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 variable power supply circuit was found in a German publication from the 1980s. The circuit is...
This simple circuit for switching RF signals was found in an RF Design from the 90s. The circuit...
We found this circuit in a 1983 English magazine, but it can be easily assembled with the BC548 or...