direction finder

American  

noun

Radio.

1. a receiver with a loop antenna rotating on a vertical axis, used to ascertain the direction of incoming radio waves.

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direction finder British  

noun

1. Abbreviation: D/F.   DF.  a highly directional aerial system that can be used to determine the direction of incoming radio signals, used esp as a navigation aid

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Other Word Forms

• direction finding noun

Etymology

Origin of direction finder

First recorded in 1910–15

Example Sentences

One involved Noonan doing celestial navigation; the other, her use of a radio “bearing” direction finder.

From Forbes • Nov. 10, 2014

Why would Earhart start out on such a hazardous journey without knowing how to operate her aircraft’s radio direction finder to the nth degree?

From Forbes • Nov. 10, 2014

In testing, the loud horn and red LED on the direction finder pointed us directly back within feet of the victim.

From Time Magazine Archive

Said the pilot: "They must have had good equipment, including a direction finder, to pick up my transmission that quickly."

From Time Magazine Archive

Otherwise, the Federal Communications Commission would pick you up, use a direction finder, and move in on your operation.

From The Electronic Mind Reader by Blaine, John