Original poster: "Gary Peterson" <g.peterson@xxxxxxxxxxxx>
Original poster: "Bill Fuller" <bill@xxxxxxxxxxx> I really don't think Tesla "intended" to generate spurious frequencies (spread spectrum in this context).
Tesla's intention was the development of a wireless system in which a complex signal was produced and transmitted, to which only a specific receiver would respond exclusively. The transmitted signal would, "be intelligible at and only at the intended receiving station." He acheived this by using a greater portion of the RF spectrum than would be used by a simple transmitter working at a single frequency. The signal was spread or distributed in both the frequency and time domains.
. . . A spark gap generates an impulse that in turn generates a huge number of frequency components. The only "useful" frequency is the resonant frequency of the coil. It's also the most dominant generated by far.
With Tesla's 1898 flat-spiral-type transmitter this "useful frequency" is the resonant frequency of the primary tank circuit.
Spread spectrum in practice has all the frequency components at roughly the same level.
This makes the mere presence of the transmitter itself nearly undetectable to unauthorized receivers, a step beyond the signal unintelligibility Tesla was able to acheive. If Tesla had modern high-speed microprocessors at his disposal he would have been able to generate the pseudo-random bit streams needed to do this. He did invent the electronic logic gate of which modern microprocessors are composed. . . . One person can only do so much. . . .
If Tesla could of generated pure sine wave frequencies, he would have used that method. Bill
But Tesla was able to generate practically undamped waves with his improved oscillators.
Gary