Fleetie wrote:
Another idea would be to use an electron gun. Electrons don't propagate
well through air, because they collide with air molecules. This effect
would increase with increasing local air pressure and density, again
reducing the received signal.

Just an idea to kick around... Any takers?


Radioactive source? Gieger counter as pickup?

'supose you could modify a smoke detector to use as a microphone.

--
Adrian C