Poor Irving Vermilya. He tried to hear Marconi’s transatlantic test signals between St. John’s, Newfoundland and Poldhu, in Cornwall, early in 1902. All he got through his cohera (sic) was a buzz generated by the neighbors’ doorbell. This illustrates something interesting, which historians of prehistoric radio should understand. It wasn’t headphones through which proto-hams were listening. They weren’t monitoring atmospherics. (That’s surprising, given that bored railroad telegraphers had been doing that along their landlines for 20 years already.) They were listening for mechanical activation of battery-operated buzzers, or in Marconi’s case, telegraph writers. So conceptualize it this way, when you try to picture Victorians and Edwardians at the wireless. They weren’t listening to radio they way we do. A signal strong enough to galvanize the nickel particles in their coherer tube would render the tube conductive, whose tiny current would then activate the buzzer circuit, powered by its own battery. After the signal stopped, a tiny hammer would tap the tube to separate the particles, and the buzzing would cease. (I still have to figure out how the hammer knew when to tap.) So what you heard was door-buzzing in Morse Code and, faintly, a lot of little plinks beneath it. It was a common demonstration to onlookers, to activate one’s receiver with a doorbell buzzer. One of Marconi’s own men did this for a journalist at the Needles Hotel station in 1899. Induction coils talk to each other, he explained, by something they called ‘Hertzian waves’. What is a door buzzer but a tiny coil, with tiny oscillations? I still don’t know why they didn’t just screw in some headphones. Arcing coils are noisy as the dickens, and would have been easy to hear.
Who says: Irving Vermilya, ‘Amateur Number One,’ QST, February, 1917, pages 8-12; Cleveland Moffett, “Marconi’s Wireless Telegraph,” McClure’s Magazine, June, 1899, pp. 99-112; ‘Future of Wireless Telegraphy,’ New York Times, May 7, 1899, p. 20.