Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mailrus!ncar!asuvax!enuxha!kluksdah
From: kluksdah@enuxha.eas.asu.edu (Norman C. Kluksdahl)
Newsgroups: sci.electronics
Subject: Re: Car electronics projects
Summary: active ECM
Message-ID: <205@enuxha.eas.asu.edu>
Date: 21 Jul 89 04:05:04 GMT
References: <14053@haddock.ima.isc.com> <1594@cooper.cooper.EDU>
Distribution: na
Organization: Arizona State Univ, Tempe
Lines: 35

In article <1594@cooper.cooper.EDU>, gene@cooper.cooper.EDU (Gene (the Spook) ) writes:
> 
> A change of roughly 3miles_per_hour_per_second or more, and the gun
> won't lock on to you.  What I have wanted to do for quite a while is
> to make a microwave generator that sweeps a few kHz on a 3MHz/24MHz
> carrier.  Active ECM!
> 
> (This, technically, is NOT a radar detector, but you might get in trouble
> with the FCC if your transmit power is too high!)
> 
One fellow I went to school with decided that simple radar detection wasn't
good enough.  He decided to do something about those nasty radars.  Being
an engineer-to-be, he decided it'd make a dandy senior design project.

First came the experimentation phase.  He carefully monitored the power 
he'd receive from a radar in all sorts of situations, then decided on an
order of magnitude higher power to jam with.  Some more playing gave him
a damn fast circuit to deduce the speed of the transmitter, based on the
frequency shift and his own speed.  Another little circuit gave him an
adjustable speed shift for the output signal.  Then came the transmitter.
Sort of archaic, fit in his trunk, not pretty, but it really worked nicely.
He found that he could drive at 85 or 90 right past the cops, who might have
been suspicious, but their radar said he was doing 55....
Last I heard, he wanted to boost the output power to see if he couldn't
actually fry the cop's detectors.

(BTW, he got a c- on the project.  imaginative and well done, but frowned
upon for its obvious illegality)

**********************************************************************
Norman Kluksdahl              Arizona State University
            ..ncar!noao!asuvax!enuxha!kluksdah
alternate:   kluksdah@enuxc1.eas.asu.edu

standard disclaimer implied