E)
We found this circuit in a PE Hobbyst Handbook from the 90s. The components are common, except the Geiger tube. The transformer is also a component that requires care when choosing.
We found this circuit in a European publication from the 1970s. The transistors are made of...
The TAA131 used in this circuit is not very easy to find today, but an equivalent low power audio...
This circuit was suggested by National Semiconductor in its Linear Application Handbook. The...