What is a characteristic of single sideband (SSB) compared to FM?

• A. SSB signals are broader in bandwidth
• B. SSB signals have narrower bandwidth
• C. SSB signals require more power
• D. SSB signals transmit more audio quality

Answer: (B)

Single sideband (SSB) is a refinement of amplitude modulation (AM) that allows for more efficient use of the available frequency spectrum. One of the key characteristics of SSB compared to frequency modulation (FM) is that SSB signals have a narrower bandwidth.

The bandwidth of an SSB signal is typically around 2.7 kHz, whereas FM signals can occupy a much wider bandwidth depending on the deviation used, often exceeding 12 kHz. This narrower bandwidth of SSB makes it particularly advantageous for long-distance communication, as it allows multiple signals to occupy the same frequency range without causing interference.

By using single sideband techniques, the carrier and one sideband are removed, which results in a more efficient transmission. This means that operators can conserve spectrum space and reduce the potential for congestion on frequency bands. Additionally, the lower bandwidth usage often translates to improved signal propagation and reception in various ionospheric conditions, a critical factor in amateur radio operations.