Found in an Elektor from the 90s, this circuit is based on components that are still common today. Power is supplied with only two batteries.
Found in a Popular Electronics from the 90s, this circuit can act as a transmitter for an audio...
This circuit was found in a 90s American documentation. The circuit uses still common components...
This circuit from a Japanese publication in 1968 uses germanium transistors from the time like the...