The Thing (opens in new tab)

I’m convinced that the government doesn’t believe citizens are any more loyal or hard to bribe than other people, but insisting on citizenship would make it easier to charge us with particular crimes if the need arose.

Apparently, during the construction of the embassy in (edit: Moscow) -East Berlin-, the construction company (surely at the direction of the KGB / GRU) placed passive bugs in the concrete (they only transmit when blasted with microwaves at the right frequency and would avoid counter-intel sweeps unless active). They built the buildings almost pre-fab style, laying the concrete out then assembiling it. It's then when the bugs were placed.

The west eventually learned about this, if I recall correctly, it was from a Russian defector by the codename of Mother.

It was called Operation Top Hat (that's where i'd start googiling). The US knew the embassy in (edit: Moscow) -East Berlin- was bugged on the first 3 floors by the Russians as well as having secret hollow support columns with clandestine access to the building. The decision was made to just not use the first 3 floors of the embassy for classified discussion. The remaining floors were built by Americans and undoubtedly under FBI/OGA watch.

IIRC there was also a network of tunnels leading from the embassy in West Berlin to under the wall to listening posts.

Edit: my memory is shot apparently. It was in Moscow, not Berlin. https://www.smithsonianmag.com/history/private-tour-cias-inc... https://www.latimes.com/archives/la-xpm-1991-07-29-mn-177-st...

I think i screwed up another thing Hanssen revealed and that was a tunnel from West Berlin to East Berlin and under the Soviet embassy.

You can still post the links that are most interesting to you, please, the google translate service is quite usable.

Chapter after chapter devoted to figuring out what the Germans were up to on the technology front, then one-upping them. Lots of engineering porn.

"Don't be an idiot. There's no way millions of people are going to PAY us to put an internet connected listening device in their homes..."

In order to get FM modulation from a passive resonator, the decay time of that resonator has to be much longer than the modulation; i.e. the resonator Q has to be very high, much narrower bandwidth than the modulation.

A back of the envelope calculation, for 3 kHz audio bandwidth, and a 300 MHz resonator, that sets the unloaded Q=100E3, which you can't get even close with a passive resonator, short of a superconductor. Not to mention the loaded Q from the monopole radiation is going to lower it even more.

You can get FM modulation out of an oscillator because the feedback is generating a negative resistance to compensate for the resonator resistance; the active circuit is a Q multiplier, getting you that massive Q.

The interrogator would have to set up not only a standing wave, but provide coherent feedback. Sort of a stand-off oscillator. Even if you had low-level FM modulation, it's still going to have the spectrum of DSB AM as the Bessel components are pretty far down.

Maybe it is doing that stand-off oscillator, but my hunch is the receiver is a coherent AM demodulator. You have the carrier available , so might as well use it.

If the diaphragm goes non-linear (say from high sound pressure), then perhaps you'd get harmonics and maybe an f/2 response. At this point it's acting like a parametric amplifier, with your carrier frequency and pump frequency. Parametric amps need a strongly non-linear reactance, hence pumping a varactor diode with a strong signal.

"Open view of a replica of a bugged US great seal on display at the National Cryptologic Museum in 2005."

Back to Nokia, I guess.