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, similar to some field strength meters. 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 countersurveillance "sweep" of the ambassador's office, using a signal generator and a receiver in a setup that generates audio feedback ("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. The Federal Bureau of Investigation, Central Intelligence Agency, the Naval Research Laboratory and other U.S. agencies analyzed the device, along with assistance from the British government agency MI5 and the British Marconi Company. Marconi technician Peter Wright, a British scientist and later MI5 counterintelligence 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. The membrane of The Thing was extremely thin, and was damaged during handling by the Americans; Wright had to replace it. 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 the distance between the membrane and the tuning post needed to be increased to increase resonance. Aftermath Wright's examination led to development of a similar British system codenamed SATYR, used throughout the 1950s by the British, Americans, Canadians and Australians. 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 Q). Maximizing the Q''-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. The CIA ran a secret research program at the Dutch Radar Laboratory (NRP) in Noordwijk in the Netherlands from 1954 to approximately 1967 to create its own covert listening devices based on a dipole antenna with a detector diode and a small microphone