This receiver was found in a Japanese publication in 1967. The circuit uses germanium transistors and details of the coils are not given. Power is supplied by a 9 V battery.
We found this circuit in an old publication. The circuit can be implemented with modern equivalent...
This circuit with transistors from a 1995 publication. The circuit is powered by a voltage taken...
This tiny photocell-powered audio oscillator was found in a book on transistors from the 1960s. The...