[TowerTalk] Voltage or Current Balun?

[Greg Gobleman]

>
> >You are better off winding an air core choke out of coax
unless you
> >have a space limitation, because impedance actually goes up by
> >somewhere around the square of the turns compared to a
one-for-
> >one impedance vs size and cost increase in a stack of beads.
>
> Why not just wind a current-type balun using a big core and
some very
> small-diameter teflon coax? You get the turns advantage of a
coil,
> without the size, weight and bulk problems of a coiled coax
balun?
>
I have wound several and that is the easy part.  These are the
W1JR type, illustrated in W2FMI's book.  The problem has been
sealing them against moisture and insects etc.  Another problem
is relieving the stress on the coax so it does not break.  Boxes
can be mounted to a boom but will be heavy, models for dipoles
need to be light and strong.  That's probably why we don't see
any commercial models of this type, said to be very promising.

Greg K9ZM




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