This commercial radio for the AM band was sold in Japan in the 1960s. The circuit has an IF of 455 kHz and is powered by batteries. The push-pull output gives a good audio power.
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...