I think the basis of Chris' claims is that equal and opposite currents
flowing in two parallel or concentric conductors makes it a
"transmission line". I can give examples where that isn't true. In any
conventional transformer with a load across the secondary, the
secondary current will flow opposite the primary current based on
Lenz's law. It is magnetic field coupling from aprimary to a secondary
that causes that effect.

KD5WNA probably just didn't read the application note carefully, and
missed that part 1 covers transmission line transformers and part 2
just transformers.

Every peer reviewed textbook I have that deals with transmission lines
states they transfer energy via TEM mode (transverse electromagnetic
mode, not electric magnetic as the "tutorial" by Trask states).

The key is all in the excitation and termination of the windings.

There is a great deal of difference in how energy gets from one place
to the other in the two systems. That's why bandwidth is restricted in
a conventional transformer mode, and loss over wide bandwidths is
generally higher in a transformer rather than a transmission line mode
of coupling.

The real title of Chris' tutorial should be "What I Think a
Transmission Line Is", because that's all he really disagrees with me
about. I think a transmission line conveys energy via TEM mode, he
thinks it conveys energy through flux coupling. We simply have a
disagreement of definitions. I was speaking very specifically about a
balun Sevik described that would not provide a balanced current source.
Chris has extracted certain sentences from a long exchange to prove
some unimportant point about him being right and me being wrong, and
totally skirted the issue of Sevik's design being flawed.

The tragedy of this is some people will think Sevik's design is a good
one, because if Chris is right about this one thing I must be wrong
about everything I said regarding Sevik's not-too-good balun
suggestion.

73 Tom