[8bitsrule]

Hmmm, fancy indeed. With 150kW feeding a dipole at 700 feet, I imagine that a cat's-whisker [0] would have done well-enough in London...

[0] https://en.wikipedia.org/wiki/Crystal_detector

[Symbiote]

Yes, I did exactly this in England 30 or so years ago. It was one of the suggestions in an electronics kit for children, the one with springs to connect the components together.