Quindar tones, most often referred to as the "beeps" that were heard during the American Apollo space missions, were a means by which remote transmitters on Earth were turned on and off so that the Capsule communicator (CapCom) could communicate with the crews of the spacecraft. It was a means of in-band signaling to simulate the action of the push to talk-release to listen (commonly referred to as PTT) button commonly found on walkie-talkies.
Read more about Quindar Tones: The Need For Quindar Tones, Implementation of Quindar Tones, Common Misconceptions About Quindar Tones, Origin of The Name
Famous quotes containing the word tones:
“And this mighty master of the organ of language, who knew its every stop and pipe, who could awaken at will the thin silver tones of its slenderest reeds or the solemn cadence of its deepest thunder, who could make it sing like a flute or roar like a cataract, he was born into a country without literature.”
—Willa Cather (1873–1947)