This 1924 receiver uses a battery for the tube filaments and a high voltage battery for the amplifier and detector circuit. The speaker is kind of high impedance era.
This simple MW radio circuit with two transistors was obtained in an Argentine publication from...
The critical components for this 1970s project are transformers. The original transistors are made...
We found this circuit in a 1990 documentation. It works with the power of the digital circuit...