Unsychronised single frequency network.

[radioman]

Here in South Ayrshire, BBC Radio 5-Live has a strange 'phasing' like effect on the audio, a bit like listening through a long tube.
Presumably, I'm receiving signals from two different transmitters so must be in one of these 'less populated areas' !
Absolute radio does sound rather distorted with excessive treble but not as bad as 5-live subjectively.

Andy