This circuit that uses a loop antenna was found in a 1924 publication. The circuit has several supply voltages and sets of audio and RF coils.
The circuit in the figure is suggested by ST Microelectronics (www.st.com) and consists of a...
The transistors of this circuit may be the BC548 or BC549 and its power supply can be performed...
This circuit is from Mullard's transistor reference manual from 1960. The circuit will also work...