TRUDO RADIO CLUB

What is SSB and why do radio amateurs use it?

Single Side Band (SSB) is one of the most popular modulation methods in amateur radio. It is a smart, efficient variant of AM that allows you to reach farther with less power.

In classic AM, two sidebands and a carrier are transmitted. These sidebands contain the same information, which means a lot of energy is essentially wasted. SSB takes a different approach: it transmits only one sideband and removes the carrier. The result is a much more efficient signal that occupies less space in the spectrum.

• Efficient power use — almost all transmit power goes into the audio signal. • Narrow bandwidth — about 2.4 to 3 kHz instead of 6–9 kHz with AM. • Strong performance with weak signals — ideal for DX and poor propagation.

Within amateur radio, there is a clear convention: • Below 10 MHz: usually LSB • Above 10 MHz: usually USB It’s not a strict rule, but it is the worldwide standard practice.

• HF voice communications on 80m, 40m, 20m, 15m and 10m • Maritime and aviation communication • Emergency communication and emergency networks • Contest traffic • Weak‑signal communication on VHF/UHF

If you are not tuned exactly to the correct frequency, SSB sounds strange or distorted. A small adjustment with the RIT or clarifier will make the signal clear and natural again.