[TowerTalk] Radial Plate Designs

[Kim Elmore]

That's interesting because it has not been my experience here in 
Oklahoma. I have seen aluminum wires corrode over a few years, but my 
solder joints (regular 60/40 stuff) have survived well. They begin to 
look dull, but I've never seen what you describe. Of course, YMMV.

Kim N5OP

On 2/11/2015 4:03 AM, Donald Chester wrote:
> NEVER use regular lead/tin solder if there is any possibility that it 
> will come in direct contact with the soil. Minerals in the soil will 
> quickly turn the solder to white powder. I once used leaded solder to 
> attach ground radials to a copper ring at the base of an inverted L. I 
> ended up having to re-solder the entire ring of radials about once a 
> month. The soldered connection would just fall apart, and the radial 
> wires would fall loose from the ring. The radials to my present 
> vertical were attached using silver alloy brazing rods, heated with a 
> Mapp Gas torch. The rods and torch are widely available at plumbing 
> suppliers, since it is against code to use regular lead solder with 
> copper plumbing for the same reason that it doesn't work with ground 
> radials; minerals in the water eventually destroy the soldered 
> connection and the pipe joint springs a leak, plus the danger that 
> lead may leach and contaminate the drinking water. The rods are not 
> cheap, but they are not prohibitively expensive either. I brazed my 
> radial system together in 1983, the soldered connections are buried 
> below grade, and the silver solder connections are as solid to-day as 
> the day they were installed, with no visible corrosion. Above-ground 
> connections exposed to the elements over the past 32 years likewise 
> remain intact. I use 15% silver content flat brazing rods, about 1/8" 
> wide and 18" long. No flux is necessary. Copper sucks up that silver 
> brazing alloy like a sponge soaks up water. Just remove any dirt or 
> scaly corrosion with a wire brush; no need to polish the copper to a 
> sheen. I could never understand why anyone would prefer to use a 
> crappy metal plate with screw-on connections, when it is so simple to 
> silver-braze connections that will last for the life of the radial 
> system and vertical radiator, and will probably outlast the life of 
> the antenna owner. A screw-on connection, especially in contact with 
> the soil and subject to outdoor temperature variations will eventually 
> fail. Those Hammy Hambone radial plates I have seen advertised are 
> considerably more expensive than a handful of silver brazing rods and 
> a Mapp gas outfit. Don k4kyv 
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-- 

Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP 
SEL/MEL/Glider, N5OP, 2nd Class Radiotelegraph, GROL)

/"In theory there is no difference between theory and practice. But, in 
practice, there is." //– Attributed to many people; it’s so true that it 
doesn’t matter who said it./