Re: Extra coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Nebojsa Kovacevic by way of Terry Fritz <twftesla-at-qwest-dot-net>" <morfeus-at-EUnet.yu>

Hello Mark!

Very good explanation. Tesla discovered that a long coil of wire behaves as
a sort of "electromagnetic
organ pipe". Some people think that this is important for creating an
"invisible wall" using TC. The
prediction is:  if we "modulate the field harmonics" a bit so that the
voltage maximum does NOT appear
at the end of the coil, but instead appears a few inches away...

Regards,
Nele

Tesla list wrote:

> Original poster: "Mark Fergerson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <mfergerson1-at-home-dot-com>
>
> Tesla list wrote:
> >
> > Original poster: "Nebojsa Kovacevic by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <morfeus-at-EUnet.yu>
> >
> > Hello All!
> >
> > Thank you all for the comments about the extra coil. I was considering that
> > coil strictly from the
> > theoretical point of view, don`t have any experiences with coils like that,
> > only with 'regular' ones. But
> > I would like to know from all of you who had the practical experiences with
> > extra coils, what are the
> > diferences, comparing the three system with two system coil? Is there any
> > dieference, and is it really
> > irrelevant?
>
>   Not from direct experience (yet; I'm still in the process of
> trying to build possibly the smallest magnifier setup ever), but
> some thoughts about "theoretical" viewpoints:
>
>   A crystal radio is a CW device, which means its internal
> currents and voltages are more or less steady state.
>
>   A TC is an impulse device, more like a set of coupled bells or
> tuning forks. That may seem to be a difference without a
> distinction, but if you look at the transfer of energy between a
> pair of bells or tunung forks _during the period of transfer_,
> you see an increase in energy in one at the expense of the other.
> The frequencies and amplitudes of oscillation are not steady
> state.
>
>   Both systems are modeled with the same sets of equations, but
> with different limits. I suppose you could compare a magnifier to
> a set of three bells/tuning forks, in which you pump energy into
> the first, and get it out of the third _before you put any energy
> into the first again_.
>
>   There's filtering going on in both systems, but to different
> purposes. In the CR case, the incoming frequency isn't what's
> wanted, it's the modulation envelope's frequency. The incoming
> frequency's energy is "sacrificed" continuously (to get the
> modulation frequency's energy to a usable level), so the
> resonator's characteristics are optimized to block one in such a
> fashion that it's rectified, and pass the rectified voltage which
> gives the modulation envelope. In the TC, the incoming (primary
> resonant) frequency is what's wanted, just at larger amplitude,
> so we change the characteristics of the following resonators to
> give larger amplitude without affecting the frequency
> (hopefully). The only "modulation" occuring is the time rate of
> energy transfer, or "bang rate".
>
>   Having said that, I'm starting to wonder about SS or VT TCs
> with their "weird" modes of operation, frinst staccato mode, in
> which it seems that other frequencies are added to (or rather
> modulated onto) the resonator frequency to get those strange
> spark shapes.
>
>   Also, I think the OP's reference to "microwave ovens" was a
> mistype; could he have meant "microwave cavities" as in
> considering the extra coil to be a generic resonator, and
> replacing it with a cavity to be excited with the output of a
> standard TC? ISTM that it's possible, if not likely to be
> especially effective.
>
>   I've always wondered how to build a microwave TC...
>
>   Mark L. Fergerson