There are two primary ways which we can be broadcasted when it comes to the traditional form of analogue radio. These two different waves are known as AM and FM. AM stands for Amplitude Modulation and FM stand for Frequency Modulation. When one is listening to the radio you cannot tell the difference, but there are many important distinctions when it comes to the different wave types. Here we will look at some of the properties of AM and FM and also consider some of the advantages and disadvantages of each.
AM is actually much older than FM. The first recorded use of AM was way back in the 1870’s while FM was first used much later in the 1930’s, and was developed by an American named Edward Armstrong. The primary difference between the two and the reason why they are called AM and FM is because of the way in which the wave is modulated. AM is modulated by amplitude and FM is modulated by frequency, hence the A for amplitude and the F for frequency.
FM is now used much more frequently in modern broadcasting, this is due to the fact that it has a much longer range than the AM wave, therefore, has the ability to reach more people. However, it also requires a greater bandwidth just like a higher internet speed but with the developments in modern technology, this is not an issue. Another benefit of broadcasting on the FM signal is that it is far less likely to suffer from interference from ‘noise’, though the word “noise” is in reference to other waves rather than what we would normally consider noise.
One downside to the FM wave is that it can be blocked by physical objects more easily than the AM wave, though the sound quality is considerably better on FM waves.