This circuit was obtained from an American 1980s documentation. The frequency depends on the crystal and the circuit may be a PNP that reaches the generated frequency.
Found in Radio Electronics from the 90s, this circuit generates signals from 100 Hz to 1.5 kHz....
Operating in the range of 1.5 to 15 kHz, this sinusoidal oscillator is based on a 741 operational. The...
This circuit was obtained in a 1973s documentation. The transistors may be BC558 for the PNP and...