Made by Topp of Japan in the mid-1960's and now something of a "cult" set among collectors, this little radio proves that super miniaturisation was possible without ICs and that curse of modern, throwaway electronics: surface mounted components. The size can be judged by comparing with a UK 50 pence piece. The only unusual parts are the transistors, even those in the audio stages, which are of the flatpack type more usually associated with UHF/microwave applications. Most of the internal wiring is done using enamelled copper wire, no doubt to save space  The line-up is conventional: self-oscillating mixer followed by two IF amplifier stages, diode detector, audio driver and transformer driven "totem pole" push-pull output.  The audio driver transformer is visible to the right of the PCB just under the aerial coil in the pic below.  How do they make them so small??