Your brain's not that far off Euro Man - it was 7kw output on 773 kHz in 1973, but it did get out really well, with the additional top-loading. Once that was off, Chicago couldn't get it to load up well - and thats the reason Atlantic was not on 385m (as the Belgians called it! They still used P O Box 385 though and constantly referred to the 'preferred' wavelength in their programmes.).
The power hike on 1187 (or 259 as the metric fans called it) to around 40kW more than made up for it though - until the triangular mast was totally stressed and collapsed in early October.