On 25 Mar, 17:38, Cecil Moore wrote:
Uncle Peter wrote:
Aluminum has good conductivity. Before the corrugated
copper lines became popular Times Wire made an
Alumafoam cable with an aluminum sheath for many
years. We still have some runs in service at several of
my work locations..

Aluminum is used extensively in cable TV coax.
--
73, Cecil http://www.w5dxp.com

That is correct Cecil but they are using a insulator instead of air
because of moisture getting in. The coax is also covered with plasic
which with the
inside insulation makes it less liable to kink or attack by ground
alkali or moisture.
Actually some of the older air insulated coax did not have a plastic
covering but these were changed out when HDTV entered the mix.
The air filled coax makes useful parts for antennas, you apply a
voltage
to the inner wire and the heat allows the spacers to soften and
separate from the outer aluminum. The outer aluminum tubing is thicker
than the norm so it can be put into use in several ways. Couplings are
hard to get unless
you manage to get some when the coax is changed out, the center wire
is solid so it is not as easy to join as corregated copper types which
are tubular in form allowing for a conductive rod to be pushed into
the joining ends and then sliding a copper tube over the outer
corregation before soldering
Art