Found in a 1980s amateur radio QST magazine, this is the conventional circuit of a medium-wave radio. Coils and transformers are commercial types.
This simple circuit, which requires a low current (50mA) relay for 5 to 12V power supplies, was...
We found this circuit in a publication from the 1970s, but it can still be assembled today by...
Found in a Motorola documentation from the 70s, this circuit makes use of transistors of the time....