Question T8A07
From subelement T8 - T8A
What is a characteristic of single sideband (SSB) compared to FM?
Why is this correct?
SSB signals have narrower bandwidth compared to FM. A typical SSB voice signal uses approximately 3 kHz of bandwidth, while FM voice signals on VHF repeaters use 10-15 kHz. This narrower bandwidth allows more SSB signals to fit in the same frequency range than FM signals. Options A and B are incorrect - SSB requires more precise tuning than FM and isn't necessarily less susceptible to interference.
Memory tip
Look for bandwidth comparisons by remembering the spectrum efficiency principle: narrower modes allow more users in limited frequency space. SSB's efficiency comes from eliminating the carrier and one sideband, keeping only the essential voice information. This pattern applies across amateur radio - more efficient modes use less bandwidth.
Learn more
SSB achieves its narrow bandwidth through spectral efficiency - by transmitting only one sideband and no carrier, it conveys the same voice information as AM in half the spectrum space. This efficiency makes SSB ideal for weak-signal VHF/UHF work and HF DXing where frequency privileges are limited. The reduced bandwidth also means better signal-to-noise ratio for long-distance communication.
Think about it
Why do you think the narrower bandwidth of SSB makes it particularly valuable for amateur radio operators working with limited frequency allocations or trying to establish long-distance contacts?