An online expert quoted the following diagram from VK5AJL.
It is labelled as a simple 1:1 voltage balun, which is to imply that it is NOT a current balun (they are mutually exclusive).
He goes on to quote:
which begs the question, under what circumstances is the current into one terminal of the secondary significantly different to the current out of the other terminal of the secondary?
Is this in fact a better current balun than voltage balun under some conditions? What?
Is it a good voltage balun?
The correct answers highlight that characterising a balun based on the way it is implemented is potentially flawed.
More at A balun puzzle – discussion .