This elementary receiver with a crystal earphone was found in Japanese documentation from the 1960s. The coil has 60 + 40 turns of wire 28 to 32 in a ferrite rod.
This circuit consists of a booster for the medium wave band. We found it in an English publication from...
This circuit converts signals from the 350 kHz to 500 kHz longwave (VLF) band to the 4.35 to 4.6...
This circuit of old documentation can be implemented with modern operational amplifiers. The...