Radio: it’s been part of our lives for over a century, bringing music, news, and entertainment right into our homes, cars, and workplaces. But have you ever wondered, “How do radios work?”

This technology, which may seem complex on the surface, is actually easy to understand once you know the basics. In this blog, we’ll explore the magic of radio technology, demystifying the process from radio waves to AM and FM broadcasts.

What are Radio Waves?

Before we delve into how radio works, it’s important to understand what radio waves are. These invisible waves are a type of electromagnetic radiation similar to light or X-rays but with a much longer wavelength. These wavelengths are measured in terms of frequency, which is the number of times a wave completes a cycle per second.

Like all electromagnetic waves, radio waves travel at the speed of light and can pass through various mediums, including air, vacuum, and certain solid objects. Their ability to carry information over long distances without significant loss makes them ideal for broadcasting.

What is Radio?

Radio is a technology that uses radio waves to carry information, such as sound, by systematically modulating some properties of the emitted waves. In other words, it’s a way of sending and receiving messages or data without a physical connection, often over significant distances.

From the listener’s perspective, the radio is a device that receives these radio waves and converts them back into sounds that our ears can hear — music, speech, or other audio content. But there’s a lot more to it when we delve into the technicalities of how radio works.

How Does Radio Work?

At its most basic, radio technology involves a transmitter and a receiver. The transmitter encodes information onto radio waves, which are then sent out into the environment. The receiver, usually a radio set, captures these waves and decodes the information, allowing us to hear the broadcast.
The process of encoding information onto the radio waves is called modulation, and it’s here that we encounter two of the most familiar terms in radio technology: AM and FM.

How Does AM Work?

AM stands for Amplitude Modulation. In an AM radio broadcast, the radio wave’s strength (or amplitude) is altered to encode the information. Essentially, the audio signal is combined with a carrier signal, resulting in changes in the wave’s amplitude that correspond to the original audio signal.

When these modulated waves reach your radio, the AM receiver demodulates the signal. It extracts the original audio information from the changes in the amplitude and converts it into sound through the speakers. AM radio is known for its long-range capability but can be more susceptible to interference and generally has lower sound quality than FM.

How Does FM Work?

FM stands for Frequency Modulation. Unlike AM, where the amplitude of the radio wave is altered, FM changes the frequency of the radio wave to encode information. This means that the audio signal causes the wave’s frequency to shift up and down while the amplitude remains constant.

An FM receiver is designed to detect these changes in frequency and convert them back into the original audio information. FM provides better sound quality than AM and is less affected by interference from electrical equipment. However, its signal range is generally shorter than that of AM.

AM vs. FM Radio: Key Differences

Understanding the basics of how radios work naturally leads us to a common question: what are the key differences between AM and FM radio broadcasts? Both have unique characteristics and uses that make them suitable for different types of content and listening environments.

AM Radio Broadcasts

AM, or Amplitude Modulation, is the more basic form of radio broadcasting. Imagine a steady wave transmitting at a frequency of 1,000 kHz on the AM band. This unmodulated wave alone carries no useful information – it’s merely a constant signal with a fixed frequency and amplitude.

When we introduce information such as voice or music, the amplitude of the signal varies in direct proportion to the data being sent. This is known as modulation. The frequency, however, remains unchanged, and this constant frequency serves as the carrier that transports the signal from the broadcast antenna to the receiver.

AM radio operates within a frequency range of 520 kHz to 1,710 kHz in the Americas, though this range varies in different regions. One of the advantages of AM radio is its ability to cover vast distances. The broader range of frequencies available for AM broadcasting allows for a higher number of stations in a given range.

However, AM radio has its drawbacks. It is more prone to static interference, such as that produced during a thunderstorm. Moreover, AM’s audio range of 200 Hz to 5 kHz restricts its sound quality, making it more suited to talk radio than music broadcasting.

FM Radio Broadcasts

FM, or Frequency Modulation, operates differently. In an FM broadcast, information modulates the frequency of the signal rather than the amplitude. To visualize this, consider a signal with a fixed frequency and amplitude. When we add data, such as music or voice, the frequency changes in proportion to the information while the amplitude stays constant.

FM radio operates within a higher frequency range than AM, typically between 87.5 MHz and 108.0 MHz. This higher frequency range, however, limits the distance over which FM signals can be transmitted, typically less than 100 miles.

But when it comes to sound quality, FM is the winner. Its bandwidth range of 30 Hz to 15 kHz allows for superior sound quality, making it the preferred choice for music broadcasts. Furthermore, FM is less susceptible to noise and interference than AM, although physical barriers such as buildings or hills can affect FM signal reception.

In summary, both AM and FM have their unique advantages and applications. While AM is great for long-range transmission and talk radio, FM offers superior sound quality and is the preferred choice for music broadcasts. Understanding these differences is key to appreciating the complexity and brilliance of radio technology.

Discover the World of Radio Broadcasting at Our Nationwide Media Schools

Radio technology is a fascinating field, from the fundamental understanding of radio waves to the workings of AM and FM broadcasts. As you delve deeper into how radios work, you gain a new appreciation for this enduring and evolving medium.

At the Beonair Network of Media Schools, with campuses in Miami, Chicago, Colorado, and Ohio, we offer a comprehensive Radio & TV Broadcasting program covering these topics and more. Our curriculum balances theoretical knowledge with practical, hands-on experience, ensuring you’re well-equipped to join the dynamic world of radio broadcasting. You’ll even spend time in a real-world studio to hone the practical skills you’ll need for your career.

Whether you’re looking to become an on-air personality, a technical producer, or explore the many other roles in radio broadcasting, our program provides the foundational knowledge and practical skills you need. Take the first step towards an exciting and rewarding career in radio broadcasting: contact us for more details or apply online today!