In 1922, a series of government committees were constituted to look into the licensing requirement for receiving, transmitting, and broadcasting radio signals throughout the British Empire.
[3][4] Operating under the callsin, 1SE (One Singapore Experimental),[5] the station used a 100-watt transmitter lent by the Marconi Company to transmit its signals from the top floor of the Union Building, Collyer Quay.
In his first Christmas Message (1932), King George V characterized the service as intended for "men and women, so cut off by the snow, the desert, or the sea, that only voices out of the air can reach them".
The Director-General, Sir John Reith, said in the opening program: Don't expect too much in the early days; for some time we shall transmit comparatively simple programmes, to give the best chance of intelligible reception and provide evidence as to the type of material most suitable for the service in each zone.
[15] The National Trade Union Congress began planning to operate its radio station in 1990, with the launch set for early 1991.
[17] Radio Heart began trial transmissions on 28 January 1991[18] and launched on 2 March by the secretary-general of NTUC, Ong Teng Cheong.
[20] Radio Heart was operated by NTUC Voice Cooperative Society Limited,[21] which also owned "other communication and publication ventures", with studios located at the basement of Singapore Labour Foundation building at Thomson Road.
[22] On 15 July 1991, transmissions of Radio Heart's 91.3 and 100.3 were suspended for 32 hours due to problems with the transmitter at the SLF building in Thomson Road.
[23] In October 1992, Heart 91.3 revamped its programming to shed its "teeny-bopper" image and to appeal to a wider audience, with each programme having a specific theme and play a wide range of music from reggae to country.
[24] The Straits Times in 1993 described Radio Heart's programming which include lifestyle, fitness and health, current affairs, education and entertainment.
The station collaborated with local magazine BigO for sourcing older music materials and relevant information.
[32] MediaWorks had the intention of buying radio stations from NTUC in March 2001, with the creation of a joint-venture between the two, taking over 91.3 and 100.3, then now known as Most Music and Heart FM respectively.
[35] Ahead of the relaunch of More Music as WKRZ, SPH MediaWorks announced that it would carry at least 22 hours of syndicated MTV content per week.
Both radio stations were simply re-branded and resume operations of Heart 100.3FM and More Music 91.3FM previously wholly owned by NTUC Media.
More Music was given a US-style name, going under the fake callsign WKRZ, and Heart FM was renamed UFM, in a tie-in to Channel U.
Although these technical constraints were addressed in the 2nd version of DAB with the AAC+ audio codec, Singapore did not upgrade to the DAB+ standard, unlike the transition implemented for digital television.