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./
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