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.

---

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

---

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

The positions of distress calls from boats that don�t have DSC capable radios can be determined by triangulating the automatic direction finder bearings from all of the antennas receiving the signal.

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

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

From Astounding Stories, March, 1931 by Various