Re: Bart's Coil

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

HI Ralph,

On 29 Nov 2001, at 21:39, Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Parpp807-at-aol-dot-com>
> 
> In a message dated 11/29/01 12:21:11 PM Central Standard Time, 
> tesla-at-pupman-dot-com writes:
> 
> > Malcolm -
> >  
> > Isn't the two side frequencies test only for critical coupling when the Qs
> > are related to coupling? My handbooks are not available at present so I
> >  cannot look this up.
> >  
> >         Kc = 1/sqrt(QpQs)
> >  
> >  John Couture
> >  
> 
> Malcolm and John,
> 
> The discussion is interesting from the back of the classroom, and that is 
> probably where I
> should remain.
> 
> The sidetones produced by over coupling are being produced in a test 
> situation using
> a signal generator. But in a disruptive coil I don't think you will find the 
> sidetones because
> the energy is not a sine wave. Nor will there be sidetones after the gap has 
> fired because
> the coupled energy is not coherent like a sine wave.

Actually you do. It is best viewed as a captured waveform on a 
storage scope. The time domain waveform is a double-sideband 
suppressed carrier envelope modulated by a linear decrement (the last 
element being due to primary gap loss). In fact, it is a requirement 
that both tuned circuits are given the lattitude to oscillate freely 
to produce this waveform. Such normally happens in disruptive 
operation (a further condition that air streamers or no streamers are 
emitted from the secondary). For example, if you connect a very low 
impedance generator directly across the primary LC circuit you will 
not get the waveform as the primary is then shunted by the 
generator's impedance.

Regards,
malcolm