Emergency Telecommunicator Certification Practice Exam

Which of the following radio bands has virtually no skip interference?

1. HF (high frequency)

2. VHF (very high frequency)

3. UHF (ultra high frequency)

4. SHF (super high frequency)

The correct answer is: UHF (ultra high frequency)

The UHF (ultra high frequency) band is characterized by its ability to provide reliable communication with minimal skip interference. Skip interference occurs when radio signals bounce off the ionosphere, which is more common in lower frequency bands, such as HF (high frequency) and even VHF (very high frequency). UHF operates at a higher frequency (typically from 300 MHz to 3 GHz), leading to shorter wavelengths that tend to propagate in a more line-of-sight manner. This characteristic makes UHF ideal for communication over shorter distances, such as within urban environments or between fixed stations. In addition to this, UHF signals are less likely to travel long distances and thus are less susceptible to being reflected off the ionosphere, minimizing the potential for skip interference. Compared to other bands like HF, which can see signals bounce off atmospheric layers, UHF remains focused on the direct path between transmitter and receiver. The other bands, such as HF, VHF, and SHF (super high frequency), have different propagation characteristics and are more prone to circumstances that can lead to skip interference. HF, for example, is known for long-range communication but frequently experiences skip propagation due to ionospheric reflection. VHF can also experience such effects under certain