Dear Andy, LF Group, There is quite a bit of info around on the US and Russian ELF systems on 76 and 82Hz respectively - signals have been received by amateurs, too - have a look at: http://www.fas.o
I did hear from a non attributable source in the academic world that at one time there was a proposal in this country to use the third rail of the railway network as an antenna for ELF/ULF communicat