[BC] Is That a Radio Station In Your Pocket, Or...

[Thomas G. Osenkowsky]

I remember hearing this story decades ago...
A new American embassy in Moscow was suspected to be bugged. Conversations
thought to be secret were found to be not secret. The conversations were
confirmed to be in two adjoining rooms. The rooms were swept and no
listening devices were found. An examination of the environment, however,
discovered two strong microwave emissions seemingly aimed at the embassy.
These were not strong enough to be harmful to persons nor did they interfere
with any communications.

The rooms then were laid in grid form and examined for any differences. The
sole difference was in the size of one of the carvings in a cast of the
American eagle. An engineer discovered that the carving dimensions coincided
with the frequency of each microwave signal, one for each room. The carving
was acting like a microphone, modulating the wave of the emission. The
emission was not pure CW, but pulsed on/off just like a radar emission.

A passive microphone that never need batteries, etc. and will not show up on
an RF sweeper.

Tom Osenkowsky, CPBE

>It would be better to invent a nano structure transducer that could
>directly convert sound waves to digital data