This 1980s documentation circuit uses a 741 in a different high-speed comparator configuration. The feed must be symmetrical. The diode is general-purpose.
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...