Found in a 1969’s EDN, this circuit provides 4.5 V with a 100mA current for digital logic. The circuit uses transistors from the era.
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...