Home radio receivers

Before the box, the headphones

The first radio receivers in ordinary homes were not furniture. They were a coil of wire, a capacitor, a lump of the mineral galena and a fine springy wire known as a cat’s whisker, usually mounted on a board. A crystal set drew its power from the incoming radio wave itself, which meant no amplifier, no batteries and no way to drive a loudspeaker. Listeners wore earphones, and that limited the audience to whoever had them on. A typical home crystal set could reach stations within roughly 25 miles.

Crystal sets were sold by the million and built at kitchen tables from published plans. Their importance was not in what they did but in what they assembled: an audience. When broadcast stations began regular service in the early 1920s, the people who could hear them were the people who already owned a receiver.

The broadcast that created the market

On the evening of November 2, 1920, station 8ZZ in Pittsburgh carried the Harding-Cox presidential election results from a shack on the roof of the Westinghouse plant. It went on air as KDKA and is generally counted the first commercially licensed broadcasting station in the United States. The origin of the broadcast is the telling part. The previous month, the Joseph Horne department store had advertised “Amateur Wireless Sets” for “$10 upwards” in the Pittsburgh papers, and then reported that its demonstration set had picked up the transmission of a Westinghouse engineer named Frank Conrad, working from his garage. A Westinghouse vice president, H. P. Davis, read the advertisement and saw a market: if the company wanted to sell receivers, it should provide something worth listening to.

The plan to sell receivers did not pay as hoped. Westinghouse had bought the commercial rights to Edwin Armstrong’s regenerative patent expecting a near monopoly, found that Armstrong had already licensed the technology to around 17 small firms, sued, and lost. Crosley and Zenith grew out of that opening.

Tubes put the whole room in the audience

The vacuum tube turned listening from a solitary hobby into something a family did together. An amplifying tube drew current from a battery or a wall socket and drove a loudspeaker, so several people could hear the same program at once. The first loudspeakers appeared around 1915, and the circuits moving behind them improved quickly: the tuned radio frequency receiver, credited to Ernst Alexanderson in 1916, the superheterodyne, invented by Armstrong in 1918, and the Neutrodyne, introduced by Louis Hazeltine in 1922 to suppress the whistles that plagued unstable early sets.

Operating one of these was a small job of work. Early TRF receivers tuned each resonant circuit with its own knob, and because the circuits would not track accurately, the knobs had to be turned together by hand. Sets rarely carried more than three tuned stages, since more than three was more than a person could manage. Linking the capacitors onto one common shaft, so that a single dial did the whole job, counted as one of the great ease-of-use advances of the decade.

Sound improved as well. The tinny horn loudspeaker gave way to the dynamic cone speaker, introduced in 1924, which reproduced music with far better frequency response. The set itself moved out of the workshop and into the living room, from a black metal box of cryptic controls to an attractive wooden cabinet with a handful of standard knobs. By the 1930s the broadcast receiver was a piece of furniture, and anyone in the house could work it.

The business that arrived with it

Atwater Kent, a Philadelphia maker of automobile ignition systems, sold its first do-it-yourself radio kits on breadboards in 1921 and complete sets from 1923, beginning with the Model 10 for Christmas that year. It moved into a $2 million plant in 1924, and in 1925 it was the largest radio maker in the United States. At its peak in 1929 it employed more than 12,000 workers and built nearly a million radio sets, among them the seven-tube metal Model 57 at $105 and the eight-tube wooden Model 60 at $80. By 1931 the company claimed over three million radios built.

The audience grew with the industry. Variety led its front page on March 10, 1922 with “Radio Sweeping Country: 1,000,000 Sets in Use.” RCA put radio ownership at 19 percent of American homes in 1925, 40 percent in 1930 and 83 percent in 1940. Networks followed: NBC launched in November 1926, CBS in September 1927, and the Radio Act of 1927 created the Federal Radio Commission to bring order to a crowded band that had outgrown amateur rules.

What it displaced

The receiver changed what households did in the evening. Music that had been paid for on records or heard at live performances now arrived free through the air, and the record industry took the damage: sales fell from $75 million in 1929 to $26 million in 1938, with a low of $5 million in 1933. Songwriters went after the stations instead, and ASCAP began collecting radio licensing fees in 1923.

Crystal sets did not vanish. They stayed cheap enough for children and for poorer households right through the 1930s, and they became the first radio that generations of students built themselves. The tube set that replaced them in the front room established the pattern the industry still runs on: a box in the home, bought once, kept for years, and filled with somebody else’s programming.