December 5, 2024

This Week in Amateur Radio

North America's Premiere Amateur Radio News Magazine

via HACKADAY: How to Operate a 500KW Transmitter

Crosley was a famous name in radio for more than one reason. The National VOA Museum of Broadcasting has a video telling [Powel Crosley Jr.’s] story, and the story behind the 500 kW WLW transmitter. WLW was an AM broadcast station often called the nation’s channel since its signal covered most of the United States. The first Crosley station was identified at 8CR, running 20 watts from [Crosley’s] living room. Quite a modest start!  By 1922, he had moved to his family business location along with 500 watts of output. Over the years, WLW got more powerful until it was finally a 500 kW giant.

Along the way, WLW had several firsts, including the first remote transmitter. The 50 kW transmitters are huge. The video also covers how Crosley made inexpensive radios including crystal radios and inexpensive tube sets.

From the technical point of view, these old tubes with 100,000-watt plate dissipation are truly amazing. There were several of them in the 50 kW transmitters. It is hard to imagine that the output would rise by a factor of 10 over the years. The transmitter used a DC generator that produced 4,000 amperes just for the tube filaments!