[Top] [All Lists]

[TowerTalk] Exothermic/Cadwelds one shots etc...

To: <>
Subject: [TowerTalk] Exothermic/Cadwelds one shots etc...
From: "Dudley Chapman" <>
Date: Thu, 26 Aug 2004 15:38:34 -0400
List-post: <>
   I think you have two choices.  You could do the rod bending thing as you
suggested, or you could cut the ground rods in half and use twice as many of
them.  The rule of thumb from the Polysphasor literature and others is that
ground rods along a radial or perimeter ground should be placed at a spacing
that is twice the length of the rods.  So if you cut the rods to 4 feet, you
would place them 8 feet apart.  The only problem with this second solution
is that you need more one-shots.

   Your concern about using the one-shots with angled rods might be
mitigated by driving the rods at an angle, but in a plane that is
perpendicular to the wire rather than along the plane of the wire.  

  From my reading I have seen that either of the solutions is used in
professional installations.  

To the List,

   As for the water-driving technique shown on the website offered a few
days ago, I have a question.  This technique is very clever, but I have read
that it's important to drive the rods into hard-packed soil so there is a
lot of contact between the rods and the soil.  Pre-drilling a hole for the
rods and then backfilling is explicitly not-recommended, unless you are
doping the soil with electrolytic stuff.  I would think that using the
water-drilling method would produce the same problem as a pre-drilled and
backfilled hole.  Does anyone have comments on this?  If I run into trouble
driving the rods, I would like to use the water method, but not if it makes
a poorly grounded rod.

Dudley - WA1X

Message: 8
Date: Thu, 26 Aug 2004 13:13:06 -0500
From: "Chuck Lewis" <>
Subject: Re: [TowerTalk] Exothermic/Cadwelds one shots etc...
To: <>
Message-ID: <003d01c48b98$55ddb6e0$>

My dilemma regarding cadwelds has to do with the fact that at my QTH there's
an impenetrable (and thick) sandstone layer 4-5 feet below the surface. I
have always had to drive rods at an angle in order to get all eight feet
buried. This seems to work well, and I would like to replace the compression
fittings with cadweld; but I'm stumped because it appears that the rod needs
to be plumb in order to keep the shot material in the mold. I suppose I
could REALLY bury the things, and use a rebar bender to turn the ends up so
they're vertical, but that's the only solution I have been able to come up

Any other suggestions from the group?

Chuck, N4NM



See:  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>