|
|
|
|
|
|
Diode used as bug simulator
Over the years, a wide variety of bug detectors, direction finders
and bug tracers have been developed. Although it is relatively easy
to locate a bug that is transmitting permanently, many new generation bugs
are remote controlled, so that they can be turned off when not needed.
|
Furthermore, bugs can be voice activated (VOX) or controlled
by another piece of equipment, such as a public addressing system (PA),
in which case the bug is likely to be turned off when the room is
checked for bugs (bug sweep).
In such cases, the only way to detect a bug is by using a so-called
non-linear junction detector (NLJD), such as the
Audiotel Scanlock Broom.
An NLJD is capable of finding bugs that are switched off completely,
by detecting the PN-junctions that are present in all semiconductors,
such as transistors, diodes and computer chips.
|
|
|
By exiting the PN-junction of a semiconductor with a strong RF signal
of a certain frequency, the semiconductor will produce harmonics of that
frequency. By looking the 2nd and 3rd harmonics reflected by an object,
the NLJD will be able to detect an electronic device. As the amount of
energy reflected by a miniature electronic circuit is extremely low, the
quality of the NLJD and its filtering is of the usmost importance,
and requires a well-trained and capable operator.
As it is necessary for the operator to train his skills regularly,
Audiotel produced a dummy bug in the shape of a
hockey puck. The puck
is made of plexiglass and carries just a
schottky diode
at the center. The diode is not connected to anything and its wires act as antennas.
|
|
|
|
Any links shown in red are currently unavailable.
If you like this website, why not make a donation?
© Copyright 2009-2013, Paul Reuvers & Marc Simons. Last changed: Tuesday, 30 April 2013 - 15:01 CET
|
 |
|
|
