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

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

From Time Magazine Archive

With a 20-m.p.h. tail wind and guided by a direction finder at Bermuda, it hit its tiny target on the nose 4 hr.

From Time Magazine Archive

Fighting his way through the tangled shrubbery, he kept his eyes constantly on the needle of the magnetic compass he had wrenched from the direction finder.

From Astounding Stories, March, 1931 by Various