lu6etj wrote in
:

Hello boys, good day for you

Is it Carolina Windom a balanced load to justify the name "balun"? We
could think in a device to transform Z and another device to block
feed line current. What do you think about it?


Miguel,

Sometimes the language we use doesn't well describe the thing we are
thinking about, and this is a case.

We could well apply a meaning to balanced, that either the currents are
equal in magnitude but opposite in phase; or that the voltages wrt some
sensible accessible reference are equal in magnitude but opposite in
phase. One does not imply the other without constraining the load
characteristic.

When we speak of unbalanced, we commonly think of a configuration where
one side is 'grounded' and the other 'active'.

The problem is that many situations in antenna systems are not purely
either, they are not balanced by one or other of the meanings above, and
they are not unbalanced by the meaning above.

So, they need to be dealt with by the more general method of considering
that there are non-zero common mode and differential voltages and
currents.

It would be most unlikely that a Carolina Windown would be balanced, or
near to it, by any defintion. The antenna is born out of a quest to sell
the disadvantage of Windom feedline radiation as a positive feature.

The way I like to explain a balun is that it *facilitates* connection of
a not-balanced device to a balanced device. A practical balun does not,
of itself, eliminate (meaning make zero) common mode current or common
mode voltage... yet we commonly use absolute words to describe its
action.

To a certain extent, that is saying that they are not ideal or perfect
devices. Some of the rules we hams have made for baluns pretty much
assure mediocre performance. Like for example what I refer to as Rule
500, that the minimum choking impedance of a current balun is ten times
the differential characteristic impedance (commonly 50, hence Rule 500).

I know English is not your first language, but be wary of applying the
meaning of words absolutely.

Owen