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Вопрос 305

What type of modulation is commonly used for VHF packet radio transmissions?

  1. FM or PMПравильный ответ
  2. SSB
  3. AM
  4. PSK

Объяснение

VHF packet is normally sent by feeding audio tones from a terminal node controller into an ordinary FM voice transceiver, so the signal on the air is frequency or phase modulated. FM is well suited here because packet keying is constant amplitude and FM receivers ignore amplitude variations.

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