This circuit, for bands above 15 MHz, was found in an Argentine publication from the 1970s. The L1 coil consists of 12 turns of wire 14 in a 2 cm shape without core and L2 consists of 3 turns of the same wire next to L1. The diode can be 1N34 and the variable capacitor can be of the type found in old AM receivers. The circuit has a good sensitivity for transmitters above 1 W.
