ARRL Technician Practice Exam

Which sideband is normally used for 10 meter HF, VHF and UHF single-sideband communications?

1. Lower sideband

2. Upper sideband

3. Both sidebands

4. FM sideband

The correct answer is: Upper sideband

Upper sideband is typically used for 10 meter HF, VHF, and UHF single-sideband communications. This preference is based on industry conventions and practical reasons. In amateur radio, upper sideband (USB) is favored for modes such as SSB (Single Sideband) because it generally provides better performance in terms of signal clarity and power efficiency, particularly at higher frequencies like VHF and UHF, where the characteristics of signal propagation make USB more effective. The decision to use upper sideband rather than lower sideband (LSB) on these bands is largely a historical standard that helps avoid confusion among operators, allowing consistent communication practices across the amateur radio community. Lower sideband is typically used on the 80 meter and 40 meter bands, while upper sideband is standard for the 10 meter band and above. Hence, knowing this convention helps ensure smoother communication and adherence to common practices within the amateur radio network.