[TowerTalk] Aluminum antenna wire

[Roger (K8RI) on TT]

You should come to Michigan.  Salt on the roads is way of life and not 
just in the winter.  Salt/brine is readily and easily obtainable, plus 
it's cheap!.  When I was young (a very long time ago), most of the roads 
were gravel. After a few months of dry summer weather, the sand and 
stone were pulverized to form that created a thick, choking dust cloud 
every time a car went by.   Brine trucks, spraying the roads were a 
common site.  This not only eliminated the dust for a few months, but 
turned those dirt roads into a concrete like surface with some big chuck 
holes to boot.  Usually by mid summer they (the county) would dig up the 
surface, spray with brine again and grade to a smooth surface.  As there 
were seldom more than a couple houses per mile, the trucks would spray a 
section starting and ending about a 100 yards each direction from the 
homes. To give them credit, there is little brine spraying in the 
summer. OTOH there is not only salt, but Calcium Chloride use as it 
works in the colder winter temps. Sodium Chloride, ceases to function on 
cold days and nites.   There was no Aluminum in cars back then. 
Telephone lines were just a pair of Aluminum clad, steel wires, about 
#10, or slightly larger, mounted on those antique green insulators.  
Switching was strictly manual with "Operators" operating large "patch 
panels". For some time my antennas were made of thole Al clad steel 
wires.   Where ever one "hit the dirt", it would show rust within a 
couple of weeks.

Most of us thought they worked quite well.. Few had  real Cu wire.  Al 
wire? Copper Weld?  What were  they?  Yagi antennas were a rarity. Gain 
antennas were Rhombics, V-beams, Bobtail curtains, or just plain long 
wire.  Nearly all antennas were home built. Aluminum tubing of strong 
alloys was almost unheard of.   10 to 20 years later we were seeing 
simple phased vertical arrays along with the introduction of the Yagi 
antenna..  As antennas were usually simple and power was relatively low, 
IIRC an outstanding signal might get a visit to see just how much power 
you were running.  Back then the FCC had teeth, not the politically, and 
selectively applied like at present, nor did they cheer-lead industries 
with agendas that would have run counter to the existing rules.

Today we have commissioners retire and almost immediately go to work for 
companies like LightSquared.  Do a search on them and their political 
involvement.


73

Roger (K8RI)



On 9/18/2015 11:49 AM, w1eqo at shaysnet.com wrote:
> I have used many types of Copperweld in my consulting business. A couple of
> times I have called their engineering staff about products.
>
> One time I asked about the aluminum on steel product, which I believe was
> called "aluminumweld." (Not to be confused with aluminum arc-welding wire)
>
> I was told if the wire was used on ground or buried I would have dust in a
> year or two.
>
> This has to do with dissimilar metal action in the presence of an
> electrolyte.
>
> Here, in New England that electrolyte can be supplied by acid rain,
> fertilizer, salt air (near the coast), or salt from plowing snow. Locally
> the City Fathers have decided that plowing with salt during smaller snow
> storms is less expensive, for them, then using an actual plow.
>
> Here the action of aluminum can often be seen on pick-up trucks and vans
> where an aluminum "running board," or step has been installed. After a few
> years, fair sized spots of rust develop where the step is attached. A few
> more years results in holes.
>
> Wikipedia has a nice page that discusses dissimilar metals. Essentially the
> two metals and electrolyte makes a battery, that has a short-circuit. The
> "trick" to using dissimilar metals is to pick two that are close on the
> voltage scale.
>
> Like copper and steel.
>
> The other thing to look at is the thickness of the copper on copperweld.
> The company uses a conductivity scale to describe thickness, measured at 60
> Hz. Very different at 1.8 MHz.
>
> In the past I recall they had a different scale where I calculated that
> their 30% conductivity for something like #10 wire was adequate. But memory
> slips with age.
>
> I do remember you will need to be careful with "copper coated" wire. A very
> thin plating does you no good at all, you are using steel with it's poor
> conductivity. Around 3% of copper, if memory serves me.
>
> Pure aluminum wore is just fine. You should use a larger size than copper
> for two reasons: strength, and conductivity. Aluminum is roughly 50% that
> of copper.
>
> I would keep aluminum from the ground, tho.
>
>
> Jim, W1EQO
>
> --------------------------------------------------------------------
> mail2web.com  Enhanced email for the mobile individual based on Microsoft
> Exchange - http://link.mail2web.com/Personal/EnhancedEmail
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk


-- 

73

Roger (K8RI)


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus