sdorsey@eng.umd.edu (Bill Dorsey) (06/14/91)
I'm working with some RAM (Radar Absorbing Material) here at work, and it occured to me that an ideal application for the stuff would be to radar- proof my car against police radar. I know police use X and K band radar to clock traffic. X band goes from 8-10GHZ, and K band something like 18-27GHZ. Now, I can get RAM that absorbs frequencies in the 8-10GHZ band with a minimum of 20dB of attenuation at 8 and 10GHZ, and 30dB of attenuation at 9GHZ. Theoretically, this will reduce the reflected signal strength on the areas covered with this material by over 100 times. This should result in much decreased range of the police radar. I run into a problem with the K-band. It's too wide for the RAM to work effectively on. Since the K-band is subdivided into a number of sub-bands (Ka, Ku, for example), I was wondering if anyone knows which band(s), other than the Ka band (for photo-radar) the police use? Around here, K-band radar is used more frequently than X-band, so I'd feel better protected with K-band police radar protection than X-band. If anyone else is interested in obtaining some RAM for experimentation, I can supply ordering information upon request. It costs around $55 per square foot (typically, a minimum order is 4 square feet). You don't need to cover a lot of your car, just metal surfaces that reflect radar back in the direction you're travelling (rear-view mirrors, bumper, possibly part of the hood, etc.). - Bill Dorsey (sdorsey@eng.umd.edu)
gd@erg.sri.com (Greg DesBrisay) (06/15/91)
Bill, I called up Cininatti Microwave (1-800-543-1608) (a maker of radar detectors) and spoke to a technical rep there about your question. She said that their detectors listen in frequency bands centered at 10.525 GHz and 24.150 GHz, and that those bands are only a few MHz wide. Greg DesBrisay gd@sri.com In article <1991Jun14.143930.28999@eng.umd.edu> sdorsey@eng.umd.edu (Bill Dorsey) writes: >I'm working with some RAM (Radar Absorbing Material) here at work, and >it occured to me that an ideal application for the stuff would be to radar- >proof my car against police radar. I know police use X and K band radar >to clock traffic. X band goes from 8-10GHZ, and K band something like >18-27GHZ. .... >I run into a problem with the K-band. It's too wide for the RAM to work >effectively on. Since the K-band is subdivided into a number of sub-bands >(Ka, Ku, for example), I was wondering if anyone knows which band(s), other >than the Ka band (for photo-radar) the police use? .... >- Bill Dorsey (sdorsey@eng.umd.edu)
bdhall@en.ecn.purdue.edu (Brian D Hall) (06/15/91)
In article <1991Jun14.143930.28999@eng.umd.edu>, sdorsey@eng.umd.edu (Bill Dorsey) writes: > I'm working with some RAM (Radar Absorbing Material) here at work, and > it occured to me that an ideal application for the stuff would be to radar- > proof my car against police radar. I know police use X and K band radar Aren't such applications illegal? Brian Hall
sdkuo@argo.acs.oakland.edu (Steve Kuo) (06/15/91)
In article <1991Jun14.211314.16835@en.ecn.purdue.edu>, bdhall@en.ecn.purdue.edu (Brian D Hall) writes: >In article <1991Jun14.143930.28999@eng.umd.edu>, sdorsey@eng.umd.edu (Bill Dorsey) writes: >> I'm working with some RAM (Radar Absorbing Material) here at work, and >> it occured to me that an ideal application for the stuff would be to radar- >> proof my car against police radar. I know police use X and K band radar > > Aren't such applications illegal? > > Brian Hall Why would that be illegal? He is simply adding material to his car (same as painting your car or adding ground effects). It just happens to be that police radar can not reflect from that material (unless there is a law saying that all cars MUST be able to reflect microwave signals). By the way, what color is this radar absorbing material? Is it a paint/paste or like a thin sticker? Steven D. Kuo N8OPH VMS: sdkuo@argo.acs.oakland.edu Ultrix: sdkuo@vela.acs.oakland.edu Oakland University, Rochester, Michigan, USA
amichiel@rodan.acs.syr.edu (Allen J Michielsen) (06/16/91)
In article <7260@vela.acs.oakland.edu> sdkuo@argo.acs.oakland.edu writes: >In article bdhall@en.ecn.purdue.edu (Brian D Hall) writes: >>In article sdorsey@eng.umd.edu (Bill Dorsey) writes: >>>...RAM (Radar Absorbing Material)...an ideal application...would be to >>>radar- proof my car against police radar. >> Aren't such applications illegal? >Why would that be illegal? He is simply adding material to his car... Actually, legally, under several conditions that is illegal in this country. If the state can prove beyond a reasonable doubt that the accused added such material to the car with the intention of impacting the states ability to inform uniform regulations, then it is illegal. However, if it is added to the car simply because it looks neat or he likes it, then there's nothing wrong. Further, there are actually about a dozen different crimes that would be committed, if proof existed. al -- Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University InterNet: amichiel@rodan.acs.syr.edu amichiel@sunrise.acs.syr.edu Bitnet: AMICHIEL@SUNRISE
ken@sugra.uucp (Kenneth Ng) (06/16/91)
In article <1991Jun14.211314.16835@en.ecn.purdue.edu>, bdhall@en.ecn.purdue.edu (Brian D Hall) writes: : In article <1991Jun14.143930.28999@eng.umd.edu>, sdorsey@eng.umd.edu (Bill Dorsey) writes: : > I'm working with some RAM (Radar Absorbing Material) here at work, and : > it occured to me that an ideal application for the stuff would be to radar- : > proof my car against police radar. I know police use X and K band radar : Aren't such applications illegal? : Brian Hall Active jamming of radar signals is illegal, passive absorbtion should not be. So far I have not seen any requirements for cars to have a minimum reflectivity. -- Kenneth Ng Please reply to ken@hertz.njit.edu until this machine properly recieves mail. "No problem, here's how you build it" -- R. Barclay, ST: TNG
wolfgang@wsrcc.com (Wolfgang S. Rupprecht) (06/17/91)
sdorsey@eng.umd.edu (Bill Dorsey) writes: >I'm working with some RAM (Radar Absorbing Material) here at work, and >it occured to me that an ideal application for the stuff would be to radar- >proof my car against police radar. I know police use X and K band radar >to clock traffic. X band goes from 8-10GHZ, and K band something like >18-27GHZ. Now, I can get RAM that absorbs frequencies in the 8-10GHZ >band with a minimum of 20dB of attenuation at 8 and 10GHZ, and 30dB of >attenuation at 9GHZ. Theoretically, this will reduce the reflected signal >strength on the areas covered with this material by over 100 times. This >should result in much decreased range of the police radar. I recall an article about making a stealth RX-7 a few years ago. Part of the method was to use radar-absorbing foam. The most effective application of this was to the front end of the car where the bumpers and hood presented a near vertical reflector back to the radar source. Naturely the article was called something like "The Worlds Oldest Trick - Foam Under the Bra". The author went on to classify the various radar reflectors he found on the car. The biggest two were the radiator and the seat backs. Angling the radiator down by a few degrees and replacing the factory metal-core seats with fiberglass reinforced ones did worked wonders for the author. -wolfgang -- Wolfgang Rupprecht wolfgang@wsrcc.com (or) uunet!wsrcc!wolfgang Snail Mail Address: Box 6524, Alexandria, VA 22306-0524
gt0869a@prism.gatech.EDU (WATERS,CLYDE GORDON) (06/17/91)
In article <1991Jun14.211314.16835@en.ecn.purdue.edu> bdhall@en.ecn.purdue.edu (Brian D Hall) writes: >In article <1991Jun14.143930.28999@eng.umd.edu>, sdorsey@eng.umd.edu (Bill Dorsey) writes: >> I'm working with some RAM (Radar Absorbing Material) here at work, and >> it occured to me that an ideal application for the stuff would be to radar- >> proof my car against police radar. I know police use X and K band radar > > Aren't such applications illegal? From my observations the only things they can get you for is actively recieving or transmitting radar rf (read jammers, etc) Passive stuff should be fair game. After all, there are no laws stating that you can't absorb rf. (as far as I know) Someone please correct if they know of such laws regulating absorbtion. I believe there are none simply because it has never come up. Regards, Gordon. -- WATERS,CLYDE GORDON-Georgia Institute of Technology Atlanta Ga 30332 ******<LANGUAGE IS A VIRUS! - Laurie Anderson-Home of the Brave>******* uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!gt0869a Internet: gt0869a@prism.gatech.edu
ssave@ole.UUCP (Shailendra Save) (06/18/91)
>> I'm working with some RAM (Radar Absorbing Material) here at work, and >> it occured to me that an ideal application for the stuff would be to radar- >> proof my car against police radar. I know police use X and K band radar > > Aren't such applications illegal? HaHaHaHaHa!......... No, these things are not illegal, and I am not laughing at that. The thing about having RAM is fine and dandy, but as you will find out (just as I did) is that the shape and size of those things are so funny, your car will look like a chameleon with overgrown spikes. The size: about 2 feet high, and shaped like a pyramid. Hope you can visualise this. Your aerodynamics get all messed up, you get wind whistle, and all kinds of unwanted stuff. And the worst part of it is that it will still not save you from radar. Why? Because there will still be parts of your car which will not have RAM on it. Like your windshield, or for that matter, lights' lenses. I attended a seminar at Univ. of Michigan, and the Prof gave a neat lecture about radar, and told us about how those things worked, and what you can do about it. There is only one fool proof way to stop getting a speeding ticket. And that is to use transit. :-) The only thing that is illegal, is to transmit. You can receive or absorb all you want. But don't listen to me. Have fun! :-) Shailendra ssave@caen.engin.umich.edu sumax!ole.uucp!ssave > > Brian Hall