Reg Edwards wrote:
John, I'm afraid you havn't the foggiest idea about how a choke balun
works. You are being confused by the Gurus' bafflegab.

I accept that statement, although I think my idea is somewhat better than a
fog. I do think I understand relative permeability, for example.

A choke balun is a device which permits a balanced circuit to be
connected to an unbalanced circuit without interference to the power
flow. In this respect it is NOT a transformer. No ratios are involved.

There are two conductors or wires in a transmission line.

In a choke balun the two wires are TOGETHER wound round a ferrite core
AS ONE WIRE. It is this pair of wires together, as one wire, which
forms the choke using the ferrite core.


But, you said, "The presence of ferrite has hardly any effect." Why are you
bringing up ferrite again? Why is ferrite used if it has hardly any effect?
Is there not a cheaper material?


The choke has inductance and inductive reactance. The reactance chokes
the current which would flow equally in both wires, in the same
direction in both wires.

Entirely independently, the pair of wires can carry the normal
transmission line currents which flow in oposite directions to each
other. If normal currents in the two wires flow in opposite
directions to each other then there is no flux induced in the ferrite
and the ferrite may just as well not be there.

So the choking action has no effect on normal transmission line
operation along the two wires.

The choke only acts on that current which flows along the line when
both wires in parallel are considered to be ONE wire.

For longitudinal currents the two wires can be considered as being
connected together at both ends. Connected in parallel. It's really a
single wire choke.

It's all very simple really. There are two INDEPENDENT currents
flowing.
----
Reg, G4FGQ


I must be more dense than I realize. I do not see an answer to my question
in your reply. If your answer is there, I would appreciate it if you would
point it out to me.

Thanks,
John