I have a powerful ultrasonic transmitter right here. It's in the frequency
range of 20-40 KHz. I recently tested it on a few dogs and birds. They can
here it but it has to be really powerful to drive them away. It has to have
a sound pressure level equivalent to your stereo at high volume, or about 15
times the maximum output of Bobsprit's home theater.

Try this:

http://www.kishelscents.com/glands.htm

Your stereo may blow your speakers with the ultrasonic sound. You need
piezo tweeters alone and have to drive it with an oscillator/power
amplifier. If you are interested I can get you the links so you can build a
system yourself. Another approach is a loud motion detector alarm (battery
powered) that you can turn off by remote. You can get it for about $40 at
Lowes or Home Depot. Also consider a small flame thrower. It's quiet and
effective.

Gilligan

"Overproof" wrote in message
news:ZqXbd.7032$_u6.6211@edtnps89...
Could either of you assist me in a search for sound wave files that are
above the audible range of humans? Where would I search to find more
information on this. I know the basics involving a dog whistle... but are
there any downloadable wav files? Could I produce such sound waves and
record them?

I have been told that prolonged exposure to such "sound" has deleterious
effects on a person's mental state. I don't know if that is true.

I hoping to keep the raccoons out of the garbage.

...any help in direction would be appreciated.

CM