Even though people these days don’t always listen to conventional radio, it remains a significant technological landscape in history and their everyday lives.
WHAT ARE THE DIFFERENT TYPES OF RADIO?
People usually categorize radios depending on their use and function. The most used today are AM, FM, Shortwave, Longwave, Satellite, Ham, DAB, Walkie-Talkie, and radio broadcasting HD radio. Each of them uses a different technology or band. A radio band determines the wavelengths and frequency used and only applies to analog radio. This article will introduce each of the types that are commonly used in our everyday lives.
RADIO WAVES
Radio waves are electromagnetic waves of frequencies used for long-distance communication. According to NASA, radio waves have the longest wavelengths in the electromagnetic spectrum. Their wavelengths, according to the radio frequencies, ranging from 1 mm to anywhere over 100 km.
A radio physically works by transmitting and receiving electromagnetic waves rapidly. A transmitter (meaning the stations) radiates the field outwards using an antenna, and the receiver (meaning the actual radio devices) picks up the field and signal and translates it into sound. The first commercial station aired in 1920, with a broadcast about the elections. The success of the KDKA broadcast in Pittsburg inspired the technology and future of broadcasting worldwide.
RADIO BROADCASTING
The radio was developed in the 20th century as the breakthrough way to broadcast audio signals for large distances and wide audiences. Although the first period was just experimental, the VHF band (very high frequency) aired commercially 40 years later.
AM & FM
Amplitude modulation (AM radio) is the oldest form of wireless radio broadcasting. Using a process called modulation, an audio signal can modify the strength of the radio waves rapidly, which AM receivers decode into sound. The amplitude is the signal strength of the carrier wave that’s varied in proportion to the message signal.
In the 1960s, the transistor was developed, allowing the smaller-sized amplitude modulation radio to become a reality. But the early types often used vacuum tubes. Although this system is fairly simple, the quality of the sound is underwhelming, especially by today’s standards, and it’s vulnerable to electrical noises. They often have a light called ‘Magic Eye’, which by measuring peak power, helps tune a particular channel precisely.
FM is one of the most commonly known radio bands. Unlike AM radio, FM focuses on the modulation of the radio frequency rather than the strength. The higher frequency used for FM allows much better audio quality, cuts down on white noise, and doesn’t let any interference in.
While technology has developed way beyond AM and FM these days, FM receivers are still used widely and even come built into smartphones today. FM and AM bands remain the main radio source in portable, home, or construction site radios.
