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The History of FM Radio

The history of FM radio: The search for sensational sound

A source of entertainment, information, and worldwide communication – the radio has had a significant impact on the evolution of humanity.

Almost a century after radio broadcasts first began, we still tune into our favourite shows every day, whether it’s in the car, at home, or on the way to work. However, few people know the complete history of radio, and what led them to enjoy the incredible sound quality available today.

The FM radio frequency is a technology that many of us take for granted. However, it’s also one of the most valuable electromagnetic waves in human discovery. Without FM radio, we wouldn’t have the emergency broadcasting services that paramedics and police regularly rely on today. Nor would we have the technology for things like microwaves or baby monitors.

In a time where digital stations like Spotify and Pandora are gaining popularity, it may be time to look back at the history of FM radio and celebrate the origins of transmitted audio.

Today, we’ll be answering questions like: “When did FM radio start?”, “Why was it created?” and “What happened to its inventor?”

Let’s dial into the incredible tale of frequency modulation.

The History of FM Radio

What is the FM radio frequency?

FM radio is a form of broadcasting transmission based on “frequency modulation.” With frequency modulation, it’s possible to impress audio signals into a radio-frequency carrier wave and maintain a high quality of sound. In the initial technology used for radio communications, amplitude modulation (AM), the wave was regulated according to the amplitude in the audio signal.

FM radio was originally discovered and implemented by a man called Edwin Armstrong. Like many inventors of his time, he was searching for a solution to the problem of ongoing static in AM frequency radios. Eventually, Armstrong found that to eliminate issues with sound quality, he needed a much broader bandwidth than AM stations could offer. The bandwidth that an FM station occupies is twenty times bigger than an AM station. This means that companies can both remove static and achieve a greater sound fidelity than AM radio.

The FM radio frequency transmits audio in a band from 88 megahertz, to 108 megahertz. This frequency band is more arbitrary than you might think. It’s based on history, rather than need. Inside the group available for the FM radio frequency, every station takes up a 200-kilohertz section of the airwaves. This means that stations exist at odd numbers on the dial, such as 88.1 or 88.7. This concept was implemented by the FCC –the company responsible for regulating much of the history of FM radio.

In 1933, Edwin Armstrong successfully received four patents for his FM technology and began to appeal to the RCA for support with his new system. The Radio Corporation of America was responsible for determining which radio innovations were permitted at the time. Although the engineers within the company were impressed by the potential of frequency modulation, the legal and sales departments saw FM radio frequency as a threat. The head of the RCA at the time, David Sarnoff decided that there wasn’t enough of a market for FM radio, particularly as he was beginning to promote television more aggressively.

Though Armstrong earned some support for his invention from companies like Zenith and General Electric, he was forced to continue developing his technology on his own. Most of his experimentation was paid for out-of-pocket, while he gradually earned the attention of broadcasters and engineers. Finally, in 1940, the FCC caved in and began authorizing commercial FM broadcasting, allocation a tiny region of 42 MHz to 50 MHz to channels in the FM spectrum. By the end of 1941, almost 400,000 FM radio sets had been sold.

The History of FM Radio

The difference between AM and FM radio

To understand the full history of FM radio, it’s important to know how the technology differs from AM radio. As mentioned above, AM radio uses amplitude modulation to transmit radio broadcasts. It’s the simplest form of radio, and it’s capable of providing a steady wave of information – although audio quality can suffer.

Alternatively, the FM radio frequency relies on modulation of frequencies to deliver audio data. Whereas AM radio could provide a steady amplitude, FM provides consistent frequency and amplitude. The rate of the signal is un-modulated and unchanged until information is introduced to the signal. When the frequency modulates between low and high, voice and music is currently being transmitted within the carrier frequency. During this operation, only the frequency of the waves change– the amplitude remains the same.

Frequency modulation radio operates at a much higher range than AM radio. Additionally, the distance scope of the FM radio is much more limited than AM. Most FM stations can only reach across a maximum of 100 miles. However, despite its limitations, FM radio is much better for music than AM. If you’re wondering “When did FM radio start?” it was at the time when people were looking desperately for a better sound quality from their radio stations.

While FM radios offer enhanced sound quality to listeners, they also require additional stations to carry signals as far as possible. FM radios are also commonly delivered in stereo. Only a few AM stations can broadcast stereo signals. Additionally, while FM signals are less susceptible to things like interference and noise, they’re frequently limited by physical barriers like hills and buildings, which impacts their overall reception. That’s why you’ll find yourself picking up some radio stations more easily depending on where you are in your town or city.

The History of FM Radio

When was FM radio invented and why?

Let’s dive a little deeper into the question of “When was FM radio invented, and why?”

During the early 1930s, the world was gripped by the impact of the Great Depression. For many, unemployment was a significant problem, and countless businesses struggled to stay afloat. Despite panic among many industries, the era of radio continued to thrive. Broadcasters throughout the United States were making billions of dollars a year, thanks in significant part to the innovations of Edwin Armstrong.

Edwin Armstrong made multiple crucial contributions to the development of radio technology. It was Armstrong that was responsible for developing the regenerative circuit and superheterodyne receiver – two solutions that improved the quality of radio dramatically. However, although Edwin made a huge difference to the quality of AM radio, he was aware of the technology’s limitations, which included issues like:

  • Limited audio quality.
  • Static interference from lighting and household appliance.
  • Nighttime interference caused by multiple stations working at the same time.

The problems with AM radio weren’t a new concept. From the initial days when wireless transmissions were first introduced, engineers were aggravated by the clicks, hissing, and grinding caused by the atmosphere. The history of FM radio began with the search for something that could reduce the static in the radio lines.

Many of the initial pioneers of radio, including Lee De Forest and Guglielmo Marconi did everything they could to improve radio quality with antennas and other innovations. However, no-one seemed capable of eliminating the problem. Finally, in 1933, Edwin Armstrong introduced his revolutionary change to the broadcasting world. FM radio delivered a range of benefits over AM, including:

  • The ability to reproduce almost the entire range of sound that human beings can hear – thanks to a wider frequency band. This is known as high fidelity.
  • The option to send more than one signal at once in a process called multiplexing. The broader band of audio is often used to provide music for offices and stores.
  • The convenience of serving a wider area than an AM station – while using the same amount of power. The way that the FM radio frequency works means that it’s possible to serve a wider area, and the stations are cheaper to operate.
  • The ability to place stations closer together in geographical terms – unlike AM stations, the signals here don’t interfere with each other. You only here the stronger station with FM, not both at the same time.
The History of FM Radio

A brief history of FM radio: The struggle to be heard

Now you know the answer to “When was the FM radio invented,” you may be wondering how it continued to develop. The unfortunate answer is with great difficulty. Although Edwin Armstrong proved that FM radio was capable of so much more than AM transmissions, he had a hard time gaining acceptance for his idea. Armstrong even managed to bounce an FM signal off the moon – this was a concept that wasn’t possible at the time with AM signals.

So, when did FM radio start gaining popularity? Not until years after its original creation. When Armstrong came up with the FM radio frequency, AM broadcasts were big business for companies all over the world. There were many organisations that wanted to keep things the same. The founder of the RCA, David Sarnoff, was one of the men happy to let FM radio die out. Sarnoff was responsible for controlling many of the technical aspects of radio’s growth. He was also responsible for the development of the ABC and NBC television networks.

When Armstrong went to Sarnoff for support with his FM radio frequency, Sarnoff was currently pushing the growth of television. He’s actually the man responsible for developing the NTSC standard for TV – a standard we still recognise today. Seeing FM as a threat, Sarnoff’s company lobbied with the FCC to have the spectrum removed entirely from Armstrong’s frequencies, and into the ones that we use today (88 to 108MHz). At the time, the move rendered Armstrong’s network of FM radio stations completely obsolete. It also meant that the radio sets Armstrong had poured his own money into became useless.

The ruling delivered by the FCC announced that the 40MHz band that FM radio had previously relied on would now be given to television broadcasts. At the time, the RCA had a substantial stake on those channels. Additionally, the RCA also had allies everywhere. Even AT&T actively supported the move in frequencies, because the loss of the radio stations for FM companies forced networks to purchase links from AT&T.

The issue grew even worse when Armstrong ended up in another patent battle with NBC and the RCA, who were trying to use FM technology, though they weren’t paying royalties. It wasn’t until after Armstrong’s tragic death that radio’s emerging golden years began. Eventually, people began to learn that FM radio was better for high fidelity music than AM broadcasts. Radio sets began to include FM bands as standard, and by the 1970s, the FM audience had grown much larger than the AM community.

The History of FM Radio

A brief history of FM radio: The struggle to be heard

The history of FM radio is long and complicated.

When discussing the question: “When was FM radio invented?” it’s easy to get caught up on how long it took for such an amazing technology to make its way into the mainstream. The FM radio frequency had everything to offer, yet the battle of businesses stopped it from achieving its potential for a number of years.

No-one felt the agony of FM radio’s struggle more than its inventor, Edwin Armstrong (1890-1954). Armstrong one was one of the greatest engineers of the twentieth century. He changed the world as we know it in an incredible way, by showing us what was truly possible with radio technology.

Edwin Armstrong was only 11 years old when Guglielmo Marconi initiated the very first radio transmission over the trans-Atlantic. Despite his young age, he was enthralled by the concept of radio and excited to explore the technology himself. He even began building his radio technology at home – including a 125-foot antenna which he erected in his parent’s yard.

Unfortunately, despite Edwin’s passion and knowledge, he spent most of his life struggling to find the right support for the FM radio frequency. When he turned to the RCA for help with his invention, Armstrong was friends with the Sarnoff at the time. The battle for the airwaves left the two men as bitter rivals. Armstrong even had issues trying to convince the world that he was the original creator of FM radio. In 1922, Edwin lost his patent for the regenerative circuit, as a man called Lee De Forest had patented the same invention in 1916. After that, the RCA’s engineers claimed that they were the first to discover FM radio frequency too.

Armstrong spent approximately 21 years in and out of courts in his pursuit of better radio technology for the masses. In the meantime, he also continued to innovate, delivering solutions to countless problems with radio technology. When Armstrong eventually introduced the FM radio to the world in 1933, customers and listeners were blown away by its rich, clear quality. When he lobbied to the FCC to create his FM broadcast spectrum between 42 and 50 MHz, Armstrong may have assumed that his troubles were soon to being over. Though most of his next steps were funded by his own money, Armstrong built an experimental tower in New Jersey for $300,000, and he began manufacturing the receivers that would pick up FM technology.

Everyone who heard the FM radio frequency was astounded by its potential. These unique broadcasts could deliver something so much better than anyone had ever heard before. A club of FM enthusiasts even started in New York, with an accompany magazine called “FM.” Armstrong was doing everything he could to prove the impact of FM. Unfortunately, he wasn’t strong enough to fight the FCC. When Armstrong’s frequency was removed from the airwaves and placed at a different broadcast spectrum, he was left stressed, and penniless. The impact on his mental health caused Armstrong’s wife to leave him, and eventually, the toll became too much.

In 1954, Edwin Armstrong jumped to his death from his apartment in New York City, found on the thirteenth floor. Though his tale ended in tragedy, Edwin Armstrong has remained one of the most important people in radio history to date. The influence of his technology is still around us today.

The History of FM Radio

When did FM radio start – and is it ending?

Now that you have an answer to the question: “When did FM radio start,” you may be wondering what’s next. In 2017, Norway changed telecommunications history by shutting off their FM radio frequency signal. The switch-off came as part of a comprehensive move to digital broadcasting. According to Norway’s government, it was all in an effort to save money. Unfortunately, however, many of the citizens of Norway were against the concept.

The move to digital radio was initially agreed by Norway’s Parliament in 2011, and a timetable for the change was introduced in 2015. More than half a century after FM radio arrived in Norway during the 1950s, the technology’s life was coming to an end.

A survey in a Norwegian newspaper revealed that the government’s decision was mostly unsupported by the masses. 66% of citizens were opposed to the idea of shutting down FM radio. The move away from traditional broadcasting meant that citizens had to buy adapters, and critics argued that the government was rushing the move to digital. Similar criticisms took place in the United States during 2009, when Congress pushed television broadcasters to eliminate analog television signals.

Over the years, other countries have considered dropping the FM broadcasting frequency, including Switzerland, and Britain. However, in 2018, the BBC in the UK announced that they were dropping all plans to remove FM radio broadcasts. According to the BBC, they believed there was no need to force millions of daily listeners to switch to digital transmission. Instead, the BBC believe that FM can continue to exist as part of a hybrid future, where they live alongside DAB frequencies and internet-based shows.

The director of BBC radio, Bob Shennan is taking steps to protect the longevity of FM radio. He has urged broadcasters to work to ensure the survival of the media, stating that switching off analogue broadcasting could restrict listener choices.

With thousands of radio stations continuing to broadcast around the world today, the history of FM radio isn’t over yet. The FM radio frequency is crucial for everything from entertainment, to space communications. If Edwin Armstrong hadn’t taken his life in a fit of frustration, he might have lived long enough to see the impact his invention had.

Stay tuned to the latest radio industry insights with Radio Fidelity.

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