This integrated amplifier was used in televisions from the 70s, with good sensitivity characteristics. The circuit was powered with 9 V.
This circuit was obtained from an English magazine from 1979, but can be easily assembled...
This low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...
This system makes use of incandescent lamps only and uses a SCR with a full wave bridge for powers...