A radio direction finder can determine the direction from which radio signals come with great precision. By taking two or more readings from radio beacons the navigator can, by using a chart showing the location of the beacons, determine the position of own vessel. Beacons are identified by a code, often a two or three letter Morse code. The codes are shown on the charts.
The RDF can also indicate the direction to another vessel, whether the vessels are to meet, and more importantly if a vessel is in distress.
ITT Mackay Marine – 4004A
Manufactured by: ITT Mackay Marine
Radio Frequencies: 200-550KHz
Radio Corporation of America – AR-8714C
Manufactured by: Radio Corporation of America
Power Requirements: 115VAC
Radio Frequencies: 190-520KHz
C Plath Hamburg – GPE277
Manufactured by: C Plath Hamburg
Radio Frequencies: 240-540KHz, 2.12-2.24MHz
Power Requirements: 220/115VAC, 0.1/0.2 Amp or 24V/12VDC, 0.5/1.0 Amp