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How a Radar Jammer Can Be Made at Home

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Make a Radar Transmitter at Home

This is an example of a finished radar jammer

This is an example of a finished radar jammer

Most road users wanting to make better time on the open road will arm themselves with an expensive radar detector. However, this purchased gadget will not work against a gun-type radar unit, a unit in which the radar signal is not present until the highway patrol has your automobile in his sights and pulls the trigger. Then, it is too late to slow down.

A better way to safely make better time is to continuously jam any signal with a radar signal of your own. When I tested with the help of a local police officer, her device displayed random numbers when I was driving towards her. Building a low-power radar transmitter is very simple.

What Is a Radar Transmitter?

When encased in the proper size resonator, a special semiconductor named a Gunn diode will transmit microwaves when hooked up to 5 to 10 volts DC. This voltage can be sourced in-car by using an 8 to 3 terminal regulator. These regulators can be picked up at almost any auto-electrical shop.

Patrol officer radars usually operate on the K band at 22 GHz, or more often than not on the X band at 10.525 GHz. Pretty much all microwave intruder alarms and motion detectors (mounted over automatic doors in supermarkets, etc.) contain a Gunn type transmitter/receiver combination that transmits about 10 milliwatts at 10.525 ghz.

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These devices work perfectly as radar jammers. If you can't get any in your area, write to Microwave Associates in Burlington, Mass. and ask for info on "Gunnplexers" for ham radio use.

The finished jammer can be mounted outside the automobile, in a waterproof enclosure, or on the dash. When on the open road, switch on the power.

How to Test Your Unit

Correct construction and fine-tuning your radar jammer can be difficult if you don't have good measuring equipment for microwaves. One simple way to test your unit is to use a conventional radar detector, preferably one that indicates which band the radar is transmitting on.

Interesting Side Effects

Your device will not jam radar behind the automobile or to the side, so be careful when passing speed traps regardless. Something interesting to observe is that any vehicle in front of you fitted with a detector will hit their brakes as you come up to large flat objects. Their detectors are being triggered by the signal your jammer is transmitting, bouncing off objects.


Many people go through the hassle to legally beat speeding tickets and pour thousands of dollars into fines and fighting them. Why not just build this little device and avoid them altogether?

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

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