Bare copper will corrode rather quickly. Insulated copper would be
better but the insulation will probably degrade in the UV. Bare SS
would probably be best. I have a split backstay where the split is
fairly high up. I ran a separate antenna from the masthead using
thin SS wire, small insulator at the top. Bottom had a small insulator and
a spring to absorb any mast pumping. Attached it to the radar arch. It
worked well, but not any better than the 23' fiberglass whip mounted to
the transome.

Doug

"maxlynn" wrote in message
news:Ygppb.52870$hp5.43787@fed1read04...
Okay, now that you have given your opinion on Kevlar as a backstay, how
about addressing the original question - i.e., is there any conceptual
problem with wrapping a bare copper wire around it and using it for an
antenna? Has anyone done this?

And, oh by the way, how would you feel about using Kevlar as a substitute
for 1x19 in steering cables? Would it shock you to know that many boats
are
using Kevlar in this highly critical application? And have been doing it
successfully for over ten years now? Use as a backstay is pretty mundane
by comparison. And others have been using it for a similar period as
backstay material. And contrary to what you suggest, the lifetime and
other
properties of Kevlar are well understood.


"Tom Dacon" wrote in message
...
This doesn't address your antenna question specifically, but I have to
say
that the idea of replacing a stainless wire backstay with rope just
creeps
me out. Sure Kevlar, in the appropriate size, could be stronger and
still
lighter than the wire, but its long-term durability raises some
significant
questions. The lifetime of stainless steel 1x19 and rod is well
understood,
as is the response to shock loading; I doubt that the same could be said
for
Kevlar. Your backstay's a pretty important rigging component - I wouldn'
t
be
inclined to screw around with it. You might also consider the long-term
cost
of more frequent replacement of the Kevlar, versus the cost of the wire
and
insulators for about a twenty-year lifetime expectancy of the SS wire
and
insulator combination.

I'm not against Kevlar in standing rigging per se, although I'd be
inclined
to use it in a "supporting role", so to speak. In fact, I'm thinking of
replacing my 7x19 SS wire running backstays on my 41' 3/4-rigged sloop
with
Kevlar the next time I re-rig, not so much to save weight as to keep
down
the chafing on my spreaders when the running backstays are housed at the
after shrouds. I just wouldn't use in in a single-point-of-failure
application such as the backstay.

Tom Dacon


"maxlynn" wrote in message
news:hDVob.49689$hp5.39655@fed1read04...
Okay, here's another question on antenna configuration. I have just
gone
through the pricing out of backstay insulators, and received the
suggestion
that a good, less expensive alternative would be to substitute a
Kevlar
backstay for the rod that I have presently, and wind a piece bare of
wire
around the Kevlar, up to near the masthead as an antenna. It is
significantly less expensive, and the Kevlar has the advantage of
being
stronger and lighter than the wire.

Anyone know of any disadvantages to this approach??


"john s." wrote in message
om...
Glenn Ashmore wrote in message
news:JRxob.119973$sp2.25191@lakeread04...
In the process of laying up the hull I incorporated a couple
hundred
sq.
ft of bronze bug screen to serve as a counterpoise. In addition
two
runs of 2" copper foil run down the center of the hull to the keel
area.
Capacitors between the foil and the keel bolts isolate any DC
from
getting back into the counterpoise. That is probably enough but
as
I
am
installing two aluminum tanks, I wonder how kosher it would be to
tie
them into the counterpoise with more capacitors.

It would add another 14 sq ft of coupling area but would it be
introducing other problems?

Glenn, I think you are overdoing it....I just have a copper strap
from
the ground of the antenna tuner to one keel bolt (external lead
keel)
and when I tested the syste,after installation (in New York), I got
a
55 report from a ham in NW Spain. The only time Herb (Southbound II)
did not hear me loud and clear was because my copper strrap had
become
corroded/
john N2ZOA/MM