ALLNET Brick'R'knowledge Diode Germanium diode AA118
The germanium diode only allows current to flow in one direction, namely the forward direction. The other direction is the blocking direction. If the diode is connected in this direction, no current flows. The germanium diode is based on the semiconductor material germanium, which means it has particularly favorable properties as a rectifier for radios. What is special is the so-called threshold voltage, which is very low.