I happened to come across this site dedicated to ELF monitoring and wondered if anyone on the board was familiar with it. Seems they're trying to get folks interested in becoming part of an ELF monitoring network of stations. Here's what they tell you that you need to get started:Antenna array - Two widely spaced probes to be placed into the earth.
These may consist of copper clad ground rods eight feet
in length, or a copper conductor strip in the earth.
ULF Receiver - Schematics are freely available.
Interface Card - A multi-channel analog to digital interface unit to couple
the received signal to the data computer.
Data Computer- A standard PC type computer and monitor.
more info at http://www.elfrad.org/
73, Ray