Radar Detectors

So are you saying not to buy? http://www.radarjammers.com/pages/whatarethey.shtml

Uncle Meat said:

I love it when people answer radar questions with a statement like this. Shows how truly uniformed about the subject they really are. A radar detector is a tool and like any tool you need to know how to use it properly.

U.M.

Click to expand...

You are correct sir! A 9/16 wrench is a great tool, but if you don't know how to use it, it's just a paper weight!

SVTdriver said:

So are you saying not to buy? http://www.radarjammers.com/pages/whatarethey.shtml

Click to expand...

Nothing by RMR or Rocky Mountain Radar will jam laser or radar and their radar detection sucks.

http://matt.simerson.net/reference/radar-scam.shtml

http://www.radarjammer.com/

http://www.wreg.com/Global/story.asp?s=3508464

http://forums.corvetteforum.com/showthread.php?t=1246356

http://www.1-radar-laser-jammers-detectors.com/support/what-are-scramblers/index.php


Here are some videos of all RMR products not jamming anything:

http://www.laserjammer.citymax.com/f/JammerTests.com_tests_rmrc450_and_Phazer_2.wmv

http://www.laserjammer.citymax.com/page/page/1124915.htm

RaDaRkInG said:

Nothing by RMR or Rocky Mountain Radar will jam laser or radar and their radar detection sucks.

http://matt.simerson.net/reference/radar-scam.shtml

http://www.radarjammer.com/

http://www.wreg.com/Global/story.asp?s=3508464

http://forums.corvetteforum.com/showthread.php?t=1246356

http://www.1-radar-laser-jammers-detectors.com/support/what-are-scramblers/index.php


Here are some videos of all RMR products not jamming anything:

http://www.laserjammer.citymax.com/f/JammerTests.com_tests_rmrc450_and_Phazer_2.wmv

http://www.laserjammer.citymax.com/page/page/1124915.htm

Click to expand...

This I know. My point however is anyone can come up with positive reviews on any product. So to say one is better judged on reviews. Is not neccessarily the best way to do it. As for the person that tested both side by side. I don't know how you did it. Since my escort goes off at random intervals anytime it is near another radar detector. And I have heard this is a common occurence if you get 2 radar detectors near each other.

i'd say about 10% of the cops on the road atm are using laser radar guns. Most of them just use Ka and K.

zoop66 said:

it doesnt matter because most patrol cars have instant on and will get your speed before you know they are there.

Click to expand...

I'am with zoop, never owned a detector saved $$$ I've been pulled over many times with no tickets, just lucky I guess In my younger years not so lucky, but I guess with age comes wisdom (also cutting your hair helps)- no I haven't slowed down, just learned how to talk my way out of a ticket. Also have you ever heard the saying "you can smell a cop"? ( not literally I have the utmost respect for police) "Drive Safe Not Stupid"

SVTdriver said:

As for the person that tested both side by side. I don't know how you did it. Since my escort goes off at random intervals anytime it is near another radar detector. And I have heard this is a common occurence if you get 2 radar detectors near each other.

Click to expand...

http://guysoflidar.com/twodetectors.html

Why it's a Bad Idea to Run Two Radar Detectors in the Same Vehicle
--------------------------------------------------------------------------------
Just because two detectors don't set each other off doesn't mean that they arent interfering with each other. Here are a few resons why you shouldn't run two together in the same vehicle.



It Could "Fool" the False Alert Filtering

Many people familiar with detectors know that false alerts can sometimes be caused by other detectors operating nearby. What is not so obvious, is during their regular sweep, most detectors are also scanning for other non-police radar frequencies that, if detected, could BLOCK or PREVENT an alert.

Superhetrodyne radar detectors contain "Local Oscillators" (or LO for short). LOs create a radar signal that is utilized to "mix down" the incoming radar signal for detection. Although the LO is only used inside the detector, in many cases because of the design etc the LO is actually "leaked" or "transmitted" from the radar detectors (this is the signal RDDs detect to know if a radar detector is being operated) Many detectors on the road have a 1st LO that operates in the 11-12 GHz range. The problem is, that these LOs also produce "harmonics" at multiples of the LO frequency. So, in once classic example, an LO operating at 11.55 GHz would produce a harmonic at 34.65 GHz.

This poses a problem for detector makers. They need to suppress false alerts from other detectors, while allowing real police radar through. So here's what they do: they take advantage of the fact that if another detector is producing a 3rd harmonic harmonic in the Ka band, the fundamental or 2nd harmonic will also be present. But with police radar, no harmonics with these characteristics would be present, since the fundamental frequency of these is in the Ka band.

So, per the above example, if Ka radar was detected at 34.7 Ghz, the detector would also check the LO fundamental at 11.558 GHz, or the second harmonic at 23.116 Ghz. If one or both of these were present, the detector would know that the Ka radar was a false harmonic from another detector and would suppress the alert. So in addition to looking for police radar, most detectors also look for these LO frequencies or ther second harmonics. If the LO frequency, the 2nd harmonic, or both are present. they can tell that the detected radar signal is not police radar and can suppress the false alerts from other detectors.

So, what if a leaky detector is nearby at the same time as police radar is?

Some of the high-end detectors also put fail-safes in place for this: they will examine the signal levels of the harmonics and the Ka radar. If the Ka signal is much stronger than the harmonic, the detector will alert anyway, just to be safe. This works great, except when another detector is operating in the same vehicle. Because the two detectors are close to each other, if one detector sees a harmonic from another, that harmonic will always be strong compared to any real police radar that is detected.

In some cases, the harmonic doesn't even need to be detected at the same time as the Ka radar for the alert to be suppressed, as long as it falls into a "time window" specified in the detector's software.

The whole thing gets pretty complex:
-there are countless frequency schemes used by different detectors, in addition to the 11.55 GHz example above.
-the oscillators are sweeping
-the oscillators in some detectors will "park" to get a closer look at suspected police radar.


All it takes for one detector to suppress a Ka alert on another is for the wrong frequency from the other detector to be detected at the wrong time.



It might cause a detector to "park" often during it's sweep

Some detectors operate by sweeping quickly to look for police radar, and when they see a signal, they "park" their LO to get a closer look at the signal to see if it is really police radar. With another detector operating in close proximity, it might see leaked oscillator interference from the other detector and "park" on different frequencies in order to get a better look. Even if it determines that it isn't police radar that caused the "park" and suppresses the alert, it will still have the effect of unnecesssarily slowing down the overall sweep, reducing the effectiveness to real police radar. This can be especially critical to POP performance.



It could raise the "noise floor"

With a microwave oscillator operating in close proximity, it likely raises the "noise floor" in different bands. The detectors use singal averaging between multiple sweeps to identify a threat-level signal, so raising the noise floor would have the effect of making it so that a stronger signal would be necessary for the detector to be able to pick out radar signals from the noise.

Even enclosing the detectors in metal isn't going to prevent this, since a lot of the leakage comes from the antenna.



It might be OK on some bands/frequencies but not others, it might work just fine until the sweeps of the two detectors coincide with each other in a certain way. But there's just no way to be sure when it is a problem and when it isn't.

You'll hear some people say that they've done run two together for a long time with no problems, but how do they know for sure?

So bottom line: to be safe, don't run two detectors in the same vehicle, especially if you are comparing performance.


http://valentine1.com/lab/DoItYourself.asp

First Problem: Detectors hate each other - Every superheterodyne receiver—that includes all of today's radar detectors—receives and transmits during normal operation. As you probably know, these detector signals sometimes set off other detectors. Out on the road, other detectors are the most common nuisance signal V1 has to deal with.

What's not so obvious is this. Even if a detector isn't set off by another one, it's internal defense system maybe be affecting its radar sensitivity. This problem compounds when you bring two operating detectors into the same car. Up close, the transmitted signals become much stronger than a normal design would anticipate, and the weak signals that wouldn't bother at normal distances can send the defense system into hyperdrive.

V1 inspects every signal it receives and decides, Is it really radar? Is it maybe radar? Is it not radar. But it isn't designed to operate within a few feet of another detector, and we know of no other detector designed for that high-stress condition either.

Here's the irony: If you put two detectors together and one of them seems sluggish, you might decide that one is inferior. In fact, it may have a superior defense system, and the detector that appears to work better may be a grotesque polluting transmitter.

It's more trouble to test detectors by powering up one at a time, but it's the only way to tell which is better at finding radar.

Second Problem: What if they don't seem very different - Since all detectors warn when they go line of sight with the radar transmitter, they often sound their warnings well before you see the radar. But as I explain at length in Radar Detector Tests, the critical test of early warning is, What do you get "when the headlights are still beyond the hill?" The point here: To test meaningfully, you need to know the location of your radar. Are you really over the hill, or are you dipping in and out of line-of-sight as you approach. If you're dipping, both detectors will seem very similar in their response.

Reliable measurements of early warning are rarely done in normal driving. I recommend this approach: find a false alarm (they don't move on you). Go out of range, preferably beyond a rise in terrain. Then approach, and note where the alert begins. Test each detector separately. Make at least three runs for each. For different bands, find different false alarms.

One caveat here: the typical false alarm is very weak compared to real radar, so range will be short and the difference between detectors will be compressed. Expect much larger differences against traffic radar.

SVTdriver said:

As for the person that tested both side by side. I don't know how you did it. Since my escort goes off at random intervals anytime it is near another radar detector. And I have heard this is a common occurence if you get 2 radar detectors near each other.

Click to expand...

All radar detectors emit a small amount of radar signal themselves. The really good ones though emit much less than Wal-Mart $69.99 special. Having two in close proximity is not a good idea as stated above.

Again... for the 100th time, a radar detector is a tool, and you need to learn how to use it properly. If you are "leading the pack" running out front all by yourself with no one in front of you for miles and a cop hits you with laser or instant-on, your screwed plain & simple. No radar detector made is going to save you in this scenario. The secret to effective radar detector use is to always have a "front door" within your line of sight. What you want is for your radar detector to pick up the scattered or reflected laser/radar signal as it bounces off the cars in front of you who are getting zapped by the cop. This gives you time to slow down. This is also why the best detectors are so expensive. Any cheap ass detector will pick up radar or laser signals that are aimed directly at it. The really good ones can effectively pick up the scattered emissions from other cars getting zapped well up ahead of you.

U.M.

P.S. One last thing... No one likes the sight of a radar detector stuck to the middle of the windsheild with the ugly power cord dangling down. The thing is that's where they work the best and if it's a V1 it also has to have a clear line of sight out the rear window too if you want to be able to pick up radar from cops approaching from behind. If you lay the detector on the dash, or have the damn thing aimed at the sky, don't expect it to pick up signals from 2 miles away.

+1 valentine one

got mine on ebay for $230

Here is a real world question, how many of you with radar detectors have been pulled over with them? and which one?

I got tagged with my 3-year old Cobra detector outside of Selena Kansas. 88 mph on the interstate about midnight. I was the only car on the road and it only went off for a second. I think the ticket was only $70, but my insurance company took note.

blbrchnk said:

Here is a real world question, how many of you with radar detectors have been pulled over with them? and which one?

Click to expand...

I've been pulled over twice with my V1. Both times I had it shut off!

U.M.