What bands does ADF operate on?

What bands does ADF operate on?

• A. High frequency bands only.
• B. Low and medium frequency radio bands.
• C. Very high frequency bands.
• D. Ultrasonic bands.

Answer: (B)

ADF relies on signals from non-directional beacons that broadcast on the low-frequency and medium-frequency radio bands. Those LF/MF signals are what the ADF receiver uses, with its loop antenna, to determine the bearing to the beacon and provide a navigational line toward the NDB. The high-frequency and very high-frequency bands are used by other navigation aids (like VOR/ILS) or for different purposes, and ultrasonic bands are not used for aviation radio navigation. So ADF operates on the low and medium frequency radio bands.

ADF relies on signals from non-directional beacons that broadcast on the low-frequency and medium-frequency radio bands. Those LF/MF signals are what the ADF receiver uses, with its loop antenna, to determine the bearing to the beacon and provide a navigational line toward the NDB. The high-frequency and very high-frequency bands are used by other navigation aids (like VOR/ILS) or for different purposes, and ultrasonic bands are not used for aviation radio navigation. So ADF operates on the low and medium frequency radio bands.