This circuit is suitable for calibrating old oscilloscopes. It was found in a 1980s documentation. It generates precise signals given by the crystal.
Found in a 90s Radio Electronics, this circuit can be used in high voltage experiments, ionizers,...
This VFO circuit generates signals from 2 Hz to 50 Hz. We found it in Popular Electronics from...
This circuit, published in the 1980s, can be applied to operational amplifiers of almost any type....