#176031 - 20/08/2003 12:29
How do radar detector detectors work?
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addict
Registered: 04/11/1999
Posts: 649
Loc: Reading, UK
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I was under the impression that Radar detectors were passive by nature, so I'm a little confused on how the science works in a Radar Detector Detector... Anyone care to point me in the right direction?
I assume that the mere detecting of the radar wave changes any response that you get, so you could detect it like that, but it just seems that the change would be so tiny as to be very hard to detect.
?
Paul.
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Paul Haigh, Reg. 4120
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#176032 - 20/08/2003 12:59
Re: How do radar detector detectors work?
[Re: phaigh]
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carpal tunnel
Registered: 30/04/2000
Posts: 3810
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Radar detectors, TV tuners, and other such gizmos use a "phase locked loop" to latch onto and follow the frequency of the signal. This requires the tuner to have an internal oscillator running at the same frequency as what it's trying to tune. Those oscillators give out trace RF emissions. That's what radar detector detectors pick up on. Likewise, it's what the roaming TV detector vans in the U.K. use to notice that you have a TV set where you didn't pay your TV tax.
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#176033 - 20/08/2003 13:08
Re: How do radar detector detectors work?
[Re: DWallach]
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addict
Registered: 24/07/2003
Posts: 500
Loc: Colorado, N.A.
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Worth noting that there are ways to make the oscillator harder to detect. Those of us part of the V1 cult appreciate Mike Valentine's efforts in this regard.
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#176034 - 20/08/2003 13:10
Re: How do radar detector detectors work?
[Re: DWallach]
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carpal tunnel
Registered: 20/12/1999
Posts: 31604
Loc: Seattle, WA
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Okay, then. Follow up question.
There are radar detectors which claim to be detector-detector prrof. As I understand it, they do this by shutting themselves down when in the presence of a detector-detector. How do THOSE work?
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#176035 - 20/08/2003 13:23
Re: How do radar detector detectors work?
[Re: tfabris]
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carpal tunnel
Registered: 08/03/2000
Posts: 12344
Loc: Sterling, VA
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A radar detector-detector-detector? Then do the cops get a detector-detector-detector-detector??
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Matt
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#176036 - 20/08/2003 13:27
Re: How do radar detector detectors work?
[Re: tfabris]
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carpal tunnel
Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
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check out this excellent radar test site: speedzones. Unbiased testing from all sides... and it includes a section for radar detector detectors. No recommendations, just test results... good stuff.
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#176037 - 20/08/2003 13:49
Re: How do radar detector detectors work?
[Re: loren]
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carpal tunnel
Registered: 20/12/1999
Posts: 31604
Loc: Seattle, WA
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#176038 - 20/08/2003 14:59
Re: How do radar detector detectors work?
[Re: tfabris]
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carpal tunnel
Registered: 29/08/2000
Posts: 14496
Loc: Canada
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They work the same way again, one more layer.
But the current Australian RDDs seem to be tuned to nab *everything* that's out there right now, including *all* of the so-called RDD-proof RD's.
Cheers
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#176039 - 21/08/2003 00:52
Re: How do radar detector detectors work?
[Re: DWallach]
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addict
Registered: 04/11/1999
Posts: 649
Loc: Reading, UK
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So RDD's actually generate Radar frequency emissions - I see!
Thanks for the info - just what I needed.
I always thought that the TV detector vans were detecting EMF output from screens - I can see how that might work.
I was also told by someone that 90% of the TV detector vans are actually empty - just there to 'scare' people into buying licences.
Cheers,
Paul.
_________________________
Paul Haigh, Reg. 4120
(mk1) 6GB, Blue, 00254
(mk2) 12GB, Red, 00357
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#176040 - 21/08/2003 00:54
Re: How do radar detector detectors work?
[Re: loren]
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addict
Registered: 04/11/1999
Posts: 649
Loc: Reading, UK
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Yeah, cool site. Thanks for the link!
_________________________
Paul Haigh, Reg. 4120
(mk1) 6GB, Blue, 00254
(mk2) 12GB, Red, 00357
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#176041 - 21/08/2003 01:08
Re: How do radar detector detectors work?
[Re: phaigh]
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carpal tunnel
Registered: 13/07/2000
Posts: 4180
Loc: Cambridge, England
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I was also told by someone that 90% of the TV detector vans are actually empty - just there to 'scare' people into buying licences. It wouldn't surprise me at all if the figure was 100%. Has anyone ever actually seen one of these vans, except on adverts?
Peter
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#176042 - 21/08/2003 01:12
Re: How do radar detector detectors work?
[Re: peter]
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addict
Registered: 04/11/1999
Posts: 649
Loc: Reading, UK
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Yup, when I was at university - a van pulls up into the Car Park for the hall of residence with TV DETECTOR VAN spashed all over the side.
There was literally an exodus to the local postoffice - funny really.
Paul.
_________________________
Paul Haigh, Reg. 4120
(mk1) 6GB, Blue, 00254
(mk2) 12GB, Red, 00357
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#176043 - 21/08/2003 02:06
Re: How do radar detector detectors work?
[Re: phaigh]
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pooh-bah
Registered: 09/08/2000
Posts: 2091
Loc: Edinburgh, Scotland
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Sounds like the perfect application of an empty van, students are easily scared.
Did this van have many aerials, and a chap from the Ministry Of Ousinge?
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#176044 - 21/08/2003 02:30
Re: How do radar detector detectors work?
[Re: phaigh]
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old hand
Registered: 14/04/2002
Posts: 1172
Loc: Hants, UK
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Apparently they have a few different technologies in the van - one is to detect the flyback in the CRT. I think this is mainly just additional to the IF detectors.
It has long been known that 9/10 detector vans are fake - I read a report a few years back thay quoted somebody who was involved in painting the wooden aerials silver! Somebody also inspected a van at a display outside a railway station - there was a nice 60cm Sky dish on its roof and bench seats in the back behind the tinted glass!
These days it's much easier for them to cross reference the database of licensees against the Royal Mail database and mailshot anybody who hasn't got a license. Friends of mine (both retired programmers) have never owned a TV but used to get regular letters and visitors accusing them of various things, until they wrote back saying that if they were contacted again they would sue for harrassment. It worked!
At the office we got a letter a few months back implying that we legally had to sign a form saying we didn't have a TV on the premises. We got a phone call a week or so later asking why we hadn't returned it, and when I said we are willing to fill it in at our standard rates they just said an "enforcement officer" would visit soon. I've not seen them yet! I wouldn't let them through the door without a warrant anyway, and they would be wasting their time because we don't have a TV here!
Gareth
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#176045 - 21/08/2003 02:35
Re: How do radar detector detectors work?
[Re: phaigh]
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carpal tunnel
Registered: 18/01/2000
Posts: 5683
Loc: London, UK
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There was literally an exodus to the local postoffice - funny really.
We just hid the TV under my bed until the van had gone away again. Not that I actually saw the van -- we just got a phone call from the other side of campus telling us that it was on the prowl -- so we just hid the TV for the rest of the day.
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-- roger
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#176046 - 21/08/2003 02:44
Re: How do radar detector detectors work?
[Re: g_attrill]
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carpal tunnel
Registered: 13/07/2000
Posts: 4180
Loc: Cambridge, England
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I wouldn't let them through the door without a warrant anyway, and they would be wasting their time because we don't have a TV here! They don't need a warrant -- like Customs and Excise, they have a statutory right of entry.
I didn't have a TV for years, and used to get letters (ranging all the way from very polite to very impolite) about once every four weeks. Once I tried ticking the "I don't have a TV" box and sending it back, but as all that did was increase the gap between letters to six weeks ("It's now time to update our records") I didn't bother again. One letter even alleged that an enforcement officer had visited but I was out.
Peter
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#176047 - 21/08/2003 03:22
Re: How do radar detector detectors work?
[Re: peter]
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old hand
Registered: 20/07/1999
Posts: 1102
Loc: UK
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To the best of my knowledge the TV gestapo has a grand total of 2 actual detector vans in the entire country. The rest are all dummies. They also can't 'detect' tv usage if it's via a PC in most cases.
They work mainly by looking for leakage from the TV flyback signal, at the horizontal line frequency of 15.7 kHz. Newer equipment also looks for TV tuner local oscillator leakage, but this is less easy to detect.
Most of the time, they simply work on the basis of bothering people who live at an address where there is no license registered, on the basis that everyone must obviously have a TV, and if there is no record of a license being assigned to your house, you're cheating them. Various friends of mine who don't own, and have never owned any form of TV, video, etc (yes, there are still a few), STILL get letters quite regularly complaining that they haven't paid for a license.
pca
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#176048 - 21/08/2003 03:24
Re: How do radar detector detectors work?
[Re: peter]
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old hand
Registered: 20/07/1999
Posts: 1102
Loc: UK
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They don't need a warrant -- like Customs and Excise, they have a statutory right of entry.
As far as I can find out, this is incorrect. The information I have is that they must have a warrant to enter, and they must be accompanied by a uniformed police officer.
pca
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Experience is what you get just after it would have helped...
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#176049 - 21/08/2003 03:47
Re: How do radar detector detectors work?
[Re: pca]
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carpal tunnel
Registered: 13/07/2000
Posts: 4180
Loc: Cambridge, England
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As far as I can find out, this is incorrect. The information I have is that they must have a warrant to enter, and they must be accompanied by a uniformed police officer. Oooh yes, you're right. Looks like I fell for an UL. According to famed constitutional lawyer Richard Stilgoe, only Customs officers and officers of gas, electricity and water boards have that power -- and that was in the 70s, of course, so I don't know whether officers of deregulated power companies have any such power.
Peter
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#176050 - 21/08/2003 05:26
Re: How do radar detector detectors work?
[Re: Roger]
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carpal tunnel
Registered: 10/06/1999
Posts: 5916
Loc: Wivenhoe, Essex, UK
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We just hid the TV under my bed until the van had gone away again.
Our halls of residence (Stephenson Hall, Sheffield) JCR ran a scheme. At the beginning of the year you sold your TV to the JCR for a pound, the JCR would then rent the TV back to you for the rest of the year for a pound, the JCR had a TV licence.
No idea whether the scheme had any legal basis, we never got raided...
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#176051 - 21/08/2003 08:10
Re: How do radar detector detectors work?
[Re: andy]
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carpal tunnel
Registered: 24/12/2001
Posts: 5528
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I don't think thats actually legit. It's the property itself that needs the TV license and each individual room is classed as a seperate residence.
TV licensing came around at university once and stuck up huge posters everywhere telling people about how they're not covered etc... and they'll be checking. I don't recall anybody ever coming around or acting suspicous outside with a van though.
When I was off campus living in a flat some guy knocked on my door saying he was from TV licensing and if I had a TV. I said no and he said oh okay and left
A battery powered TV however is covered under your home one though. Not sure what they'll say to a inverter and a huge battery though
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#176052 - 21/08/2003 09:08
Re: How do radar detector detectors work?
[Re: tman]
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carpal tunnel
Registered: 10/06/1999
Posts: 5916
Loc: Wivenhoe, Essex, UK
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A battery powered TV however is covered under your home one though. Not sure what they'll say to a inverter and a huge battery though
They have got that one covered. Not only does the set need to be solely battery powered but the batteries also have to be internal.
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#176053 - 21/08/2003 09:49
Re: How do radar detector detectors work?
[Re: andy]
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carpal tunnel
Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
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Wow. I had no idea there was a TV tax in the UK. That would never fly in the US. What exactly is the tax for? I'm guessing it goes to pay for the BBC and other aerial channels? How does it work if you have cable? Excuse my ignorance... =]
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#176054 - 21/08/2003 09:53
Re: How do radar detector detectors work?
[Re: loren]
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carpal tunnel
Registered: 24/12/2001
Posts: 5528
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It's used to fund the BBC. The other channels are all advertisment funded whilst the BBC channels don't have any adverts.
You still have to pay it even if you've got cable/satelite. I think a guy few years back managed to avoid the licensing fee because he only wanted to watch videos and had all of the tuners removed. They took him to court for it but he won.
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#176055 - 21/08/2003 09:54
Re: How do radar detector detectors work?
[Re: loren]
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carpal tunnel
Registered: 30/10/2000
Posts: 4931
Loc: New Jersey, USA
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That would never fly in the US. I guess you never heard of PBS.
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#176056 - 21/08/2003 09:59
Re: How do radar detector detectors work?
[Re: robricc]
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carpal tunnel
Registered: 23/08/2000
Posts: 3826
Loc: SLC, UT, USA
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Last i heard... PBS didn't send around vans threatening to fine you if you didn't donate during the pledge drive!
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#176057 - 21/08/2003 10:01
Re: How do radar detector detectors work?
[Re: loren]
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carpal tunnel
Registered: 15/08/2000
Posts: 4859
Loc: New Jersey, USA
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...yet...
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Paul Grzelak 200GB with 48MB RAM, Illuminated Buttons and Digital Outputs
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#176058 - 21/08/2003 10:01
Re: How do radar detector detectors work?
[Re: tman]
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carpal tunnel
Registered: 10/06/1999
Posts: 5916
Loc: Wivenhoe, Essex, UK
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Some people hate the TV licence and the fact that it funds the BBC. To me however the world would very much worse for the loss of the BBC. What would I do without my daily intake of Radio 4 ?
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#176059 - 21/08/2003 10:02
Re: How do radar detector detectors work?
[Re: loren]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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You obviously missed an episode of The Simpsons. Elmo knows where you live!
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#176060 - 21/08/2003 10:06
Re: How do radar detector detectors work?
[Re: andy]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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Are there radio licenses, too?
And there's something to be said for disparate funding for disparate social programs. It doesn't always make sense or work, but TV seems an appropriate place. If those folks don't like the TV tax, they can just get rid of their TVs and not pay it. If they're watching it, then they need to be paying. Seems simple enough to me. It's kinda like HBO or Showtime or whatever in the US. Of course, it's not required that you get a premium cable channel in the US to see the rest....
And the output of TV doesn't really benefit anyone except those who watch TV, so it's not a broad social program whose lack of funding would affect those who aren't interested.
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Bitt Faulk
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