This crystal or galena radio is one of the many versions available on this website. This is from a documentation from the 70s. The coil is formed by 50 + 50 turns of wire 28 in a ferrite rod.
This modulator circuit was found in an American documentation from the 90's. The circuit uses a...
The integrated circuit used in this 1982 project is not very common today. It can be adapted to...
We found this circuit in a 1993 documentation. It is a high input resistance millivolimeter whose...