This is the typical circuit of a local oscillator for a superheterodyne FM receiver. The circuit was found in a 1980s documentation and is typical of early and early receivers.
The circuit shown in the figure can be used to detect vibrations or to provide amplified acoustic...
Found in a 90’s Popular Electronics, this circuit applies to almost any operational amplifier. With...
We found this circuit in an old American documentation. The table gives the values of the...