@Mark Ollig
In the 1920s, radio evolved from small experiments into a powerful new medium for sharing information and entertainment wirelessly across America.
Westinghouse station 8ZZ in Pittsburgh, the direct predecessor of KDKA, broadcast live the results of Warren G. Harding’s presidential win over James M. Cox at about 545 kHz Nov. 2, 1920, before newspapers could report them.
The station aired the first Major League Baseball play-by-play broadcast from Forbes Field in Pittsburgh Aug. 5, 1921, using a telephone as a microphone; in case you were interested, the Pittsburgh Pirates beat the Philadelphia Phillies 8 to 5.
According to a Feb. 12, 1922, article in the New Jersey Trenton Sunday Times-Advertiser, “President Harding is the latest notable wireless fan,” noting that “a radio phone has been placed in the presidential study in the White House.”
“The President proposes to make excellent use of the wireless and is planning to give some part of each of his busy days to listening-in. A radiophone is also to be installed in the press room in the White House,” the article stated.
WLAG in Minneapolis began broadcasting Sept. 4, 1922, at 720 kHz.
It was acquired by Washburn‑Crosby Co. and became WCCO Oct. 2, 1924.
WCCO moved to 810 kHz in 1928 and transmitted at 50,000 watts by September 1932, reaching much of the Upper Midwest.
In 1941, it transferred to 830 kHz and was long promoted as “the station that serves the nation.”
Nationally, radio saw the launch of the National Broadcasting Company (NBC) in 1926 and the Columbia Broadcasting System (CBS) in 1927.
Radio owes much to Edwin Howard Armstrong, an American electrical engineer and inventor born Dec. 18, 1890, in New York City.
Armstrong was fascinated by gadgets from a young age, building a homemade antenna tower and conducting electrical experiments.
In 1912, while studying at Columbia University, Armstrong discovered that feeding some of a radio tube’s output back into its input could make weak signals regenerate into much stronger ones.
In 1914, his regeneration design obtained US Patent 1,113,149, titled “Wireless receiving system.”
However, Lee de Forest, an American inventor and electrical engineer, had patented the Audion tube in 1907, and claimed it was the same basic idea as Armstrong’s, and so he should not own the rights or collect any royalties.
This argument over who really invented regeneration in a circuit ended in 1934 when the US Supreme Court sided with de Forest.
Many engineers believed Armstrong was the one who had actually turned regeneration into a practical, working radio circuit.
In 1918, while serving in the US. Army Signal Corps during World War I, Edwin Howard Armstrong developed the superheterodyne receiver.
His design mixed the incoming station signal with a locally generated signal and shifted the result to a fixed intermediate frequency that was easier to amplify and filter.
After amplification at that intermediate frequency, the receiver recovered the audio signal.
This approach produced clearer voices and music with less “bleed-over” from nearby stations, and it remains the basic architecture of most modern radio, television, radar, and cellular receivers.
Starting in the 1920s, home radios tuned into AM stations, typically from about 550 to 1,500 kHz, until the AM band was extended to 1,600 kHz in 1941.
In the early 1930s, Armstrong engineered wide-band frequency modulation, or FM, which changed the signal’s frequency rather than its amplitude, making it much less susceptible to electrical noise.
He tested the system at extremely high frequencies and launched the experimental station W2XMN in Alpine, NJ.
Assigned 42.8 MHz (megahertz) in 1938, the station began regular broadcasts in 1939, demonstrating that FM could deliver high-fidelity sound far superior to AM.
Minnesota engineers soon joined this high-frequency frontier.
In 1939, Minneapolis station W9XHW operated at 42.30 MHz with 50 watts from the Nicollet Hotel.
W9XHW was an experimental “Apex” station using amplitude modulation (AM) on very high radio frequencies above the standard AM band to provide wide audio bandwidth and higher‑fidelity sound.
Because it still relied on AM, it remained vulnerable to lightning and man‑made static, letting engineers see how Armstrong’s FM system improved on earlier high‑frequency AM.
Some Twin Cities broadcasters were also testing Apex signals.
KSTP’s high-frequency station W9XUP began “ultra-short-wave” Apex tests in 1938 at 25.95 MHz, then shifted to 26.15 MHz in 1939.
WTCN’s W9XTC, active in 1939, operated as an experimental FM transmitter on 26.05 MHz.
The Apex era of experimentation effectively ended when the Federal Communications Commission (FCC) eliminated the Apex band Jan. 1, 1941, reallocating its spectrum to the new FM broadcast band.
The FCC then used those former Apex channels to launch the first commercial FM band from 42 to 50 megahertz, replacing high‑frequency AM with Armstrong’s new static‑resistant system.
In March 1941, Nashville’s W47NV went on the air at 44.7 MHz as the first licensed commercial FM station in the United States.
In June 1945, the FCC moved FM broadcasting from 42 to 50 MHz up to 88 to106 MHz.
The band was expanded again in 1946 to 88 to 108 megahertz.
The change disrupted many early FM stations, including Armstrong’s, but the core technology adjusted to the new allocation and eventually became the standard for high-quality broadcasting.
FM radio faced strong opposition from the Radio Corporation of America (RCA) and the AM radio establishment, which saw it as a threat to their existing investments.
In 1940, RCA offered Armstrong $1 million for a nonexclusive license to his FM patents with no royalties.
He refused, insisting that RCA pay royalties as other licensees did.
Years of lawsuits followed, with RCA President David Sarnoff applying financial and legal pressure while Armstrong fought to defend his work and reputation.
The struggle took a heavy toll on Armstrong, and by the early 1950s, he was financially strained and physically exhausted.
Edwin Howard Armstrong, at the age of 63, took his own life in New York City, NY Feb. 1, 1954.
His wife, Marion, carried on the litigation, securing several important settlements, including a significant deal with RCA.
In 1983, the US Postal Service paid tribute to Edwin Howard Armstrong with a 20-cent commemorative stamp featuring his portrait alongside an illustration of his frequency modulation invention.
