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 obtained from General Electric documentation from the 1980s. FET operations are from...
This circuit is from an American documentation from 1976. The FET can be the BF245 or MPF102 and...
This amplifier has a few Watt output, using old transistors. The speaker is 45 ohms, but with...