Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
Why is flat coil geometry significant in this or any other context? Is
there any electrical or functional difference between using a flat
secondary and a helical secondary, beyond one being much more difficult
to fabricate?
Perhaps I'm not understanding something correctly, but my understanding
of an "undamped wave" is just a waveform that stays at a constant
amplitude, as is the voltage coming out of an AC socket, an RF
transmitter, or CW oscillator. A "damped wave" is what you get in a
disruptive Tesla coil, where the amplitude begins at some peak value and
diminishes exponentially with time. Aren't all of these references to
undamped waves just referring to the output of a very high frequency
mechanical CW alternator - a high frequency variant of what powers our
power grid?
Vacuum tube Tesla coils and some non-disruptive solid-state coils do
generate CW, or undamped waves, but Tesla lacked the technology to do
this using active devices. Did he couple a mechanical high frequency
alternator into a matching resonant transformer, to boost the voltage
and produce a true CW Tesla coil? Was resonant-rise involved? While in
theory he had the technology to do this and could have built a CW coil,
the only coil topology he used that I'm familiar with is with disruptive
spark gap technology. I can't figure out just what he was doing from
the text you cited. Perhaps vagueness was his intent?
Gary Lau
MA, USA
> Original poster: "Gary Peterson" <g.peterson@xxxxxxxxxxxx>
>
> Ed, Bill, and Mike,
>
> It's good to know we are all in agreement that Tesla's 1898
> flat-spiral type transmitter is, in fact, a spread spectrum Tesla
> coil RF transmitter. The unanswered questions are 1) is the
> transmitted energy spread out in the intervening portion of the RF
> spectrum between the upper and lower frequencies, and, if so, how
> much of the transmitters RF energy appears in this region? 2) If
> there is RF energy in the intervening portion of the band, does this
> energy contribute to the operation of the wave complex receiver?
>
> As for my comment about Tesla being able to "generate practically
> undamped waves," I was giving him benefit of the doubt in regards to
> one of his methods, which had been used, and still is, for creating
> damped waves. A search for "undamped" in "NIKOLA TESLA ON HIS WORK
> WITH ALTERNATING CURRENTS and Their Application to Wireless
> Telegraphy, Telephony and Transmission of Power : An Extended
> Interview" produces results directly related to the 1898 flat-spiral
> transmitter. For example,
>
> "In the meantime, as I was developing all this, I had
> already struck a new line of effort toward producing vibra-
> tions; namely, I had developed a system permitting me
> to take the ordinary current of any main and transform it
> into any kind of vibrations I desired, either damped or
> undamped." [p. 11]
<massive snip (please see original post Subj: Re: Wire Length)>