The circuit presented is a receiver for the medium wave band. Again, the components are all common, the coil consists of 100 turns of very thin wire, wound on a ferrite rod measuring around 10 to 30 cm, with a socket on its tenth turn. Carefully observe the variable capacitor and coil connections in the circuit. Tests can be carried out by moving the lead socket upwards, to improve sensitivity, however this worsens selectivity, but can be done according to the reader's needs. If necessary, it is possible to add an antenna, using a capacitor of around 10 to 100 pF on the hundredth turn of the coil, that is, on the side opposite to ground. In this circuit, the ground wire is not necessary, but in certain cases, it improves reception. A headset or even a small speaker can be used, depending on the case. The germanium diode accepts several equivalentes.
