Boomerang™ Series - NonLinear Junction Detector

The Boomerang™ is truly the king of all Nonlinear Junction Detectors. The Boomerang detects the components in infrared and ultrasonic transmitters, microphones, tape and digital recorders, surveillance transmitters (audio and video), and other eavesdropping devices hidden in walls, ceilings, furniture, etc., even when they’re inactive!

ISA’s Boomerang, while not quite the beauty of some other NJD’s, compensates by having the most brawn and highest accuracy available. The Boomerang is by far, the most sensitive, durable, reliable and intuitive NJD on the market. Rest assured that if you need your information secure, the Boomerang is just the brute to maintain your security.

The Return of the Boomerang

The Boomerang transmits a low power microwave signal from its antenna. When the signal is received by a transistor, diode, or other semiconductor in a covert listening device, aka "bug", the semiconductor radiates or reflects radio frequency energy called harmonics. This reflected harmonic energy is detected by the Boomerang’s hypersensitive receiver and its response is what makes the Boomerang so unique. No other NJD on the market can compare to the Boomerang’s receiver’s sensitivity; and with Nonlinear Junction Detectors, sensitivity is key! This allows the operator to quickly and accurately determine if the hidden electronic device requires further investigation, therefore, drastically reducing search time.

Specifically, the Boomerang detects two different types of harmonic signals, displaying the difference between an actual threat and a false return caused by dissimilar metals. Semiconductor components primarily radiate a frequency that is 2x’s that of the signal transmitted from the Boomerang; this signal is called the second harmonic. Often, more than 90% of the signal radiated by a semiconductor is second harmonic. Dissimilar metals not used in semiconductors, radiate a substantial amount of signal that is 3x’s that of the Boomerang's transmitter. This is called the third harmonic.

The Boomerang's antenna mounted display, shows the level of both signals. All the operator does, is visually compare the levels of second and third harmonics on the LED bargraph meters to instantly determine whether a threat or false return has been detected. Simple!

Proven Reliability

The Boomerang’s proven reliability has made it a favorite among Government and Law enforcement agencies worldwide. It utilizes surface mounted components and integrated circuits throughout. Its circuitry is uniquely designed to operate at low stress levels for exceptional longevity and has ultrastable crystal controlled oscillators to provide trouble-free operation without the need for factory calibration or periodic maintenance.

The Boomerang Models

The Domestic Standard

The NJD-4 Boomerang™ is the FCC approved model available domestically in a low power configuration (100 mwatt). The NJD-4 is recommended for use by civilian groups within the United States.

The Agency & International Model

The NJD-5 Boomerang™ is the high powered unit, available to U.S. Federal government groups and recommended for use outside of the United States. The NJD-5 has a 500 milliwatt transmitter for greater detection range, especially in dense materials. The NJD-5 also has an integrated multistep attenuator to allow the user to control the actual detection range by lowering the transmitter output.

The Truth About Nonlinear Junction Detectors:

What the others won’t tell you!

When comparing Nonlinear Junction Detectors, the most critical component in the performance of a detector is the receiver’s sensitivity, not the power of the transmitter.

ISA's NJD-5, with only 500 mwatts of transmitter power, will detect a standard test target for at least 16 feet (5.1 m) in a laboratory setting. Field tests of other manufacturers' products indicate that the NJD-5's detection range is 2-3 times greater. Even though others have transmitters that have 3 to 6 times the power, competing products just do not have as great a detection range.

In other words, the Boomerang's receiver has a much greater sensitivity. This translates into more reliable operation, greater detection range and extended operating time between battery charges.


Transmitter Power NJD-4: 100 milliwatts
Transmitter Power NJD-5: 500 milliwatts
Operating Frequency: 915 MHz
Receiver frequencies: 1830 & 2745 MHz
Antenna Polarization: Horizontal/Vertical, with lockable swivel mount
Power: Internal rechargeable gel-cell battery, external 12VDC, 110-240 VAC
Operational Weight: 16 lbs.