I am trying to build a balun. I chose the one on this web site as I like the
design
http://www.hamuniverse.com/balun.html
It states that, and I quote
"The number of turns is not critical because the inductance depends more on
the length of the wire (coax) than on the number of turns, which will vary
depending on the diameter of the plastic pipe that is used."
But it does not give the formula. It just says 18 to 21 feet.
I plan to use 4 inch pvc and I want to cover as much of the upper 11 meters
as I can. Am I better off at 18 or 21 feet?