On Fri, 21 Jan 2005 12:06:42 -0600, "Richard Fry"
wrote:

The outside of
the outer conductor of the coax feedline still will be coupled into the
received and/or radiated fields,

Hi OM,

What you fail to bring into this is the "degree" of coupling. The
transmission line being orthogonal is in the plane of the dipole's
null - hence zero conduction. It only supports conduction through
either direct connection (which the BalUn/Choke breaks) or loss of
symmetry (not falling in the plane of the dipole's null or the
environment distorting that electrical plane - an unbalanced dipole).

As an illustration of this, consider the effect of a 1/2-wave dipole
suspended near, and parallel to another 1/2-wave dipole. Only one dipole is
driven.

This, again, reveals the nature of "degree" of coupling. That is, in
your scenario the second dipole MUST be parallel AND broadside. If it
were parallel and online, the coupling would be considerably (10 - 15
dB) less.

So how important is the balun in the total RF system?

What is the "degree" of coupling?

73's
Richard Clark, KB7QHC