Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!psuvax1!psuvm!bhb3
From: BHB3@PSUVM.BITNET
Newsgroups: sci.electronics
Subject: Re: the undetectable radar detector
Message-ID: <89339.001211BHB3@PSUVM.BITNET>
Date: 5 Dec 89 05:12:11 GMT
References: <89333.113354BHB3@PSUVM.BITNET> <1840016@hpsad.HP.COM>
Organization: Penn State University
Lines: 48

In article <1840016@hpsad.HP.COM>, billk@hpsad.HP.COM (Bill Katz) says:
>
>Brent Beseler writes:
>
>>Would the following idea work:
>>
>>Suppose the reciever horn of a detector is mounted in front of the engine    l
>gril
>>etc. in a hidden location.  Right behind the horn would be a microwave       e
>amplifi
>>r circuit.  That would feed into a cable.  The cable would run to a well     d
>shiel
>>ed reciever.  This system would not emit the 11.5 Ghz frequency that the
>>radar detector detection systems use.
>>                                          Brent H. Besler
>>                                          FOrd Motor Scientific Res. Lab
>
>
>        Yes, it is possible for a system such as you describe to be built
>that would not radiate the local oscillator.  In addition to a preamp, a
>filter would also help.  (You would ideally have a separate filter/preamp/
>mixer for each band)  As you state you would also need a well shielded
>receiver.  This is a non-trivial task, depending on how close you want to
>be able to get without your LO being detected.  Shielding 11GHz effectively
>is tough, but can be done.  I doubt it can be done at the prices they sell
>commercial radar detectors for.
>
>______________________________________________________________________________
>
>   _   /|       -ACK!        Bill (the) Katz     Internet: billk@hpsad.hp.com
>   \'o.O'       -PFHHHT!     Hewlett-Packard         UUCP: hplabs!hpsad!billk
>   =(___)=      -COUGH!      Signal Analysis Div.   Phone: (707) 794-2300
>      U         -ACK!        1212 Valley House Dr.    Fax: (707) 794-4452
>                             Rohnert Park, CA 95428
>______________________________________________________________________________

I searched for plans or kits for detectors and came up with a simple design
in the July 1986 Radio Electronics.  It is not a superhet circuit, but it
would be a no emmision system if it works as well as claimed.  It would need
to have a spearate circuit for K and X.  My knowledge of microwabe circuit
is pretty minimal, but we have a good 1984 book on solid state microwave
circuit in the library and it seems IMPATT diodes work well as low noise
microwave amps.  A clever detector would use spearate oscillator circuits
not working at 11.5 Ghz.  Of couse importing detectors into Cananda is
probably illegal, but then CMI adds to seem to hint they ship to Canada.
If price were not an object, it would be a good product.

                                                    Brent H> besler