> certain metal objects If I remember correctly it isn't the metal object itself that receives the AM radio, there has to be a diode. In practical terms, diss

> certain metal objects If I remember correctly it isn't the metal object itself that receives the AM radio, there has to be a diode. In practical terms, dissimilar material junctions - where one is a semiconductor and the other a conductor - form a crude diode. Mercury-amalgam fillings in teeth (with the tooth being the semiconductor) are the apocryphal 'accidental AM radio receiver.'