Installing a solar powered lighting and power system for a stables today and tested the LED floodlight. The owners radio that was on cut off. Soon as I disconnected the lamp radio came back on. It is a battery radio and the lamp was on the other side of the building so 12 metres away. I know LED can emit some strong frequencies and interfere with radios but this was very apparent. I understand DAB radios do suffer from this problem. Will do more research tomorrow but worth knowing and finding a solution as we will switch on all the internal lights tomorrow so the radio will be swamped.