I read a news piece today about how the Tx. DPS is about to start usng "radar-detector detectors" to target big rigs illegally using detectors. I can understand being able to pick up a jammer, it transmits a signal. I thought a detector was passive. Anybody know how they can be picked up?

Couldn't this somehow be twisted around into an illegal search? It sounds similar to the way authorities were using thermal imagers to detect people using heat lamps to grow weed in their closets.

I guess somebody will just have to invent a radar-detector-detector-disabler.

I don't know how it all works off the top of my head, but I have notes around here somewhere.

Anyway... I bought a radar detector about a year ago, and it has the VG2 capability. It turns off if it senses a radar detector-detector.

Seems like a lot of the high end radar detectors have the VG2 built in.

Av.

I have always wondered about this myself, and since I got another damn ticket monday AM, the question has taken on added significance. (I drive a commercial vehicle in a State which does not allow detectors in them.)
Any technical info on this?

Super-heterodyne receivers generate an internal frequency to function.  This internal signal can be transmitted back out the same path an incoming signal travels ie. back out the antenna.  Superhet receivers need an antenna trap to contain spurious radiation from the internal frequency source.  Upper-end detectors have antenna traps.

Don't know about the VG2 shut-off tho'.

I guess the detector-detector could pick up spurious rf being sent off by the radar detector's internal oscilator. The detector- detector would have to be pretty sensitive to do it though.

So, it would be possible to actually build a frequency generator that could effectively "blind" a detector-detector? It wouldn't be of much use on desolate highways, but it seems like it would work in say, Dallas.

Yes DPS has a new thing going, busting big rigs speeding. I thought it was against the law nationaly for 18 wheelers to run detectors anyway. I had a CDL but dropped it back down to a class C because of the cost and having to retake part of the written test everytime I renewed it.

Wonder if they are stepping up enforcement because of the Mexican trucks that are about to start coming over the border or is this about revenue enhancement?

I believe radar detectors are forbidden in any vehicle that requires a CDL to operate because of federal law. There may also be similar laws in individual States, genrally federal law must be enforced by federal officers.

Places that have outlawed radar detectors have have radar detector detectors for years, VA comes to mind, not sure tho'.

Ponyboy, big rigs, as comercial vehicles, have genrally less protection than a private persons private vehicle.

Radar detectors supposedly, tho' passive by design, "leak" out certain telltale electronic "emmisions", the detector detectors can detect those emmisions. My understanding is the range is very limited due to the weak signal of the emissions.

On the other hand I really don't think big rigs should be speeding..............If they get in a crash the more speed the longer the trail of destruction.  

I am pretty well convinced that my detector is oftentimes activated by other vehicles' detectors. Happens frequently.

Most good radar detectors have "Stealth" capabilities, which means they are effectively invisible to VG2 (radar detector detectors). Big rigs have the CB, which I would think would be a pretty good way to avoid tickets. I don't think rigs should be speeding and I doubt many would take the chance using a radar detector. My detector has Stealth, but I mainly just want that so that the cops dont know I have a detector. If I get pulled over, they cant see the detector visually, but if they know I have it, chances of getting off with a warning are low. I am all about speeding on an open interstate, but when I get around traffic (other cars, etc), I slow it down because other cars are unpredictable.

All electronic devices emit spurious "noise" from their internal components, radar detectors included.  So these "fingerprints" if you will can be detected.  VG2 is supposed to be a way to disguise this noise so it can't be detected.

I don't know about the rules for commercial vehicles but I am personally opposed to outlawing things like radar detectors.  I view the authorities use of radar as electronic warfare and radar detectors as electronic counter measures (ECM)  I have a military background in electronic warfare by the way.  So radar detector detectors are electronic counter-counter measures (ECCM) and I have the right to counter that, on and on.  

If I ever live in a state that outlaws detectors I will hide mine and have it relay info to me remotely.  

My 2 cents.

LOL ! I used to drive 18 wheelers years ago and I know EXACTLY what you mean.

This is actually true in some models. There was mention of it in some "Radar Detector" review... My ex-GF's Uniden used to go off if powered up next to my Escort detector.

The Val's are nice, but pricey and I need cordless... My cig lighter is located in the center console.

All Radar detectors generate Radar frequency energy. The reason is simple- to be quick enough to be useful, the sensor needs to be 'pre-loaded'. This is the full cup principle: the cup is filled until just prior to spilling...1 more drop is added and it over flows. Likewise the circuit is saturated to just before the point of triggering the alarm, so any additional radar energy will immediately set off the alarm. That is why some detectors will false alarm from other detectors. The better the detector, the more sensitive the internals, and the less spurrious signal exists to bleed into the environment.

I've seen a Radar detector detector under prototype up in Toronto at the Mfg.

It basicly looks like a typical gunn diode feed horn inside a box that picks up the Lo of the detectors.. they work pretty good too.

I was told that they were pulled over by the Police for having a radar detector when they were testing it out..So they found out that the radar detector detectors will rat on themselves [:)]

You are totally correct!!!!!

Two Words.....Valentine One, one of the most expensive, and damn well worth it. It has the "Anti" VG2 system, multiple "hit" capability, and has saved me well over what I paid for it in potential tickets.

I used to work in defense electronics and did a lot of cool ECM and radar counter measure projects for the AF and Navy. I can't & won't talk about 'em and forgot most of it anyway, and besides, it was not really classified since the technology is documented in the public domain and I was never privy to the actual operating freqs & signatures anyway. I won't bore y'all with the tech details except to say the RDD works off the radiated emissions from the first stage mixer LO of the RD. High end RDs like the Valentine are very low emitters, and the cop would have to be pretty close to bust you, well within sight. Turn the sucker off if you see smokey.

OT but years ago in engineering school I built me a handheld gadget "black box" that emits a tiny amount of police freq X and Ku when you mash a button (perfectly legal power level). What does it do? It sets off every radar detector within sight, and I used it to fuck with tailgating speeders that bothered me! Mash that sucker and watch the brake lights come on BWAHAHAHAHA! [:D] I need to root thru the junk in the basement and find that sucker for my next road trip - I plumb forgot about it until I read this thread.

Don't hate me for havin' some fun, OK? [:D]

Wow, broke 800 posts.

Car and Drivers latest test.

[url]http://www.caranddriver.com/xp/Caranddriver/features/2002/february/200202_feature_detectors.xml [/url]

I drive a tractor-trailer for a living.  It is illegal to use a radar detector in a commercial vehilce.  That includes buses and 18-wheelers, etc.  It is a federal law, like all of the other regulations that we fall under.  The federal laws are enforced by the State agency responsible for the highways.  "Mr DOT" is basically the state trooper/highway patrol.  They perform all the inspections, run the weigh stations, and enforec the commercial vehicle statues.  The state gets most of the revenue generated by this, and also gets funding from the feds to support the enforcement.  Sort of like the Interstate highway system is maintained by the state, and patrolled by the state, but a great deal of th epie comes from federal funds.

As far as detectors-detectors go, they pick-up the oscillation from the super-het circuitry.  The VG-2 is the actual device that picks it up, so VG-2 protection is what is marketed as "invisible" to detector-detectors (the VG-2 detector built in Canada).

It is also a state law here in VA that all detectors are illegal, and it's a pretty healthy fine.  

About 20% of the State Trooper cars here now have a newer "detector-detector" in them that will detect a "VG-2 stealth technology" detector.  Just because it says it's invisible to a detector-detector on the box, don't bet on it.  One of our drivers triedon out with one of the state troopers on our normal route and he was able to pick up the radar detector, even though it was supposedly "invisible to detctor-detectors".  He told us on the radio that he could also pick it up TURNED OFF, but he had to be pretty close.  There was no reason to doubt him, as he didn't tell him he had it.  The trooper just came on the radio and told us he could pick it up and identified which of the three rigs in our "convoy" had it.  Needless to say that driver brought it right back for a refund.  

It could be that TXDPS is getting the newer stuff.

Ross

No disrespect, but......

No fucking way. Period. End of story.

No power = no radiation, no exceptions. Unless the cop had the "Harry Potter" model magical radar detector detector, this is an engineering impossibility.

What he picked up [b]might[/b] have been anything with a microprocessor in it : engine control computer, cell phone, CD player, etc...

If the detector-detector is transmitting RF, it may listen for distortions reflected back.  A detector has some interesting resonant chambers that I imagine would reflect or harmonize weakly even in the absence of the device being on.  It's getting power, just not from its battery.

Oh puleeeeeez, Louise! Resonant chambers my ass.

Open up your radar detector and look.

This is not magic.  When you shoplift your Harry Potter books, the "don't-steal-me" tag that gets you arrested at wal*mart works in a very similar way to this possible "detector-detector" scenario.  It isn't powered.  It resonates and retransmits an RF signal that the detectors at the door put out.  The detectors look for the tell-tale signal reflected back.  

Radar detectors that I have seen have a 'bullhorn' type waveguide that leads to the detector components that resonate/activate on specific frequencies, allowing the rest of the detector to make decisions like "is this really radar" based on the signal recieved.  They're fancy antennas for microwave.  Waveguides work both ways, so unless you shield the open end when not in use, you will get distinct reflections back from various components (including the waveguide itself) when hit with radiated energy.  Perhaps these mystical detector-detectors do something with this behavior.

Skip the Harry Potter and get a subscription to the Journal of Electronic Defense.

Would small amounts of residual energy from any capacitors in the detector cause the unique detector signature to be "noticed" by a detector-detector?  If the unit were  recently turned off, it could still have that small amount of energy.  Then again, if a cop has that sensitive of a detector-detector, then he would probably get all sorts of false alarms.

I would recommend the Escort Passport 8500 for the best bang for the buck. It is a good detector and will pick up cops well. It will false occassionally, mostly due to passing other cars that have leaky detectors, but most detectors do unless you are out in the middle of Montana. The KA range (what a lot of cops are using now) on this detector is excellent. It has a "phone plug" power cord (RJ-45 or something like that) basically it's just like the wire you plug in the phone jack on a house phone). It comes with the standard curled cigarette adapter, but you can just buy you some cheap phone cable and hard wire that into the 12V (only 12V when car is running) and ground and put it where you want and you'll have power without having to pay $30 for the hardwire kit. If you are into car electronics this is no big deal,just need a multimeter. If you have the bucks, go with the Valentine One, but it is significantly more expensive from what I've seen. This is where I bought my detector, they had prices that could not be beat on the Escort brand (since I didnt see many people selling Escorts on the net). [url]www.radarcity.com[/url]

I've also heard good things about Escort's SR1, this is a stealthy custom installed system that puts the radar antennas on the front and rear of the car with a display unit installed inside the vehicle. I think Radarcity also sells this unit, it's just not on their website. They were selling it about a year ago. [url]http://www.escortstore.com/sr1.htm[/url]

i like what i do better its called dont speed!

None taken.  I don't really see the need for the cussing, but hey, that's your deal.

I've noticed many plug in devices, not just detectors, that have a LED that indicates you have power going to it whether it's turned on or not.  Seems to me that some portion of the device would have power going to it, and therefore could be detected.  

Either way, it had no problem picking up a brand new, mid-quality radar detector that was supposedly "VG-2 detector-detector invisible" while it was on.  

Ross

I agree the passport 8500 is the most bang for the buck.
[url]www.escortradar.com/8500.htm[/url]

Here is site where they test detectors
[url]http://www.radartest.com[/url]

For you rich guys ya might want to take a look at this baby
[url]www.escortinc.com/srx.htm[/url]
Its built into your car and has laser shifting ability.

Get the book:  How to Drive Fast Without Getting Tickets (I think that's the title).  I read it once a long time ago and the advice is really good.  Never had a radar detector, never had a speeding ticket. I drive like hell all over, especially on the motorcycle.  It's all about knowing their tactics and knowing when you can get away with what speeds, mainly.  You don't need fancy electronics, you just need to pay attention--situational awareness and all that.  

Cops have basically two tactics--lie in wait, sometimes with more than one unit or come up from behind and pounce.  That's about it.

The stuff about airplanes used for traffic enforcement is just so much scare tactic bs.  I've seen that one time in all my years of driving--and I drive a ton because I never could stand dealing with flying and that was before 9/11.  "If it's within 1000 miles and I really want to get there, I drive."

Besides with cops using instant-on and LIDAR, or just going by their speedo or using a stopwatch, a radar detector isn't all that helpful.

It still pisses me off that they are "banned" in some states.  Hey if they want to ban something, ban traffic profiteering by law enforcement and the corrupt municipalities that they answer to.