Many thanks to SWLing Post contributor, David Day (N1DAY), for sharing the following guest post:

Crystal Radios – Construction, Listening, and Contesting

By David Day – N1DAY

The date was November 2, 1920 and the world was about to change forever when radio station KDKA out of Pittsburgh PA made its first broadcast of election results from the 1920 presidential election.  For the first time in history people knew who won the election before reading about it the next day in the newspaper.  Radio had arrived!

However, hearing the election results was not as easy as powering up an AM radio receiver because radio electron tubes had only been invented a few years earlier and they were still too expensive for most people to afford in a radio set.  After KDKA’s historic broadcast, large 50,000 watt stations began popping up in all major cities around the world.  Even though a tube-driven radio was not yet commonplace, many people listened to these stations on their crystal radios.  The frenzy around radio in the 1920’s was not unlike the excitement around cell phones and the internet today.  If you didn’t have one, you were simply living in the past.

A family listening to a crystal radio in the 1920’s

Fortunately, in the early 1920’s the crystal radio had been around for a while and it was easy to make or purchase a completed set on a limited budget.  The beauty of the radio was that it was a passive device needing no power source other than the radio station’s broadcast that was received by a good antenna about 50 feet long and 15 or so feet above the ground.  Crystal radios derived their name from use of galena crystals as detectors. Continue reading →