This Japanese commercial radio with 5 transistors is from the 60s and is powered by 6 V. It is a conventional superheterodyne configuration with good performance.
This circuit was found in an old documentation and can be implemented with BC549 transistors. The...
This circuit was obtained in a 1978 English magazine. This circuit is one of many that the reader...
Found in English documentation from the 1980s, this 3 transistors siren directly drives a small...