Sealed unit

In 1924 Ernest Fisk (later Sir Ernest) of AWA - Amalgamated Wireless (Australasia) suggested the introduction the sealed unit system (or, more commonly sealed set or sealed receiver) where radio sets could only receive the transmitting service (or services) to which they were licensed. Under this model, the Government would issue a licence to transmit on a given wavelength (or frequency in modern terminology) and oversee the manufacture of receivers locked on that wavelength. The owner of the transmitting licence could then charge the receiver's owner a recurrent fee that would be used to run the station. This was seen as preferable to the British situation where the Government backed a monopolistic service (the British Broadcasting Company as it was then) and collected a single licence fee from each household with a receiver. There appears to have been little attention at the time to a third possible model; that of the licensee charging for advertisements, as was done in the United States.