If you're scared of the foam, or can't handle the truth, then
You've been warned!

Off-Axis Radar Detector Test

An "off-axis" radar detector test hasn't been done before, at least not in recent history. So, the Guys of LIDAR spent two days testing the most sensitive radar detectors to see how they would respond when encountering radar at different angles.

The Test Course

We used the test course that we normally use for laser jammer testing: a 2000+ feet of straight stretch at the end of a dead-end road.

The Radar Detectors

The capability of a radar detector to detect off-axis radar relates directly to the design of it's horn antenna. These types of antennas are directional by nature, but just how directional are the individual designs used in today's top radar detectors? Our test was designed to help answer that question. Since many different models of detectors use the same "platform" along with the same horn antenna, we selected one example of each of the top four most sensitive platforms ever produced. Three of these platforms are in current production, while one platform is from the recent past but is no longer produced (included as a reference).

Beltronics STi Driver A4M9 - "M3" Platform
Currently, no other detectors use this platform, although the STI-R will be using it when it becomes available.

Escort 8500 X50 - "S7" Platform
This platform is no longer produced, and was superseded by the "M4" platform.
Some other detectors which used this platform are older 8500 X50's, BEL RX-65's and BEL Vector series detectors with the FCC IDs QKL8500 and QL4G1S7.

Escort 9500i - "M4" Platform
Some other detectors which use the M4 platform are currently-produced Escort 8500 X50's, BEL RX-65's and BEL Vector series detectors with the FCC IDs QKLX5M4 and QL4G7M4.

Valentine One v3.858
Valentine research does not have multiple models, so nothing else uses this platform.

The Radar Guns

We used the following radar units:
  • MPH Enforcer, Ka Band - 33.8 GHz
  • Stalker ATR, Ka Band - 34.7 GHz
  • Kustom Golden Eagle, Ka Band - 35.5 GHz
  • Kustom Falcon, K-Band

Sorry to disappoint, but the foam doesn't look all that evil.

Eccosorb is specially-designed foam which absorbs radar. In this test, the Guys of LIDAR used layers of Eccosorb in front of the radar units to reduce the radar signal, or make it weaker.

Why? Because a detector's job is to sniff out weak signals.

The further away you are from the radar, the weaker the signal becomes. Today's high-end radar detectors can detect radar miles and miles away in the right situations. Because of this, radar detector tests commonly use hills, terrain, or other means to reduce the radar signal for test purposes. But every test situation is different, and these methods can sometimes yield sporadic results. And for this test, we needed conditions where the angle of the radar vs the detector could be precisely controlled.

Enter Eccosorb. The Eccosorb allowed us to reduce the radar signal in a highly-controlled manner, and allowed us to test on a straight course where the angles could be precisely controlled. This method of testing also reduced or eliminated some of the unpredictability that occurs with other methods, and yielded highly-repeatable results.

In addition to the Eccosorb in front of the radar, the sides and rear were also surrounded with Eccosorb just for good measure to help prevent any stray radar reflections.

Please remember: what these test results provide is an indication of "relative sensitivity", or how the detectors might compare against themselves or each other. Just like any other radar detector test (foam or not), the absolute distances in the results cannot be applied to any situation other than the specific test conditions.

In this test, just like any other, it's the ratios that matter.

Test Methodology

We tested the detectors by exposing each one to a specific set of controlled conditions.
  • All radar guns were held in a fixture for test purposes.
  • Only one detector was tested/powered on at a time.
  • All detectors were mounted level, and high in the middle of the windshield.
  • Between runs, the power was cycled on the detector under test.
  • Each detector was tested in it's most unfiltered mode, with POP turned off.
  • The test vehicle traveled at approx. 20 MPH
  • The course was completely clear of other vehicles
The idea behind this test was to see how the detectors would respond to radar at different angles, so that we could determine how much sensitivity dropped off as the angle increased.

The radar was aimed straight down the test course. The test vehicle proceeded down the test course and stopped at the first alert from the detector under test. The distance back to the radar vehicle was measured by using an LTI Ultralyte in survey mode. We did test runs with each radar detector rotated at 0, 15, 30, and 45 degrees.

A special test fixture was constructed which allowed us to easily pivot the detectors to specific angles while they remained mounted level.

The Results

  • Only the right side was tested. However, the results in the charts below were duplicated for both the left and right sides for the purpose of illustration. It might be easy to assume that both sides would have the same results, and in most cases this might be true. However, this might not necessarily be true in all cases.
  • The detectors are sorted from left to right based on their average at 0 degrees.
  • We attempted to test the BEL STi on 33.8 GHz, but were unable to do so because of sporadic behavior on that frequency. We plan to get this STi updated (with the 33.8 GHz fix) and use it in a future test.
  • X-Band was not tested due to time constraints.

Ka Band - 33.8 GHz Averages

Ka Band - 34.7 GHz Averages

Ka Band - 35.5 GHz Averages

K Band - Averages

In addition to the detailed testing above, we also did some experimenting. We used less Eccosorb so that we would have a stronger radar signal, and we positioned the test vehicle at 1000 feet from the radar source. We set the detectors at 90 degrees, and then slowly rotated them towards 0 degrees until we got an alert. We did this for both the left and right sides.

Unfortunately, these results aren't very conclusive, because this scenario puts all detectors against each other at 1000 feet, regardless of sensitivity. This would be more conclusive if all of the detectors were equal in sensitivity, but of course that is not the case. We decided to publish the results anyway, just for reference.

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