General exam question G8A01
Subelement G8, SIGNALS AND EMISSIONS· Group G8A
How is direct binary FSK modulation generated?
- A.By keying an FM transmitter with a sub-audible tone
- B.By changing an oscillator’s frequency directly with a digital control signal (correct answer)
- 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
WhyDirect binary FSK modulation is generated by changing an oscillator's frequency directly with a digital control signal. Direct binary FSK is generated by feeding a digital data signal straight into an oscillator's frequency-control input, shifting the oscillator's frequency between two values as the data toggles between its two states, answer B. It isn't produced by keying an FM transmitter with a sub-audible tone, isn't done through a computer data protocol interface, and isn't a repurposed CW keying input acting as a tone generator, so A, C, and D describe other, unrelated methods.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2023-2027 NCVEC Element 3 pool (public domain); the explanation above is original writing, see our methodology.
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