modulating a carrier

Discussion in 'Wireless & RF Design' started by TORSKI, Apr 27, 2006.

  1. TORSKI

    Thread Starter New Member

    Apr 27, 2006
    1
    0
    How effiecient will be to modulate a carrier in an FM transmitter circuit using signals form the RS-232 of a computer? Is there device I need to do that effectively?
     
  2. Papabravo

    Expert

    Feb 24, 2006
    9,898
    1,722
    In bandwidth terms it will be very inefficient. A narrow band FM voce channel is about 25 kHz wide. Broadcast FM stations are separated by 200 kHz to prevent interference between adjacent stations.

    For bandwidth efficiency it is hard to beat PSK31 and varicode.
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    If you have a sound card, why not use its output and a standard mixer? Or pad it down a bit and just run it into the microphone input of the transmitter?
     
  4. DAY DUDE

    New Member

    Apr 28, 2006
    2
    0
    What are you trying to do?
     
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