FM vs AM

Types of AM signals:

  • Modulating Waves (AM Radio)
  • Pulse Carrier
  • Pulse Amplitude Modulation (PAM) Used by most manufacturers of perimeter fence.  
  • Pulse-Duration Modulation (PDM) (Morse Code) Used by one manufacturer.
  • Pulse-Code Modulation (PCM)
  • Pulse Position Modulation (PPM)

Types of FM signals:

  • Modulating Wave ( FM Radio, Police, Fire and Aircraft Communications)
  • Phase Modulation – (PM)
  • Frequency Speed Spectrum (Cell Phones)
  • Frequency Shift Keying  (FSK; Teletype) Hidden Fence

FM ADVANTAGES

  • Electrical noise sourced (televisions, computer monitors, light dimmers, motors, etc. are AM).
  • FM receivers ignore AM signals.
  • FM receivers can work in electrical noise environment.
  • Output power remains constant with the amount of modulation.
  • Less risk of receiving partial signal.
  • Virtually eliminates risk of false correction from other sources.