This simple transistor tester was found in a Japanese magazine in 1967. It tests general purpose transistors of both the NPN and PNP type and is powered by 4 batteries (6 V).
Figure bellow shows how n 4027 can be cascaded to form a divide-by-2. The maximum input frequency...
This medium wave commercial receiver from the 1960s was found in a Japanese publication at the...
This bistable and monostable Vox circuit was found in a 2002 documentation. The 556 is a double 555...