RE: Longitudinal Waves

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

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.

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.

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.  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.

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.

Dave