This circuit is suitable for calibrating old oscilloscopes. It was found in a 1980s documentation. It generates precise signals given by the crystal.
So This circuit was published in a 1982 English magazine, but can be easily assembled using BC548 for...
With this circuit it is possible to tune an AM signal using a 5k potentiometer (4k7). The circuit was...
This power source was found in a 1968 Electronics World. The transistors are from that time. The...