The Evolution of Radio: The
First Audio System
In November, 1906, a group of radio operators in
Machrihanish, Scotland, were astounded to hear their equipment talking to them. The Scots
were participating in a series of experiments set up by US-based Canadian inventor
Reginald Fessenden, who had erected 400’ towers at Machrihanish and at Brant Rock,
Massachusetts, outside Boston, and had successfully made radio contact between the two in
both directions.
Radio in those days meant Morse Code, and this experiment
consisted of sending the code for the letter "D" three times every ten seconds,
and receiving a similar reply. The regular pattern ruled out unintentional signals.
Fessenden had successfully sent code messages by radio over a distance of 60 miles as
early as 1900, and Italian-Irish inventor Guglielmo Marconi had sent the letter
"S" from Poldhu in Cornwall to Signal Hill, Newfoundland in 1901.
Radio technology grew out of the observation, decades
before Marconi or Fessenden, that electric currents could influence objects like magnets
at considerable distances. At first it was thought that the electricity must be conducted
by some undetectable substance that was dubbed "ether." In 1887, Germany's
Heinrich Hertz brought together a group of disparate theories and formulated the first
basic description of electromagnetic waves. These are of high enough frequency that they
radiate outward, behaving almost exactly like light.
Marconi had enough time and money to indulge his penchant
for electrical experimentation, and he conducted his first successful experiments in 1895
in his father's garden at Pontecchio, Italy. The following year, he relocated to Britain
and had soon established a radiotelegraph link between England and France.
After a career of varying jobs, academic and otherwise --
he briefly worked with Thomas Edison -- Reginald Fessenden dedicated himself entirely to
radio development in 1900, and in that year he made the first crude transmission of the
human voice. By 1902, he had come up with -- and patented -- the fundamental principle of
AM radio, the heterodyne. In 1906, he was doing some experimentation with his voice radio
system by sending a message from his lab at Brant Rock to nearby Plymouth, Massachusetts,
and it was this that his Scottish colleagues heard an ocean away.
On Christmas Eve of that same year, Fessenden made history
by transmitting the first true broadcast, in which he played a violin solo ("O Holy
Night"), read a biblical excerpt, and wished his listeners a Merry Christmas.
For the time being, however, voice radio remained a
curiosity, and radio was dominated by wireless telegraphy, providing, among other things,
the first reliable communications with ships at sea. Then, World War I intervened, and
radio was given over to military uses.
Afterwards, however, it was clear that entertainment would
join radio's other uses. Even before the war was over, David Sarnoff -- an employee of the
American Marconi Company -- sent a memo to his staff in which he described a "radio
music box" that would also bring such diverse matter as lectures and baseball scores
into the home. This same David Sarnoff had distinguished himself in 1912 by staying at his
radio post for 72 hours to receive the names of the survivors of the Titanic as its
rescue ship approached New York
American Marconi was absorbed into the new Radio
Corporation of America (RCA), and Sarnoff would serve for decades as head of its
subsidiary, the National Broadcasting Company (NBC). His dream of a radio in every home
became a reality very quickly after the war.
American histories usually credit the beginning of regular
broadcasting to the first music programs of KDKA in Pittsburgh in November, 1920. That may
not even be accurate in a US context -- WWJ in Detroit predated it by several months --
but for North America, there's little doubt that Marconi's station XWA in Montreal was
first, in December 1919. XWA changed its name to CFCF in 1920, and it still operates under
that name, although under different ownership; British-controlled Marconi sold it some 50
years later to comply with Canadian ownership rules.
Whichever station was first, growth was explosive: by 1922,
there were 564 stations operating in the United States, up from just eight a year earlier.
In Canada, 34 stations were on the air by 1924.
Other countries were just as enthusiastic. Britain and the
Netherlands had regular radio by 1919, Australia and New Zealand in 1922, France and the
Soviet Union the same year, and so forth. In most countries all aspects of broadcasting
were tightly controlled by governments; the United States went in a totally different
direction, with an entirely commercial system.
What made that possible was the development of network
radio. As early as 1922, phone lines were used to connect stations in New York and Chicago
(for a football game). By 1926, NBC had a permanent network of stations across the US.
Canada's first network was run by Canadian National Railways in the late 1920s, to provide
entertainment to passengers on its trains.
Throughout the development of early radio, it would be hard
to overstate the contributions of amateur radio operators, an enthusiastic group to this
day. One major area they pioneered was radio using high carrier frequencies (and thus
short wavelengths). At first this sort of transmission was considered suitable only for
very short distances, but in 1921 a group of "hams" succeeded in communicating
across the Atlantic using very little power, and by 1923 the first commercial short-wave
station was on the air. The following year, the British adopted short wave for their
Empire radio service, and by the end of the decade, virtually every country was using the
technique for its international broadcasting.
At first, the enjoyment of radio was a solitary occupation,
as it could only be listened to using headphones. A number of efforts were made to attach
a larger diaphragm to an earphone mechanism in order to increase output, but it wasn't
until 1925 that C.W. Rice and K.W. Kellogg came up with the modern moving-coil loudspeaker
and radio became a family pastime. By 1928, radios were being installed in cars, and in
1925, Toronto's Ted Rogers Sr. introduced a method of powering radios from house current,
rather than cumbersome batteries.
For its first four decades, radio had mostly used
Fessenden's amplitude modulation (AM) in one form or another, but it had its limitations.
One was narrow bandwidth, although that was primarily a choice made when allocating space
in the radio spectrum, and not very important in the days of low-fi headphones and
speakers. More serious was its susceptibility to interference from storms, appliances,
passing automobiles -- indeed, anything that could produce a spark.
Both problems were addressed by Major Edwin Howard
Armstrong, who first demonstrated his new frequency modulation (FM) system in 1939. It was
impervious to atmospheric noise, and could deliver a full high-fidelity audio signal. By
the end of World War II, there were approximately 150 FM stations on the air in the United
States, and about half a million receivers able to pick up their programs.
All of those became instantly obsolete in the summer of
1945 when the broadcast regulators in the US moved FM to another part of the radio
spectrum, to make way for television. It would be another two decades before FM made a
significant impact in North America, and another ten years or so before it emerged as a
mainstream medium.
The advent of television fundamentally altered the role of
radio, especially in North America. With the notable exceptions of CBC Radio in Canada and
National Public Radio (NPR) in the United States, network radio ceased to be a factor, and
radio became even more the radio music box David Sarnoff had envisioned, offering a
mixture of music, news, traffic reports, and advertisements. Gradually, a desire for
better quality in that music saw a shift toward FM radio, which began broadcasting in
stereo in 1961; now we're in the early days of the next stage: digital radio.
Broadcasting may be the most obvious application of radio,
but it's really only a small part of what the technology offers. Every time we make a call
on our cell phone, use the garage door opener, order a cab, or even nuke some microwave
popcorn, we owe a debt to Marconi and Fessenden and the other radio pioneers.
...Ian G. Masters
ian@mastersonaudio.com
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