Please don't consider Chris as speaking for me, or accurately
presenting everything I said.

We all know how easy it is to lift selective portions of long exchanges
and make things sound any way we like.

The original topic was Sevik's 4:1 balun on a single core, where that
balun is made up of two 1:1 ratio choke baluns with parallel inputs and
series outputs. The imputs are excited in a transmission line mode
(differentially) and the outputs in series. The balun cores provide
only ground isolation through common mode impedance. I have a similar
balun built by MFJ, and it has terrible balance. It actually is an
offset voltage voltage balun.

Early on I specifically excluded transformer-type baluns.

I think the problem is Chris thinks we can feed a transmission line
end-to-end on a single conductor and contain energy within the line
area. As far as I see, there is nothing causing the line to operate in
a TEM mode, but it behaves only as a simple 1:1 transformer.

I beleive this is at the root of the poor efficiency and poor SWR
bandwidth of Chris' "balun".

The bandwidth problem would be caused because a transmission line in
TEM mode would have distributed capacitance cancelling series
inductance of the leads, a transformer winding does not. This also
gives rise to the distributed capacitance tending to pull the load side
to the voltage balance of the source winding, causing a problem with
high frequency balance.

The isolation transformer method has the advantage of much better low
frequency isolation and allowing a single core, but falls on its face
for SWR response, power handling for a given core size, and high
frequency balance and common mode isolation.

I think the real argument or disagreement is if the lines in a parallel
or coaxial wound primary and secondary like Chris used are in TEM mode,
or simply acting as a transformer. My contention is it is a
transformer, and those who think any two parallel or concentric
conductors when fed start-to-finish or tend-to-end on one conductor
forces a TEM mode are not viewing the system correctly.

It will be interesting to see what others think. I have a partial
analysis on my web site in a 4:1 balun analysis , and I'll be adding
more information to that as time permits.

Please, just the technical facts. I'll speak for myself.

73 Tom