Richard Clark wrote:

On Wed, 23 Aug 2006 02:18:21 GMT, Owen Duffy wrote:



Apart from the challenge of making reliable connections to aluminium,
are there other "issues" that come to mind in using such wire for
antennas?



Hi Owen,

I've used ordinary house wiring for long-wires and they have survived
100# limb falls that ripped out my matching box from its post. The
survival was with the wire, not the box.

[warning to Reggie, the prose that follows contains literary
allusions]
What price tensile strength?

The worst thing you can do is pull a wire tight in an attempt to
totally eliminate sag. The inverse sine angle of its depression
magnifies the stress by huge amounts. A slight sag will never yield a
tensile failure in the most pedestrian of wire.

73's
Richard Clark, KB7QHC


As long as gravity exists will it ever be possible to get a perfectly
horizontal dipole? In spite of a strong tensile component there will
always be a vertical component due to gravity (with a centre feed there
will also be the weight of any cable and perhaps a balun as well). The
net effect is a sag called a catenary. Granted an infinite tension on
the antenna wire would probably overcome the vertical component but the
wire might not survive. The question for this relative neophyte is,
what effect does the sag have on antenna performance?

--
Paul S. Hinman - VE6LDS
long West 113 deg 27 min 20 sec
lat North 53 deg 27 min 3 sec
Maidenhead Locator DO33gk