I’m not in the least bit a techie kind of guy and there will be a lot of others who fully understand the linked article below long before I do. But I still found this fascinating. It’s a brief history of the engineer who invented the directional antenna in those pre-historic days of radio, and how it changed the medium to allow a lot more stations on the AM band.
 
In the early days of radio, there were a number of stations on the same or adjacent frequencies that interfered with each other at night, causing huge headaches for the government and broadcasters alike. And one of them may surprise you – it pitted the super-powered WLW Cincinnati (700 AM) against CFRB, then at 690.
 
The story of how the then mind-boggling 500,000 watt signal from Ohio killed 'RB here in the 30s is one I’d never heard before, but it’s just one of many that changed the industry forever. It’s long, but if you’re into this kind of stuff, it’s a worthwhile read. And the pics are kind of neat, too. (If you’re not interested in the rest, you can scroll down to the WLW section.)
 
The Development of the Directional AM Broadcast Antenna

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