[Antennas] Ground Conductivity

Sat Aug 29 19:42:09 EDT 2009

Buried coaxial cable was used to transmit video, triggers etc. from the remote radar site to the ATC Tower. This cable was buried in a trench which had at its bottom, a layer of gravel, then the cable, 6 inches above the cable was run a #6 bare ground wire, that was attached to buried ground rods every 100 feet. After being covered with dirt with appropriate markers (concrete), there were on many occasions where nearby lightning hits would destroy the line drivers at the remote end and the line receivers at the indicator end. 
> From: kargo_cult at msn.com
> To: antennas at mailman.qth.net
> Date: 2009年8月29日 15:52:43 -0700
> Subject: [Antennas] Ground Conductivity
>> I was told this about one of the towns I service
> as inside telecom worker: a power line - not sure 
> how high voltage - fell to the ground. It landed over
> a buried telephone cable about 3 foot deep. It
> didn't damage the line under the place it dropped,
> but at a box a couple hundred feet away, a 
> several-pair splice was burned. In the opposite
> direction, toward the telco central office 1500 
> feet away, a fuse was burned out and a circuit
> card died. I wouldn't have thought there would
> be much of a voltage spike left undissipated at
> the 3 foot depth of the cable. The earth up here
> in this western Oregon valley has pretty good
> conductivity. I wondered whether the same 
> thing would have happened in some dry rocky
> soil like maybe Arizona. -Hue Miller
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