Re: Resonance, and now magnifiers

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 



With maggies another nice transmission line can be formed with some 4 inch
wide flat copper strip that is siliconed onto some 8 inch wide flat acrylic
plate.  The copper strip is attached to both sides leaving a long conductor
with very low inductance.

Dr. Resonance

 >
 > >This 'middle' capacitance affects the 3/4 wave mode more than
 > >the 1/4 wave mode, so we now have the means of tuning each mode
 > >with some independence of the other.  This tends to be done by
 > >splitting the coil at the appropriate point and maintaining the
 > >connection with a piece of wire (the 'transmission line' of
 > >magnifier terminology).  The resonator now finds extra
 > >capacitive loading near its 3/4 wave voltage maxima: the top
 > >end-effect C of the secondary, plus the transmission line C,
 > >plus the lower end-effect C of the tertiary.
 > >
 > >If done correctly, the 3/4 wave mode is now timed to reach
 > >a voltage peak simultaneously with the fundamental after a
 > >certain (design choice) number of RF cycles have elapsed.
 >
 > On my large magnifier, I use a 12 inch wide, fifteen foot long strip of
 > aluminum flashing as a transmission line.  The surface area is quite
large,
 > because both exposed sides provide capacitance, as opposed to a cylinder
 > which has an inside surface area that is wasted. The magnifier system
loves
 > the capacitance, and Paul's explanation does a very good job of explaining
 > why.  The transmission line, if designed as a large capacitance, acts as
an
 > additional energy storage device, as well as bringing that 3/4 mode
 > resonance more into "tune" with the extra coil/topload.
 >
 > Tesla ,himself, said adding capacitance to the top of the secondary of a
 > magnifier would improve operation (Colorado Springs Notes, September 19
 > 1899 page.)
 >
 >
 > >Why bother going to all this trouble?  Well the 3/4 wave
 > >mode is excited anyway, to some extent, whether we like it
 > >or not.  So rather than waste that energy, we might as well
 > >try to use it.   The extent to which higher modes are excited
 > >in any coil depends on how the primary induction is distributed
 > >along the coil.  If we want to achieve high coupling (for what-
 > >ever reason) we cannot do so by spreading the primary along
 > >the secondary, for reasons of voltage breakdown.  So we have
 > >to apply strong coupling to just a short region of the
 > >secondary at its cold end.  It's this highly end-concentrated
 > >coupling which tends to put a greater proportion of the bang
 > >energy into the higher resonances of the secondary.  Therefore
 > >it's a natural evolution of the TC to try to tame and exploit
 > >these.[*]
 >
 > [snip again]
 >
 > Paul's extensive message is certainly one I am archiving - it's packed
full
 > of good insights.
 >
 > Bert Pool
 >
 >
 >
 >
 >
 >