"Antonio Vernucci" wrote
So, I decided to instead use an RF choke that quenches the common mode
RF. I firstly built a thick ferrite core by taping together five
3/8"OD ferrite rods, 6-inch long. I then made 10 turns of a very thick
insulated red-black twin lead on it. The turns are widely spaced, so
as to have low capacitance between adjacent turns.
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Congratulations. You have just re-invented the choke balun. It's what
many people use. It is the best choice. Very often it is wound on a
ferrite ring. It has no impedance or turns ratio.

Or it may consist of a number of ferrite sleeves which slide over the
transmission line.

It is a mistake to use a balun between tuner and transmission line
which has a definite impedance or turns ratio.
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Reg.