[TowerTalk] grounding radials: solid or stranded?

[Tom Rauch]

> By spreading the current out into many filaments, Litz
wire reduces the
> losses due to skin effect compared to the SAME amount of
the conductor in
> single strand. A given current filament is farther from
any other filament,
> so the magnetic coupling is less.

Only when the wire occupies more physical area. For a given
area solid is better over wider frequency ranges, such as
with lightning or HF RF currents all the way down to DC.

> It's the same reason that if you take the same amount of
copper and make a
> tube, instead of a solid round bar, it will have less AC
resistance, and why
> wide flat strips have less resistance and inductance.

That's right, but only when you increase area (diameter)
occupied by the conductor.

> Woven braid, where all the strands are uninsulated, is an
entirely different
> story, although comparing the same number of strands in a
solid bundle, vs a
> woven layer around a dielectric core might be instructive.

Coaxial cable manufacturers already know that answer. That's
why the lowest loss cables for a given conductor size have
smooth conductors in current carrying areas.

73 Tom