Found in Unitrode documentation from the 1980s, this circuit makes use of PUTs, currently common components. The circuit must be powered with voltages around 15 V.
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...