Rave FM was the soundtrack to my last year at school, usually while hooning around backlanes looking for parties in Notts and Leics. I remember those Marcus Garvey ads. There were also a couple of big raves like Fantazia at Donington in 1992
That happened 2 miles from home but i was in Corfu with my mates, it was just after our A-Levels.
The commercial radio station Trent FM had a rogue show on Saturday nights called 'Get on the good foot' presented by Mark Spivey that played bang up to date techno, house and hardcore for a couple of years too.
It was never obvious where all this weird, hyper new music was coming from. Could have been Chelmsford, Berlin or Jupiter. It wasn't seen as London thing.
There was also a test FM station playing nothing but field recordings of birdsong and audio test signals, rising and falling tones. It would have been test broadcasts for soon-to-be-launched Classic FM. That had its uses at 4am too.