For the oldschool radionics, look up "Hieronymous" - "Ruth Drown" - "Charles Cosimano" - "Albert Abrams" | For the newer stuff, refer to Don Croft and related information at educateyourself.org | Other keywords: psionics, psychotronics, radionics instruments.
The simplest radionics device you can build is a three dial box. It uses three potentiometers, a witness well and a stickplate, connected in a closed circuit and mounted in a box. The potentiometers have plastic tuning knobs, the witness well is a small copper plate or pipe end cap, and the stickplate is a metal plate or flat coil beneath a flat piece of plastic. More advanced devices incorporate crystals, magnets, power symbols, flat spiral designs, orgonite, electric current, and more dials and witness wells.
Example of some fancy radionics instruments:
http://www.copenlabs.com/radionicsukuk.htm
It's all very subjective and tricky to work with, but since it's fundamentally a form of magick the effectiveness of any device depends on how strongly your subconscious believes it works. I have heard stories of psychic idiot savants who could do amazing things with the devices they created - one gave up his device for study, and it was found to be nothing more than a lunchbox with a dried piece of salami and other random items inside.
Radionics is most effectively used in agriculture since the etheric fields of plants are simpler and more yielding than those of animals and humans. Here's a PDF of one such device, the Cosmic Pipe:
http://www.acresusa.com/toolbox/reprint … _jun97.pdf
Acquiring fringe knowledge is like digging for diamonds in a mine field.