Building a simple Natural Radio Receiver is not too difficult for anyone with basic construction skills. Most of these circuits use readily available parts, and the layout is not overly critical. Just remember that since these circuits are high-gain and the input impedance is high in the case of E-Field receivers, keep the input and output sides of the circuitry separated.

Radio Waves Below 22 Hz

Renato Romero’s site has several diagrams of Natural Radio receiver circuits and many design ideas.
http://www.vlf.it