Inventor John Sargrove and the mass production of his radio invention by machines.
Robot radio. Various shots of inventor John Sargrove working blueprint for his new invention: a radio that is easy to mass produce. He sits at a desk in front of a blackboard with diagram on it, we see him drawing on blueprint with compasses and looking at models of radio.
On shop floor of radio / wireless factory. Various shots of machines involved in assembly line style manufacture of the radios. Most of the industrial process is automated, only a few workers operate the machines. M/S female factory worker fitting completed radio into its case.