I first heard it on a holiday in North Wales. The lady in an ice cream stall on the sea front at Llandudno had it on in the background. Took me a while to twig it was actually on Long Wave as you instinctively looked for 252 metres rather than Khz.
There is an interesting video on Youtube of the Clarkestown transmitter site. Two water cooled 300Kw Continental Electronics units were used in parallel during the daytime. The electricity bill for running them even in 1990 was £1100 a day, so someone had to have deep pockets to keep the station on the air.
https://www.youtube.com/watch?v=BdeFTOjkpzY