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Re: Singing like a banshee



>From 100624.504-at-CompuServe.COMMon Jul  8 16:34:26 1996
>Date: 08 Jul 96 16:48:38 EDT
>From: Alan Sharp <100624.504-at-CompuServe.COM>
>To: Tesla List <tesla-at-poodle.pupman-dot-com>
>Subject: Re: Singing like a banshee

Alan Sharp wrote:

>Greetings All,

<snip>

>I did consider modulating it with a siren type oscillator or even music - 
>(Wagner as it should be heard) it would become a class
>class D amplifier driving the air very directly -
>the only singing tesla coil in captivity.

>Alan Sharp (UK)

Alan, All,

For the purpose of maintaining an accurate historical record I must 
dispute your claim.  I don't mean to demodulate your parade, but 
voice and music, superimposed on the output streamer of a vacuum 
tube T.C. has been a common display in my own lab for years (both 
through plate supply modulation and control grid modulation).  It is 
always a crowd pleaser!  I cannot, and do not lay any claim to this concept.

The early , turn of the century work in radio broadcasting was full 
of experimental techniques to try to allow the modulation of voice and 
music upon the disruptive discharges of early spark transmitters.  
Reginald Fessenden succeeded in an early broadcast of heretofore 
unmatched high quality voice and music programming on an experimental
basis which knocked the socks off those shipboard radio officers 'sparks' that
happened to tune into his experiments with their wireless code station sets at 
sea.  As I understand it, Fessenden used a very high break rate synchronous
alternator and slaved rotary break that produced a sub-carrier frequency of 
some 5 KHz or more.  His very high speed mechanical devices were reportedly
short lived.  With a break rate of 5 KHz , according to Nyquist's Theorem, audio
information to 2.5 KHz will be absolutely intelligeable.

The successful voice modulation of a high-powered spark gap 
oscillator powered Tesla coil is a back burner project I've been 
working on.  If you listen to the first vocals from the Black Sabath 
song Iron Man, and imagine this acoustical voice energy coming entirely from the 
discharge of a medium-large coil you have an idea of what I expect to 
accomplish.  Again, this will not be new, but IT WILL be fun!

Happy Coiling!, rwstephens