Newsgroups: alt.2600
Subject: Jamming Police Radar
Date: Sun Jun 12 21:35:23 1994


>>Has anyone ever successfully jammed a microwave or laser gun?

> I seem to recall a device from a few years back that emitted microwave
> were shifted just right in the car's forward direction to make the car
> like it was always going 55, or whatever you dialed in for it.  It mus
> have had some kind of linkage for the speedometer, or you just told it
> your actual speed and then your "measured" speed.

 Simple. You present the microwave signal with a return LARGER than the
return of your car... the gun will TRY to lock onto IT, instead of you.
(this is in fact how they work, they attempt to lock onto the strongest
signal return avail)

 Now, how DO you present a LARGER target than your car? Well, we're
talking microwaves here, not visible light ;)

 I'm sure that most folks in here have heard of "chaff", the radar
reflective aluminum strips used to fool missile radar ... they WORK by
being cut to a precise size ... the OPTIMUM size for reflectivity of a
certain wavelength, thus they return a larger signal than a massive jet
fighter, even though they are fractions of an inch in size.

 Now, you might ask "so... I've presented the radar with a target that
returns a larger reflection than my car... but it's MOVING along WITH
me, an will accurately reflect my speed on the gun" ...

 Ahhh, but it is NOT mounted to your car; police radar needs for a
target's speed to be relatively CONSTANT before it locks on, and
displays a speed reading, thus you must make the speed of your "chaff"
change rapidly ... by mounting it on a speaker behind the grill of your
car.

 You drive the speaker with audio noise, the chaff on the cone vibrates,
the police radar sees the chaff, and NOT you, viola; it can't lock on,
and the speed display remains blank.



                                            Jkay@Vnet.Net


 * Where's yer PANTS, BOY?!