What is VHF/UHF Operation? Exploring the World Above HF

VHF (Very High Frequency) and UHF (Ultra High Frequency) operation in amateur radio refers to communication on frequencies above the traditional High Frequency (HF) bands. These bands offer unique characteristics and opportunities for amateur radio enthusiasts, distinct from the long-distance capabilities of HF.  

Key Characteristics and Applications:
  • Frequency Ranges:
    • VHF typically encompasses frequencies from 30 MHz to 300 MHz.
    • UHF covers frequencies from 300 MHz to 3 GHz.  

 

  • Line-of-Sight Propagation:
    • VHF and UHF signals generally travel in a straight line, limiting communication range to the horizon or “line-of-sight.”  
    • This characteristic makes them ideal for local and regional communication.

 

  • Repeaters:
    • Repeaters are a crucial component of VHF/UHF operation.
    • These automated relay stations extend communication range by receiving signals on one frequency and retransmitting them on another.  
    • Repeaters are often located on high elevations to maximize coverage.  

 

  • Simplex Operation:
    • Simplex operation involves direct communication between two stations on the same frequency, without the use of a repeater.  
    • This mode is commonly used for short-range communication.

  

  • Mobile and Portable Operation:
    • VHF/UHF is widely used for mobile communication from vehicles and portable operation from handheld radios.  
    • This makes it ideal for public service events, emergency communications, and outdoor activities.

 

  • Digital Modes:
    • Digital modes like packet radio, APRS (Automatic Packet Reporting System), and digital voice modes (e.g., DMR, D-STAR, Fusion) are prevalent on VHF/UHF.  
    • These modes enable data communication, location tracking, and clear digital voice transmissions.

 

  • Satellite Communication:
    • VHF/UHF frequencies are also used for satellite communication, allowing operators to make contact with stations around the world via amateur radio satellites.  

 

  • Specialized Applications:
    • VHF/UHF is used for specialized applications like amateur television (SSTV), microwave communication, and experimental projects. 
Advantages of VHF/UHF Operation:
  • Local and Regional Communication:
    • Provides reliable communication within a local or regional area.

 

  • Mobile and Portable Convenience:
    • Enables communication while on the move or from remote locations.

 

  • Digital Communication Capabilities:
    • Offers diverse digital modes for data and voice transmission.

 

  • Emergency Communication Support:
    • Plays a vital role in emergency communications, especially for local coordination.

 

  • Simpler antenna systems:
    • Due to the shorter wavelengths, antenna systems are often much smaller than HF antenna systems.

 

VHF/UHF operation provides a dynamic and engaging aspect of amateur radio, offering opportunities for local communication, digital exploration, and public service. It’s an essential part of the amateur radio experience.