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

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

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

From Forbes • Nov. 10, 2014

Best known is his Learmatic Navigator, a combined automatic radio direction finder and directional gyro, for which he got the Frank Hawks Memorial Award last December.

From Time Magazine Archive

She still gave no position and the Itasca's direction finder could not get a bearing because she had failed to adjust her radio to its frequency.

From Time Magazine Archive

If only he could find—but there it was: a direction finder.

From Astounding Stories, March, 1931 by Various