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From: Kenneth Carrigan <carrk@erols.com>
To: Keely Net List <:KeelyNet@DallasTexas.net>
Subject: Re: Ultrasonic Heterodyning
Date: Tuesday, February 02, 1999 1:04 AM
In order for waves to mix, there needs to be a nonlinear junction. As in a
'diode'
function for electrons, and ferrous products that contain oxides or
dissimilar
metals.. all have some non linear juntions. For sounds waves to mix, there
also
must be some non linear materials. I hear that air is non linear when a
high
enough power and high frequency is utilized.. but do not know this for
certain.
v/r Ken Carrigan
Hi all!
I know that if two sound waves are beat together, you get the two
originals, the sum and difference waves.
Question: If you beat the output of two ultrasonic transducers, can
the difference be heard if it is within the audible range?
EXAMPLE: Two transducers, 1 at 40KHz, the other at 39KHz are next
to each other pinging away. Will you hear the 1KHz difference, or must your
acoustic detection abilities be in the ultrasonic to hear the beat?
BillP