Radar detector detector

A radar detector detector (RDD) is a device used by <a href="/facts/Police/rrdGISgt">police</a> or <a href="/facts/Law_enforcement/eneRFUdL">law enforcement</a> in areas where <a href="/facts/Radar_detector/bcbnJE0Q">radar detectors</a> are declared illegal.
<a href="/facts/Radar_detector/bcbnJE0Q">Radar detectors</a> are built around a <a href="/facts/Superheterodyne_receiver/S2SA0NCV">superheterodyne receiver</a>, which has a <a href="/facts/Local_oscillator/VQ5vQMEH">local oscillator</a> that radiates slightly. It is therefore possible to build a radar-detector detector, which detects such emissions (usually the frequency of the radar type being detected, plus about 10 MHz for the <a href="/facts/Intermediate_frequency/9mPpJtSA">intermediate frequency</a>). Some <a href="/facts/Radar_gun/UNB925gj">radar guns</a> are equipped with such a device.
However, like any device that detects stray emissions from electronic equipment, it is easily defeated by using adequate shielding.

Radar detector detector open-in-new

Radar detector detector