[TowerTalk] Aluminum clad wire

[Roger (K8RI)]

On 12/30/2010 2:14 AM, Grant Saviers wrote:
> I've been looking for aluminum clad steel wire for an antenna project
> and this led finally to a source for aluminum clad high tensile steel
> ($90 for 3000'  11 ga).  Certainly a LOT cheaper than copper or
> copperweld alternatives.
>
> http://www.kencove.com/fence/Aluminum+Clad+Wire+11-11.5+Gauge_detail_WAC11.php
>
> It took quite a bit of googling to find this, but now the question is
> why not use this for all wire antennas because it is cheap, very
> strong,  low-stretch, and corrosion resistant,
Corrosion resistant is a *relative* term. It is resistant, not corrosion 
proof.  Even though there are NO power, or chemical plants within a 100 
miles to the SW (prevailing wind direction at least 50% of the time) 
even copper weld is brown with in 1 to 2 years. Clean it to solder and 
it's just bare steel.

In this atmosphere I doubt Aluminum would fare as well. Yet my step 
daughter and grand daughter have horses fenced in with the Al clad and 
it appears to do well just a few feet off the ground.

Use split nuts and a dielectric compound, Never-seeze, or even Noalox 
and then weatherproof the joint.

As Al is verboten for electrical work *except* from the meter to the 
panel, I doubt (but I haven't checked) if the local electrical suppliers 
would have anything useful. Hard drawn copper is good and particularly 
so with #10-14, but that's fast approaching the point where the weight 
becomes a problem.  There is little substitute for copper clad or Al 
Clad steel when going with long antennas that are center fed. There is a 
LOT of sag even in a half wave, center fed, 75 meter sloping dipole when 
hanging RG-8 size cable and a balun from the center. That means a LOT of 
tension on the antenna to keep it half way straight. Yet if you have the 
height, you can pull a copper clad dipole *nearly* straight, but it'll 
take a strong and well guyed tower to hold it.

I figure my slopers have close to 400# tension on them which is just 
200# under the guy line tension.

73

Roger (K8RI).