This circuit utilizes a 12AU7 or 12AX7 dual triode to receive medium wave range signals. The circuit is powered by low voltage, having at the output a transformer of the type found in tube radios. We can power both a low impedance headset and a speaker. The coil consists of 20 + 80 turns of 26 to 30 enamelled wire on a ferrite rod and CV is a variable capacitor obtained from an AM radio for use. Power can be supplied with voltages from 12 to 13 V.
