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Re: Wire Length

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

Wikipedia defines spread spectrum as, "methods in which energy generated at a single frequency is deliberately spread over a wide band of frequencies."

This matches up fairly well with what Tesla was doing in 1898. The "single frequency" is that at which the primary circuit vibrates when energized."

The Wikipedia definition is incomplete in that it implies that the only way to generate a spread spectrum signal is to modulate a single frequency one. That's not necessarily true as there are other ways to generate a "wide band of frequencies" - filtering and modulating of a random noise signal is example with which I'm familiar

Tesla was using a narrow band transmitter and receiver for each of his frequencies and correlating the outputs to decide whether or not a [two tone] signal was present. Two (or several for that matter) relatively narrow band signals don't equal a "wide band of frequencies".