Sony 'SRF201' VHF/FM stereo headphone radio, 1985.
© Science Museum / Science & Society Picture Library
This Japanese pocket radio has all the electronics needed for an FM receiver integrated into one slim chip, mounted in a case the size of a credit card and not much thicker. The chip itself occupies only a fraction of the space, most of which is used to accommodate batteries and the large tuning capacitor. In later models the capacitor was replaced by a tiny diode.