[TowerTalk] Ground rod connection: Cadweld or ????

Jim Lux 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
>similar method.

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.

Jim, W6RMK

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