[TowerTalk] Ground rod connection: Cadweld or ????
jimlux at earthlink.net
Mon Apr 24 17:21:58 EDT 2006
At 12:20 PM 4/24/2006, K7LXC at aol.com wrote:
>In a message dated 4/23/2006 8:34:02 P.M. Pacific Daylight Time,
>towertalk-request at contesting.com writes:
> > HI All:
> > I am putting in a ground system at my new QTH. Will have a ground ring at
>the tower with (4) ground rods, plus (2) radials plus a home run separate
>but in parallel with the RF and control cables running to the tower from the
>shack (about 90 ft).
> > There will be three rods along each radial leg.
> > I know Cadweld (or equal) is the best ground wire to rod connection, but
>what should I use as 2nd best? Cadweld seems to be rather expensive, and
>takes some skill to implement.
> The two connection methods approved by the National Electrical Code
>are 1) exothermic (CadWeld, etc.) or 2) mechanical, which means clamps or
I think the actual wording is something along the lines of:
"exothermic welding, listed pressure connectors, clamps or equivalent
means." That last "equivalent means" leaves a fairly wide scope for stuff.
If you don't care about complying with electrical codes (there are
applications where this is the case), you could also consider "hard
solder/brazing" (i.e. silver soldering). It's quite secure and rugged, and
not too hard to learn how to do. You WILL need a suitable torch to do it
though (oxy acetylene with a suitable tip makes it easy..oxy MAPP also
works).. you can rent the torch and gear at most rental places.
Mind you, things like FAA-STD-019 say things like "Soft soldered or brazed
connections shall not be used...."
A lot depends on what you're trying to do, and where you're doing it. A
commercial telecom installation on a mountain top is a very different
matter from an experimental antenna out on the lower 40.
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