This is the circuit of a MW commercial radio obtained in a 1967 publication. The transistors are made of germanium and are powered by 4 common batteries.
A second type of bandpass filter, which uses only an operational amplifier, is shown in the...
This is a version of the previous circuit that includes a tone modulator based on a Hartley...
This detector is from the 1990 Motorola Dataar Databook, but can be adapted to work with more...