Pete: You mentioned having a "Spark Gap" for some type
of short wave radio - containing Cesium-137, and asked
for info about how it might work. I don't have anything
to add, but you might contact Paul Frame, a Health
Physicist at ORISE in Oak Ridge (framep@orau.gov).
He has a wonderful collection and display of old devices
using radioactive materials.
Tom Walkiewicz walkiewicz@edinboro.edu
Dept. of Physics 814-732-2468
Edinboro University
Edinboro, PA 16444