The FM radio frequency is one of the most overlooked, yet valuable electromagnetic waves in human discovery. Without it, emergency broadcasting services wouldn’t exist, neither would the technology for baby monitors, or microwaves. But while the FM radio was a crucial contribution to history and entertainment as we know it, the history of FM radio is full of drama, politics, business, and everything no inventor wants to face, but ultimately has to.
That being said, this article will go through the ups and downs, and the entire story and major milestones of FM radio.

Many stations still use FM as the primary mode of broadcasting. Its predecessor, AM broadcasts were prone to a lot of interference and were seriously lacking audio quality, resulting in the need to develop a better alternative, that ultimately became what we know as FM radio today.

What is FM Radio Broadcasting?

Frequency modulation radio (or FM radio) is a form of broadcasting transmission that is based on frequency modulation, which is the reason the sound quality can become much better than that of AM radio. It’s one of the most significant milestones in radio history, and its discovery is linked to the name of Edwin Armstrong.

Today, wide-band FM is used worldwide as the best way to provide a quality sound over broadcast radio, meaning a more accurate reproduction of the original audio. Its discovery was a contribution to raising the overall sound quality and still remains as one of the leading technologies in quality radio. FM radio was the first to introduce stereo audio which was a major leap in the history of radio and is still a crucial part of our listening experience.

This means FM broadcasts have what is called “stereo multiplexing”, which is capable of switching fast between the left and right audio signals. It is a stereo receiver that helps stereo FM radio stations broadcast in what is called stereophonic sound. This stereo receiver contains the additional circuit and parallel signal paths to reproduce two different channels. In contrast, AM has a monaural receiver, which only receives a single audio channel which is a combination of the left and right channels. To make listening to the radio a better and easier experience for the audience, an FM receiver often has a stereo to mono switch, allowing the listener to choose between the two versions.

The Difference Between AM and FM

To understand the history and meaning of the development of FM technology, we must first understand the workings and problems of its predecessor, AM radio, and how FM differs from it. AM radio uses amplitude modulation to transmit radio broadcasts. It is one of the most primitive and simplest forms of radio technology, and while it’s fully capable of providing a steady wave of information, the audio quality suffered greatly.

Because of FM’s ability to modulate frequencies when broadcasting audio data, it provides consistent frequency and amplitude, whereas AM radio could only serve with a steady amplitude. This is because, with the use of FM, only the frequency of the radio waves changes, while the amplitude remains untouched.

While FM radio operates at a higher frequency range compared to AM, its distance scope is slightly more limited, with most FM stations reaching a 100-mile radius or less. Additionally, while FM’s contributions tackle almost all struggles of AM radio, its signals are frequently limited by physical obstacles like buildings and hills, impacting their overall reception. As a result – reception is based on your positioning, and when driving through a rougher area, reception can come and go easily.

The Growing Need for & History of FM Radio Broadcasting

During the early 1930s, the world was devastated by the impact of the Great Depression. Despite the fact that a huge part of the population was struggling with unemployment and businesses found it hard to stay afloat, broadcasters all throughout the United States were still making billions of dollars a year. Those were mostly thanks to the contributions of one Edwin Armstrong in radio technology, and the launch of television broadcasting in some parts of Europe and North America. (By then, one of the first TV stations was live broadcasting from the General Electric facility, under the name of WGY Television.)

Edwin Armstrong has made many major contributions to the history of radio. These include the development of the regenerative circuit and the superheterodyne receive. Both solutions improve the quality of radio -, and the development of the ABS and NBC television networks. And while he made a crucial impact on the development of the AM radio, Armstrong, like many other inventors of his time, was aware and was looking for a solution to the many problems and setbacks of AM frequency radios, which included:

  • Static interference from weather and even household appliances
  • Limited audio quality
  • Interference caused by multiple stations working at the same time

Finally, in 1933, Armstrong introduced something even Lee De Forest and Guglielmo Marconi would envy. He came to the conclusion that in order to eliminate sound quality issues, he needed a much wider bandwidth than AM stations could offer, potentially solving some problems that the AM signals faced due to AM’s lower bandwidth.

His FM radio occupied a bandwidth twenty times larger than that of the AM station, and did, in fact, solve almost all problems that AM faced, including:

  • An ability to reproduce almost the entire range of sound available for the human ear. This is thanks to a wider frequency band, and is known as “high fidelity”
  • Multiplexing: the option of sending more than one FM signal at once
  • An ability to serve a wider area than an AM station, while using the same amount of power
  • The convenience of placing stations physically closer to each other, thanks to the fact that its signals don’t interfere with each other.

Inside the band available for the FM frequency, each station takes up a 200-kilohertz section, meaning that stations exist at odd numbers on the dial, such as 88.5 or 88.1. This concept was introduced by the Federal Communications Commission (FCC), the agency in charge of regulating radio.

In Europe and Africa (also called the International Telecommunication Union (ITU) Region 1) and in Australia, this is known as VHF Band II, ranging from 87.5 to 108 MHz. In America (ITU Region 2), it ranges from 88 to 108 MHz.

The AM band is very different, as its lower bandwidth makes the quality poorer, but this allows it to have more stations available on any frequency. Some of the world’s earliest radio stations have switched to FM broadcasting, like New York’s WRUC licensed in 1915, and Seattle’s KJR licensed in 1919 both became FM stations in the late 1990s. Most of these stations are still operating today on FM frequencies.

The Authorisation of FM Broadcasting

In the year 1933, Edwin Armstrong was granted four patents for his FM radio technology. With this, he began to appeal to the Radio Corporation of America (RCA) with his new system. The RCA was in charge of granting permissions for radio innovations at the time. But despite him being granted these patents, he still ended up in a patent war with NBC and the RCA, who was trying to use his technology without paying royalties. In fact, Armstong’s full authorization to go through by the FCC took almost a decade, and it wasn’t until after his early death that both stationary and portable FM radio’s golden years began in the 1960s.

The head of the RCA at the time, David Sarnoff, viewed the FM technology as a threat, due to the fact that it had relied on the 40MHz band which was used for television broadcasts. At that time, Sarnoff was punching the growth of television more aggressively, and the RCA had a substantial stake in the channels that used these bands.

Therefore, the ruling delivered by the FCC announced that the 40 MHz bands in question would be given to television broadcasts, and while Armstrong did earn some support from companies like Zenith and General electric, Armstrong was forced to continue his work on his own, financing the development from his own pocket. This move in frequencies was also greatly supported by AT&T because the loss of FM radio stations meant that networks were forced to purchase links from AT&T. It wasn’t until 1940 that the FCC began authorizing commercial FM broadcasting on a tiny spectrum (42 MHz to 50 MHz). But this isn’t even nearly the end of the history of FM radio. The complete life and death of Armstrong is a tragic one tale all radio enthusiasts know of.

People were welcoming the technology of FM radio with open arms, discovering that it was much better than the quality AM could even offer. But even well after the battles with the FCC and the RCA for authorization, despite its great potential and crucial contributions to radio technology, the wars in business stopped FM radio from achieving all it could. Unfortunately, these battles and the aforementioned band change killed Edwin’s passion and knowledge as he was struggling to find the support that FM radio frequency needed. His battle with the RCA turned a dear friendship with David Sarnoff into a bitter rivalry, and Armstrong even had to convince the world that he was, in fact, the creator of the technology, as the RCA’s engineers claimed that they were the first to discover FM frequencies. The inventor spent approximately 20 years in and out of courts, fighting for his invention, and in his pursuit to offer better technology for the masses.

Finally, when the audiences saw what an amazing invention this was, and when the FCC granted him a spectrum, Armstrong assumed his troubles were over, and finally he could be proud of what he had done. He continued his work by building an experimental tower in New Jersey funded by himself and began manufacturing radio receivers that would pick up FM broadcasters.

W2XMN was his first experimental FM radio station, making him one of the first-ever station owners, and the first when it comes to FM stations. But unfortunately, even his hard labor and the audience’s reaction to the technology weren’t enough to fight the FCC. Ultimately, the FCC removed Armstrong’s frequency from the airways and placed it on a different broadcast spectrum, leaving Armstrong devastated, and broke, as his FM radio network basically became obsolete. This final blow to his mental health caused his wife to leave him, and eventually, it all became too much, and the inventor jumped to his death from his apartment building in New York City in 1954. 

FM Radio in Europe

After World War II, FM radio broadcasting was introduced to Germany. In 1948, a new wavelength plan was set up for Europe. Because of the results of the recent war, Germany was given only a small number of medium-wave frequencies, which weren’t good for broadcasting. Therefore, Germany began its broadcasting on UKW, or “Ultrakurzwelle”, meaning ultra short wave, nowadays called VHF.

After experimenting with amplitude modulation and AM stations, it looked like FM was a much better alternative to VHF than AM. Because of this history, FM radio is still referred to as “UKW Radio” in Germany to this day. Many other European nations followed this change later when the superior quality of FM was realized.

One of the first FM stations in Europe was the Hungarian Kossuth Radio – the second most popular station of Hungary – which marks an important milestone in the history of radio, as the Antenna Hungaria broadcasts it with a heaping 2 MW power on 540 kHz, making it the most powerful medium wave transmitter in the world, and is among the most powerful radio transmitters of the world. Successful reception of the Kossuth Radio broadcasted by this antenna was reported from as far as Michigan, United States, and Kuala Lumpur, Malaysia. Since 2013, this transmitter site has been a preserved industrial monument.

FM Radio in the Present & Future

After tackling the long and bumpy history of FM radio, it’s also important to talk about what’s next in the technology’s future. In 2017, Norway made a decision that would impact FM radio’s future, and telecommunications history greatly. They shut off their FM signal as part of a move towards digital radio. This move to digital radio (DAB) and the switch-off of FM was agreed upon by Norway’s Parliament in 2011, and the timetable for this change was introduced to the masses in 2015. More than half of the citizens of Norway were opposed to the idea of shutting down FM radio, similar to the reaction the United States got in 2009 when Congress moved to eliminate analog television signals.

Over the years, other countries, like Switzerland and Britain considered joining this move by dropping the FM frequency, however, the BBC in the UK announced in 2018, that they were dropping all plans to remove FM radio. They believed there was no need at all to force millions of listeners to switch to digital transmissions. Instead, they suggested that FM continue as part of a hybrid future, where it works alongside DAB and internet-based broadcasting. The director of BBC radio, Bob Shennan said that he will be taking steps to protect the longevity of FM radio.

Today, thousands of radio stations continue to broadcast using FM, so the golden years of FM aren’t over yet. It still is a crucial part of entertainment programming, emergency communications, non-native-language programming, and even space communications. Stations like the San Francisco-based KDFC, which offers 24 hours of classical music programming daily, or the New Jersey-based WKXW, and the Los Angeles honed KIIS-FM rely on FM to offer quality entertainment to the masses. The biggest question is, can these radio channels and the complexity of FM radio live on in the digital age?

The story of the development and golden years of FM radio is one of the most well-known among tech savvies. Armstrong’s contributions to the technology of radio changed the face of entertainment for good, and without it, humanity would take decades if not centuries to get to where we are now. Sadly, the politics of it all, mixed with business interests slowed down the process even more. Without these obstacles, the golden age of the FM radio would have been here decades earlier, launching a beautiful career for its inventor.