Voice and music from a spark-gap transmitter?
Imagine being a radio enthusiast in California in 1912. You had a crystal set and used it to hear CW transmissions. There were rumors of someone named Fessenden on the East Coast who was able to periodically transmit voice with a rotating contraption but that was too far away on too long a wavelength to reach California.
But then one evening – a Wednesday evening to be precise – you hear a tune by composer John Philip Sousa coming through your headphones. It was 1912 – how was this possible?
That transmission would have been coming from the transmitter and studio of Charles Herrold in San Jose. His “arc-fone” transmitter was powered by 500V DC pirated from that cities’ streetcar lines and he called his weekly broadcast the “Little Hams Program” since radio enthusiasts even at that early date were known as hams.
Often utilizing his wife as an announcer, Herrold would give away pieces of galena as prizes to those who listened to his broadcasts – prizes that increased his number of listeners.
Keep in mind that the first commercial radio station in the US (KDKA) wouldn’t begin broadcasting audio until 8 years after Herrold.
Herrold continued his broadcasts until 1917 when America’s entry into World War I shut down all but military radio transmissions.
When you have a free hour, check out this interesting documentary on Herrold’s invention and how it tickled the ether over 100 years ago.