Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!usenet.ins.cwru.edu!cwjcc!neoucom!aablue!jb From: jb@aablue.UUCP (John B Scalia) Newsgroups: sci.electronics Subject: Re: Radar Theory Summary: Max speeds to most radar units Keywords: Kustom Signals Message-ID: <1163@aablue.UUCP> Date: 17 Jan 90 18:00:50 GMT References: <1990Jan12.042446.8799@waikato.ac.nz> <1990Jan15.164544.29488@utzoo.uucp> Reply-To: jb@aablue.UUCP (John B Scalia) Organization: A A Blueprint Co., Inc. - Akron, OH Lines: 34 In article <1990Jan15.164544.29488@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >Legal aspects aside, there's nothing hard about sending back a false signal >that overpowers the real one (the radar probably locks onto the strongest >signal, and reflections are fairly weak), although you'd have to be careful >to stay within the limits of the radar unit. A signal saying "500 mph" is >probably beyond what the radar's electronics are willing to consider as >plausible, and possibly beyond what they can receive at all. That is, it >might just light up its "something's wrong" light, or it might ignore your >signal altogether and go for the next strongest one. Indeed, they do this, or at least the Kustom Signals KH-11 does this. This used to be, I haven't paid attention lately, one of the best "smoking gun" units the troopers could get. A couple of us, local road racers of the legal on-the-track types, managed to have a state trooper time us on the straightaways. We were told the max the KH-11 would register was 165mph and upto 200mph, it simply flash the 165 reading. I don't recall being told exactly what it would do beyond this, other than a higher signal would be rejected. The trooper, though, had all kinds of problems with us as we were using very low slung, tube framed, fibreglass bodied formula cars with basically zip frontal area for reflecting the signal, although I got clocked at 135mph in my Formula Ford. I think if you were to try something like a nonsense jammer, pick a value around 140mph absolute or a +70mph relative. I shouldn't think any unit would have a problem with these numbers, and who'd believe it anyway? For what it's worth, jb@aablue.UUCP -- A A Blueprint Co., Inc. - Akron, Ohio +1 216 794-8803 voice UUCP: {uunet!}aablue!jb (John B. Scalia) Just a little more nonsense to clutter up the net.