This circuit was found in a 1967 RCA documentation. The components are of the time. The circuit limits the current to 50 mA when the battery is fully charged.
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...