This circuit was found in a Popular Electronics documentation from the 90s. It is possible to switch the frequency of an oscillator by voltage. The circuit can act as a shield.
This circuit is from an American publication of 1977. The tunnel diode admits equivalents and the...
This circuit was obtained from an English magazine from 1976. The circuit operates two LEDs and...
Found in 90s Popular Electronics this circuit amplifies signals over a wide range of frequencies....