Community broadcaster Radio Adelaide has been granted an injunction in the Federal Court against 891 ABC Adelaide rebranding itself to ABC Radio Adelaide.

The current 891 ABC Adelaide call sign was to be changed to ABC Radio Adelaide as part of a national rebranding of the broadcaster's capital city stations to be rolled out from January 2017.

But the Federal Court heard Radio Adelaide was concerned the renaming would cause confusion between the two broadcasters and would harm Radio Adelaide's brand, which had been built up by volunteers over four decades.

Justice Natalie Charlesworth allowed the injunction on Friday afternoon, saying while the logos and branding were quite different between the two broadcasters, there still might be confusion when the names were heard over the radio.

"Radio services are by their nature to be delivered orally and received aurally — even if they may be marketed by visual uses by words," she said.

"The phrases Radio Adelaide and ABC Radio Adelaide share a much closer resemblance than the visual words."

She said there was value to the ABC in having a nationally consistent naming convention, but that there was evidence to suggest the ABC predicted its new name change would not be well received by Radio Adelaide.

The court heard the delay to the roll out of the rebranding could cost more than $100,000.

The trial is expected to begin in April.