ST 500 "Piranha" Operation Manual: Use Guidelines
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When localizing a GSM signal source in an energetic way, difficulties may arise. The signal level
in different places of the room will be approximately the same, and it is difficult to determine
where the signal level is at its maximum.
Setting the minimum gain value will also not solve this problem. Localization is recommended
with the antenna turned off. In most cases, this will allow to determine the installation location of
the GSM device.
9.2. GUIDELINES FOR USE OF "IR DETECTOR" CHANNEL
The IR DETECTOR channel is intended for the detection and location of eavesdropping devices
that send transmissions within the infrared range to a special IR receiver.
The operation range of such a system may be hundreds of meters, provided there is an
unobstructed line of view
between the IR transmitter and IR receiver. As a rule, the receiver
will be outside the inspected room, with the IR transmitter inside and directly opposite a window.
Search for the eavesdropping device should begin from the window, while directing the IR-
sensor (fig.2, 5) at the suspected location of the IR receiver.
Search algorithm:
1.
Turn on the test sound source in the checked room.
2.
Turn on ST 500 and activate IR DETECTOR.
3.
Direct the IR sensor at the suspected location of the IR receiver.
Important! The detection range of the IR detector is 50-70 cm.
4.
Observe the changes in the signal level on the indicator (fig.20, 2), the waveform shape
(fig.20, 4) and the sound volume in the headphones.
An increase in the signal level should indicate that an active IR source is within the field of
view of the IR sensor (±20
0
).
Signs of "THREAT" signal:
High signal levels, test sound heard in the headphones
High signal levels, test sound not heard in the headphones, oscilloscope picture typical for
a digital signal
The signal is localized using the received signal level indicator (fig.20, 2). The IR signal
source is set at the point where the signal level is at its maximum.
For more precision, use the DIFFERENTIAL mode.
9.2.1. SELECTION OF "FALSE" SIGNALS
When approaching a radio signal source (WiFi router, DECT base, etc.), the received signal
level may increase due to pickups on the instrument's input circuits. To select "false" and IR
signals, close the IR sensor with your hand (fig.2, 5). A significant decrease of the signal level on
the indicator (fig.20, 2) indicates that a signal in the IR range. When receiving a "false" signal,
the level on the indicator does not change.
