The Perfect “Grab & Go” Radar Detector

R4 item banner scaled

that is great

updated platform

tremendous range

Automatic silence memory

Not very well

Some soft screen colors

No alert directional arrows


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As the successor to the trusty R3, the Uniden R4 offers improved false alert filtering, Gatso detection, and two Low Noise Amplifiers (LNAs) to increase overall range. Basically, the Uniden R4 takes everything great about the R3 and improves it a bit, but there’s a price jump to consider.

As of this writing, the R3 retails for $299 on Amazon, while the Uniden R4 is $350. Is it worth spending the extra money to get the R4 upgraded? In this review, I hope to help answer that.

How do I use my Uniden R4

The Uniden R4 sits alongside Escort, Cobra, Radenso and K40 units in my collection of radar detectors. While my Escorts are nice with all the Bluetooth features, sometimes I don’t need all that “stuff” when I’m driving. My goal was to find a “grab and go” radar detector for quick trips around Detroit with a reasonable range and good false alert filtering.

Initially, I searched for two cheap Cobra units, but was satisfied with only one and developed a love/hate relationship with the other (in hindsight, I was probably too lenient in my original review of the 480i). That led me to purchase a Uniden R3 which, while more expensive than the Cobra units, was much more reliable and fun to drive. I have since ordered an R4 to replace the R3 as my “grab and go” radar detector.

Uniden R4 in depth: what it offers

The R4 comes with a 12V DC power cable with an RJ11 connector, hook and loop tape for dash mounting, and an owner’s manual. Two different windshield mounting brackets are included. There is a larger single suction cup mount and a mount with two smaller suction cups. Uniden also includes a carrying case.

new platform

The Uniden R4 is built on a completely new platform, giving it an edge over the R3 in terms of detection range and available features. For example, the R4 has an auto silence memory function that automatically blocks false alert locations, which is very convenient. The R4’s new platform also houses dual LNAs to detect radar sources farther away than the R3. Also, the R4 can detect the Gatso radar used by the latest radars.

These are all the key differences between the Uniden R4 and R3 and may help you justify the price increase.

As for the new platform of the R4, a good comparison is the vehicle platform, or rather, the architecture and the chassis. Every vehicle has a “platform” on which it is built. Imagine the difference between a vehicle built today and a decade ago. The new vehicle will be safer, consume less fuel, drive better and have more technological features. The updated architecture or platform allows such things to come true.

The same analogy can be applied to the Uniden R4 and R3, just slightly smaller.

Radar and laser protection

The Uniden R4 will alert you to X, K and Ka band radar and laser guns (LiDAR). I have the X-bands turned off, but the Downriver communities south of Detroit use the instant-on K-band, so I doubt my R4 will ignore the K-band completely. While you might get the occasional false K band with the R4, the new auto mute memory feature is quick to save them.

You can experiment with the K and Ka filters in the settings menu, including a slicer filter. Since Ka is more common here in Michigan, I have my R4 set to reduce Ka segmentation. In narrow targeting, the R4 scans only US-spec pistols versus the entire Ka frequency range (or wide targeting). Since the R4 is not observing the full Ka frequency range, it has a faster response time, which is useful in an area where instant-on Ka-band radar is present.

The R4 can also detect POP, MRCD, MRCT, RT3 and RT4 transmissions (RT3 and RT4 being the separate frequency ranges of the aforementioned Gatso radar). This means the Uniden R4 will alert you to a wide variety of radar sources, from patrol cars and speed traps to traffic cameras and other photo enforcement devices.

When alerting you to a red light or speed camera, the R4 will display a traffic light or camera icon and the corresponding distance (in feet) to the alert.

OLED display and all threats

The R4’s OLED screen will display the frequency when a particular radar band is detected. The corresponding signal strength indicator moves from blue to white, then to yellow and orange, and finally to red, depending on how close you are to the threat. Audible alerts are also issued, with the tones getting faster the closer you get to the radar source. You can also set the R4 to announce the frequency of any radar band it finds.

The R4 will simultaneously detect up to four radar bands and display each one visually via the All Threats feature in the settings menu. The strongest signal is designated priority and is displayed front and center on the OLED screen. Any other signal appears on the left side of the screen and looks like a small digital graph. Below this digital graph is the type of radar band, followed by bars of signal strength that rise vertically as you get closer to the source.

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The default setting for the All Threats feature is off, but turning it on will give you more situational awareness. Since the R4 doesn’t have alert directional arrows, having All Threat on will give you an idea of ​​everything going on in the immediate area.

For me, the All Threat feature is useful north of Detroit in Oakland County. Novi Road runs between Northville and Walled Lake, taking you right through Novi in ​​the process. You’ll pass several shopping malls including Twelve Oaks Mall, different apartment complexes, and even cross I-96. It’s a heavily patrolled area and there’s a good chance you’ll find more than one police car with its Ka radar activated (at the time of writing, the state of Michigan has a contract with DBA Stalker Radar & Video).

Uniden R4

Available on Amazon

sensitivity modes

Like the R3, the Uniden R4 has City and Highway modes. In City mode, the sensitivity of the X and K bands is reduced to prevent false alerts, while the Ka bands remain at their highest sensitivity. In Highway mode, all bands reach maximum sensitivity to give you the fastest reaction time on the open road. You can further optimize the sensitivity levels of the R4 through the advanced mode.

The Uniden R4 has an auto sensitivity mode, which the R3 does not. Auto sensitivity is speed dependent, switching between City and Highway modes at a preset speed. In the settings menu, look for “Auto City Speed,” where you can set the R4’s shift point between City and Highway in 5mph increments between 10 and 60mph.

The auto sensing mode makes the Uniden R4 an excellent “grab and go” radar detector. I have already lent my R4 several times to relatives on a weekend getaway or a business trip. Auto mode is nice because I can “set it and forget it” for them. Just attach it to the windshield and go!

Here in Detroit, I have the threshold at max, 60 mph, so my R4 doesn’t switch to highway mode until I exceed that speed. There are roads in the Detroit metro where you are still in the city but driving in an area with a higher speed limit. If you use Auto Sensitivity mode, it is best to set the switch point between City and Highway based on where you live.

Mute memory and mark location

When you find an alert that you know to be false, press the Mute/Dim button on the front of the unit or the Mute button on the power cord. You will then see “Mute On” appear on the screen. Press one of the buttons again to save that GPS location and frequency to the R4’s memory. When you pass that location again, the R4 will display the alert and frequency on the OLED screen, but it won’t make any sound. At this point, I’ve lost count of how many CVS and Walgreens doors I’ve stashed in my R4!

Mark Location (listed as “user location” in the owner’s manual) works similarly, but you’ll use it for areas with a known radar source or a place where they “like to sit”. Upon entering this area, press the Mark button to save that location. The R4 will play a voice message the next time it is near that saved location.

memory quota

The updated R4 platform supports a feature called Memory Quota, something the R3 does not. Memory Quota allows you to set the individual number of Mute Memory and Mark Locations. In total, the R4 can save up to 2000 points between the two, but you can allocate them one way or the other in 50 point increments.

For example, I have my silence memory set to a maximum of 1750 assignments, which means I have 250 for marked locations. I tend to find more Mute Memory locations here in Detroit, so I want the highest possible allocation. However, I could drop that allocation to Mute Memory in 50 point increments if I need more space for the marked locations.

R4 Item Banner

Available on Amazon

Is the Uniden R4 worth the money?

If you’re a fan of radar detectors or like to own the latest toys and gadgets, then yes, the Uniden R4 is worth every penny. I will certainly always trust my R3, but I don’t regret upgrading to the R4.

If you’re new to radar detectors and want to buy your first, the R4 is a good choice. It is easy to learn and use and will warn you well in advance when a radar source is nearby. However, if you’re on a budget, go for the R3. Although it has fewer features than the newer R4, it’s still a good radar detector for your daily drive.

As of this writing, the R3 retails for $299 on Amazon, while the Uniden R4 is $350.

Carl Anthony is Managing Editor of Automoblog and a member of the Midwest Automotive Media Association and the Society of Automotive Historians. He is a member of the board of directors of the Ally Jolie Baldwin Foundation, a former president of the Detroit Working Writers, and a loyal fan of the Detroit Lions.

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