This timer with two unijunction transistors and one SCR was found in an American documentation from 1964. The unijunction transistors could be the 2N2646.
This circuit was found in documentation two years 80. Transistors can be modern equivalents. Or...
This circuit, very critical due to the frequency at which it operates, was found in an American...
This stereo circuit with the 2002 integrated circuit. The power is 6 W per channel with 16 V of...