We found this circuit in an old American publication from the 1980s. Transistors can be general-purpose types like the BC548, and the tuning frequency is given by the L and C components.
This circuit can make use of almost any operational amplifier and the diodes are for general use....
An old analog TV that is not in use can be turned into an oscilloscope for low frequencies...
This simple transistor radio with only two germanium transistors was found in a Japanese magazine from...