This sensitive medium wave (MW) radio pick up the local station without the need of an external antenna. The transducer is a piezoelectric type or crystal earphone. L1 is formed by 20 + 80 turns of 26 or 28 AWG wire on ferrite core. The 20 turns winding is the indicated by 1-2. Variable capacitor is any type used in small transistor radios for the MW band. P1 is a volume control.
Three Transistor AM Radio
