This VCO with discrete components was found documentation from the 1980s. The central frequency with the indicated components is 8 kHz. A BC548 can be used for Q1.
The sensors in this circuit, found in a 1999 documentation, are stripped wire tips at different levels...
This traditional crystal oscillator configuration can use any CMOS gate configured as an inverter. R1...
This amplification stage circuit with a germanium transistor was found in a 1980s documentation. The...