Which statement best describes SSB in communications?

• A. SSB is spectrally efficient, producing the narrowest bandwidth among AM, FM, and SSB, and is used for long-range HF voice.
• B. SSB uses the widest bandwidth among the three and is used for local VHF communications.
• C. SSB demodulation requires complex detectors but is easy to generate.
• D. SSB is only used for data transmission.

Answer: (A)

SSB is a method that makes efficient use of spectrum by transmitting only one sideband (and typically no carrier). This means the signal’s bandwidth is about the same as the original modulating signal, not doubled as in standard AM. By eliminating the unused sideband and the carrier, power and spectrum are used more efficiently, which is especially valuable on HF where long-range, long-distance propagation is common. That efficiency is why SSB is favored for long-range HF voice communications.

The other statements don’t fit because SSB does not have the widest bandwidth—it is actually narrower than AM or FM. It isn’t primarily used for local VHF communications, where other modes like FM are preferred for fidelity and simplicity. Demodulating SSB isn’t intrinsically easy and often uses a detector with a reinserted carrier (a beat-frequency oscillator) to recover the audio, while generating SSB requires precise filtering to select one sideband and suppress the other and the carrier. SSB is also used for voice, not only for data transmission.