RE: Phazer radar/laser jammer?

[DeWitt Harrison <de@aztek-eng.com>]

At 01:18 PM 1/20/98 -0500, Josh Pinkert wrote:
> [ ... ] As previously mentioned, C&D did an article
>testing the passive units.  According to their tests, the passive units
>that they used (I know Rocky Mount. Radar was in the test) did NOT reduce
>the effective range of the radar gun. [ ... ]

That's what I remembered too. Thanks for the corroboration.

>And I don't think subjective accounts of radar escapes counts as a valid test.
>There are many other factors that could account for a lack of police response.

Exactly. But such experiences can be very convincing anyway.

>There is ONE jammer I've heard of that really does work.  But it's only for
>laser.  I don't remember the name, but it's the license plate frame that
>emits laser when the cop target's your license plate.  Apparently, in
>combination with one of the diffuser covers, it can be extrememly useful in
>foiling laser.    Anyone used either or both of these?

I thought that same C&D article also discounted the license plate cover for
_passive_ laser defense, at least. Maybe somebody has an active laser emitter
to blind LIDAR. But that might get into legally tricky territory =:-0

Here is a little material from http://www.mr2.com:80/TEXT/radar_faq.txt. There's
a lot more.

>  Jammers usually come in 2 flavours, passive and active. The passive variety
>are those sold by Rocky Mountain Radar and others under the Spirit or Eclipse
>brands. These are supposed to get the incoming radar signal, scramble it up
>and retransmit back to the radar gun (without amplifying it further). The
problem
>with this theory is that the antennae is about 1 inch square, which is
minuscule
>compared with the frontal area of the car. Any signal sent out by the jammer
>would be drowned out by the reflections from the car and rejected by the noise
>cancelling software of the radar gun.
>   A test published on the Net by John deArmond and a test in Car and Driver
>(not surprisingly) found that these only make your bank balance invisible and
>not your car invisible.
>  Active jammers are the more interesting (and illegal ones). In this case,
the unit
>sends out a strong signal to drown out the reflections from the car. The
only unit
>for which I have seen independent test results is the VCDD Stealth, which sells
>for around $US700! The makers claim it is legal, but do you want to be a
test case
>to find out?
>  This works by combining a low quality radar detector with the
transmitter, When
>it detects a signal, it transmits in that frequency range. Both Car and
Driver and
>NZ Autonews did tests on  and it works with some serious provisios:
>- It only works from the front.
>- It doesn't work well at short range 
>- It only works on X and K band
>- It is very large and bulky
>- It sets off every other detector within miles
>  Given these faults, the high price and the likelihood of it being illegal
or made illegal,
>I don't think it can be justified.
>  There is another jammer advertised on the net with some interesting
claims. The
>URL is: http://www.shore.net/~adfx/2484a.html
>  There is a review of this on: http://www.orst.edu/~varineb/jammer.htm. I
have not
>had anything to do with this jammer and would like some more info if anyone
gets one.
>  Despite their claims for legality, I still have my concerns as listed above.

DeWitt Harrison    de@aztek-eng.com
Boulder, CO
88 5kcstq