DJ Geeneus was 16 when he broadcast his first pirate radio show from a tower block in Tower Hamlets, east London.

With decks and mixer balancing precariously on top of a homemade transmitter jammed between the sink and the cooker of his friend's 18th floor flat, Geeneus leant out of the window, pointed his aerial towards Hackney – and turned the music up loud.

Sixteen years, countless rooftop broadcasts and dozens of brushes with the law later, Rinse FM, often called the most influential pirate station on air and credited with bringing artists such as Dizzee Rascal and grime star Wileyto the public consciousness, is finally going legit, to the slightly bemused delight of its 32-year-old founder. "Getting the licence gave me the strangest feelings. Nothing don't faze me ... but that did," he said.

Will he miss anything about being a pirate? "Getting on the roof," he says. "Now I know I'm never going to do it again, I'm going to miss it."

As well as running successful club nights in London, the station also has a label that has just seen artist Katy B make it into the top five of the UK charts. Her track On A Mission has been viewed more than 2.7m times on YouTube.

Geeneus, who goes by the name G and whose real name remains a mystery even to many friends, set up Rinse with a group of friends including the grime star Wiley and grime DJ Slimzee, because other pirate stations told them they were too young to be on air. "We didn't know what we were doing, but it was great. We didn't switch off the whole time, someone would be DJ-ing while someone else was flaked out on the floor. We freestyled — and we still are, really."

Geeneus reckons he has transmitted from every tower block in east London. "I've been arrested about 15-20 times," he said. "Never been charged though, I always managed to talk my way out of it." He fared better than Slimzee — who was rewarded for his time spent on Tower Hamlets rooftops with an ASBO banning him from going above the fifth floor of any building in the area.

In the early years, the station operated on a shoestring, with Geeneus scrounging for £1 subs from DJs, asking for transmitters for Christmas and stealing the cables from his mum's iron and vacuum cleaner to stay on air.

"We sold everything we had to keep it going", he said. "That excitement of listening to radio just drew us in. You hear a good show and you just want to get over there and get on air."

Things changed when Geeneus met Sarah Lockhart, 35, who was working for a record label distributor handing out test pressings to pirate DJs to create a buzz about the tracks. Five years ago she quit her job, the two joined forces, and the battle to get a licence began. "We were both obsessive about new music and the station but because it was illegal you couldn't talk about it and we wanted to change that," she says.

Lockhart, like Geeneus, left school without any qualifications, but the 100-page application document submitted to Ofcom was largely her work. "That was like my degree – and I passed," she said.

After dozens of meetings, setbacks and disappointments Rinse was granted a community licence on 17 June. Unlike a commercial licence, they cannot sell it on for profit and as part of the deal the station must continually prove its worth to the community it serves. Geeneus and Lockhart have already set up the Rinse Academy, giving hands-on training and opportunities for budding MCs and DJs to shine.

"Pirate radio has been like a pressure valve for kids every since Radio Caroline and we are carrying on with that," said Lockhart, who also wants to work with pupil referral units, the last landing places for difficult children kicked out of the standard school system.

Geneeus insists that radio kept him on the straight and narrow.

"Everyone I knew at school is in prison," he says. "I do feel a responsibility to show young people that there is an alternative. That there are other ways of doing what you want in life."

In their small but impressively professional new studio on a trendy east London backstreet, its clear the station has come a long way. Heated episodes, such as Wiley spending his show drunkenly berating a rival only to have the DJ turn up at the studio with his crew, are a thing of the past.

"It's very different," says breakfast DJ Scratcha. "When I started you had to climb in through a secret opening in a shop shutter and pull yourself up into this little room called the treehouse. Over the years it just got better and better."

In the middle of his set, DJ Dappa turns down the pounding beat for a moment to shout out to the Clapton crew, but these days - thanks to the station's internet broadcasts - he could be hailing listeners in Denmark or Detroit.

Geneeus insists that the success – and new-found acceptance into the legal broadcasting world – is not going to change how things get done at Rinse. Listeners shouldn't expect pop music or car insurance adverts. "I'd rather be pirate and do what I want than legal and do something I can't stand," he said.

What then, does the future hold? "I don't know ... a national licence would be nice," he said with a smile. "We are just going to go on doing what we do — but amplified."

Pirates that rode the waves

Radio Caroline The most legendary pirate station of them all, Caroline broadcast from a former passenger ferry anchored off the coast of Suffolk. Founded in 1964 by businessmen Ronan O'Rahilly and Oliver Smedley, the station was home to DJs such as Chris Moore – who presented its first show – Tony Blackburn, Johnnie Walker and Robbie Dale.

London Weekend Radio Run by Jonny Haywood and Keith Green, , London Weekend Radio began broadcasting from Lawrie Park Road in Sydenham over bank holiday weekends in 1981. Radio Luxembourg's Peter Anthony worked under the guise of Oscar J and Pete Tong and Tim Westwood also got their first breaks at the station.

Dread Broadcasting Corporation Sometimes credited as Britain's first black music radio station, DBC was set up in west London in 1981. Calling itself "rebel radio" it played reggae, soul and R&B and provided a platform for presenters and singers such as Ranking Miss P and Neneh Cherry.

Kiss FM Founded in London in 1985 by Gordon Mac, the station played edgy new music and provided a platform for new talent such as Judge Jules and Trevor Nelson. It was granted a licence in 1990 and was eventually sold to the media giant Emap, moving to a more mainstream output.