[kwlug-disc] Grounding for antenna

[John Johnson]

On 2014-06-13 11:02, rbclemen at gmail.com wrote:
> In any urban environment, lightning will tend to strike the tallest grounded metal object in your neighbourhood, which will be the light posts, not your antenna.
Not necessarily. Rewind this thread to the video of the SUV being hit by 
lightning while on a highway and while surrounded by telephone and hydro 
poles.
Granted, this was on a rural highway and was not in an urban 
environment. But the "lumpiness" of the charges in the atmosphere and 
ground will conspire to go against any of the common "rules of thumb". 
Rural or Urban.

And while we are talking about lightning myths I will stir the pot with 
this left over from the same video:
With respect to lightning, the insulation provided by the tires on the 
SUV is inconsequential.
At the voltages involved everything becomes a conductor, tires included.

The tires on the SUV may provide some protection for low to medium 
voltages up to 13.8 kVac maybe more. As with lightning, the insulation 
may break down or suffer from creep, with higher voltages.

There is a section on antennas in the following article:
http://en.wikipedia.org/wiki/Insulator_%28electricity%29

jsquared
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