This trigger uses two switching transistors that can still be found with some ease. The circuit is from an old documentation and its purpose is to speed up the switching of logic circuits.
To use the instrument for AC measurement, the tips are A and B. For CC use tips A or B for...
The interesting circuit shown in the figure, can have its gain digitally controlled and present two...
This simple MW radio was found in a 1975 publication, but it can be mounted with BC548...