[net.auto] Another radar jammer question

mzal@pegasus.UUCP (Mike Zaleski) (08/16/84)

In a number of articles about building radar jammers,
one point that is always mentioned is that a good one
is expensive.  However, given that a cheap radar
detector often jams (i.e. sends false signals to)
other radar detectors, it seems that a radar jammer
would be quite cheap.  Can someone explain this
appearant paradox?

-- Mike^Z    allegra!pegasus!mzal    Zaleski@Rutgers

dmmartindale@watcgl.UUCP (Dave Martindale) (08/16/84)

A cheap radar detector does not have to emit much energy for it to be
detected by another nearby radar detector when there is no real radar
signal present.  It would require considerably more signal strength
to reach the radar gun at a higher power level than the signal bounced
off the car itself when the car is in range.

Also, a simple continuous-wave microwave signal in the right frequency
range is enough for a radar detector to decide that there is a transmitter
out there somewhere.  But for a transmitter to jam the radar gun,
it should be modulated, or perhaps have its frequency locked to but shifted
slightly from the gun's transmitted signal.

Radar detectors just look for the presence of a signal which is assumed to
mean that there is a radar unit nearby.  Radar guns are measuring a particular
parameter of a reflected signal, and are thus harder to fool than the
detector.