Theremin's Bug Let Soviets Spy On USA For More Than 7 Years (hackaday.com)

szczys writes: Theremin, yes the same Theremin who built the instrument that made the Star Trek theme song famous, had a hand in espionage as well. Albeit not a willing one. Turns out his life is actually quite tragic. In addition to that story, Adam Fabio takes a trip through the details of "The Thing", a bug installed in the US Embassy by the Soviet Union during the cold war. It used no batteries, instead depending on a carrier frequency transmitted by the "listener", causing the resonant cavity to transmit back the audio from the room at a higher frequency. Pretty nifty, and so was the hiding place: a hand-carved wooden seal of the United States. Beware Greeks Bearing Gifts, right?

Comments

oblig. FTFY

[NotQuiteReal]

Beware Geeks Bearing Gifts

Engineer should have written the article

[mykepredko]

I cringed at the sentence "Receive tuning (if it can be called such) was achieved by the precisely cut antenna." which is actually how EVERY radio is tuned; the antenna is a component of the resonant circuit which forms the receiver.

I've read about the bugged seal for years, when I was a kid it was used as an example how how nasty Soviets could never be trusted. It's an interesting story - but honestly, the story of the US embassy built in Moscow in the early 1980s is much more interesting. I knew two people involved with the analysis of the building and it's a fascinating case of hubris. The US felt that they could detect any passive resonant cavity devices using the same techniques they used for "The Thing" and, more importantly, for active radios, they could detect them by a non-linear junction detector (https://en.wikipedia.org/wiki/Nonlinear_junction_detector) which finds the P-N junctions of diodes and transistors.

The Soviets, knowing this, simply dumped a bunch of diodes in the concrete used for the building meaning that everywhere in the building, the diodes would be found and could not be distinguished from any other electronic devices in the building making the search for bugging devices impossible.

My friends spent several months chipping at the concrete walls of the embassy and never found any listening devices, just diodes which were labouriously separated from the concrete. It's interesting to see articles of the day (http://www.nytimes.com/1988/11/15/world/the-bugged-embassy-case-what-went-wrong.html?pagewanted=all & http://articles.latimes.com/19...) claiming that listening devices were found in the building but what I was told was that there were a few pieces of rebar which were not properly installed and about $500 worth of diodes mixed into the concrete. The claims of listening devices are most likely exaggerated to lessen the embarrassment that the Soviets had pulled over such a big coup over on the US for what amounts to petty cash.