AM and FM in mobile phones.

Replies

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  gohm

  Reason being is AM radio has been phasing out for many years. Such a small group still listen to AM that electronic manufactures wouldn't cater to the feature. between the internet and satellite technology, you now can get information sent world-wide. Short wave and sideband are other older, though still used means.
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  durga ch

  transmitting should not be a problem right Gohm?
  I suppose hobbist still do it, juts that bulk manufacturing doesnot happen for AM radios.
  
  By the way engg4world , any specific reason for you to rewind back in time 😛
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  divyamoorthy89

  hi im doing my third yr elec & electronics eng..i need som project ideas..if u can mail to #-Link-Snipped-#ks
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  devendra_jntu

  In am we are using carrier of frequency with in KHz range these frequecy signals are reflected from the ionosphere and covers large range where as in case of fm carrier frequency of order MHz those can be penetrated through ionosphere and covers small range.so while providing am band it should not be used by any one in world,but fm band can be used by one in the world by maintaining some distance between fm stations to avoid interference.......................😁
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  arunhero99

  Devendra, its refraction, not reflection for AM on the ionosphere. anyway, effect is same.
  And interference by noise is heavy for AM actually. any drop/variation in power of the signal can change the amplitude disrupting the whole data. Otherwise devendras explanation is apt.
  FM is line of sight (LOS) and AM is skywaves.AM is avoided nowadays as contolling the direction of refracted wave (directivity of fall) is too expensive and power consuming. Stary refractions can cause disruptions to local transmission.
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  engg4world

  Thanks i got it .......i will come up with much more in detail with some examples...i am trying to research on signals.
  
  thanks very much once again.😀
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  sauravgoswami

  well there are many form of transmitting signal these days apart from AM and Fm,although they are not as popular.