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… 🙂

7 Replies to “Why Can’t we use FM Radio Without Headphones? | Radio explained”

  1. you can use it without the headphones you just have to plug a speaker wire or an old headphone wire into it and then the FM radio will play on the speaker you can just cut the old headphones off just use the plug in the phone then your phone thinks the headphones are plugged in

  2. I connet 3.5mm jack to mobile and its length only 3-4cm(cut it)and then radio also works..u said it required mainly 19cm length?

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