How to test a radar detector


Last updated on March 4th, 2023

We are supported by our readers. We receive a commission if you purchase something through our links with no extra cost to you.

Radar detectors are excellent devices that help you avoid speed traps and hefty fines. However, before you can fully trust your newly bought device, it is advisable that you test it and ensure it is running properly. But how do you test a radar detector?

In this article, we are going to tell you how to test a radar detector and everything else you need to know about these money-saving devices.

How to test a radar detector_featured

What is a radar detector?

Radar detectors are devices that detect police radar waves and warn you of impending speed traps. These detectors monitor for incoming radar waves and emit audible and visual cues when they detect police radars.

In simpler terms, these devices let you know that you should slow down to avoid getting fined for speeding, possibly saving you from hefty fines.

Why test a radar detector?

Most people buy radar detectors to avoid getting caught speeding. Although radar detectors can be costly, they should pay for themselves by allowing you to avoid a single speeding ticket.

Since you are counting on the radar detector to avoid fines, it is essential to ensure that it works. Therefore, before you start blazing down the highway, you should test your radar detector and make sure you won’t run into any unpleasant surprises.

The essential parts of a radar detector

Radar detectors are complex devices that require a few parts to function properly. Before you can know how to test your radar detector, it is essential that you understand how they function—that way, you can troubleshoot any problems that may arise.

But to understand the parts of a radar detector, we first need to understand how a radar works. Radars are composed of these key components:

  • Frequency source: This component lets the detector operate at the designated frequency. Most radar detectors use crystal oscillators as a frequency source.
  • Radar transmitter: The radar transmitter is responsible for amplifying the signal from the frequency source and making sure it is usable.
  • Antenna: The radar antenna broadcasts the radar’s signal.
  • Receiver: The receiver detects incoming signals and converts them into an electrical signal.
  • Processor: This component is responsible for processing the received signal and translating its data.

Radar detectors are built very similarly to radars. The main difference is that there is no need for a radar detector to transmit its own signal. For that reason, radar detectors usually do not have transmitters or antennas.

Most radar detectors are basically composed of a receiver, a processor, and a warning system that can display visual warnings or emit alarm sounds.

Types of radar detectors

Radar detectors usually come in one of three different types. They can be:

  • Wired radar detectors: These detectors are usually mounted on the windshield and have the best detection range. They are directly connected to the battery and do not require any battery changes.
  • Cordless radar detectors: This type of detector functions quite similarly to the wired one, but it requires battery changes. These are great if you change vehicles often, as you can take them with you.
  • Remote-mounted radar detectors: These detectors are usually mounted somewhere else on the vehicle other than the windshield. They are a great choice if you are looking for something that the authorities (or thieves) have a hard time finding.

How to test a radar detector

After purchasing your radar detector and before you can start relying on it to detect speed traps, it is essential to test it. While testing a radar detector might not exactly be the easiest task in the world, going through the trouble can potentially save you thousands of dollars in the long term.

But, before you get started, you will need to set up a testing environment.

Things you will need

Like we said, testing a radar detector isn’t necessarily a simple task. The main difficulty of the test comes from the things you will need.

First of all, you will obviously need your vehicle and your radar detector. Depending on the complexity of the test, you might also want the help of an extra person; however, it is not mandatory.

The other thing you will need is a radar gun. To test a radar detector, you need to hit it with radar waves. The radar gun can be placed in a stationary location or you can attach it to a different vehicle. While the stationary radar is enough for testing purposes, using a mobile radar gun can help you understand the limitations of your radar detector better.

If you choose to go with the mobile radar gun, then you will need the aforementioned extra person. Besides the radar gun, they will also need their own vehicle.

Testing method

To test your radar detector efficiently, you should first conduct the test in a secluded location, away from traffic and other interferences. After verifying that the radar detector works, you can also choose to perform a similar test in a regular location to test its real-world efficiency.

After choosing your location, you need to set up the radar gun in a place without any obstacles. The radar waves need to be able to hit your vehicle directly. The same premise applies if you are using a mobile radar gun.

After you’ve prepared everything, you can turn on the radar gun and distance yourself from it. Go as far away as you’d like and speed towards the radar. Notice at what distance from the radar gun the radar detector triggers (or if it triggers at all). The farther away the radar detector notices incoming radar waves, the better it is.


Although the radar detector test is pretty straightforward, some problems may arise. If your radar detector does not notice any incoming radar waves, then it might not exactly be the fault of the radar detector. The radar gun could be faulty, or there could be an obstacle blocking the radar waves from your vehicle.

If you are comparing several different detectors, you should not test them all at once. Turning on different radar detectors at the same time can reduce each radar detector’s efficiency. You need to do it in turns, and you should also place each radar detector on the same spot in the windshield.

Harsh weather can also reduce both the radar gun’s and the radar detector’s efficiency. For more accurate results, make sure to perform the radar detector test on a sunny day.

Using your radar detector

If your radar detector passes the test, then you are good to go. Remember that a radar detector might be a pricy investment, but that it should pay itself off after preventing a couple of speeding tickets.

However, you should also remember that speeding is dangerous and that you should avoid it whenever possible.

Photo of author


Thomas S.

With a background in government supply and a keen interest in emerging technologies, I have developed a passion for the realm of stealth technology. My expertise lies in analyzing the latest advancements in spy gadgets and high-tech products, with a particular focus on those available to the public that offer a modern-day James Bond experience. Through my work, I strive to uncover the most cutting-edge innovations in the field and provide valuable insights to fellow enthusiasts and industry professionals alike.