“The thing about John Campbell is that he liked things big,” Isaac Asimov once wrote. “He liked big men with big ideas working out big applications of their big theories. And he liked it fast. His big men built big weapons within days; weapons that were, moreover, without serious shortcomings, or at least, with no shortcomings that could not be corrected as follows: ‘Hmm, something’s wrong—oh, I see—of course.’ Then, in two hours, something would be jerry-built to fix the jerry-built device.” Asimov’s description could apply to many other writers of the thirties, whose heroes often solved monumental engineering problems overnight, but it speaks in particular to the singular personality of John W. Campbell, Jr., who achieved his greatest fame as the editor of the magazine Astounding Science Fiction, later known as Analog.

Many of the protagonists of pulp science fiction were inventors, and countless early “gadget stories” revolved around the development of spaceflight or atomic power by a solitary genius. During the period associated with Campbell’s editorship, these characters evolved into the figure of “the competent man,” who triumphed over all obstacles using the tools of engineering. Such breakthroughs are more difficult in real life, and Campbell, who learned this the hard way, has sometimes been viewed as a frustrated inventor who channeled his ambitions into the magazine—although he also never gave up on the hope of making a discovery that really would change the world. He spent much of his time in his home workshop, pursuing avenues of investigation that paralleled his work in print, in a relatively unknown side of his career that sheds a surprising light on the genre that he did so much to define.

Campbell was born in New Jersey in 1910, and his idealized sense of himself as a resourceful experimenter was shaped by his childhood. His father, John W. Campbell, Sr., was a chief engineer at AT&T who lectured his ten-year-old son on the principles of physics. As a boy, the younger Campbell loved his Meccano set, and he spoke fondly in later years of his youthful inventions—the backyard catapult that conked him on the head, the crane with a worm gear that won a prize, the radio receiver, the electronic eavesdropper, the car assembled from two batteries and an old Studebaker starter motor. He fixed bikes, repaired appliances for neighbors, blew up his basement with a chemistry set, and often had reason to remember his father’s favorite saying: “Well, it was a good idea, John. But it didn’t work. Now clean it up.”

When Campbell went off to college at the Massachusetts Institute of Technology, he brought some of his old habits with him—he put together an experimental setup in class to prove one of his teachers wrong, and he invested the money from his first science fiction sales into rebuilding a Model A Ford. After graduating from Duke, where he had transferred after flunking German at M.I.T., he found professional success more elusive. A series of jobs at Mack Truck, the Pioneer Instrument Company, and the chemical firm Carleton Ellis failed to lead to the kind of research role that he wanted, and his frustration was reflected in his fiction. Writing much later of one of his first mature stories, “Forgetfulness,” Campbell said that it amounted to his unconscious rejection “of an up-till-then idea that I wanted to be the Great Inventor.”

After Campbell unexpectedly landed the editorship of Astounding in October 1937, he transferred most of his creative energies to the magazine, but he continued to tinker at home. When he and his wife Doña bought their first house in Scotch Plains, New Jersey, he turned the basement into his workshop, and a visit there became a rite of passage for writers. The author Lester del Rey recalled a typical night with Campbell: “That evening, after supper, we inspected his fuel battery. He had written a story about one once”—“The Battery of Hate,” which was published in Amazing Stories—“but I didn’t know he’d actually built one.” (This appears to refer to a series of experiments performed by Campbell in developing a battery that involved the use of the element cobalt. Campbell persisted in these efforts for over two years, but they led only to a series of confusing results that he couldn’t explain.) The editor was also an enthusiastic amateur photographer, writing to his friend Robert Swisher that his hobby provided a convenient outlet for his “homemadegadgetmania.”

During World War II, Campbell found various outlets for his inventive tendencies. At the invitation of Harry Walton, an editor for Popular Science, he wrote a series of twenty articles on home electronics projects, including a remote baby monitor that he illustrated with a picture of his sleeping daughter. He recruited the writer George O. Smith, an electrical engineer, to spend a weekend every month at the house in New Jersey, where Smith worked on various gadgets—and also got to know Doña, whom he married after the Campbells divorced in 1950. At parties, Campbell asked guests to sing into a microphone hooked up to an oscilloscope, which displayed their voices as undulating waveforms, and he pitched technical ideas for the war effort to Robert A. Heinlein at the Naval Aircraft Factory, although none was ever put into practice.

After the war, Campbell got into ham radio, which he used to discuss story ideas with Heinlein in Colorado Springs, and hi-fi equipment. When his marriage to Doña ended, he lost himself in work on his stereo system, and after he remarried in 1951, his efforts in home audio inspired his most ambitious project as an inventor. While tinkering with an amplifier that he had made from scratch, he was left unhappy with the results: “Music comes out in such a fashion that a piano, saxophone, and trumpet are almost indistinguishable.” Reasoning that music was based on complex wave patterns, he found himself wishing for a device that could generate any arbitrary waveform—or electrical signal—on demand, which would allow him to conduct “bench tests” on the equipment that he was building. Eventually, he arrived at a potential solution, and he became convinced that it was the big idea that he had been seeking for most of his life.

On October 8, 1954, Campbell wrote a letter to Arthur Z. Gray, the head of his parent publishing company, Street & Smith, to describe what he had in mind. He took pride in his ability to predict future technological developments, joking that he could have taken out a patent on the fundamental principles of the atomic bomb in 1940, but he had never been able to translate this talent into financial success. Now he had an idea that seemed to have vast commercial potential: “There is a need for a waveform generator. I want to get a patent on it, and get it now.” Campbell thought that such a generator could be used to produce the complex synchronization signals needed for color television, the waveforms used by radar, customized timbres for an electronic musical instrument, and applications that even he couldn’t foresee. He compared himself to Philo T. Farnsworth, the inventor of television, who had made “some nice money” by patenting concepts that were utilized by legions of innovators to come.

The underlying mechanism was straightforward. You simply drew any waveform that you wanted—no matter how complicated or strangely shaped—as a silhouette on a piece of transparent material. A photocell would be placed behind the transparency and a vertical ribbon of light swept horizontally across the silhouette. Because the intensity of the light striking the photocell at any given point depended on how much was obscured by the silhouette, the photocell circuit could be designed to produce an electrical signal with a waveform that precisely matched the shape that had been drawn by hand. The setup was basically the opposite of an oscilloscope—it translated a visual representation into a signal, rather than the other way around—and it made it possible to generate unusual waveforms, including one shaped like the New York skyline. Figure 1 shows a silhouette possibly similar to the one used by Campbell in such a test, where the narrow white rectangle represents the vertical beam of light that would scan from left to right.