ABC Radio Perth begins broadcasting on FM frequency 102.5 after a century of AM

After more than a century broadcasting on AM, the ABC has moved to a brand new FM frequency in Perth, in a move executives have attributed to transmission challenges.

ABC Radio Perth is now on air at 102.5 on the FM band, with the old 720 AM channel expected to be switched off permanently in late April.

Station manager Danielle Benda said the change would result in a "markedly improved listening experience".

"Radio listeners in Perth would be familiar with the shortcomings of AM radio transmissions in the metropolitan area where there is a lot of electrical interference," she said.

Ms Benda said FM provided a "richness and clarity that simply hasn't been possible on the AM band".

The switch to FM comes after 102 years of ABC Radio Perth broadcasting on the AM band.

The ABC's managing director Hugh Marks said the audio quality of 720's AM signal was becoming more obvious in the age of streaming and digital radio.

During the daytime, AM frequencies largely rely on the ground itself to carry the signal, with moist soils like marshlands performing best — and Perth's dry, sand-heavy soil makes for a poor transmitter.

AM broadcasts are also vulnerable to interference from electrical infrastructure like power stations and electric train lines.

Broadcast focus

Initially branded as 6WF, ABC Radio Perth was established by Westralian Farmers (now Wesfarmers) and has been broadcasting since June 1924.

The station has undergone several frequency changes over the years and has been sent to air via a large transmission tower on a bush block in Hamersley since the 1930s. 

The switch is part of a suite of changes the Australian Communications and Media Authority has announced on the FM band, which will also see ABC Radio National move from 810 AM to 103.3 FM and NewsRadio commence a simulcast on 104.1 FM.

NewsRadio will continue to broadcast at 585 AM to fulfil its obligations to broadcast the proceedings of Federal Parliament on a medium wave under Commonwealth legislation.

Some regional listeners have voiced concerns they will lose reception of ABC Radio, as regional areas often have little to no FM coverage.

Mr Marks said regional stations would remain on their AM bandwidth, although some listeners on Perth's outskirts may need to pick either AM or FM, depending on which is clearer.

"There will be some areas around the outer parts of Perth where people might need to retune to one service or another," he said.

Mr Marks promised public radio would have an enduring place in the media landscape, and said the switch to FM transmission proved the ABC is investing in the future.

"There's always been a lot of talk about the future of radio — does it have a future? And it does," he said.

"This service that you provide to your audience — some people come here every day, some every now and then, some only when they need it — but the existence of the service, and the work that you and your colleagues do, is so important. And I can see that way into the future."