This circuit is from an English documentation from 1969. The circuit can be designed based on modern equivalent transistors. Diodes are general purpose types.
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...