I have fond memories of demonstrating an NDB approach / hold into the BBC longwave radio transmitter at Droitwich (I think... ?) for my IMC rating. You could just about get 198 longwave with 200 on the ADF
I remember the controllers at Birmingham getting itchy as we hurtled around and around on the edge of their playground.
A summer or two before, I did a bit of work experience in light aircraft maintenance at Liverpool and one of the mechanics lamented the retirement of a colleague who could get the BBC on the aircraft radio while they worked on the ship. When that colleague left the knowledge left with him. I remember trying to work out how it was done. I was flummoxed until I did that IMC test... great stuff.
Hard to believe that was a decade ago, wow.