VHF
Understanding VHF
VHF was the first frequency range widely exploited for commercial broadcasting and mobile communications. Its favorable propagation characteristics (good range, moderate building penetration) and practical antenna sizes made it ideal for early radio and television broadcasting.
VHF Applications
| Service | Frequency |
|---|---|
| FM broadcast | 88-108 MHz |
| TV Ch 2-6 | 54-88 MHz |
| TV Ch 7-13 | 174-216 MHz |
| Aircraft voice | 118-137 MHz |
| Marine VHF | 156-162 MHz |
| Amateur 2m | 144-148 MHz |
| Public safety | 150-174 MHz |
Wavelength: 10 - 1 m
Half-wave dipole at 100 MHz: 1.5 m
Half-wave dipole at 144 MHz: 1.04 m
Propagation: line-of-sight + diffraction
Range: 30-100 km (elevated antennas)
Frequently Asked Questions
What is VHF?
VHF covers 30-300 MHz. It is used for FM radio, TV broadcasting, aviation and marine communications, amateur radio, and public safety. VHF wavelengths (1-10 m) require larger antennas than UHF but provide reliable line-of-sight coverage.
What is the difference between VHF and UHF?
VHF (30-300 MHz) has longer wavelengths, better diffraction around obstacles, and fewer channels. UHF (300-3000 MHz) has more bandwidth, supports more services, and provides better in-building coverage for some applications. Most modern wireless services use UHF.
Why is VHF used for aviation?
VHF aviation communications (118-137 MHz) provide reliable air-to-ground coverage over long distances due to the clear line-of-sight path from aircraft altitude. The propagation is very predictable, which is critical for safety-of-life communications.