K40 Electronics RD850 Radar Detector

Having experienced K40 Electronics' hardwired Calibre Bluetooth-capable radar/laser detection system, we were interested in seeing how the lower-priced RD850 unit stacked up. Portable dash-mounted radar detectors are a dime a dozen, but only the RD850 comes with a one-year speeding ticket guarantee. As long as you don't tear pavement in school zones, construction zones, or while completely toasted, K40 will pay for any speeding tickets you rack up within one year after purchase. This is a very good thing because, when you think about it, a radar detector is just a warning device, not a free-for-all cloaking field.

The RD850 is a simple-to-use unit, utilizing a cigarette lighter power plug and either suction cups or a visor mount for installation, perfect for leased or rented cars. Radar and laser detection comes from both the front and the rear, with a "5-window" design that helps the unit pick up on signals that aren't directly dead center. During our experience with the unit, the RD850 picked up signals easily. During freeway commutes, the unit worked fine, but on city streets, detection was far too sensitive. The RD850 features both audio and four-bar LED visual indication of laser and radar detection, and it let us know with beeps and flashes every few minutes.

For full sensitivity, the RD850 is shipped out with none of its filters turned on. This is great if you're on the interstate with just fields and highway patrolmen to keep you company, but in a major metropolitan city, you're going to want to turn on the Ka-band filter and turn off X-band detection to prevent false alarms. The Ka-band filter is activated using a single button press and, using the supplemental instructions from K40, we turned off X-band detection in four simple steps.

Once we turned off X-band detection and activated the filter, the RD850 began to work just as incredibly as advertised. False alarms were down and we were saved by the RD850 during two separate radar encounters. In the first occasion, we crested a hill with the RD850 blaring, finding a speed trap waiting on the hidden, downhill portion, while another time we were given advance warning of a highway patrolman sitting, radar gun ready, on the shoulder of the freeway. Considering that the RD850's $300 MSRP is well below the cost and hassle of a single, big speeding ticket, we don't see any downside to having one. After just a few calibration tweaks, K40's RD850 can reliably save your ass from racking up speeding tickets. When it comes to your driving record, it's better to be safe than sorry.