This circuit was published in Radio Electronics magazine in June 1959. The circuit uses an inverter with transformer to generate the high voltage of the Geiger tube.
This is a shunt circuit to be used on a multimeter, expanding its scales to measure high currents....
This circuit from an old documentation includes the power supply for the 117 V power grid. It can be...
Although MOSFETs of the type indicated are not very easy to obtain, one can have the circuit as a...