This commercial receiver from the year 1958 uses two AA cells as Power supply. The circuit is intend to receive MW station and the transistors are germanium types not easy to find today.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...