Ham Radio General Class Practice Test

Which sideband is most commonly used for voice communications on frequencies of 14 MHz or higher?

1. Upper sideband

2. Lower sideband

3. Vestigial sideband

4. Double sideband

The correct answer is: Upper sideband

The upper sideband is the most commonly used sideband for voice communications on frequencies of 14 MHz or higher due to its efficiency in bandwidth usage. Upper sideband (USB) is preferred in high-frequency (HF) amateur radio communications because it helps minimize interference from other nearby signals. In the HF bands, particularly above 14 MHz, USB is utilized primarily because it allows for clearer, more intelligible voice transmissions. The characteristics of radio waves at these frequencies enable better propagation when using USB, as it ensures that the signal stays within the allocated channel without introducing unnecessary bandwidth consumption. In contrast, lower sideband (LSB) is typically used in the lower HF band segments, mainly below 10 MHz. Vestigial sideband and double sideband are less common in amateur voice communications because they are generally used for other types of transmissions, such as television or specialized data modes, which are not the primary focus of voice communications in the amateur radio community. Thus, for voice communication at the specified frequencies, the upper sideband is established as the standard practice.