5AN started transmitting on 15 October 1937 with equipment located in the central telephone exchange, and a radio mast located in Post Office Place. The station transmitter moved to Brooklyn Park, the site of 5CL on 4 May 1944. The radio mast was moved from the east side of the building to the south side to make way for an airport road in 1952. The airport made the transmitter site inconvenient so it was moved to the Pimpala Transmitting Station, at the corner of Sherriffs and Hillier Roads, Reynella, and opened on 20 September 1961 by Postmaster-General C W Davidson.
The ABC radio studios, previously in a converted church and stables on Hindmarsh Square, and "Football House", on the opposite side of the square, relocated to an eight story building in Collinswood, the home of the ABC television studios, in 1974. In the 1980s the radio manager was David Hill. In 2000 the 5AN branding was replaced with "891 ABC Adelaide".
The power level of 5AN was upgraded to 50 kW in the early 1950s. The transmitter for this was housed in the same building as for 5CL. The transmitter was manufactured by STC. The final stage of the transmitter contained three parallel 3J/261E air cooled triodes running in class C amplifier at 90% efficiency. These were driven by a class B modulator with the same type of valves.
7:00pm–10:00pm Peter Goers, Evenings (broadcast throughout South Australia and into Broken Hill, NSW)
10:00pm–2:00am Tony Delroy, Nightlife (broadcast nationally)
All ABC Local Radio stations in South Australia, as well as 999 ABC Broken Hill (which is located in New South Wales, but is on Central Time) simulcast 891 programs when not airing local programming. On Fridays, during the AFL season, Sonya Feldhoff and Peter Goers co-host the Afternoon program.