There are just a few of these high power stations left in the world. WRMI in Florida is a shortwave broadcast station with a vast array of transmitters and a huge antenna farm. It’s like the last of the Mohicans.
This video explores some of the inner workings of a radio broadcast era that is slowly fading away,
Interesting video. It also led me to a good one about the history of KFI’s transmitters. Over the years they’ve gone from a building full of ancient RCA gear to their current Nautel transmitter that’s about the size of a refrigerator.
I was in high school at the close of the Cold War, which coincided with a sunspot maximum. In those happy evenings, the 40 and 49 meter bands would be jam-packed with signals from around the world, every evening. 5 kHz intercarrier whines, adjacent station splatter, and stations being granted permission to operate slightly outside the official broadcast bands were relatively commonplace.
One evening, I recall hearing a broadcast on HCJB that stated that “station planting,” using low power FM transmitters strategically placed in population centers would likely replace reaching large areas via shortwave in the near future. At the time, I thought that the prediction was poppycock. Indians who live in the mountains of South America don’t listen to FM, I thought, and they never will. I also couldn’t comprehend how a station with the relatively limited coverage of FM could ever reach enough people in sparsely populated areas like those to be worth the investment. Nevertheless, HCJB picked the direction in which they wanted to go, and they still persist with their new plan of hyper-localism (such as delivering programming in indigenous South American languages) and of acting as a content provider for local stations worldwide.
I remember back in the 70s when China was on 1040 kHz with a huge signal to the East, aimed at Japan, in Japanese. Their ERP was supposed to be in the 8 million watt range. I know it boomed in here on the West Coast. One Winter morning, I finally lost the signal around Noon local time!