How to Conduct Long Range Radar Detector Testing Properly

Radar detector test: 33.8 Sample Test Results

IMHO, testing radar detectors to see how they perform is a fantastic thing to do. You learn SO much, the results you share are incredibly beneficial to others, not to mention we need lots of different testers using different terrains, different test courses, and different detectors all working together to help us put together the big picture in a way that no single test could tell us. There’s many different types of tests you could do and I’d actively encourage people conduct their own tests because of how incredibly beneficial it is to not only the community, but to the testers themselves. Here’s some of the biggest benefits I’ve found to doing radar detector testing:

  • You can find out which radar detectors offer the best performance and longest detection distances
  • You can see how much terrain such as hills, curves, trees, and straightaways impact detection range
  • You can see how much different settings and filters impact the performance of your detector
  • You can see how much advanced warning the radar detector provides before the radar gun can pick up your vehicle’s speed
  • You learn SO much about radar in general when you get behind the radar gun
  • You provide incredibly valuable information to others

Now the thing is, while radar detector testing is tremendously useful, it’s also very very easy to make mistakes in a way that would totally invalidate your results, produce inaccurate results, and would completely mislead anyone reading the results. In fact some mistakes are so common (running two radar detectors next to each other at the same time is the biggest one. Never do this!!) that almost everyone makes the same mistakes when first starting out so I’d like to cover both the do’s and don’ts of how to conduct a radar detector test properly.

Something to be aware of though is it’s very easy to inadvertently conduct the tests incorrectly which would make your results completely invalid and thus provide inaccurate and misleading results to anyone looking at your results. This actually happens a LOT and so I want to go over the basics of how to properly conduct a radar detector test.

Radar Detector Testing: Valentine One vs. MPH Bee III

Valentine One vs. MPH Bee III

Equipment Needed

  • Radar Detectors: Even if you have only one detector, you can test how things like terrain, traffic, and even the detector’s settings impact performance.
  • Radar Gun: You’ll want your own radar gun to set up different test courses. You can pick them up on eBay or on RDF’s Buy & Sell area. You can get inexpensive used guns pretty easily. Something simple with a single antenna is fine. No need for crazy fancy features just for simple long range testing. If you want a new gun, the Bushnell Velocity is an K band gun you can get for less than $100 so it’s a popular first radar gun. Use a rubber band to hold down the trigger so it’s set to Constant On, set the gun down on the dash of the radar vehicle, and now you have a radar source. Using speed signs on the side of the road as your radar source is convenient, but typically not recommended because their radar signals are often different than what you’ll see in police radar guns.
  • Portable Power Supply: Many radar guns, especially handheld ones, are battery operated. If yours uses a cig. lighter, you can plug it into your radar vehicle and leave the car running during testing. Alternatively, you can get a portable USB battery and a USB to cig. lighter adapter for your radar gun. It can also be used to keep cameras or phones charged too.
  • Cameras: (Optional, highly recommended) If you use your phone’s camera, dashcam, or a GoPro, you can shoot videos of all the results. This is good not only for showing people the course and the results, but they’re helpful to go back later and see exactly where each detector started alerting, verify if traffic impacted the results, or double-check your results in general. (If you’re using a camera in each vehicle, clapping at the start of each run when both cars are together will help you sync the videos later when you’re editing.)
  • Distance Measurement Tool: You’ll want a way to accurately measure how far away a detector alerts. You can use Google Maps’ distance measurement tool and look back at your videos, but that’s very tedious. You can use your vehicle’s odometer, but that’s only precise down to a tenth of a mile. You can use an OBD-II tool, but that’s expensive. You can use an app on your phone which is simple and convenient, but sometimes you may have some GPS drift inaccuracies. There’s many different apps that can do this. Personally I use V1Driver (an iOS app for the V1) which has a nice distance measurement tool built in. Simply mark the location of the radar gun and start driving. Your phone will tell you how far away you are from the radar source which you can jot down when the detector goes off or just go back later and reference your video footage. (More info here.)

Using V1Driver to measure distances during RD testing (radar gun is 302 feet away)

Test Prep

  • Decide what you’re testing: In this case we’re testing long range detection
  • Get people to help: Ideally you’ll want 1-2 test cars (1 radar car and 1 RD car) and multiple people for different roles such as radar operator, RD car driver, RD handler, and someone taking notes or logging GPS coordinates.
  • Select Day & Time for testing: Testing always takes longer than you think, you’ll need time to set up equipment, do a few test passes and ensure the test course works (have a backup course ready), check every detector’s settings, perform the actual test runs, etc.
  • Secure all the equipment you’ll need
  • Ensure batteries are all fully charged
  • Bring snacks and drinks

Selecting a Test Course

Terrain can have a HUGE impact on detection range. Flat, long straightaways can provide for miles and miles of warning (and lots of driving back and forth during testing). Curves, hills, and foliage will all reduce detection range and can lead to different detection “zones” where every detector goes off at the same time. You can crest a hill or round a bend, the radar signal goes from zero to HERE I AM! almost instantly, and every detector will alert at the same spot. It’s definitely good to know that many detectors will alert in the same location, despite differences in sensitivity, but you won’t get to see the differences between detectors and so ideally it’s good to find test courses that show separation between detectors while also remembering that many times different tier detectors will produce similar results. You’ll also find that detectors perform differently when the signal is coming from straight ahead (on-axis) versus when the signal is being detected from an angle (off-axis). No one test will show all of the relevant information so looking at multiple tests on different test courses helps paint a more complete picture.

Finding good test courses takes time and honestly some experimentation and trial and error. Search around on Google Maps or think of locations that you already know about that could work.

  • Separation: A course that provides separation between detectors
  • Radar car spot: A safe place to park the radar car on the side of the road
  • Turn-arounds for RD car: Convenient turn-around locations on both ends of the course for the RD vehicle
  • Minimal traffic: Minimal traffic which will otherwise impact the results and provide additional variables
  • Hopefully no concerned neighbors: Ideally a relatively rural location that won’t get people nearby concerned when you keep driving back and forth
  • Good weather: Constant weather throughout the test runs (rain can reduce detection range)
  • No extraneous radar sources: A location free of false alerts like speed signs and automatic door openers

Here’s some discussion regarding test course selection on RDF.

Radar Gun Setup

Decatur Genesis II set up for radar detector testing

Decatur Genesis II set up for radar testing

Set up your radar gun the way a police officer would. Aim it down the test course to where you’d want to clock approaching vehicles. Radar guns are fairly directional and moving the radar gun or antenna will change the results and won’t provide for the same testing conditions for each detector so you’ll want to keep the radar antenna fixed the whole time. If you have a handheld gun, lock down the trigger with a rubber band and lay it down on the dash.

Make sure the antenna has a nice clear view of the road. (Notice in the photo above that the antenna has been propped up on rolls of tape to make sure it clears the wipers and all.)

You can also conduct additional tests like approaching the radar gun from the side or from behind, but the traditional setup is driving directly into the radar gun’s beam as if an officer is looking to clock your vehicle.

Note: If you have a handheld gun that you’re laying down sideways, this only works with circularly polarized guns like the Stalker II. If you have a linearly polarized gun like the Stalker ATR or Kustom Falcon HR, those guns do have to be held vertically when transmitting so you’ll need to rig up a mount to keep it vertical or use the dash mounts available for those guns. You can also set the ATR down on your dash upside down with the handle sticking up into the air. That’d work too.

Tips to Avoid Common Mistakes:

  • Turn off your A/C fans: Running the A/C fans can lead to interference in the radar gun and artificial speed readings. Turn off your A/C fans or move the antenna so that no interference occurs. (Even if the radar antenna isn’t pointing directly at your dash, the radar beam can travel down the windshield, pick up the AC fans, bounce back, and still be detected by the radar gun.)
  • Don’t move the radar gun. The radar gun’s beam is fairly directional and you don’t want to start introducing variables that will mess up your results. Keep the gun stationary. If the antenna moves during or between runs, even a few degrees, you’ll have to start over.
  • Nothing in front of the radar gun: Ensure the radar gun has a clear view of the road ahead and has no problems clocking traffic. If people are hanging out near the radar vehicle during runs, no milling around in front of the radar gun and blocking the signal.

Radar Detector Setup

Escort Redline being tested

Before we get into this, let’s start with the biggest thing:


This right here is the single biggest mistake people make. It may seem counter-intuitive because if you want to compare detectors, why not just put both of them on your windshield next to each other and see which one alerts first? Seems like the easiest way to do it, right? Well here’s the deal…

Radar detectors aren’t just detectors. They also inadvertently emit radar signals back out which is why they can be picked up by radar detector detectors. These emissions will cause problems for other nearby radar detectors (cheap Cobras are especially notorious for this, causing Ka falses on nearby detectors in other vehicles) and when you run multiple detectors at the same time, these emissions will cause problems including delayed alerts, missed alerts altogether, and more false alerts. Even detectors like the Redline which are otherwise stealth to RDD’s, when placed in close proximity to other RD’s, even they can cause problems with other nearby RD’s.

Escort has a good explanation of it here, along with a very blunt, but accurate statement about it:

The next time that you see a side-by-side radar detector review you will know that the reviewer knows little to nothing about radar technology and that their results are worthless.


If you’d like to see this on video with one detector putting another to sleep, check out this video and discussion.

Hopefully that makes the issue clear. This mistake is one of the single biggest and most common mistakes and is the primary reason I’m doing this article so I have to address it in no uncertain terms. Anyway, now that that’s done, let’s talk about how to set up your radar detector properly. The goal is to keep everything as consistent and identical as possible so we don’t introduce any additional variables.

How to Set Up Your Radar Detector Properly:

  • Same Placement: Mount every radar detector in the exact same location on your windshield. (I typically run my detectors high in practice but often run them low on the WS so that it looks better on video. You can run them either way, but keep it consistent.) You can even use tape on the WS to mark where the detectors should go.
  • Clear view ahead: Make sure the RD isn’t being blocked by your wipers or anything up ahead.
  • Mounted Straight and Level: Make sure your detector aimed straight forward, not up or down, not left or right. Radar detectors are fairly directional.
  • Same Settings: Make sure every detector is configured with comparable settings and check every detector before starting.
  • Nothing else on windshield: Remove other RD mounts from windshield during testing to ensure no obstructions.
  • Test multiple copies if possible: Due to variances in manufacturer tolerances, it’s recommended to test multiple copies of detectors when possible, ideally 3 of each model.

Doing Test Runs Back and Forth

Okay so you’ve got everything set up and ready for testing. Here’s the general idea of doing the test passes:

  • Record relevant info for each run: At the start of each run, write down or speak to the camera any relevant information such as detector settings. ie. “Redline vs. K band, second pass, Highway mode, TSR On”
  • Start far away: Start far away from the radar gun, farther away than any detector can detect (this may take some experimentation) and start driving towards the radar gun.
  • Bootup time: Some detectors start detecting radar almost as soon as they start up. Others may take 10-20 sec between when they look like they’re up and running and when they’ll actually start detecting radar. Give them enough time to boot up when starting with each new detector.
  • Keep space between you and vehicles ahead: Don’t follow other traffic too closely.
  • Ensure traffic isn’t messing with your results: Even vehicles at a distance can mess up your results. If they block the signal you’ll get artificially short detections. If they reflect a signal around a bend that would otherwise block the signal, you can get artificially long signals.
  • Do multiple passes: For many different reasons, you will always find slight differences from run to run so it’s best to do multiple passes with each detector to ensure consistency and accuracy of results. It’s tempting to do fewer passes to save time, but this is important.
  • Log your alert distances: When the detector goes off, if you have a distance measurement tool, log the alert distances. I use V1Driver (iOS, $10). Additional popular tools include Waypoint (Android, free, no longer on app store), GPS tape measure (Android, free), or an OBD-II measurement tool ($529).

Presenting Information

Once your testing is complete, you’ve got a lot of information. How should you present it? You can make a video, you can create charts, you can post the raw test result data, you can explain your results with commentary, etc. Choose what works best for you. Here’s some relevant information that you can share:

  • Objective of your test
  • Radar detectors tested
  • Relevant RD settings
  • Info about test course: Distance, type of terrain, traffic levels, photos of course, videos of the test runs, Google Maps satellite views, etc.
  • Test Data & Results: Alert distances, if the results were consistent between runs,
  • Conclusion: Share your personal summary of the results

Once you have everything put together, post your results onto the testing section of RDF!

Here’s some examples of test results presentations:

Remote RD Testing on 33.8, 34.7, & 35.5:

TXCTG’s compilation of Uniden R3 beta testing:

34.7 testing down a curvy road:

For more tips and tricks and general discussion of RD testing, check out this thread on RDF.

The results from hundreds of tests like this are a big part of what I use in my radar detector recommendations and they help me bring you guys very accurate information.

Finally, a big thank you to @CJR238, @Dukes, @hiddencam, @jdong, @Nine_C1, @Brainstorm69, and @Jag42 for their contributions to this article! 🙂

This website contains affiliate links and I sometimes make commissions on purchases. All opinions are my own. I don’t do paid or sponsored reviews.

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Skip to comment form

    • Harry on June 25, 2017 at 5:15 pm
    • Reply

    Hi Areial,

    I hope the contents of this video are false since I have a Max 360! Let me know your thoughts.


    1. Hey Harry, yes they are. That video is actually what inspired me to finally put together this post. Same thing with this video which addresses the issues more specifically:

      Unfortunately testing two RD’s side-by-side is all too common so it’s good to be aware of the issues with this sort of testing.

    • Kirk Aubertine on November 5, 2017 at 6:59 am
    • Reply

    Randomize your run order and record date/time of every run. Every test run should have the same probability of some special cause effecting the results.

    • david sanegor on September 29, 2018 at 3:05 am
    • Reply

    Hey buddy what about a test with one on the rear windshiedl and one on the front windshield? Why you ask? To detect polarised guns from a patrol car coming up behind you, while your driving along, so you can cover yourself front and rear

    Would they still interfere?

    1. They would interfere, yes. Not a good idea. If you want that, you’re better off sticking with a detector that’s been designed from the ground up to function with two antennas and thus give you arrows. Running two separate units to create your own arrows or to improve rear detection isn’t a good idea.

    • Robbie on October 7, 2021 at 1:31 am
    • Reply

    Great job I am getting the escort redline 360

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