> >The ground you put in the concrete i.e. the rebar would not be optimum.
> >Concrete is a very good insulator. The common 8' copper clad steel grd
> rod
> >is hard to beat.
>
> EUR At 1.8 - 30 MHz, in garden-variety soil, RF penetrates only a few
> inches. Thus, an 8' gnd rod has substantially less RF-R if it is buried
> horizontally, just under the surface than if it driven in vertically.
> However, a vertical ground rod works ok at 60Hz. At the frequency of
> lightning {c. 100kHz} horizontal would still have the least RF-R. In
> order to protect from a direct strike, the feedline needs to be
> disconnected and tossed out the window.
>
> ::Since I can't toss them out the window very easily (runs through a wall,
> and too many runs, anyway), I do the second best thing and make sure the
> coaxial cable feedlines are longer and more circuitous than the antenna
> lightning ground, which is right at the base of the tower, under the
> antennas. That run (lightning ground) is straight, short and very low
> impedance (copper flashing .060" thick, solid copper and very wide),
> compared with the coaxial cable conductors. Since we rarely have any
> lightning here, I haven't had the chance to see what fails from a nearby
> strike; however, when I lived back east (NJ), lightning was a daily
> occurrance in the summer months and a similar system seemingly prevented
> any station damage for many years. -WB2WIK/6
>
>
>
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