Radio receiver circuit for long and medium wave
This simple radio receiver circuit for long and medium wave range (depending on mounted oscillating circuit input).
Oscillating circuit (coil) are made on a ferrite bar. If you wish to listen long waves winding "1-2" has 135 turns and 3-4 has 20 turns. If you wish to receive medium wave winding "1-2" has 75 turns, and "3-4" has 7 turns (wire used must be CuEm 0.15mm). In parallel with the winding 1-2 is necessary to connect a 40-400pF variable capacitor. Listening signal is made using high impedance headphones to 1000-2000 ohms, which have a capacitor of 10nF in parallel.
Entire assembly to be supplied with a voltage of 3 volts DC .