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 highly-sensitive circuit causes a relay to be closed when the other is open or still...
The coil is formed by 70 + 5 turns of 6 to 30 AWG wire on a 1 cm to 10 cm ferrite core. The...
This mixer with amplification stage has two inputs, but it can be expanded. The input impedance is high...