[TowerTalk] Conductive Concrete and Grounding

[Tom Rauch]

> This is difficult for me to comprehend.  Either is current
is flowing in one
> direction or the other.
>
> Are you saying that there are multiple waveforms?

It isn't *stationary*  DC. Ignoring the reversals in
polarity, lightning has a rapidly rising and constantly
changing waveform with a great deal of high frequency
energy. That's why we hear it on VLF through HF radios for
thousands of miles, and can even hear it on VHF and higher
at shorter distances.

That's why a DC block that passes HF and why a shunt feed on
a grounded tower does very little (if anything) to reduce or
eliminate lightning damage.

That's why we have to treat it like a radio frequency
signal.

73 Tom