When selected, which radio has an ADF option that provides pilots with active direction finding signals?

• A. UHF 1
• B. UHF 2
• C. VHF 1
• D. HF 3/4

Answer: (A)

Automatic Direction Finder (ADF) gives pilots a bearing to a ground-based beacon, typically an NDB, by using a directional sense/loop antenna. When you select the ADF option on a navigation radio, the system tunes to the beacon frequency and displays the relative bearing, giving you active direction finding signals to steer toward or away from the beacon.

In this setup, the radio that includes the ADF capability is the UHF 1 unit. The other radios shown (UHF 2, VHF 1, HF 3/4) are configured for voice communications or long-range HF operations and do not provide the ADF bearing function. So the UHF 1 radio is the one that supplies the ADF bearing information to pilots.