For as long as I have been in seismic, people have been trying to build =
a
good energy source for engineering seismic studies.  Let me define such =
a
device for you experimenters out there.

1) A person ought to be able to carry it around
2) It needs reasonably high frequency output (ping instead of thunk)
3) Build it for $1000 or even $2000 in lots of 10 units, using new
commercially available and machined parts.
4) It should be safe, even when used by students
5) There should be no significant regulatory issues (a problem with
dynamite, the perfect source)
6) Operating supplies available in third world countries.
7) And last but not least, it needs to work better than a sledgehammer =
used
with a seismograph that can stack multiple impacts.

The in-hole shotgun comes close, but it is possible to shoot yourself in =
the
foot, blow your hand off, and in one case, blow your brains out.  The
associated liability prevents any real company from producing the =
device.
Even if you made it impossible to accidentally hurt yourself, under our =
tort
system, you would still be liable for intentional injuries.

Geostuff will be happy to sell the device using our worldwide network of
contacts, assuming it works and is reliable. Mechanical things tend to =
self
destruct.
=20
Doug Crice          http://www.geostuff.com
Wireless Seismic            http://www.wirelessSeismic.com
12996 Somerset Drive                phone 1-530-274-4445
Grass Valley,  CA  95945  USA    fax 1-530-274-4446
=20


I know a gun fired in the ground is not a good source and that's=20
why I included a drop hammer lifted by a bank and dropped back=20
on the rod that is attached to a steel plate that sets on the=20
ground. I may have to use a propane to lift the slide over the=20
piston instead of a blank shot gun shell,




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