This type of product is advertised almost everywhere that it helps you avoid tickets etc. I imagine that it must transmit a signal on the same freq. as the radar gun at the moment it receives the police transmission. Even at low power can this still meet part 15 of the FCC rules or any part for that matter? I happen to drive slowly but millions of people don't. Can someone please tell me how it works? How can something like this product which for all intents and purposes "interferes with police business" be legal? Just wondering. Lenny
Like anything else, it's legal until they decide to prosecute.
And the police have been coming up with more and more creative ways of prosecuting.
For example, making a video or audio recording of a police officer is now construed as illegal wiretapping and they will do their best to put you in prison for it.
As in all aspects of life, the best course is to consider, "Is somebody going to find someway to throw me in prison for this?"
If the answer is even remotely a "yes", then don't do it.
No kidding? So if I use my digital recorder to record a police officer giving me a ticket and he says something illegal the recorder catches, I could go to jail for recording it? I would think the recorder would be considered a personal security device and I could record anything I wanted as long as I was there. I record a lot of conversations without people knowing, and the cops usually record traffic stops. I haven't been stopped in over twenty years but all the cops in a nearby town a as crooked as they can be, everyone knows they control most of the crime in our area.
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Is Obama an Internet Junkie? Why does he think it is the US governments
mission to spend $18,000,000,000.00 billion dollars to get high speed
Internet to all Americans? Shouldn't private companies do that? A better
use of that money would be to build Waste Incinerators that cleanly burn
trash and generate electricity for every city in the US. There are
already 140 in the US, lets build more, and stop dumping trash in the
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In Pennsylvania it's illegal to record someone without his permission without a court order. AFAIK even police cars with video recording equipment don't record the audio.
I can see that the situation of those people videotaping the police could be construed as disturbing the peace, but if they hadn't made a big scene of it, and if the police weren't doing anything illegal, the police shouldn't be afraid to be filmed. Video can help keep cops honest. With all the cell phones that can take video, there should be a law allowing anyone to take video of anything that happens in front of them, including audio recording anything. Anything else would be a violation of our civil rights, otherwise cities with CCTV cameras, where video of citizens committing crimes are used against them, that video should be excluded. The law should be fair for everyone or fair for no one. I've often thought cops should have to wear a video camera that also records audio, for their entire shift, then downloaded and saved when the shift is over. Thats just how I feel and I'm by no means a liberal.
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Is Obama an Internet Junkie? Why does he think it is the US governments
mission to spend $18,000,000,000.00 billion dollars to get high speed
Internet to all Americans? Shouldn't private companies do that? A better
use of that money would be to build Waste Incinerators that cleanly burn
trash and generate electricity for every city in the US. There are
already 140 in the US, lets build more, and stop dumping trash in the
oceans.
Every time something is proposed to make them do their job correctly and legally, they throw their hands up, "But we can't do our job!" and the assorted unions step in to block it as well.
The "management" gets involved and finds new creative ways to distort laws to their own purposes to "protect their own."
You have a good imagination. The illegal ones are essentially radar jammers. That's not as easy as it sounds as getting the timing just right so that it coincides with a radar *PULSE* is tricky. Most handheld radars now work on several bands simultaneously, making a universal radar jammer somewhat difficult and expensive to produce.
The FCC fails to appreciate such products:
Note the $25,000 fine. Intentional Part 15 radiators (as opposed to incidental radiators) are restricted from operating in various bands (15.205) which include all the radar bands. Nice try.
Careful. I've received a ticket for driving too slowly on the freeway.
How what works? There are dozens of products, varying from crude jammers to ultra-sophisticated military ECM rehashes. Each works somewhat differently. This might help:
47 U.S.C. S 333 of the FCC rules clearly states that active radar jammers are illegal. Note that S 333 is up for revision due to intentional cell phone jamming in prisons etc.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
One approach was describe several decades ago in a 'build it yourself' project in 'Radio Electronics' magazine.
Speed radar works by sending a high frequency pulse and comparing the frequency of the returned signal to the original. The frequency shift of the return pulse will be proportional to the relative speed of the radar gun and the object generating the reflection.
The R-E article was for a 'radar gun calibrator'. By taking the received signal, amplifying it, modulating it, and transmitting only one of the sidebands, a synthetic 'echo' would be produced with the precise frequency offset desired.
As far as selling them, don't bother. You can make more money by selling tinted plastic license plate covers, claiming they will 'fool photo speed enforcement cameras'. Of course, the real fool with be the person sending you his money.
Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:
How are the HANDHELD radar guns multi-band? they would have to have multiple Gunn oscillators,too.
And more than one feed horn.(antenna) Most that I've seen on police cars are pretty small units.
AFAIK,most radar guns are Doppler,and the receiver reads the strongest signal it receives,so transmitting a signal from your "jammer" overpowers the reflected radargun signal.That jammer signal has to be near in freq to the gun's signal,or it will be rejected,because it would indicate a higher speed than the gun will measure or considers reasonable.Then the speed gun would light it's "interference" indicator.
do you have any information on or links to these multi-band radar speed guns?
snipped-for-privacy@yawhoo.com wrote in news: snipped-for-privacy@4ax.com:
one "calibrator" I've seen was a simple one transistor oscillator,and it was for checking radar DETECTORS. at a short range,it would set off X-band detectors. IIRC,it used a MF914 transistor and stripline PCB. or maybe MF912....
OK, the answer... 1. They don't typically work, and 2. they are not legal.
In theory one could build a jammer circuit, that would work with one specific brand/mdel of radar gun, however such a system may not work with other brands or models, and as well any attempt would violate federal law absolutely and many states also have prohibitions against such devices.
PeterD wrote in news: snipped-for-privacy@4ax.com:
"in theory",one could build a channelized EW(electronic warfare) suite such as military aircraft use,and it would work with all known radarguns. Cost would be prohibitive,though. Just fitting one to your vehicle would be a real Project.
BTW,I wonder if a broadband whitenoise type of jammer would work,burying the radargun's signal in the noise. You'd need substantial power and have to cover each band used for radar speed guns.it could be triggered by the first radar pulse and xmit long enough for you to pass the patrol car or to slow to posted speed after being alerted.
Still highly illegal,though.
then there was that guy who made a "stealth" car,faceted like the F-117. no radar return,no speed measurement. :-)
Maybe, but I've worked with horn antennas with several octave bandwidth. It's not the horn that's bandwidth limited. It's the waveguide feed. Figure about 0.6 octaves per standard waveguide number:
Since only one feed need be active at a time, it's easy enough to build a switch or just imbed the Gunn diodes or DRO (dielectric resonant oscillator) and detector diodes in the throat of the horn, where no waveguide is necessary. Or, just forget about the switch and use multiple patch antennas on a PCB to feed the horn antenna:
(Note: This is an X band design, which is NOT commonly used in current police radar guns).
I'm wrong on the dual band feature. Kustom Signals advertises a "dual K band" device (RP-1) for either K (24Ghz) or Ka (33-36Ghz) bands. I wrongly assumed that this meant that the device was dual band. It really means that it has two antennas, one internal and one external.
My apologies for the wrong info and thanks for the corrections.
The problem is for the jammer to figure out what frequency to jam and then to synchronize the pulse repetition rate to that of the radar. That's not easy when it could be arriving on X, K, Ka, and possibly Ku bands. It doesn't take very long to get a reading and if the jammer is listening on the wrong band or simply too slow, it will be too late.
I have two of these radar guns, in rather poor condition:
While totally obsolete, one does function well enough to measure speed. I must admit that I've never tested it for jamming tolerance. Tempting to build this ummm... tester:
No, nor could I find any. There might be some patents but after a few minutes of zero luck, I gave up. I recall discussing the problem during a show with someone from Kustom Signals, who indicated that a solution to a potential jamming problem was to frequency hop through the available bands. At the time, only X and K bands were available, so I assumed that this was the current technology. Apparently not.
Radar Gun FAQ:
Ramsey Radar Gun:
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# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS
No RF involved. It generates a tone that modulates the Gunn diode bias voltage, thus simulating a doppler shift.
You might be thinking of the Highway Zapper Radar Activator.
It's an X band radar jammer that triggers radar detectors, but doesn't seem to interfere with the police radars.
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# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS
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