Soviet “Great Seal Bug” Part 2—How It Worked

Between 1945 and 1952, a carved wooden Great Seal of the United States hung in the residence of the U.S. ambassador to the Soviet Union in Moscow. The plaque had been presented to ambassador W. Averell Harriman by the Young Pioneer Organisation of the Soviet Union. Unsuspected by the Americans, the device contained a passive listening device.

In Part 1 on 2023-03-28, “Reproducing the Soviet ‘Great Seal Bug’ ”, the history of the bug, how it was presented to the U.S. ambassador, and how its presence was finally discovered are discussed. The bug inside the seal contained no battery and no active electronic components. How can a chunk of metal, however cleverly fabricated, possibly pick up conversations in its vicinity and covertly transmit them to a listening station in a different building? In this episode we learn how this was done.


How clever were the Russians who made this! This video, which I found only partly comprehensible (my bad), also reminded me of the beauty of metal machining. The process, I find to have a certain inherent aesthetics. The finished products, especially those which leave surface evidence of the machining in the form of swirls, circles, etc, I find very beautiful. Once upon a time, in my mind, I considered creating works of art consisting of various machined metal parts (along with cut or fractured glass) lighted imaginatively and variously by illumination delivered by fiberoptic threads or small bundles. These would run behind the ‘canvas’ surface and emerge so as to direct the light precisely where desired.


It was developed by Leon Theremin, while he was a slave laborer for Stalin. He coincidentally also invented the theremin: