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Non Linear Junction Detectors

Non-linear junction detectors (NLJD) are devices designed for search and detection of different types of covert listening devices, various electronic appliances and transmitters comprising of semiconductors. The principle of NLJD equipment operation is based on emission of high radio frequency energy in an area. Detectors have a sensitive receiver designated for reception of objects’ echo signals which, for operator’s convenience, are marked down with sound or displayed on graphical user’s interface.

Depending on the model, non-linear junction detectors are capable of detecting almost any electronic appliance in any operational mode: active, stand-by, switch-off. The designation of such devices consists in detection of radio microphones, microphone amplifiers, dictophones in premises (walls, floors, ceilings, furniture, etc.). Non-linear junction detectors acquired a reputation as perfect means of counter-espionage, as embassies and other diplomatic posts are known to be most popular targets for eavesdropping equipment. Specific models of NLJD are used by the police in search for weapons during events involving great masses of people. Detectors are used for providing location secure from covert listening devices in different organizations. Non-linear junction detectors can serve multiple purposes and have a wide range of implementation, starting from ground detectors up to equipment used for detection of mobile phones. Wide range of NLJD is presupposed by the type of material or surface for search operations – ground detectors are preferable for object detection in soil, portable detectors tuned to appropriate frequency are better in search within wooden furniture.

One shouldn’t neglect the importance of correct frequency tuning of NLJD equipment for different types of search environment (for instance, concrete walls). Bugs or wires (as covert listening devices are commonly called) can be set up deep in concrete columns and they still will be transmitting signals. As an interesting fact, in 1970s Americans detected wires in the concrete columns of the American Embassy in Moscow. The bugs were installed during the construction of the building, and there was no other way to extract them except for complete destruction of the building.

Non-linear junction detectors have a very peculiar designation, therefore their usage is conditioned by goals set by customers. Taking into account great variety of NLJD equipment there is a specific model for any purpose you may require.

The Company’s priority is a development of Non-Linear Junction Detector (NLJD)  technology. Current NLJD products line include models for various applications.

Why Non Linear Junction Detectors?

NLJD technology has proven to be most effective in detection of semiconductors containing multiple layers of silicon, a P-Type and an N-Type. The point where they meet is called a Non Linear Junction. 

Non Linear Junction also appears in nature:

• dissimilar metals in contact with one another;

• the rust on metals resulting from corrosion.

Radio monitoring systems

Radio monitoring systems are powerful computerized systems, designed for monitoring and analyzing the electromagnetic environment. Such systems are usually designated for permanent automatic monitoring in a particular or several selected areas so that any signals (threats) could be detected.

The majority of up-to-date radio monitoring systems commonly represents quite a variety of parts and subsystems that comprise an integrated functional unit. Among the elements of radio monitoring systems one can usually observe PC hardware and software as well as specific computerized equipment. Among them – receivers, antennas, direction finders and analyzing equipment. As a rule, within a radio monitoring system they represent specific automated systems with functions of visualization, monitoring and analyses. They contain various distributed, intelligent subsystems for location and measurement of electromagnetic emissions functioning in a consistent way within the monitoring system. Another important role within the system plays the workflow and tasks on the whole monitoring process, the information flow and its management.

One should keep in mind that the variety of modern radio monitoring systems has different characteristics depending on the purpose of the system. For instance, the application of original digital receiver increases the operation speed and effectiveness of the radio monitoring system in quite a significant way. The reduced characteristics of mass and dimension result in enhanced operation convenience. The sensitivity of receiver, high resolution and high scanning speed guarantee one hundred per cent detection of suspicious sources of electromagnetic radiation within different frequency ranges depending on the customer’s requirements.

The basic algorithm for radio signal detection in the problem zone is based on the use of separated antennas that make measurements of signal field intensity. During the inspection of areas in question, this kind of method allows to perform a precise detection of eavesdropping devices in operation, within the specified area and in case the operate different types of data encoding (various complicated types of modulation, encryption, enciphering, etc.).

Another advantage of radio monitoring systems is the option of classification of detected signals according to the given pattern, which gives the opportunity to select only the signals from the database, that were recorded during previous monitoring sessions.

The proper software of radio monitoring equipment allows to perform any type of task during the process of monitoring. All the above said characteristics improve the process of radio monitoring, increase the reliability, processing speed and stability of the system which operates on the round-the-clock basis. For the customer convenience the radio monitoring equipment can be used stationary or for the purposes of mobile radio monitoring.

In the end – the last but not the least – depending on the customer preferences or due to specific monitoring tasks, the radio monitoring hardware can be modified further.

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Kazım Özalp Mah. Kırçiçeği Sokak No:8/4 Gaziosmanpaşa 06700 Çankaya, Ankara


+90 312 448 0229