Jamming Ol' Smokey

Last updated: 2023

Rocky Mountain Radar jammers

For those seeking more protection than a detector can deliver, there's a veritable smorgasbord of gadgets claiming they can cloak your car with an impenetrable electronic shield. Some promise protection from radar, others from lasers; some claim they can defeat both. Another group promises protection from photo radar.

Passive radar jammers claim to jam radar by receiving the inbound microwave beam, mixing with it some white noise, then reflecting the altered signal back to the radar, so confusing it that no speed is displayed. Active radar jammers transmit a signal designed to make the radar disregard its own return signal, placing it in an endless loop trying to acquire a speed. Not surprisingly, it's a federal felony to possess or use an active radar jammer.

There's no federal law banning laser jammers although some states forbid their use. One anti-laser product that's 50-state legal is Veil, a clear coating said to reduce a laser's effectiveness. Learn more about Veil.

Passive jammers transmit nothing and are perfectly legal. Passive jammers were invented by Mike Churchman, proprietor of Rocky Mountain Radar. We first tested Churchman's magic boxes in 1993 and have since tested all his products, including the best-selling Phazer ($200), claimed to jam radar and laser and Phantom ($350), claimed capable of both detecting and jamming lasers and radar.

See how Rocky Mountain Radar jammers and others fared in our latest laser jammer test.

In reaction to past stories we've written for Automobile Magazine, the BMW Roundel, Mercedes Star, AutoTronics and Car Audio & Electronics, among others, the resourceful Churchman quickly renamed these same boxes--the new appellations include Illusion, Shadow, Eclipse, Patriot and Avenger among others--and continued doing business without missing a beat. He's also produced several private-label versions with names like Barrier-RDR and Barrier-LSR.

Except for the Phantom, which contains rudimentary radar-detection circuitry, each is essentially an empty box with a 12-volt power cord, a cheap cast-plastic waveguide assembly, one or two front-mounted LEDs, a basic power-supply circuit and a button or two. Press the button and an LED lights up, accompanied by a tinny bird whistle. ("Our patented 'FM Chirp', " company salesmen proudly proclaim.) We've tested these products a dozen times against every front-line police radar gun and laser, finding all of them utterly worthless.

Interestingly, while we were riding with Texas Highway Patrol trooper Mack Wallace near Houston recently, he stopped a Dodge minivan with Colorado plates. On the dash was a new Phantom jammer. The van pilot was told he'd been speeding. "Impossible," he said, "my Phantom jammed your radar."

"Didn't seem to be doing much jamming when you came by me," deadpanned the trooper. "I got you at 69 in a 55. Maybe you should take it back, ask for a refund."

Gatso Type 24 controller

On another occasion, for a film production we borrowed a Gatso photo radar unit, complete with marked Ford Explorer police vehicle, and were operating it next to busy six-lane I-225 near Denver. On the rear of the radar van we had mounted a giant speed display. During a break, we noticed a new Monte Carlo pass by several times, a time-consuming maneuver since it entailed a six-mile round trip between freeway exits. Then the Chevy pulled in next to us and the passenger window slid down. "I jammed your radar," the twenty-something driver said gleefully.

And how, I asked, had this been accomplished?

"With this," he said, pointing to a Phantom jammer on the dash. "I came past you three times and the sign didn't show my speed until I was right on top of the radar."

"The radar's supposed to work that way," I told him. "Target speed isn't read until the vehicle is within about 50 feet."

No way, he insisted. The jammer saved him. And it worked equally well against lasers.

"Tell you what," I told him. "We've got a new Kustom ProLaser II and an LTI Marksman. Why don't you back up about 700 feet on the shoulder and when you're ready, flash your lights and drive toward us. We'll try to get you on the lasers."

He loved the idea. When he was in position I handed the LTI laser to an assistant and hefted the ProLaser. When the pleased Phantom owner flashed his lights and started rolling, we both aimed and fired. Each laser displayed a target speed before he'd gone 30 feet. On impulse I snatched up a Kustom HR-12 hand-held radar when he'd closed to about 500 feet, pulling the trigger to lock in his 35 mph target speed. When he pulled alongside, we showed him all three readouts.

"This can't be," he said. "I just paid $350 for this jammer--and it's so good they'll pay for any tickets I get."

Watchful Eye fake jammer increased the radar's range thanks to its big, reflective antenna.

Another passive jammer is the Mirage 2001, a.k.a. The Watchful Eye, priced variously from $150 to $250. As we prepared to test one, company exec John Turner insisted that we separate radar and target car by 3,000 feet. Forget it, we told him. Typical radar target range in the real world is more like 700 feet. Turner left in a huff with his jammer.

After purchasing a Mirage/Watchful Eye we discovered that it had an alarming tendency to increase radar capture range. We found that at long range--over about 1,400 feet--the jammer's big antenna reflected enough extra energy to pump up radar range by as much as 500 feet. Try explaining that to the arresting officer.

One jammer that worked--sort of--was the Phantom RCD ($600). Originally labeled the Stealth VRCD, it was designed by David Sullivan, a Silicon Valley microwave engineer of exceptional talent. The Stealth employs four powerful Gunn oscillators--the same gadgets that generate a radar gun's microwave signal--to produce a strong jamming signal. It does so after it detects the police radar and deciphers its exact center frequency. Then it broadcasts a return signal which the radar accepts as its own. But target speed varies so wildly that the radar dismisses it as noise and continues trying to lock on. So engaged, it refuses to display a target speed.

Stealth VRCD

When tested a prototype Stealth VRCD we found it capable of amazing feats. On one occasion, while doing a test for Truckers News magazine, it made a barn-sized Kenworth cab-over tractor disappear from five of our seven radars even at point-blank range. But its performance was spotty--sometimes it refused to jam anything--and we found that bumpy roads tended to set it off accidentally.

Another big drawback: only X- and K band were covered. The prohibitive cost and extra bulk imposed by adding Ka-band dissuaded inventor Sullivan from attempting a triband unit.

Worse, when the current generation of police radar with DSP (Digital Signal Processing) began appearing in 1993, we learned that their lightning-fast signal processing will easily outwit the Phantom RCD's slower, analog circuitry. And since DSP radar has replaced the older units, driving today with a Stealth can be risky.

Shadow license plate cover

License plate covers began appearing in 1990 not long after photo enforcement became popular. Most use a clear prismatic material that's claimed to allow the plate to be read from directly behind the vehicle. Get off-angle a bit and the plate becomes obscured. Great concept but as we discovered, the execution is a bit flawed.

Recently we rounded up every plate cover available and tested them against each type of photo-enforcement threat--red light and speed cameras, and photo radar. We also tested spray-on material that claims to make the plate so reflective that the glare overpowers the camera and overexposes the photo.

None of this stuff worked. The Photo Blur and Photo Blocker sprays proved especially worthless. Learn more.

There are more countermeasures we'll examine in a future story. Meanwhile, be advised that the countermeasures market is positively awash in fast-talking con men, fringe loonies and mad-scientist inventor types.