Definition
A unit of frequency equal to one thousand cycles per second (1,000 Hz). Used to express the frequency of electrical signals, radio waves, and oscillations, particularly in the lower and medium radio frequency bands.
Plain English
A measurement of how fast something cycles or repeats, where one kilohertz means one thousand cycles every second.
Context Anchor
Seen in avionics information, electrical system descriptions, radio equipment data, and maintenance test procedures when a frequency is given.
Derivation
From 'kilo-' (Greek 'chilioi', meaning thousand) plus 'hertz', named after German physicist Heinrich Hertz, who first proved the existence of radio waves in the 1880s. So kilohertz literally means 'a thousand Hertz' — a thousand cycles per second.
Why Pilots Care
Certain navigation beacons and low-frequency radios are tuned and identified using frequencies in kHz.
Analogy
It is like kilometers compared with meters: 1 kilometer is 1,000 meters, and 1 kilohertz is 1,000 hertz.
Intuition Check
Do not treat kHz as a specific frequency by itself. It is a unit that tells you the number is in thousands of cycles per second.
Example Sentence 1
Example Sentence 2
Some older marker beacons operated on frequencies measured in kHz.