> An easy method of mounting these choke baluns wound around (or inside)
> a PVC form is to suspend a 2" (or whatever needed to fit over the
> boom) piece of PVC inside the larger form, then slip it over the boom.
> I leave about 1" of the inner piece extending out from the larger
> form, slit the end and secure with a hoseclamp to the main boom.
How do you keep the boom from being a shorted turn, and reducing
inductance of the balun to nearly zero?
Any time a conductive slug or ring is placed inside a coil, the
counter magnetic forces from eddy currents cancel some of the
reactance. If it is a large long metal slug, even steel or iron, the
inductance will really drop dramatically.
I have wound RG-8 on 4" thin wall PVC forms for many years using
all types of coax and never had a single balun failure ever. I use
nylon or delron spacers to hold it off the boom, or rope to hang it
from a dipole.
73, Tom W8JI
W8JI@contesting.com
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