This commercial radio with 3 earphone listening transistors was manufactured in Japan in the 1960s. The medium-wave circuit uses germanium transistors and is powered by a 9 V battery.
This circuit is from the 1983 Intersil Databook. This is a configuration that is still used today...
This shield circuit, from a documentation from the 70s, employs an optocoupler with two SCRs to...
We found this circuit in the 1982 SGS Linear Integrated Circuits manual. The integrated circuit used...