Jim Lux wrote in
:

Owen Duffy wrote:
....
thickess so that the RF resistance is similar to copper, but the
strength comes largely from the copper core.

I think you mean the strength comes from the steel core?


Yes, thanks Jim.

FWIW, when they say 30%, that means that the wire has 30% of the
conductivity of the same diameter copper wire, not that it is 30%
copper. You have to look in the mfrs tables to see what the cladding
thickness is.

Yes, IIRC it is rated on its 60Hz resistance as a competitor to HDC
aerial power applications.

Odd that there aren't suppliers in Australia.. Maybe because there
isn't an existing telegraph/telephone cable infrastructure in rural
areas? In the U.S., there were and still are millions of miles of the
stuff installed before carrier telephony, coax, optical fibers, etc
became common. And, it's still used for MV power distribution, much
of which is still above ground.

Yes, pity that. Remember that we had a monopolistic telecomms market
until ~1995. I did scavenge a littel copper clad steel (3.2mm) on one
occasion, but most aerial phone cables were HDC.

My article mentions an aluminium clad HT steel fencewire which looks
interesting for antennas, but it does bring the issue of corrosion
resistance connection to aluminium. Unfortunately, this wire is only
available in 1km rolls.

It turns out that HDC is probably the best available wire in Oz (JERD is
a VK5), but gal fencewire or stainless steel are eminently suited to
lossy antennas like TTFD etc.

I do remember Roy discussing the resistivity of rust, but I don't recall
figures... does anyone have any figures for the resistivity of the rust
coating on a rusted steel wire? I guess its permeability is also relevant
to RF resistance.

Owen