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 was found in English documentation from 1995. The circuit uses a period sensor and...
Found in a 1958’s publication, this receiver uses components that are nbot easy to find in our...
Using the 4046 PLL integrated circuit, this circuit generates signals from 60 Hz to 1.4 kHz via...