Russian Espionage and Electromagnetic Fields: The Story of the Theremin (2017)

[1] http://www.gaudi.ch/OpenTheremin/index.php/opentheremin-v3

(If people are interested I can try to find source links, but I’m the former Co Chair of the Bob Moog Foundation.

The Guinness world record for the largest theremin concert was set by a matryomin ensemble:

https://www.youtube.com/watch?v=OnlsfeRNw1I

Every now and then, almost yearly now, the conspiracy theory scene pings one of my favourite theories: the Russkies have the electromagnetic spectrum well and truly under their grasp, and can disable any other military simply by flicking the off switch. They've discovered some way to do this, and it works every time.

Its a far-fetched and bizarre concept, and surely there are detractors and supporters of the theory - but for the sake of a thought experiment, imagine it were the case.

Would you use this capability, much?

Or, would you use it sparingly, in such a way as to avoid detection - say, introducing the odd power-cycle glitch here, maybe a spike there - just enough to keep your target occupied, but not enough that they'd wise up to so much sabotage.

I mean, you wouldn't just fly over a US destroyer/carrier fleet, and demonstrate it, overtly, naturally...

Would it instead be better for people to believe such capabilities are impossible - and if this is the case, how do we prevent a hundred years of Tesla's and Theremins' from stumbling onto the technique again, hmm...

The Thing was operating more than half a decade before it was detected, during which it listened in on 4 US ambassadors. And when they first found it they couldn't really figure out how it worked because it didn't have any electronics in it. Eventually Peter Wright at MI5 managed to reverse engineer its workings:

"To operate the device, the NKVD aimed a continuous 800MHz radio signal at the seal from a listening post in the building across from Spaso House [the embassy]. The Thing's thin diaphragm at the top [...] vibrated with the sound of a voice. Those vibrations created modulations in the reflected radio signal that bounced back to the listening post. The Thing did not require power in the same way a mirror does not require power to reflect light. The radio transmitter and receiver code-named LOSS (or REINDEER by the Russian techs), were a marvel of signal processing considering the technology available at the time." chapter 12 p. 164

It's so cool to me that there is probably amazing tech out there right now, being used for all kinds of espionage operations which we will only find out about in 30 years or so.

[0]: https://en.wikipedia.org/wiki/The_Thing_%28listening_device%...

This 'explanation' makes the instrument appear even more magical. It's less mysterious to describe it in terms of a resonant LC oscillator, where C (capacitor) value, i.e. its capacitance, is affected by the presence of hands or other conductors between the theremin plates/antennas. A sidenote, in common implementations the C change is later translated into L value, i.e inductance, change. More details [0]

Speaking of the mentioned clever espionage device. In modern days the similar principle is applied but using lasers and room's windows for vibrating surface. However, the thicker glass used in contemporary thermal packs may dampen the acoustic vibrations; still, by itself it's an acoustic resonator and the question is how sophisticated is the receiver.

[0] https://electronics.stackexchange.com/questions/11573/how-do...

Lenin died in 1924.