ADF operates in which frequency range?

ADF operates in which frequency range?

• A. 100 to 400 MHz
• B. 2 to 6 GHz
• C. 30 to 300 MHz
• D. 10 to 100 kHz

Answer: (A)

Automatic Direction Finder works by receiving radio signals to determine the direction to a beacon. In this context, the ADF is designed to operate in the VHF region, roughly 100 to 400 MHz. This range provides reliable, line-of-sight reception with reasonably compact antennas, allowing quick and accurate bearing information for navigation. Frequencies much lower (longer than 100 kHz) can involve unpredictable skywave behavior and require different hardware, while much higher frequencies (GHz range) are used for other systems and would complicate the ADF design. The 100–400 MHz span best fits the equipment’s intended design and typical navigation beacons, so it’s the appropriate range.

Automatic Direction Finder works by receiving radio signals to determine the direction to a beacon. In this context, the ADF is designed to operate in the VHF region, roughly 100 to 400 MHz. This range provides reliable, line-of-sight reception with reasonably compact antennas, allowing quick and accurate bearing information for navigation. Frequencies much lower (longer than 100 kHz) can involve unpredictable skywave behavior and require different hardware, while much higher frequencies (GHz range) are used for other systems and would complicate the ADF design. The 100–400 MHz span best fits the equipment’s intended design and typical navigation beacons, so it’s the appropriate range.