Spread Spectrum Surveillance Modules

[Dave Del Torto]

[From the TSCM-L Technical Security Mailing List]

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TSCM Intelligence Update - Spread Spectrum Surveillance Modules

New Spread Spectrum Surveillance Modules

There are some new spread spectrum products coming into the US by way of
China, and are starting to show up in Spy Shops on the West coast, Chicago,
and Miami area.

Two sided, four layer, surface mount PCB, several RF and audio IC's,
several pots, coils, etc. Device is a raw module, designed for covert
installations in an office or SOHO environment.

SM connector for antenna, micro molex connector for power and
computer/serial interface.

PCB is 1.5 mm wide, 3.25 mm long, and .5mm thick.

Products are all based on a cordless telephone chip set, 780 Mhz to 980
Mhz, Direct Sequence Spread Spectrum (BPSK/QPSK?).

Analysis of RF section indicates good response from 610 Mhz to 1090 Mhz.

Serial data rates between 56 kb/s and 784 kb/s (12 full audio channels
capable).

Devices have a two way RS422 serial port to facilitate setup prior to field
usage.

Programmed RF power levels range is spec'd between 50mw and 250mw, suspect
the circuits will operate as low as 5mw. Evaluation of the RF amp indicates
that RF section should support a full watt of power with no problem.

Recommended voltage is 3/6vdc, but circuit should work fine on 9 or 12vdc.

Connections for two or three wire transducers. Audio path is thru pre-amp,
compander, CODEC, and controller. Looks like it can support two elements,
each with its own tunable preselector.

Large amount of 60 hz filtering, suspect they were originally designed for
installation into power strips (APC, Best, Woods, etc).

Look for the low level multihump signature on the spectrum analyser, and
take a REAL hard look at all surge protectors.

Be sure to "box" all electrical artifacts encountered on a TSCM sweep.

Well engineered, suspect cost to manuf. is under $35, should be popular,
most of the spy shops are selling these for $1500 to $3000.

More details to follow after the holiday, should have an update by that
time regarding the VLF devices being built by Thompson, and E-Systems.


 --James M. Atkinson