Cosor 'Melody Maker', all electric radio receiver, 1931.
© Science Museum / Science & Society Picture Library
This Model 235 Cosor Melody Maker was a popular mains-powered TRF (Tuned Radio Frequency) radio receiver manufactured between 1928 and 1931. The majority of the sets were factory asembled, but listeners who wished to save money could put the radio together themselves from a kit. The tuning dials were marked with numbers from 0 to 180, meaning that listeners had to keep a list of dial settings and corresponding radio stations. It was only on later models of the radio that dials marked with station names appeared. Tuning was a complicated proces, so much so that listeners were advised to switch their sets on ten or twenty minutes before a programme started to allow sufficient time to tune in.