Spy Shops 600 West Oakland Park Blvd. Wilton Manors FL. 33311 954-563-1779 Serving since 1986

Non-Linear Junction Detector


A non-linear junction detector (NLJD) for detecting the electronic circuits commonly found in improvised explosive devices and radio transmitters.

Most sophisticated electronic circuits contain semi-conductors which are non-linear junctions. The detector can find these by emitting a very high frequency signal which stimulates the non-linear junction into emitting another signal of a different frequency. The detector, which contains a highly sensitive receiver capable of picking up this frequency, indicates the proximity of the device by means of an audio alarm.

The detector consists of a control unit, which also contains a rechargeable battery, and is worn on the user`s belt or with the shoulder straps supplied. The control unit also contains a speaker which emits an alarm, although the headphones (supplied) can be used for covert use.

The anntena wand which contains the transmitter and receiver is extendable from 300mm to 800mm to allow the ground to be searched with the operator in a convenient standing position. A soft plastic foam cover protects the antenna, as well as the surfaces being scanned, from damage.

Four diodes mounted on a printed circuit board are supplied as a reference test piece.

All items are supplied in a robust foam lined carry case.

An optional external battery is available to facilitate extended periods of use if required.

Example of threat response - searching a department store for incendiary devices.

Typical applications for the use of a non-linear junction detector are the following:

VIP Protection support
The NLJD can be used to search for both `bugs` and electronic IEDs prior to a VIP visit. 

Threat response
It can also be used for searching large complex areas where devices may be hidden in any number of places. e.g. incendiary devices placed in department stores or conference halls.

Post incident follow-up
Because semi-conductors do not need to be powered to be detected, the NLJD can be used to find parts of circuits after an incident to provide forensic evidence or intelligence regarding the source of the device.