Found in a Popular Electronics from the 90s, this circuit presents the difficulty of obtaining the Geiger Tube. The other components are common, admitting equivalents.
This circuit was found in an EDN from the 90s. The circuit employs a double 555 and uses the...
This circuit was obtained from a 1977 magazine, but can still be mounted using BC548 for TR1 and...
This indicator makes use of an LM339 voltage comparator circuit that contains 4 internal...