On Sun, 7 Oct 2007 15:14:03 -0500, "Lord Garth"
wrote:


"John Fields" wrote in message
.. .

snip


Years ago, for the U.S. Navy, I designed and built a 40kHz projector
using a hollow spherical segment of PZT8 as the projector and a
couple of ENI 1kW power amps to drive it, underwater.

When we fired it up a visible, golf-ball sized area of cavitation
appeared at what was the focal point, the center of the sphere.

Pretty neat machine. :-)

I'll post pictures if anyone's interested.



Please do!

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OK...


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JF