage in destructive interference
and cancel.

2. Do the in-phase antenna currents radiate? YES!, just
as they are supposed to do because the fields from the
two wires engage in constructive interference and re-
enforce each other.

Let's look at the balanced output terminals of the current
balun at the source. Instantaneous current is flowing out
of one terminal while instantaneous current is flowing into
the other terminal. I'm sorry, but that is differential,
transmission line current.
--
73, Cecil http://www.w5dxp.com