fm modulation

Discussion in 'Wireless & RF Design' started by rd_aec057, Jul 19, 2005.

  1. rd_aec057

    Thread Starter New Member

    May 2, 2005
    2
    0
    anybody can explain me why fm signals can not be received from far distance from fm station
     
  2. n9xv

    Senior Member

    Jan 18, 2005
    329
    1
    By FM signals I assume you mean the 88 to 108-MHz VHF broadcast band. These frequencies rely primarily on sky wave propagation rather than ground wave propagation. Sky wave propagation being a function of antenna height. For a given transmitter antenna height, the higher the receiver antenna the better the reception. Although VHF is not quite "line of sight" this priciple is used to calculate reception/communication distances. Rough terrain and buildings can adversely affect the reception path as well.

    Take a look at the spreadsheet attachment.
     
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