This 6-transistor Japanese radio for the medium wave range was manufactured in the 1960s in Japan. The circuit is superheterodyne with a 6 V power supply.
Using the LM3909 this circuit was found in the January 1992 issue of Radio Electronics magazine....
This circuit can work with almost any JFET. The circuit is from an Electronics Now from April...
The presented differential amplifier, indicated for instrumentation, was obtained in the 1994...