The codename Tinsel referred to a type of equipment carried by

RAF The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and ...

bombers A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped from an aircraf ...

and used for jamming

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

night-fighter A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time after the Second World War) is a fighter aircraft adapted for use at night or in other times of bad visibility. Night fighters began to be used i ...

controller's speech

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

-frequencies during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. The equipment consisted of an

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum *Digital audio, representation of sound ...

microphone A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...

mounted inside one of the bomber's engine

nacelle A nacelle ( ) is a "streamlined body, sized according to what it contains", such as an engine, fuel, or equipment on an aircraft. When attached by a pylon entirely outside the airframe, it is sometimes called a pod, in which case it is attached ...

s, the output of which fed into the aircraft's standard T1154 radio

transmitter In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna (radio), antenna. The transmitter itself generates a radio frequency alternating current, which i ...

. The

wireless operator A radio operator (also, formerly, wireless operator in British and Commonwealth English) is a person who is responsible for the operations of a radio system. The profession of radio operator has become largely obsolete with the automation of ra ...

could listen in to the frequencies used by the defending forces and then, when he heard a German transmission, tune his transmitter into the Luftwaffe frequency and transmit the amplified engine-noise on the same frequency, thus jamming the enemy transmission. Although not very effective as a jammer, the noise produced merely acted as background noise to the transmitted speech, Tinsel did have the effect of making the night-fighter crew's job of distinguishing the instructions received from the ground more difficult.

See also