Soviets attempted to repeat this in the 80s when passive eavesdropping devices were embedded into concrete slabs and columns used in a construction of new US embassy and supplied by local contractors [1].<p>From what I remember the case lingered well into Perestroika period when complete documentation on this project was passed to the Americans as a gesture of "goodwill and friendship", presumably in exchange for chicken leg imports (aka "Bush legs") and other Western luxuries.<p>[1] <a href="https://www.nytimes.com/1988/11/15/world/the-bugged-embassy-case-what-went-wrong.html" rel="nofollow">https://www.nytimes.com/1988/11/15/world/the-bugged-embassy-...</a>
If you are a high ranking government official and receive a gift that you want to keep in your office, then make a replica, and put <i>that</i> on your wall instead.
The creator is interesting:<p><a href="https://en.wikipedia.org/wiki/Léon_Theremin" rel="nofollow">https://en.wikipedia.org/wiki/Léon_Theremin</a><p>And his most famous creation:<p><a href="https://en.wikipedia.org/wiki/Theremin" rel="nofollow">https://en.wikipedia.org/wiki/Theremin</a>
Lev Termen is a legend. His work and inventions (as a young engineer; under Ioffe; in prison, etc) shows a huge breadth. Such coupling of talent in physics and engineering has always been rare.
For a moment I was so excited. I thought my favorite road trip oddity made it to HN.<p><a href="https://en.wikipedia.org/wiki/The_Thing_(roadside_attraction)" rel="nofollow">https://en.wikipedia.org/wiki/The_Thing_(roadside_attraction...</a>
I always wonder why open source mass surveillance isn't in fuller swing. Imagine a Kickstarter for $2 credit card-sized disposable listening devices which can mesh network for autocorrelated quality-enhancing signal reconstruction and 3d localization. They could be hidden behind objects and hard to detect. With a cellularly connected golf ball-sized gateway, they could egress data or receive updates. At this price point, there would be even less harbor from clandestine listening.
Maybe someday the Soviet side of things will be declassified, and we can read the technical account from that end. Would be interesting.<p>There seem to be some technical unknowns in the article. I don’t think you can get FM back from the passive cavity, just AM, unless you can pump the cavity with feedback. Same goes for re-radiating at a harmonic. Maybe if the Q of the cavity were super high. Again, would be interesting to see the technical details of the receiving equipment.
First stumpled upon this because it's mentioned in the slides of <a href="https://idlewords.com/talks/our_comrade_the_electron.htm" rel="nofollow">https://idlewords.com/talks/our_comrade_the_electron.htm</a>
I wonder if there are any uses for mechanically modulated retroreflectors today. NASA is investigating fully mechanical rovers for Venus because semiconductors do not work very well at Venusian temperatures while mechanical devices do[0]. To get data back from a fully mechanical device they propose to use retroreflectors. Although the bandwidth they can achieve with their approaches, using semaphore messaging with retroreflectors and looking at the doppler shift provided by spinning disks, is low. Perhaps by using a device like the thing they could transmit data at acoustic rates. I am also curious if there are more down to earth applications for devices like the thing other than espionage.
[0]<a href="https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170002798.pdf" rel="nofollow">https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/201700...</a>
It seems like with recent meta-material advances, you could create an object that was a hidden bug, without any hidden parts. Like if you tuned one of those metal concentric ring windchimes just right, it could modulate a radio signal based on acoustic vibrations.
The description of the operation of this thing always seems incomplete. From the Wikipedia article:<p>>The length of the antenna and the dimensions of the cavity were engineered in order to make the re-broadcast signal a higher harmonic of the illuminating frequency.<p>That wouldn't actually work by itself. There would have to be some sort of non-linear element to cause the harmonics. Chances are there was something like a varactor in there. The original technical description probably omitted critical details because spooks are like that...
It isn't hard to imagine that the recent occurrence of mysterious illnesses at US and Canadian embassies (news.ycombinator.com/item?id=17891427) may be related to this. Perhaps they are activating or experimenting with some new type of device. Given that the Theremin type of device confounded detection for years we probably won't actually know for a while.
Yeah... theramin's bug. This is a great story! What a brilliant example of passively powered electronics from 75 years ago. Now it's all the rage to build this king of functionality into passive sensors, etc.
> The device, a passive cavity resonator, became active only when a radio signal of the correct frequency was sent to the device from an external transmitter.<p>Super interesting, especially given this was early 1940s.
and now..just imagine what China has been listening to on all the cells sent out from their factories into our homes ;-) Privacy & Secrets are soo 2000.