Why Can’t We Use Fm Radio without Headphones? - Radio explained

when you try to assess FM radio your phone commands to put in headphones you are probably irritated, why is it ? that we have phones that can help us communicate with the other side of the world without any problems but we can't create a more efficient way of listening to the radio after all the radio has existed for about a century now even so how is it that our 21st century phones can access this age old technology without the assistance of a simple wire something seems fishy here before we try to answer this question let's look at how the radio works Radio means the act of sending energy from one place to another without any form of direct wired connection radio waves move from one piece of equipment called the transmitter travel through the air wirelessly are not then collected by another piece of equipment called the receiver it goes something like this first you capture sound energy from a recording or a voice and then convert it into electrical energy this energy then flows into a tall antenna that boosts the strength of the electric energy you can control this boosting process depending on how far you want the signal to go from the location of the antenna the electrons in the electric current becomes agitated and then start moving back and forth to create invisible electromagnetic radiation in the form of radio waves these waves then travel at the speed of light to the receiving antenna this in turns convert the radio waves back into electric current this sound energy is then decoded from this electric current to graze your ears with the sound of radio music before moving to the topic if you are not yet subscribed to my channel please go ahead and subscribe by clicking on the red button down below because it helps me to keep making more videos like this now moving to the topic antenna if you see modern transistor radios they usually have two different antennas one antenna is coiled inside of it while the other is extended externally why do we need two separate antennas in the first place this is because radio is usually emitted in two frequencies one is the frequency for AM radio that is amplitude modulation and the other is the more popular FM radio frequency modulation the main distinction between these two is that FM radio waves travel a short distance but at a much higher frequency around 85 - 100 MHz while AM radio utilizes waves that travel a greater distance at a much lower frequency around 1000 KHz therefore FM signals have frequencies that are ten times greater than their AM counterparts a single antenna cannot pick up both of these highly different frequencies it is the frequency of the radio wave that determines the length of the antenna basically a greater wavelength means a longer antenna for example to catch an FM signal you need an antenna that is roughly 90 centimeter in length unfortunately modern phones simply don't have space to integrate antenna inside them however they have a more interesting option in the form of headphones you see headphones act as the perfect antenna headphones are insulated metal wires with a coil surrounded a magnet at one end and the thick metal jack at the other it works as an antenna by picking up the energy in a radio wave and then supplying it to a tuner moreover they are usually more than 90 centimeter in length it is an ideal scenario for pickup FM signals all we need is a simple metal wire to do the trick which is why you can listen to the radio even when you connect the phone to external speakers with an ordinary USB cord therefore in reality you don't necessarily need the headphones to play FM radio on your cell phones however with the current level of technology it is possible to have an internal antenna instead of relying on headphones there are several phones that give you the option of listening to FM radio without the headphones but most phone companies opt out of it including built-in antenna would only contribute to the weight of the phone making them unattractive and bulkier instead it is universally acknowledged that it simply makes more sense to depend on our headphones to act as the antenna for our FM radio needs Hope you like this video if you have any queries and want more videos like this please let me know in the comment section below and don't forget to subscribe my channel thanks for watching bye for now see you on my next video... :)