(Fwd) RE: Longitudinal Waves

["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 Dave,
     
On 10 Feb 2002, at 19:09, Tesla list wrote:

> Original poster: "David Thomson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>
> 
> Hi Malcolm,
> 
> >Would you please describe (in enough detail that they may be implemented)
> the unique effects and how to produce them?
> 
> Gladly.  I have already succeeded in producing longitudinal waves.  It
> wasn't until tonight, however, that I fully understood what I had done.  To
> transmit longitudinal waves, you need to build a flat spiral secondary coil.
> I have built several of these coils and in different configurations and
> sizes.
> 
> I built these coils with the intent of generating long sparks.  I was
> disappointed when I didn't get the long sparks, but I was intrigued by the
> greater positive aspects of the coils.  A flat spiral secondary coil does
> not load the transformer, capacitors, wires, coils, or spark gap.  In fact,
> the spark gap runs near totally silent.  It's unbelievable how quiet and how
> cool a flat spiral secondary system will operate.  You can run the system
> continuously for any length of time and the system will still remain cool.
>
> Here is a sample of the output I received from a trifilar wound flat spiral
> secondary coil...
> <http://www.tesla-coil-builder-dot-com/FlatSpiralSecondaryTrifilar.htm>
> 
> I have also done similar experiments with single wound flat spiral secondary
> coils and with similar results.
> 
> The greatest spark I could generate through a fluorescent tube on the
> secondary terminal was five inches.  It doesn't sound like much for a 15KV
> 60mA NST.

> While running my coil, I became increasingly bold and left my computer
> running while also running the coil.  The coil and computer are only 10 feet
> apart.  Right next to my computer is a 100 Watt PA amplifier.  The amplifier
> is in the same plane as the coil, but the computer was not.  When running
> the coil, the amplifier would suddenly output so much noise you could not
> hear yourself think.  The amplifier and coil were on completely separate
> grounds and completely separate breakers.  After about 20 minutes, the
> amplifier finally blew.  When the amplifier blew, the volume was near
> completely off.

I suspect signal was being coupled to the output stage through the 
speaker leads. I once had to debug a problem like that for a friend 
who was holding a party. Turned out there was a ham operating CW at 
150W PEP a few doors away. Common mode chokes (hi-u ferrite rings) 
reduced the problem but getting him to go off air for the duration of 
the party cured it.
 
> Tonight it suddenly occurred to me that a flat spiral coil is not designed
> for outputting high voltages in the terminal.  In fact, the high voltages in
> a flat spiral secondary occur near the outer windings.  Flat spiral
> secondaries are designed to output longitudinal waves in a plane with the
> coil.  The components in my PA amplifier were affected by this energy
> transfer.  The fluorescent tube could not draw a long hot spark from the
> terminal, but this turns out to be a good thing.  Any energy put into the
> coil will go to producing both longitudinal and transverse waves.  The
> transverse waves are greater in a solenoid coil due to the geometry of the
> windings.  In a flat spiral secondary the longitudinal waves are greater.
> Instead of putting energy into my flat spiral secondary as transverse waves,
> I was efficiently producing a greater proportion of longitudinal waves.

Sounds like it was radiating like crazy. I visited the website to 
have a look. How wide is the main gap set?     Judging by the stated 
tuning range of 50 - 100kHz, the Q of  the system appears to be very 
low. There is a lot of power being lost, probably in somewhat 
broadband radiation. I suppose the key question is: Is there anything 
about the results that cannot be accounted for by more conventional 
e.m. theory? What *proof* do you have that you are producing 
longitudinal waves? What characteristics should one look for?  

> Longitudinal waves do not propagate in the same manner as transverse waves.
> Transverse waves are voltage waves.  There are two voltage waves in every
> transverse wave, each of opposite polarity from the other.  If left to
> themselves, these waves will eventually attract each other and damp
> themselves out.  And even when the two waves cancel out, the longitudinal
> component of the wave is still there.

Forgive me for saying so but that sounds a bit dubious to me. I've 
never heard of waves attracting each other. And what happens to the 
energy that was in them following cancellation? 

  So instead of trying to receive
> longitudinal energy as we would with a voltage wave, through transverse
> potential differences, we now have to design the antenna to be sensitive to
> longitudinally varying densities of energy.
> 
> We can look to sound to see how this is done.  A resonating chamber will
> accumulate sound and amplify it at certain places within the chamber, thus
> increasing the air pressure for those locations.  This is how all resonant
> musical instruments amplify sound without electronics.  To capture the
> longitudinal energy of a flat spiral secondary we need only construct a
> chamber that captures the longitudinal pressure and turn it into an
> oscillation.  I have figured out how to make such a resonant chamber, but I
> must not say what it is until I have tested it thoroughly and see if it has
> patent value.  At some point soon I've got to use my knowledge to make some
> money or I won't be able to continue my research.

A standard 1/4 wave resonator is such a chamber.
 
> By the time you have figured out how to wind a flat spiral secondary of
> suitable quality and size, I will have been able to test this idea of mine
> and start the patent process if it is warranted.  In a few weeks I'll post
> the methods for working with longitudinal waves, that I have found.

I'm sure that winding a flat spiral can't be all that difficult, even 
with rather fine wire ;) I'll sit back and listen to what other list 
members have to say for awhile before deciding whether it will be 
worth the effort.
     Good luck with the patent application.

Regards,
Malcolm


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