Following is an article by Car and Driver on cordless detectors

Cordless detectors, 4/97:

========== Cordless detection might be convenient, but there's a price to be paid.

BY DON SCHROEDER

If you own a radar detector, think of the last time you drove naked -- no, not without clothes, without your detector. Maybe you just weren't up to pulling it out, mounting it, plugging it in. Or maybe your cell phone was hogging the lighter socket.

The first cordless, battery-powered detector, the Escort Solo, went on sale eight years ago. It quickly accounted for a third of Escort's detector sales and had the cordless market pretty much cornered until last year, when Bel introduced its 945i model. In our April issue, we tested six top-of-the-line models, one of which was the Solo. We attached the Solo's backup power cord and considered it as we did those other conventional detectors. This month, we assess the Solo and its Bel competitor from a cordless perspective.

We now discover that cordless detectors require extra scrutiny. Under battery power, the Escort and the Bel don't scan continuously for radar and lidar, but rather in short intervals, or "blinks," with a rest in between. The batteries last longer, but at a cost to some sensitivity.

To determine which detectors spent the most time hunting, and which spent the most time asleep, we checked the blink frequency and duration with an oscilloscope. Finally, we measured how long each detector works on a fresh set of batteries.

Our rating system is explained in last month's test. In a nutshell, we assign points for radar and lidar (or laser) sensitivity, for selectivity (the ability to remain sensitive while avoiding false alarms), and for how effective the city filtering modes are at reducing those false alarms. We also rate the detector's ergonomics (how informative the detector is and how easy it is to use) and the loudness of its warnings. By holding the cordless models to the same standards as the top-of-the-line models, you can compare ratings directly in deciding if you want to go cordless. Here's how the two battery-powered models fared.

Escort Solo

The Solo is not a stellar detector under battery power, but it's competent in most respects. It's also convenient, thanks to its thoughtful design and an abundance of programmable features.

The Solo provided adequate sensitivity to X- and K-band radar, but the range at which it could find those bands improved by about 20 percent when we used the backup cord. In the face of the still-uncommon Ka-band, though, the Solo was a weak performer. On battery power, the Solo was virtually oblivious to the presence of instant-on Ka-band radar even at distances of less than 100 feet. Drivers facing Ka and photo radar would do well to consider the Bel.

The Solo was not as prone to false alarms. We counted only eight in our 14-mile test loop around Ann Arbor. The Solo has four city filtering modes. Engaging the most aggressive mode that still allowed some X-band sensitivity cut the number of falses to one, which would have earned the Solo a full five points for its city score if not for its weak overall sensitivity in this mode using batteries.

The Solo is sufficiently sensitive to lidar, but its field of view to incoming laser beams narrows considerably under battery power -- only 42 degrees total looking ahead and 17 degrees behind. Use of the optional power cord, which improves these numbers to a quite acceptable 104 and 24 degrees, respectively, is advised if lidar is in play in your area.

The Solo's control buttons respond sluggishly. Otherwise, this detector is exceptionally easy to use. Its windshield mount is compact and easily adjusted. Discrimination among the three radar bands and lidar is excellent, in both the visual and audible warnings. And those warnings ramp up smoothly in urgency as incoming signal strength increases. That makes it easy to judge the distance of the threat. The Solo has many features that can be custom-tailored, from varying audible signals to disabling the auto-off function, which shuts the Solo down with a warning if no incoming signals are received for 45 minutes. The signal-strength meter shows battery life briefly when powering up and powering down.

The Solo will drain its two alkaline AA batteries in about 42 hours. It has an 8:1 sleep-to-wake ratio versus the Bel's 6:1 ratio, but it performs that sweep two times per second versus one for the Bel. Regarding safety radar, the Solo distinguishes Safety Alert signals and discriminates among four different hazards. The Solo's box proclaims it has a "Smartshield VG-2 rejection system," yet the VG-2 detector detector can smell this detector coming nearly three-quarters of a mile away.

The Solo is $200 from the factory; the transformer-equipped power cord is another $30. Considering the Solo's increased performance using the car as the power source, we recommend using the cord with it.

Bel 945i

Using batteries, the Bel detector offers more consistent lidar and radar detection than does the Solo. It would have ranked ahead of the Solo if it were easier to use and offered better warnings.

The 945i has sufficient sensitivity to all three radar bands under battery power. Like the Solo, it has a difficult time with instant-on Ka-band while cordless, although it manages to provide warnings at least a tenth of a mile away. Range improves across the bands by about 30 percent when it's plugged in. The Bel's city mode cut the number of false alarms from 10 to 3. This earned the 945i a full five points for its city mode because sensitivity was only marginally affected. The Bel scores poorly on selectivity because of its relatively weak overall sensitivity compared with the best detectors. This was the most likely candidate to receive false alarms from other detectors (see chart below left).

The Bel's lidar performance was consistent with either power source. Forward lidar sensitivity was on par with the Solo's, and forward field of view was an impressive 97 degrees, also with either power source. Field of view to the rear, however, was only 9 degrees, meaning it would likely miss most rear-fired laser beams.

Ergonomically, the Bel frustrates. Its visor clip is simple, but the windshield mount is unwieldy and must be adjusted with a screwdriver. The 945i's chirping alarms make the ears' job of distinguishing the bands next to impossible. The visual alerts are of little help, either, because the LED letters flash only briefly with battery power, requiring you to train your eyes on the detector for a few seconds to determine what threat you're facing. The Bel needs louder warnings, too. On batteries, they're quiet to begin with, and they drop to an average of only 73 dBA with the optional power cord attached. That's quieter than some car interiors at a 70-mph cruise.

The Bel will run through a pair of AA alkaline batteries in about 40 hours. Its sleep-to-wake ratio is 6:1, but it looks for radar only once a second, which can cause an increased warning delay compared with the Solo. The Bel's auto-off feature, which shuts down the detector after an hour without incoming signals, cannot be switched off. This detector distinguishes among four different SWS signals (see sidebar below). The "VG-2 guard" mentioned in this detector's advertising does not shield it from the infamous detector sniffer, which could find it nearly a fifth of a mile away.

The Bel costs more than the Solo, but we've found it discounted as low as $215. A 945iM for motorcyclists includes earphones and a reflector attachment that allows the 945i to be used vertically, in a breast pocket. This detector rates seven points higher with an optional power cord plugged in. If you use the cord often, be sure the volume is set high enough.

Our results clearly indicate the sacrifices involved in going cordless. Neither of these detectors offers the performance of the class-leading Valentine One detector. Run them on batteries, and their performance is reduced even further.