This 6-transistor Japanese commercial radio was manufactured in the 1960s. The receiver is a super heterodyne type with germanium transistors and is powered by a 9 V voltage.
This dual adjustable power supply was found in the June 1990 issue of Radio Electronics magazine....
We found this simple alarm circuit in a 1986 documentation. The circuit uses sensors of the NA...
This circuit, from a 1973 documentation, can be made with BC549 transistors. The frequency depends on...