The only things I know for sure is that no balun covers from DC to
daylight,
or even 1.8 to 30 Mhz.

==============================
Fred, I'm afraid you're wrong.

Slide a sufficient number of ferrite beads over the coax line and it
will easily cover 1.8 to 30 MHz. Alternatively, wind sufficient turns
around a largish ferrite ring of the correct grade of material.
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Reg.