AM vs FM

[DragLvr911]

Alright i had a small discusion with my heavy computer damaged brother and he tried saying the differance between am and fm is a tech thing and that it had nothing to do with the wave length nor the fact that its a different frequency modulation .. can someone please clearify the trueth behind this matter.

 

[feedbak]

AM is amplitude modulation and FM is frequency modulation.

 

[DragLvr911]

AM is amplitude modulation and FM is frequency modulation.

Oh .. ok .. hmm im still confused XD .. all i knew about them is the length of the waves .,. damn the ham radio test

 

[feedbak]

Oh .. ok .. hmm im still confused XD .. all i knew about them is the length of the waves .,. damn the ham radio test

it has to do with the carrier signal carrying the data or music etc. AM modulates it by amplitute which cuts off some of the audio (i believe as i am trying to remember back to school) and thus sounds hollow. FM modulates the data by frequency which carries more of the sound.:

AM
http://en.wikipedia.org/wiki/Amplitude_modulation

FM
http://en.wikipedia.org/wiki/Frequency_modulation

 

[gmclam]

RF = Radio Frequency. An "unmodulated wave" is often referred to as a "dead carrier". If you 'temporarily' change the amplitude (level) of the wave, it is Amplitude Modulation. If you 'temporarily' alter the frequency of the wave it is Frequency Modulation.

The frequency of the wave determines its wavelength, usually expressed in meters. To calculate the wave length, take 300 and divide by the frequency. That means a frequency of 150MHz is 2 meters.

AM does not change the frequency nor wave length.
FM does modulate the frequency and wave length at a specific moment in time.

 

[zz0468]

We used to joke about AM being up and down, and FM being back and forth. A gross oversimplification by several orders of magnitude. But that is, in essence, the difference between am and fm.

 

[slicerwizard]

AM flashlight - sends information by varying the brightness.

FM flashlight - sends information by varying the color.

Radio is no different.

 

[loumaag]

gmclam provided a great explanation. It sounds as if your argument deals with wave length of any significance. The answer, as gmclam explains, is that FM will change the frequency in a moment of time; however, the change is a slight change centered around a frequency and the affect of that change on wavelength is negligible. In other words, a 2-meter ham signal with a 5 KHz deviation is still a 2-meter ham signal.

 

[jmp883]

....hmmm, and I always thought that AM stood for Almost Music and FM stood for Funky Music