Amateurs by 1907 were numerous, and intrusive, and many of them backward technically. Electrical World took notice of a policeman’s son in Washington who jammed the Navy Yard and harassed professional operators. From New York Lee De Forest thundered that the lad typified ‘the ubiquitous amateur with his high-school Ruhmkorf coil’ (pictured), who was not only a vandal but a slovenly practitioner of outdated and disruptive arts. Roving detectives were needed, and robust legislation at the Federal level. Improper damping was causing chaos, he foamed. Communications must be limited to the sustained oscillation methods. “The day of the barbarous spark discharge is numbered,” he prophesied, “and the sooner it is classed with the filings coherer the better.”
Says who: Lee De Forest, “Interference with Wireless Messages,” Electrical World (June 22, 1907) XLIX, 25: 1270.
Picture source, forum page, Model T Ford Club of America. Heinrich Daniel Ruhmkorff was a German instrument maker, d. 1877, who commercialized at mid-century earlier iterations of the induction coil. This model is probably a Ford variant. Amateurs cannibalized these routinely for spark gap transmitters. The resulting signal was a wideband splatter.