t has no star names, 25 members of staff (some of them students) and broadcasts nothing at all for 50 weeks a year. You've probably never heard of Radio Wimbledon, but for thousands of sports fans outside Britain, this tiny broadcasting operation, which began life in a couple of portable offices on the roof of an equipment store, is their ticket to the Wimbledon tennis fortnight.
Just before this year's tournament the station signed a deal with an Indian mobile phone company, which, for the first time, is bringing the station's mixture of ball-by-ball tennis commentary and discussion to a potential 20 million mobile phone users on the sub-continent. Already Radio Wimbledon can be heard by 4.5 million satellite radio subscribers in the United States. Plus, at its peak there have been 600,000 listeners across the world on the internet.
Not bad for a station that was brought to life as an ultra-local low-powered FM station in 1992 by the All England Club, partly to warn motorists on their way to the tournament about traffic jams on the A3.
The radio signal - 87.7FM, under a "restricted service licence" - still continues, but as station editor Steve Butterick admits, the overseas deals and the internet streaming at www.wimbledon.org mean that "we've become a much more international station - we can't just think we're broadcasting for five miles in the Wimbledon area."
For almost a decade, Radio Wimbledon had ball-by-ball commentary to itself internationally, as the BBC's rights package banned it from transmitting its Radio 5 Live coverage overseas. In the United States, an offshoot of CBS bought a broadcasting package that would have allowed it to offer its listeners non-stop commentary but it decided instead to offer regular updates. American media executives consider the idea of tennis matches on the radio rather quaint and silly - despite the fact that we've been listening to them in Britain for 80 years.
Broadcasting rights pose no problem for the All-England Club's own station, says Butterick, smiling: "Because I work for the rights-holder, I've never really had to worry about where we broadcast to."
Thus, while the likes of Michael Stich, Pat Cash and Annabel Croft pass Wimbledon judgement on Five Live, much of the rest of the world turns to the rather lesser known voices of former players Warren Jacques, Sue Mappin, Lucie Ahl and others on Radio Wimbledon. (Unusually, Judy Murray, the tennis coach and mother of star British player Andy, will this year be appearing on both stations.)
Butterick, a producer who has spent his career with LBC and Five Live, says that Radio Wimbledon has a good relationship with its BBC rival - "we share material with them" - but "I think the coverage that we provide is different. I think we are able to be slightly faster on our feet." During the women's final, for example, Radio Wimbledon uses a woman commentator and a woman summariser. "I don't think the BBC has ever done that," says Butterick. "So you could say I don't have their resources, I don't have their reach, but in some ways, because we're smaller and because there's slightly less tradition, I am less beholden to the past."
The narrow target of his station also means that tennis will not be crowded out by trivial subjects such as world news or World Cup football, both of them vying for broadcast space on Five Live. And, by a cruel twist of fate, men's finals day - 9 July - falls on the same day as the football final. If the tennis overruns, Five Live may well leave London SW18 to go over to Munich (though, if that does happen, the BBC will doubtless move tennis to its digital station, Five Live Sports Extra).
Radio Wimbledon's commentators are also able to be a little less impartial than their BBC rivals. If Tim Henman is playing, the station wants him to win. "We allow ourselves to be slightly coloured by the match. On the whole, we're not jingoistic, but we allow a certain amount of patriotism to show through. I think it's just natural," says Butterick.
Sometimes, being so close to the action can have its dangers. Players listen to the station as it is piped into their dressing rooms and played in the cars that transport them to and from the matches. Two years ago, a commentator said he would rather have his toenails removed without anaesthetic than watch another set like he'd just seen. Young French player Virginie Razzano stormed into the studio - and was not immediately convinced by Butterick's subsequent explanation that the comments were aimed at the women's game in general, rather than Razzano's in particular.
But, just as being the voice of the All England Club has its strengths, does it not also have its weaknesses? Butterick says that he has "absolute editorial freedom" to criticise the Wimbledon authorities - and, indeed, he has regularly carried dissenting voices who are unhappy with the way that British tennis is run.
In fact, he can only recall one slap on the wrist. "I was asked by a former chief executive why a chap [the American tennis coach and Independent columnist Nick Bollettieri, who has trained Andre Agassi, Monica Seles and Maria Sharapova] was saying 'Wimpleton' rather than 'Wimbledon'."
Butterick didn't really have an answer. "It was just his accent," he says. "Loads of Americans say Wimpleton, don't they?"