425:: "I produced a wooden carving of the Great Seal of the United States which was given by some Russians to the United States Ambassador to the Soviet Union and which hung in his office behind his desk, and which contained an electronic device which made it possible for persons on the outside possessing a certain type of technical device to hear everything that went on. I produced that as a piece of evidence, and it is direct, fresh, authentic evidence, to show the effectiveness and the thoroughness of Soviet espionage."
31:
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192:(FM) for the re-radiated signal. The post had machined grooves and radial lines into its face, probably to provide channels for air flow to reduce pneumatic damping of the membrane. The antenna was capacitively coupled to the post via its disc-shaped end. The total weight of the unit, including the antenna, was 1.1 ounces (31 grams).
351:
The simplicity of the device caused some initial confusion during its analysis; the antenna and resonator had several resonant frequencies in addition to its main one, and the modulation was partially both amplitude modulated and frequency modulated. The team also lost some time on an assumption that
294:
who overheard
American conversations on an open Soviet Air Force radio channel as the Soviets were beaming radio waves at the ambassador's office. An American State Department employee was then able to reproduce the results using an untuned wideband receiver with a simple diode detector/demodulator,
114:
Its design made the listening device very difficult to detect, because it was very small, had no power supply or active electronic components, and did not radiate any signal unless it was actively being irradiated remotely. These same design features, along with the overall simplicity of the device,
402:(PEs) were developed for the CIA as a result of the research. In 1965, the NRP finally got a reliably working pulsed cavity resonator, but by that time the CIA was no longer interested in passive devices, largely because of the high levels of RF energy involved to activate them.
180:, or 75 micrometers) and fragile conductive membrane. In the middle of the cavity was a mushroom-shaped flat-faced tuning post, with its top adjustable to make it possible to set the membrane-post distance; the membrane and the post formed a variable capacitor acting as a
210:(see below); accounts differ on whether holes were drilled into the beak to allow sound waves to reach the membrane. Other sources say the wood behind the beak was undrilled but thin enough to pass the sound, or that the hollowed space acted like a
397:
research contract and were known as Easy Chair Mark I (1955), Mark II (1956), Mark III (1958), Mark IV (1961) and Mark V (1962). Although initially they could not get the resonant cavity microphone to work reliably, several products involving
98:
parlance as "illuminating" a passive device. Sound waves (from voices inside the ambassador's office) passed through the thin wood case, striking the membrane and causing it to vibrate. The movement of the membrane varied the
143:
is most likely, equivalent to a wavelength of 91 cm). It used a straight rod, led through an insulating bushing into a cavity, where it was terminated with a round disc that formed one plate of a capacitor. The cavity was a
298:
Two additional State
Department employees, John W. Ford and Joseph Bezjian, were sent to Moscow in March 1951 to investigate this and other suspected bugs in the British and Canadian embassy buildings. They conducted a
565:
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factor was one of the engineering priorities, as this allowed higher selectivity to the illuminating signal frequency, and therefore increased operating distance and also higher acoustic sensitivity.
345:
officer, ran the investigation. He was able to get The Thing working reliably with an illuminating frequency of 800 MHz. The generator which had discovered the device was tuned to 1800 MHz.
68:, on August 4, 1945. Because it was passive, needing electromagnetic energy from an outside source to become energized and active, it is considered a predecessor of radio-frequency identification (
818:
1390:
360:
Wright's examination led to development of a similar
British system codenamed SATYR, used throughout the 1950s by the British, Americans, Canadians and Australians.
363:
There were later models of the device, some with more complex internal structure (the center post under the membrane attached to a helix, probably to increase the
1395:
251:
65:
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the signal so that sound picked up by the microphone could be heard, just as an ordinary radio receiver demodulates radio signals and outputs sound.
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frequencies, but it was also able to act as half-wave or full-wave ; the accounts differ. Given the radio technology of the time, the frequency of
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311:("howl") if the sound from the room is transmitted on a given frequency. During this sweep, Bezjian found the device in the Great Seal carving.
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showed off the bugging device in the Great Seal to illustrate that spying incidents between the two nations were mutual and to allege that
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The length of the antenna and the dimensions of the cavity were engineered in order to make the re-broadcast signal a higher
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The membrane of The Thing was extremely thin, and was damaged during handling by the
Americans; Wright had to replace it.
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56:(or "bugs") to use passive techniques to transmit an audio signal. It was concealed inside a gift given by the
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signal of the correct frequency was sent to the device from an external transmitter. This is referred to in
53:
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in the
Netherlands from 1954 to approximately 1967 to create its own covert listening devices based on a
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presented the bugged carving to
Ambassador Harriman, as a "gesture of friendship" to the Soviet Union's
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and other U.S. agencies analyzed the device, along with assistance from the
British government agency
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the distance between the membrane and the tuning post needed to be increased to increase resonance.
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235:, an electronic musical instrument. In Russian, the device is called Эндовибра́тор (endovibrator).
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819:"Operatie Leunstoel: hoe een klein Nederlands bedrijf de CIA hielp om de Russen af te luisteren"
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The existence of the bug was discovered accidentally in 1951 by a
British radio operator at the
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George F. Kennan, Memoirs, 1950–1963, Volume II (Little, Brown & Co., 1972), pp. 155, 156
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where a U.S. spy plane had entered their territory and been shot down. The U.S. ambassador
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790: page 15. 26 May 1960. Retrieved 2008-08-29.; see also less-broken link
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History of the Bureau of
Diplomatic Security of the United States Department of State
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The original device was located with the can under the beak of the eagle on the
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Replica of The Thing which contained a Soviet bugging device, on display at the
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for seven years, until it was exposed in 1952 during the tenure of
Ambassador
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the radio waves that struck and were re-transmitted by the Thing. A receiver
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made it very reliable and gave it a potentially unlimited operational life.
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In May 1960, The Thing was mentioned on the fourth day of meetings in the
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Passive Resonant Cavity & "Spycatcher" Technical Surveillance Devices
364:
232:
196:
145:
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and a small microphone amplifier. The devices were developed under the
75:
The Thing consisted of a tiny capacitive membrane connected to a small
278:
The seal opened exposing the Soviet bugging device, on display at the
882:
Spycatcher: The Candid Autobiography of a Senior Intelligence Officer
381:
ran a secret research program at the Dutch Radar Laboratory (NRP) in
246:
to spy on the US. On August 4, 1945, several weeks before the end of
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136:
122:
91:
29:
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had magnified this particular incident as a pretext to abort the
148:
round silver-plated copper "can", with the internal diameter of
69:
941:
625:"Design How-To: Eavesdropping using microwaves – addendum"
339:
327:
279:
140:
95:
35:
492:
Hacking Exposed Linux: Linux Security Secrets & Solutions
937:
214:
to concentrate the sound from the room onto the microphone.
496:(third ed.). McGraw-Hill Osborne Media. 2008. p.
258:. It hung in the ambassador's Moscow residential study at
932:
How the Soviet Union spied on the US embassy for 7 years
238:
The device, embedded in a carved wooden plaque of the
793:"United Nations Security Council Verbatim Report 860"
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131:The device consisted of a 9-inch-long (23 cm)
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227:The Thing was designed by Soviet Russian inventor
176:. Its front side was closed with a very thin (3
922:– Security Management, Ken Stanley, April 2010
526:"The Cold War spy technology which we all use"
252:Young Pioneer Organization of the Soviet Union
953:
545:
543:
8:
657:, University of Illinois Press, Urbana, 2000
303:"sweep" of the ambassador's office, using a
66:United States Ambassador to the Soviet Union
960:
946:
938:
575:. Vol. 14, no. 14–17. p. 35
566:"The eavesdroppers:'Fallout' from R&D"
307:and a receiver in a setup that generates
605:. Vol. 77, no. 3–6. p. 23
409:, convened by the Soviet Union over the
481:
295:similar to some field strength meters.
127:Design of The Thing's cavity resonator.
1210:Chinese espionage in the United States
231:, best known for his invention of the
934:, Hackaday, Adam Fabio, December 2015
817:Maurits Martijn (24 September 2015).
741:"Easy Chair covert listening devices"
455:Soviet espionage in the United States
103:"seen" by the antenna, which in turn
7:
1396:Soviet Union intelligence operations
1391:Soviet Union–United States relations
1205:Chinese intelligence activity abroad
1271:Interpersonal (HUMINT) intelligence
691:from the original on March 12, 2016
655:Theremin: Ether Music and Espionage
553:. Crypto Museum. 23 September 2021.
25:
1106:Computer and network surveillance
1141:Short-range agent communications
928:, October 2011, pp. 136–137
338:, a British scientist and later
776:United Nations Security Council
407:United Nations Security Council
316:Federal Bureau of Investigation
240:Great Seal of the United States
199:of the illuminating frequency.
1:
916:, Spybusters, Kevin D. Murray
821:(in Dutch). De Correspondent.
168:in (17.5 mm) long, with
564:Pursglove, S. David (1966).
158:in (19.7 mm) and about
90:, became active only when a
84:active electronic components
82:; it had no power supply or
1386:Inventions by Léon Theremin
685:"The Great Seal Bug Part 1"
445:Nonlinear junction detector
320:Central Intelligence Agency
284:National Cryptologic Museum
40:National Cryptologic Museum
18:Passive resonant cavity bug
1422:
687:. Murray Associates TSCM.
596:"Electronic Eavesdropping"
594:Brown, Robert. M. (1967).
551:"The Thing Great Seal Bug"
799:. 26 May 1960. p. 16
759:"Pulsed Cavity Resonator"
324:Naval Research Laboratory
1361:Covert listening devices
914:The Great Seal Bug Story
250:, a delegation from the
86:. The device, a passive
54:covert listening devices
1091:Covert listening device
1061:Intelligence assessment
52:, was one of the first
27:Covert listening device
683:Murray, Kevin (n.d.).
629:EE Times (Eetimes.com)
287:
135:(quarter-wave for 330
128:
42:
1340:Targeted surveillance
795:(S/PV.860 ed.).
633:United Business Media
415:Henry Cabot Lodge Jr.
334:. Marconi technician
277:
188:(AM), with parasitic
126:
33:
1376:Espionage techniques
1266:Industrial espionage
1066:competing hypotheses
886:. New York: Viking.
190:frequency modulation
186:amplitude modulation
182:condenser microphone
343:counterintelligence
301:countersurveillance
208:W. Averell Harriman
62:W. Averell Harriman
1217:Cold War espionage
1184:Front organization
1158:Surveillance tools
1136:Phone surveillance
1131:One-way voice link
1086:Concealment device
858:Memoirs: 1950–1963
844:Memoirs, 1925–1950
635:. 12 November 2005
524:(21 August 2019).
370:). Maximizing the
288:
242:, was used by the
129:
77:quarter-wavelength
50:the Great Seal bug
43:
1371:Espionage devices
1348:
1347:
1002:Agent provocateur
867:978-0-394-71626-8
653:Glinsky, Albert,
603:Electronics World
573:Electronic Design
507:978-0-07-226257-5
423:1960 Paris Summit
419:Nikita Khrushchev
411:1960 U-2 incident
244:Soviet government
16:(Redirected from
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1406:Diplomatic gifts
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848:. Little, Brown.
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765:. 30 March 2017.
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747:. 30 March 2017.
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400:passive elements
330:and the British
305:signal generator
264:George F. Kennan
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133:monopole antenna
88:cavity resonator
48:, also known as
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729:. 2 July 2017.
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391:detector diode
387:dipole antenna
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309:audio feedback
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184:and providing
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1401:Surveillance
1323:Surveillance
1111:Cyber spying
1096:Cryptography
1035:Resident spy
1020:Double agent
1000:
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860:. Pantheon.
857:
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812:
801:. Retrieved
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726:
723:"Easy Chair"
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693:. Retrieved
662:
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639:24 September
637:. Retrieved
628:
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609:12 September
607:. Retrieved
602:
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579:12 September
577:. Retrieved
572:
559:
530:. Retrieved
522:Harford, Tim
516:
491:
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470:Trojan Horse
404:
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362:
359:
350:
347:
336:Peter Wright
313:
297:
289:
248:World War II
237:
226:
201:
194:
172:of about 10
130:
113:
74:
58:Soviet Union
49:
45:
44:
1313:Stay-behind
1222:Recruitment
1179:Canary trap
1077:Devices and
1025:Field agent
532:17 February
260:Spaso House
174:nanohenries
109:demodulated
101:capacitance
1355:Categories
1308:Sexpionage
1288:COINTELPRO
1281:safe house
1261:False flag
1198:Operations
1172:techniques
1168:Tradecraft
830:References
803:2024-04-02
528:. BBC News
450:Ragemaster
395:Easy Chair
212:soundboard
204:Great Seal
170:inductance
1366:Espionage
1232:black bag
1116:Dead drop
1045:Spymaster
969:Espionage
695:4 January
383:Noordwijk
356:Aftermath
270:Discovery
137:megahertz
105:modulated
46:The Thing
1298:SHAMROCK
1151:microdot
1054:Analysis
878:(1987).
856:(1983).
840:(1967).
788:S/PV.860
689:Archived
429:See also
256:war ally
233:theremin
223:Creation
197:harmonic
1293:MINARET
1237:wetwork
786:.
465:TEMPEST
389:with a
218:History
163:⁄
153:⁄
141:330 MHz
80:antenna
1328:Global
1254:MASINT
1249:SIGINT
1101:Cutout
985:Assets
980:Agents
890:
864:
782:
504:
368:factor
322:, the
146:high-Q
119:Design
64:, the
1013:Agent
1008:Cover
778:
599:(PDF)
569:(PDF)
476:Notes
92:radio
1333:Mass
1303:FVEY
1030:Mole
888:ISBN
862:ISBN
697:2022
641:2013
611:2021
581:2021
534:2020
502:ISBN
377:The
314:The
178:thou
70:RFID
1381:KGB
1170:and
784:860
498:298
379:CIA
340:MI5
328:MI5
282:'s
280:NSA
96:NSA
60:to
38:'s
36:NSA
1357::
761:.
743:.
725:.
671:^
631:.
627:.
601:.
571:.
542:^
500:.
318:,
266:.
165:16
161:11
155:40
151:31
961:e
954:t
947:v
896:.
870:.
806:.
699:.
643:.
613:.
583:.
536:.
510:.
372:Q
366:Q
286:.
20:)
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