Triggered wave generator/piezo questions

[Paul Perry]

At 01:06 PM 29/08/99 -0700, you wrote:
>Watch out... most "hydrophone" apps are for ultrasonic frequencies... might
not be a
>good drum trigger... unless you use a steel plate for a head....
>
.no, I'm not trying to convert an ultrasonic depthfinder head to a drum pickup
(and I wouldn't try either, they are probably tuned or something)..
what I was interested in, was picking up fish noises. And the man said, that
it's a
goodides to surround the piezo pickup with some rubbery stuff to stop it from 
cracking if the final epoxied unit gets a good whack.

paul perry melbourne austarlia