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سؤال 403

What is meant by the term “baseband” in radio communications?

  1. The lowest frequency band that the transmitter or receiver covers
  2. The frequency range occupied by a message signal prior to modulationپاسخ درست
  3. The unmodulated bandwidth of the transmitted signal
  4. The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency

توضیح

Baseband is the frequency range the message occupies before it is modulated onto a carrier and after it is demodulated, for example roughly 300 to 3000 Hz for communications-quality voice. It is not the receiver's tuning range or the transmitter's oscillator frequency.

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شروع تمرین
سؤال 403: What is meant by the term “baseband” in radio… · FCC Amateur Extra Class (Element 4) · Questena