GeneralG8A01
How is direct binary FSK modulation generated?
B
Answer
Signals and emissions
Type
A
By keying an FM transmitter with a sub-audible tone
B
By changing an oscillator’s frequency directly with a digital control signal
C
By using a transceiver’s computer data interface protocol to change frequencies
D
By reconfiguring the CW keying input to act as a tone generator
Answer Notes
Frequency Shift Keying (FSK) is a digital modulation scheme where digital information is transmitted through discrete frequency changes of a carrier signal. In direct binary FSK, the transmitter's oscillator frequency is shifted back and forth directly by the high and low states (1s and 0s) of a digital baseband control signal.
This differs from Audio Frequency Shift Keying (AFSK), where audio tones are fed into the microphone input of an SSB or FM transmitter. Direct FSK generates a cleaner signal because it avoids the audio amplification and modulation stages entirely.
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The bandwidth of a band-pass filter is measured between what two frequencies?
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What is the name of the process that changes the phase angle of an RF signal to convey information?