Which type of modulation is most commonly used for VHF and UHF voice repeaters?

Which type of modulation is most commonly used for VHF and UHF voice repeaters?

• A. Phase modulation
• B. Frequency modulation or Phase modulation
• C. Digital modulation
• D. Single sideband

Answer: (B)

Frequency modulation is the most commonly used type of modulation for VHF and UHF voice repeaters due to its ability to provide better sound quality and greater resistance to noise and interference compared to other modulation types. When using frequency modulation, variations in the amplitude of the audio signal are translated into variations in the frequency of the carrier wave. This results in a more robust signal, which is particularly beneficial for voice communications where clarity is crucial. In the context of VHF and UHF communication, repeaters are strategically placed to expand the range of radio signals, and frequency modulation's characteristics allow for improved audio fidelity over greater distances. Thus, when voice signals are transmitted over these frequencies, frequency modulation is preferred over other methods, leading to fewer dropouts and clearer audio. While phase modulation might also be used in some scenarios, frequency modulation is the standard for voice repeaters in these bands, making it the most applicable choice here. Digital modulation and single sideband are more commonly associated with different applications and modes of operation, primarily in data transmission or long-distance communication, rather than standard voice communications.

Frequency modulation is the most commonly used type of modulation for VHF and UHF voice repeaters due to its ability to provide better sound quality and greater resistance to noise and interference compared to other modulation types. When using frequency modulation, variations in the amplitude of the audio signal are translated into variations in the frequency of the carrier wave. This results in a more robust signal, which is particularly beneficial for voice communications where clarity is crucial.

In the context of VHF and UHF communication, repeaters are strategically placed to expand the range of radio signals, and frequency modulation's characteristics allow for improved audio fidelity over greater distances. Thus, when voice signals are transmitted over these frequencies, frequency modulation is preferred over other methods, leading to fewer dropouts and clearer audio.

While phase modulation might also be used in some scenarios, frequency modulation is the standard for voice repeaters in these bands, making it the most applicable choice here. Digital modulation and single sideband are more commonly associated with different applications and modes of operation, primarily in data transmission or long-distance communication, rather than standard voice communications.