What is the approximate bandwidth of a VHF repeater FM voice signal?

• A. 2 to 5 kHz
• B. 5 to 10 kHz
• C. Between 10 and 15 kHz
• D. 15 to 20 kHz

Answer: (C)

The bandwidth of a VHF repeater FM voice signal typically falls within the range of 10 to 15 kHz. This range is based on the technical characteristics of frequency modulation (FM) used for voice communications. In FM systems, the bandwidth is determined by the modulation index and the signal's deviation from the center frequency. For VHF (Very High Frequency) bands, a standard FM voice signal occupies around this bandwidth, allowing for clear audio quality while minimizing interference with adjacent channels.

The values you've seen in other options are either too narrow or too expansive for FM voice communications in the VHF range. A bandwidth between 2 to 5 kHz would be too limited for the fidelity needed in voice communications, while 15 to 20 kHz exceeds the typical requirements for VHF FM voice, which is designed to deliver effective communication with efficient use of spectrum space. The 10 to 15 kHz bandwidth ensures adequate audio quality while fitting within the design specifications for most VHF FM repeaters.