- Thing (listening device)
The Thing, also known as The Great Seal bug, was one of the first
covert listening device s (or "bugs") to use passiveelectromagnetic induction to transmit an audio signal.Operating principles
The Thing was very simple by today's standards, but ingenious. It consisted of a tiny capacitive membrane (a
condenser microphone ) connected to a small quarter-wavelength antenna; it had no power supply or active electronic components. The device, a passivecavity resonator , became active only when 330 MHzmicrowave s were beamed to the device from an external transmitter. Sound waves caused the microphone to vibrate, which varied thecapacitance "seen" by the antenna, which in turn modulated the microwaves that struck and were reflected by "The Thing". A receiver decoded the modulated microwave signal so the sound that the microphone picked up could be heard, in the same way that an ordinaryradio decodes modulatedradio waves into sound.Theremin's design made the listening device very difficult to detect, because it was very small, had no power supply or active components, and did not radiate any signal unless it was actively being powered and listened to remotely. These same design features plus the overall simplicity of the device made it very reliable and gave a potentially unlimited operational life. Assuming that the device had never been discovered, it could easily have worked for 50 years or more.
Use in espionage
Theremin's device was embedded in a carved wooden plaque of the
Great Seal of the United States . OnAugust 4 ,1945 , Soviet school children presented the bugged carving to U.S.Ambassador Averell Harriman , as a "gesture of friendship" to the USSR'sWorld War II ally. It hung in the ambassador’s Moscow residential office until it was exposed in 1952 during the tenure of AmbassadorGeorge F. Kennan [George F. Kennan, Memoirs, 1950-1963, Volume II (Little, Brown & Co., 1972), pp. 155, 156] . It was then that the existence of the bug was accidentally discovered by a British radio operator who overheard American conversations on an open radio channel as the Russians were beaming microwaves at the ambassador's office. TheCIA found the device in the Great Seal carving after an exhaustive search of the American Embassy, andPeter Wright , a Britishscientist and formerMI5 counterintelligence officer, eventually discovered how it worked. [cite web|last=Murray|first=Kevin|title=THE GREAT SEAL BUG STORY|url=http://www.spybusters.com/Great_Seal_Bug.html|accessdate=2007-03-24] [cite web|last=Davis|first=Henry|title=Eavesdropping using microwaves - addendum|url=http://www.audiodesignline.com/howto/173602214|accessdate=2007-03-24]United Nations
On the fourth day of meetings in the
United Nations Security Council , convened by the Soviet Union over the1960 U-2 incident where a US spy plane had entered their territory and been shot down, the US ambassador showed off the bugging device in the Great Seal to illustrate that spying incidents between the two nations were mutual and to allege thatNikita Khrushchev had magnified this particular incident under discussion out of all proportion as a pretext to abort the1960 Paris Summit .UN document |docid=S-PV-860 |type=Verbatim Report |body=Security Council |meeting=860 |highlight=rect_155,148_530,482/rect_453,130_530,148 |page=15 |accessdate=2008-08-29|date=26 May 1960 ]Notes
References
* cite book
last = Wright
first = Peter
authorlink = Peter Wright
title = Spycatcher: The Candid Autobiography of a Senior Intelligence Officer
year = 1987
publisher = Viking
location = New York
id = ISBN 0-670-82055-5
* cite book
last = Kennan
first = George
authorlink = George F. Kennan
title = Memoirs, 1925-1950
year = 1967
publisher = Little, Brown
* cite book
last = Kennan
first = George
authorlink = George F. Kennan
title = Memoirs: 1950–1963
year = 1983
publisher = Pantheon
id = ISBN 978-0394716268
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