Ray, I'm with Mike on this one, certainly as far as ground wave coverage is concerned. According to my propagation model. At 120 km distance 4kw on 648 will give approximately the same signal as 100kW on 1548 khz over average ground, thereafter 648 will be stronger. The saffron green Tx is worse than that because it beamed straight through the concrete of London which is a very poor conductor. Skywave of course is a different matter and 1548 was one of the strongest UK signals which could be heard in southern France.