This experimental AM radio circuit was found in a 1979 English magazine. It can be fitted with a BC548, powered by a crystal or piezoelectric headset. The antenna must be long, and earthing is important. The coil consists of 10 + 20 turns of wire 28 in a ferrite rod for L1, and L2 consists of another 70 turns of the same wire in the same rod. The variable can be obtained from a disused AM radio.
