Ideal, quite possibly. Practical and/or necessary for most hams, not
really.
And how many new hams will see this and think "Wow. There's no way I could
put up a vertical. I don't know how to braze (or have the money to spend to
do so)."
There are literally thousands of hams worldwide with regular soldered
radials and not all the connections "immediately dissolved into a white
powder." Radials soldered with silver solder and with regular solder and
some just clamped and bolted. Depends considerably on whether the radials
are buried, pinned to the grass, the type of wire and gauge, location of the
station, acidity/alkalinity of the soil, potential weather, etc.
Heaven only knows how many hams use commercial or some version of homemade
radial plates and have never have any issue with them. Me included, and for
many, many years. When checked with a ratchet and socket occasionally, they
were all as tight as when I did them initially. And not all of us have
freeze-thaw-freeze cycles that would ever loosen a connection, or one
antenna that we put up 30 years ago that we would continue to use (part of
the fun is using different antennas - at least for some of us).
Do what works for you. If the soldered connections do seem to deteriorate,
then do something else, if the antenna is a permanent one. Silver solder,
use a plate, or possible braze next time. Or elevate the vertical and use a
counterpoise - often works much better anyway.
One opinion. Mine.
mike, k5wmg
Michael Goins
Professor, Writing
University of Texas at San Antonio
Instructor, English
Northwest Vista College
Michael Goins
2508 Timbercreek Road
Pipe Creek, Texas 78063
713-417-5221
A thousand words a day, minimum. Five days a week. For life.
Michael Goins, Owner/Editor
Natural Awakenings-San Antonio/Hill Country magazine
Currently distributing 20,000+ magazines in 450+ locations here with an
online edition that gets emailed across the globe!
There are 87 Natural Awakenings editions, printing more than 1,361,150
million copies, distributed at 42,414 locations, and read by more than 3.5
million people nationwide.
*
*
*
*
On Sun, Mar 27, 2011 at 12:23 AM, Donald Chester <k4kyv@hotmail.com> wrote:
>
> Back in the 70's I bonded a radial system to the common point at the base
> of my inverted-L using ordinary lead/tin solder. I quickly discovered that
> the solder reacted with moist earth and almost immediately turned into a
> white powder, and the soldered connection literally fell apart, just in a
> matter of weeks. I ended up re-soldering the radials about once a month for
> the entire winter season. I would never recommend using lead/tin solder
> for any outdoor connection exposed to the elements, particularly where it
> is in contact with the soil. Slopping roofing tar over the soldered
> connection might extend the life of the connection through one season
> without having to re-solder, but I would not trust this to be a satisfactory
> permanent solution. Nor would I use any of those Hammy Hambone "radial
> plates" on the market that use screws to hold the
> radial wires to the base of the antenna. The freeze-thaw cycle will
> eventually cause the screw connections to work loose and result in
> poor connections. The radials must be solidly BRAZED to the common point.
>
> To bond your radials to the common point and join together other outdoor
> connections, I recommend the following: Buy a small tank of Mapp gas and
> brazing nozzle (don't try to use a propane torch nozzle). I bought mine
> back
> in 1980 for just a few bucks, but now I think the outfit runs $30-$50,
> but it is well worth it. Buy some silver alloy brazing rods (not cheap,
> but not outrageously expensive either). They come in flat sticks about
> 18" long and 1/8" thick. You don't need any flux, and the copper
> doesn't have to be polished; just scrape off any flaky scale and clean
> off any paint or grease. The heat from the torch will burn away the
> dull oxide patina on the copper and you will see a dull metallic pink hue
> beneath the flame. Heat the copper until the brazing rod begins to melt
> - pretty much the same as you would with regular lead/tin solder; let
> the hot copper do the melting, not the flame itself. If it is away from
> direct sunlight, the copper should display a dull red glow. Once the
> melting point of the silver alloy is reached, copper will soak up the stuff
> like a sponge
> soaks up water. I have never seen it blob up and run off the copper the
> way lead solder sometimes does when the metal doesn't want to take
> solder. Just be careful, because it is very easy with Mapp gas to
> overheat the joint and melt the copper wire. Never let the
> copper reach a bright orange. With a little practice, maybe after 2 or 3
> radials, you should have the hang of it.
>
> The Mapp gas outfit and
> brazing rods are sold at welding and plumbing supply stores.
> Sweating copper pipes with ordinary lead/tin solder is
> against code, because of concern about lead leaching into the water, and
> I would suspect that the lead joint would deteriorate with moisture and
> minerals in the water, just as it does in contact with wet soil. The use
> of silver brazing for plumbing work has created enough of a demand for the
> material to keep the price reasonable. I have also
> seen Mapp gas sold at Lowe's, but didn't check on the silver rods. They
> make several grades of silver rods (based on silver content I suspect);
> I would explain to the salesmen at a plumbing or welding supplier what
> you intend to do, and they might be able to recommend which grade would
> be best. I don't recall which I purchased, but I would look for what
> holds up best in contact with the soil and best adheres to the
> copper during the brazing process using the Mapp gas torch. The cheapest
> may not be the best.
>
> During the soldering process,
> the alloy will melt and turn to a bright shiny silvery texture, almost
> like liquid mercury. When finished, the joint will cool down and turn to
> sort of a charcoal grey when it hardens. I put up my present vertical and
> radial system in the early 1980s, and after almost 30 years, the bonded
> connections
> show no signs of deterioration, and the brazing looks almost exactly the
> same as the
> day I put it together. OTOH, some screw-on ground clamps I attached to the
> guy anchors have worked completely loose and I can wiggle them by hand.
>
> Don k4kyv
>
> _____________________________________________________________
>
> This message was typed using the DVORAK keyboard layout.
>
> http://www.mwbrooks.com/dvorak/
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