Special Microphones


Laser Room Monitoring System

A secret surveillance is necessary. However, the operator is not able to enter the target room in order to place a transmitter. The solution to this problem is our Laser Room Monitoring System GD 7800.

This system allows the operator, to carry out an undetected surveillance operation from outside the building.

GD 7800 consists of three parts :

a laser transmitter
a laser receiver
an amplifier unit

This system is operated by transmitting an invisible infrared beam to the window of the target room. The window pane vibrates slightly, due to sound waves emanating from speech. The beam is reflected from the window pane according to the law of optics, i.e. the angle of incidence is equal to the angle of reflection. The reflected beam, modulated by the window pane vibrations, is picked up by the receiver and converted into electronic signals, which it filters, amplifies and feeds into a recording unit. The recording unit is connected to an amplifier with speaker or headset.

Both, the transmitter and the receiver are built into standard single lens reflex cameras, allowing for perfect concealments. The complete set will be supplied in a camera case with built in recorder, 2 pcs. Of tripods and 1 micrometer platform with adjustable Y/X axis and searchtone - detector.

Technical Specifications

Laser Transmitter

Laser Type
:
Semi-conductor Laser
Emitted Wave Length
:
790 - 820 nm
Output Power
:
20 mW automatically contr.
Power Supply
:
8 x 1,5 V AA Battery
Current Consumption
:
approx. 100 mA
Beam Focussing
:
135 mm
Target Finder
:
through lens
Connectors/ Mounting
:
power supply /tripod
Operating Time
:
approx. 50 hours cont.
Other Features
:
search tone on / off for adjusting

Laser Receiver

Receiver Unit
:
noiseless PIN-Diode
Wave Length
:
Infra-red
Power Supply
:
12 V, 8 x UM2 (Baby)
Current Consumption
:
30 - 300 mA
Lens
:
500 mm
Amplifier unit
:
connected by cable w/Laser Receiver
Amplification
:
adjustable
Connections
:
Headphone, Recorder, Speaker
Voice Filter
:
Equalizer , adjustable
Operating Time   50 - 100 hours
Transport Case   470x380x220 mm
Weight   10 Kg