2007-04-09 04:24:04 · 4 answers · asked by Anonymous in Cars & Transportation ➔ Car Audio
AM is line of sight and won't penetrate concrete.
FM bounces off things, an can penetrate some concrete.
2007-04-09 04:32:25 · answer #1 · answered by Mr. KnowItAll 7 · 0⤊ 0⤋
There could be a few reasons. 1) Many FM stations run antenna in the tunnels so you can pick up their station. 2) If you looked at AM signals on an oscilloscope you would see that they are very tall. That means that they can get int erupted by anything in their way. FM signals are shorter and less prone to interference.
2007-04-09 11:36:11 · answer #2 · answered by Tom M 3 · 0⤊ 0⤋
Difference in methods of transmission of signal.
FM= Frequency modulation where they vary the sound by changing the frequency slightly up or down.
AM= Amplitude modulation varies the currant side of the signal.
(As I recall) FM has more penetrating power, and a lot depends on where the station is that you listen to.
2007-04-09 11:35:19 · answer #3 · answered by Wisdom 6 · 0⤊ 0⤋
AM is great for long distance's in flat states. FM is for shorter distances like cities w/ building or mountains.
AM: Amplitude Modulation
FM: Frequency Modulation
http://www.drawgroup.org/~jyu/writing/SciBug/AMFM.html
2007-04-09 11:41:16 · answer #4 · answered by looking4answers 4 · 0⤊ 0⤋