Overseas Efforts To Outwit Microwave Detectors

Press, Volume C, Issue 29553, 30 June 1961, Page 9

Overseas Efforts To Outwit Microwave Detectors

AMERICAN drivers are re- ** markably radar conscious and many attempts have been made to devise a counter to the many traps set up on their roads. Their efforts have been concentrated on jamming or distorting the radar beam. The successful methods are usually either illegal, very

e-.pensive, or highly impracticable. Many drivers have made use of tinfoil in an attempt to confuse the radar in the same way as aircraft dropped tinfoil during the Second World War to confuse the anti-aircraft defences. The idea is obviously ill-founded, for instead of confusing the traffic microwave, the tinfoil provides a better reflector. Noise Some drivers have tried to evade conviction with noise. A few have put ball-bearings in the hubcaps, others hav* sounded their horns. All these tricks help the traffic officers to hear them coming. One driver filled his hubcaps with uranium ore. and another painted all the ‘ chrome on his car with : luminous paint. Neither ; method was successful. ‘Chains and straps for earthing static electricity also : have no effect. There are two methods to upset the radar. One is to (transmit another radar sig-

| nal which will cause interference and the other is to create a false target for the radar beam. Radar transmitters have been used successfully, but the equipment is very expensive and hard to tune. A person using such a transmitter in New Zealand would face a charge of operating an illegal transmitter, for which the maximum fine is £lOO. One way of making a false target is to cover the car with drains that jiggle in the direction of the car’s travel Another is to festoon the car with fluorescent tubes driven by alternating current. The ionised gas inside the tubes reflects the radar and the speed of the flashes creates the required speed effect. Both methods are obviously impracticable—and in either case one would have to engage a remarkably astute lawyer to explain just why one were driving such a vehicle on a public highway.