Radar Detector Signal Types

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James Burleigh

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So I got myself this here radar detector for Christmas and strapped it to my dash shelf and off I go speeding around because now I'm invulnerable and everything. And so it goes off all the time and yet there are never any cops around (yet, anyway).

But here's my question:

The thing is an alphabet soup of signal types: X, K, Ka, Pop, Spectre 1 and VG-2. What in the hell does it all mean? I have no idea what to think the threat is when one or the other comes up on the screen.

I've researched the forum and found plenty of info on type of detector to get and whether they're useful or not, but didn't find any information on how to interpret the signals. And of course the user manual is about as useful as, uh, I don't know--tits on a radio? :glare:

Anyone able to help sort this all out?

Thanks,

Jb

 
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Jb, what you are getting are called false alerts. Automatic door opener's on stores doors, and possible micowaves, motion sensors and intrusion alarms are usually operating on the "X" band, the same as "X" band radar but are usually pointed downwards and inside a building and will produce a weak signal on your RD vs. a strong reading from the police. A good RD unit will help eleminate these false signals. Most units though have a "city" setting and "highway" if not equiped with an "auto" mode that will set it for you. If your getting all these false signals in town make sure your unit is set on "city" and not "highway". You didn't say what kind of RD unit you have. "POP" mode is an instant on radar or if your unit is equiped "Lazer", and of special note that as of the beginning of this week in CA the CHP are now using "LIDAR" as in lazer! A good RD unit will pick up an officer using this unit at a long distance and this is how you can be alerted. If you get even a weak signal on the "POP" mode or "Lazer" is to be taken seriously. But if you are lazered by the officer yourself it is too late to correct your speed and you are nailed. But if you go here...RD website and there you will find tests results and some good info. Hope this helped. PM. <>< :D

 
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Thanks, Pain. I didn't want to say what kind of detector 'cause I didn't want to get off on a tangent of how bad my model blows.

I've set it to highway, since most of my riding is freeway. Maybe that's wrong. Should I default to city, since I'm in the Bay Area metro area? And highway is for more rural?

Jb

 
The thing is an alphabet soup of signal types: X, K, Ka, Pop, Spectre 1 and VG-2. What in the hell does it all mean? I have no
I'll help where I can, but I'm pretty sure that regional differences are large.

Ka band - is used by almost all NC State Highway Patrol and is probably the same in many states. It's typically an instant-on radar that sends out a "searching signal" which is too short for the detector to typically pick up. What that means is that as soon as you see the Ka warning in NC, you better slow your ass down and hope that it is checking someone ahead or behind of you. I can say without question, that NC SHP will hold the unit off in traffic and wait until they are right on a motorcycle. It's clear and blatent profiling.

K band - is the next most popular thing I see. It's used by a lot of city police and almost all those roadside radar speed signs. A common trick around here is they set up the radar sign and let it sit for a few days. Then they will position the cop a couple hundred yards on the other side with a K-band radar in his car. The idea is to get speeders accustomed to the false alarm of the radar sign, so they can nail you with the cop car radar. Yes, it's fun around here.

X band - is something I see very little of. Typically only small town cops with very short range radar use X-band in this neck of the woods. But it doesn't travel very far and can be extremely lethal over a hill or around a curve.

Door openers typically use K-band. So you will commonly see the K-band blip at a low level. Airport radar systems can also bounce off concrete overpasses and other large objects to produce low-level blips of K and X band.

I have virtually no experience with any of the other bands. Have not run into them yet in the southeast. Who's next???

 
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Thanks, Pain. I didn't want to say what kind of detector 'cause I didn't want to get off on a tangent of how bad my model blows.
I've set it to highway, since most of my riding is freeway. Maybe that's wrong. Should I default to city, since I'm in the Bay Area metro area? And highway is for more rural?

Jb
If your driving on surface or city streets use "city". If your out on the freeway or out of town use "highway". PM. <><

 
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Who started this? Not me!

Anyhow Western Mass. State Patrol has a nasty trick of rolling with X band. If you have your detector set for city or think X band is always a false alarm they got ya.

I found my new X50 came with the POP mode off, well I turned it on and every ride it goes off a few times always with another car rolling by the other way. This is always a false alarm, I think it's picking up the other cars radar detector. I left it on POP though cause it wakes me up!

Ka alarm means drop anchor quickly.

I've never seen a laser alarm. I think laser has to be shot at you stationary so you should be able to spot someone on the side of the road pointing a radar gun at you. Of course you can't very well see this at night. As I understand you don't get a laser alert, only a laser alarm that will confirm you've just been nailed.

I'd say the detector saves me a third of the time.

Being alert saves me another third of the time.

The cb radio and police scanner save me about a tenth of the time.

Yes I get stopped a lot, I'm not a good rider :ph34r:

Did you know you can pay your Mass. tickets online?

 
Yeah, Ka is what CHP uses almost exclusively, and I've never had a false Ka signal. It's like a Matrix agent detector. You see it, check yourself quick!

A radar detector is by no means the be all to end all. It's just a tool to compliment your arsenal, just like GPS. Live by it, die by it.

Instant on and laser will give you no useful warning.

Thanksgiving day I got to find out how the laser part works. It went off right before I saw the guy moving quick around the back of his car and waving us to the shoulder for 85 in a 70 on Hwy 99. I saw the car, but didn't consider it a threat until I saw the officer standing outside the rear passenger door. By then it was too late. Fortunately for me, he extended some professional courtesy.

Earlier in the trip, a patrol unit was parked up ahead, behind some other parked cars, and flipped on his radar as we approached.

Day before yesterday, I took the long, twisty way home from an appointment. Right about the spot where I got stung by the bee almost two years ago, in a 55 zone, my detector started chirping that familiar Ka tune. I slowed to 58, thinking it would be cool. He was following a couple of other cars that were heading my direction. The signal weakened as he passed, then I looked in the mirror to see him flipping around. Damn! You've got to be kidding me, 3mph over! He proceeded to nail the vehicle behind me that was catching up since I slowed. That guy must have been moving, as I passed him quite a ways back. He'd probably have been able to afford an Escort for the fine he'll pay, and a V1 for what it'll cost in the end, provided he can do traffic school to clear it. I can't, as I hold a commercial license and am held to a higher standard, which sucks, 'cause I'm a professional speeder on the commercial side.

 
I'd say the detector saves me a third of the time.Being alert saves me another third of the time.

The cb radio and police scanner save me about a tenth of the time.

Yes I get stopped a lot, I'm not a good rider :ph34r:

Did you know you can pay your Mass. tickets online?
Thanks, all. This has been very helpful.

I just want to say, the quote above is motorcycle poetry. A bit on the Dadaist side, but poetry nonetheless. :D

Jb

 
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Radar basics: The radar gun emits a radio frequency focused into as narrow a beam as possible then shuts off. The radar beam strikes every hard object in its path and all the reflections are returned to the antenna in the radar gun that is listening for the echoes. The return signal will have been modified by the Doppler Shift effect (frequency expands or contracts proportional to speed difference). The radar gun uses the amount of Doppler Shift (phase angle shift) to calculate the speed of the object that produced the largest return signal.

The opponent, the radar gun: A stationary radar gun can be set for one of several frequency ranges and the distance (power) of the signal. The gun can be set to read speed from a few hundred feet to several miles. A moving radar must also have active speed sensing for the radar unit and compensate the echo reading for the speed of the moving radar gun.

The playing field: In the early 60s the FCC opened up the X band (10.525 GHz; 10.525 billion cycles per second) for general public use. The intended applications could be automatic door openers and burglar alarms which are still used today. Radar guns moved into this frequency ‘band’. X band makes a widely dispersing beam and takes a lot of emitted power to return a signal strong enough to be detected. For a door opener this is no problem but for a long range radar beam this is not so good. Because of these limitations, this band is rarely used for speed radar any more and it is the largest offender for false radar speed control signals.

The FCC opened up additional frequencies for public use over the years to keep up with improving technology. The new bands are K (24.150 GHz) and Ka bands (33.4 - 36.0 GHz). In 1987 photo radar started useing 34.3 GHz. In 1991 Stalker (a brand of radar guns) started using 34.2 - 35.2 GHz and in 1992 BEE 36A (a model of radar gun) started using 33.4-34.4 GHz. Within these frequency bands there are specific ranges which speed control radar is allowed to use, they don’t have use of the whole band. Alerts on K band, and more importantly Ka band, are more than likely to be real traffic radar and not "false" alerts. K and particularly Ka bands produce much narrower beams and do not need nearly so much power to return a useable signal. This reduces radar ‘scatter’ making it harder for radar detectors. The lower power additionally makes it harder for radar detectors.

Radar gun use: Primitive speed control radar in the 60s was shaky at best. The radar units had to be turned on for as much as a half hour to warm up enough to be stable. Some even had mini ovens to hold the components at a constant temperature. The guns operated at high output levels and sprayed a large area with radar waves. This was radar detector nirvana. As technology improved, the guns reached a point where they could simply be turned on and used, but if the beam was shut off it couldn’t instantly turn back on and read accurately. This 'always on' beam was good for radar detectors. Technology moves up. Now the guns can be turned on ‘instantly’ with a pull of the trigger and they can immediately read the return signal – ‘instant on radar’. This gun still needed to have the beam turned on for significantly long times (in electronics terms) to acquire and measure speed. Technology move up. Now guns can turn on and produce a very short signal pulse at very low power (POP) and the gun can still make accurate speed measurements.

Newer guns now use ‘spread signal’ technology were the gun emits more than one frequency when the trigger is pulled. This is an old military radar trick to prevent a signal from being detected.

Radar detectors: The radar detector has one or more internal antennas which feeds a receiver where the signal gets amplified. The signal then goes to a ‘mixer’ where the radar signal gets mixed with an internally generated signal resulting in only one output signal, no matter what the antenna sees. This signal gets sent to a computer controlled signal manager. For a radar detector to ‘see’ X band, the internal signal generator must be altered to an accommodating frequency and sniff for a signal. The radar detector then changes the internal signal to accommodate K band and sniff for a signal, and so on with Ka. If a signal is detected in any of these bands the detector then must determine if it is real speed control signal or spurious (false) like a burglar alarm or door opener. If the software determines the signal is a threat it send an audio/visual alert with a tone appropriate for the band detected. The V1 will also process for signal strengths from all its antennas and illuminate arrows to show the direction of the threat.

The significance of this is that the radar detector is always very busy. It can not ‘stare’ at any one frequency, it has to hop from band to band. With older radar guns this is no problem, they have their signal on long enough for the detector to eventually acquire the signal and do a threat evaluation. The newer POP radar guns produce a signal so short that it simply comes and goes. If the radar detector was looking anyplace but at that very frequency it will miss the pulse, thus no warning. Also, the newer guns use a very, very low power signal which drastically reduces the distance that they can be detected from. Advantage speed patrol.

LASER (LIDAR): [skooter sez]Using the speed of light that the pulse is traveling, it measures the time it takes to hit the target and return to calculate a distance. Then compares that distance with the distances calculated from repeated pulses to calculate the target's speed.[/skooter sez] The light beam is so narrow that the LASER gun usually has to have a scope sight similar to one on a rifle. Because of the pencil beam, there is almost nothing to fan out and scatter so there are no stray signals for your detector to detect. All the officer has to do is pull the trigger on the LASER gun and bam, your day is shot (so to speak).

Working in our favor is the fact that the LASER gun is so precise. LASER enforcement is not mobile, requiring a road side setup. The officer has to stand in the open, track, target and shoot the suspect vehicle. Then must read the speed, run for the cruiser, divest of the gun, buckle up and initiate pursuit. Or, they must work as a team with a spotter and/or gunner, and a chase team. In almost all cases it is hard to hide LASER enforcement if you are observant.

"In almost all cases it is hard to hide LASER enforcement if you are observant."[ponyfool amends] Shooting the target vehicle from behind, from on top of an overpass. If the officer has a steady hand or braces the unit, no windshield mounted laser detector, not even the V1 or X50, will ever even know the speed was measured. The ONLY detector capable of detecting this type of reading is a rear mounted license plate frame sensor, and only then if the officer aims for the plate (which is the typical aiming point because of the reflective material). [/ponyfool]

Detector Detectors; VG-2; Spector: Back to the radar detector and that internal signal generator (super heterodyne). The sensitivity of the detector is related to how strong the signal generator is, so in all quality detectors it is very strong. The bad news is that this signal ‘leaks’, well actually sprays out of the detector and out of your car at very significant power. This frequency is always close to X, K & Ka but not precisely the same as the radar gun frequency. A radar detector detector has an antenna tuned for this slightly off kilter frequency. It works good! Damn good. In fact, the only way you can really hide is to shut off the detector. Radar detector manufacturers have tried to work around this by using a second, different signal generator frequency. This is just too simple and the new detector detectors have no problem anymore. Some new radar detectors claim to be shielded and resistant to detector detectors. While improved, they still are readily detectable, only now, instead of being detectable at miles, the detection range is smaller fractions of a mile. The Radar Detector Detector VG-2 scans the 11.4 to 11.5 GHz range. The Spector, now in I, II, III models scans for radar detectors across a wider range of frequencies.

Police use radar detector detectors (hence forth called RDD) to sense when radar detectors are in use, particularly where radar detectors are illegal. Some police departments consider it useful to know that a car being tracked is using a radar detector. When your detector specifications claim VG-2 and/or Spector it means that your radar detector is shielded with the intention of making it undetectable to VG-2 or Spector RDDs. Some radar detectors like Cobra go so far as to give you an alert that the police are using a RDD in your area.

VASCAR (Visual Average Speed Computer and Recorder): Silent and deadly. This is a manual time/distance calculation. It used to be performed by stop watches and time/distance tables. It is now making a reemergence with modern electronics. The speed control officer will find two reference points and measure the distance between them. As a vehicle passes the first reference point, the timer is started, as the vehicle passes the second reference point the timer is stopped yielding the elapsed time. Straight time/distance calculation yields mph. This is also how aircraft measure speed. If the two reference points are too close together human reaction times will taint the readings, and if the reference points are too far apart depth of perception will effect readings.

RADAR works best when the target vehicle is directly in line with the antenna (180 degrees forward or backward). As the angle between the target and the radar unit becomes less, the speed error goes up (cosine error). With VASCAR the speed observer needs to be as close to 90 degrees as possible.

Pacing: Officer simply moves at the same speed you are, either behind you or shielded by another vehicle. There is no excuse if you are bagged by this technique.

 
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How can someone find out if laser is being used in your area, is their a data base or web site with this info?

Or does anyone know what is used in Utah?

 
I probably should have mentioned that I ALWAYS leave my detector on Highway. I'll take the false alarms and process them myself rather than risk missing a valid warning.

Also, around here we have trees that lose their leaves in Winter. If the trees are sparsely positioned along the road side and cast harsh shadows at frequent intervals across the road. The alternating bright sun/dark shadows can occur at just the right frequency to create a false laser alarm. Trust me, it will wake you up.

It took me a couple months to determine exactly why my RD was triggering Laser alarms when I knew that guy's mobile home was not a laser-base hideout. This seems to be a condition that rarely, if ever occurs with the RD inside a cager. I believe it's because of the typical angle of the light coming from the side and how the cager's windshield diffuses and filters the light.

But with the RD exposed to the elements and receiving direct sunlight in rapid pulses, false Laser alarms are very possible.

 
Have you posted that info to the FAQ's yet? Good, usable stuff.
Thanks! I will sent it along when complete.

I'm waiting for the, "your full of shit, everything you said is all wrong, and the -- but you forgot/missed" contingency to check in first. :lol:

 
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Have you posted that info to the FAQ's yet? Good, usable stuff.
Thanks! I will sent it along when complete.

I'm waiting for the, "your full of shit, everything you said is all wrong, and the -- but you forgot/missed" contingency to check in first. :lol:
They are too busy taking traffic school and writing checks to their lawyers.

:hmmsmiley:

 
Have you posted that info to the FAQ's yet? Good, usable stuff.
Thanks! I will sent it along when complete.

I'm waiting for the, "your full of shit, everything you said is all wrong, and the -- but you forgot/missed" contingency to check in first. :lol:
You're full of shit. There. That's done. Now you can post this thorough and informative post where it belongs.

Thanks!

Jb

 
X band - is something I see very little of. Typically only small town cops with very short range radar use X-band in this neck of the woods. But it doesn't travel very far and can be extremely lethal over a hill or around a curve.
IIRC, proximity burglar alarms use this band. I've had mine go off in the parking lot at work when someone has their burglar alarm set on their cage.

FYI, CHP uses Ka band...and the suggested reaction is correct: slow down until you see where they are. On I-80 the CHP is using some sort of device with "binoculars" (?). I assume that is a LIDAR targeting device as the oficers are stationary.

 
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