Beware Speed Traps! (Speed Camera Detectors in General)

Member Name: huddro

Product:	Speed Camera Detectors in General
Date:	12/10/01 (3750 review reads)
Rating:

Advantages: Keeps your speed down

Disadvantages: Doesnt get all speed traps

Let me take you back a month or so. Driving my girlfriends car, I join a very straight road, with fields either side, linking Buckhurst Hill and Chigwell. The traffic is moving at a brisk pace and I maintain that speed. Parked at the side of the road is a little red Citroen van and as we pass Lordpercy informs me there is a mini Gatso on a tripod in front of it … Bugger!

Now let me bring you forward a couple of weeks, I wake up on a cold Monday to find a nice letter from those friendly chaps in the Essex Police force stating that I have been photographed at 45mph in a 30mph and what is worse in a Volvo!!

May I state at this point that I do not condone speeding but I do object to cameras being used to raise revenue for the boys in blue especially on roads where the speed limit is too low for the road conditions. There is no way anyone can tell me an unmarked red van taking pictures of speeding cars reduces accidents, perhaps if it was sign posted then people would slow down but hey I am getting off the subject now.

I decided that I did not want to become an unofficial source of revenue for Essex police and so thought it was time to look into some sort of detection equipment, if Essex police are not going to warn me of cameras I may as well warn myself. Overall the effect is better as I slow down well before any speed trap thus slowing other traffic and we have achieved the Government aim of reducing road speed and none of us drivers have been hit in the pocket!

First I looked at Geodesy, by Morpheus, see Lordpercy’s review, but this only maintains a database of fixed permanent Gatso camera sites and lets face it most people know where all the fixed cameras are in their local area. What I wanted was something that would identify the mobile Gatso cameras, and the hand held Laser speed detectors.

Discussing this at work I realised I knew nothing about this subject then a good friend offered to lend me his Rad
io Shack model 22-1654 to see how I got on and a little research later I was fast becoming an expert on this technology. Now, to tell you about this, and pass on some relevant information so you can make a considered opinion on detectors. I need to explain some basic details on how radar and laser detection equipment works so a little lesson:

Radar Technology
The name Radar is derived from the term radio detecting and ranging. It is a method of scanning by means of high frequency radio waves. The radio waves are transmitted out in a cone shape and reflect back from objects in their path. The reflected beam gives information on the speed and direction of the target vehicle.

Civilian radar frequencies were established at the end of the Second World War in the USA and the frequencies adopted by nearly all the other countries in the world.

The government originally used a frequency range called X band (10.525 Ghz +/- 50 Mhz and 24.150 Ghz+/- 100 Mhz), introduced in the 60’s but this is now commonly used in such things as automatic shop doors and thus can cause your detector to beep constantly.

The next switch was to the lower frequency K band (24.150 GHz+/-100Mhz Frequency Range 24.050-24.250 GHz), in the 70’s as this was more difficult to detect.

Ka band, (33.4GHz-36GHz. +/- 100Mhz), was introduced in Europe in the 80’s and is in widespread use throughout Europe it was recently introduced to the UK and is the common source of frequency for Gatso cameras.

The latest frequency is Ku, (10.70 - 12.75 GHz. +/ - 100Mhz) utilised in mini-Gatso cameras and very difficult to detect due to the low power employed by the actual cameras.

There are two types of radar unit: a permanent broadcast where a constant signal is transmitted and the reflected waves analysed (no longer very common as too easy to detect) and instant ON (Pulse radar). Pulse radar transmits only after the operator has sel
ected a target, and only long enough to get a speed-reading, for example a Gatso speed camera. This makes pulse difficult to detect.

The one down side to radar is that the beams bounce off of static objects in a number of directions in an effect called radar reflection. It is therefore possible to detect these waves even before you have turned a corner!

And now there is a new threat, the new kid on the block so to speak, Laser detection!

Laser Technology
Laser stands for Light Amplification by Stimulated Emission of Radiation. It transmits electromagnetic radiation a little like your own microwave. The major difference being that light has a much higher frequency than a microwave.

The light beam from the laser is very thin at a range of 1000m it is only 3 metres wide compared to the similar radar beam that is minute!

The biggest detection problem is that it takes only 0.3 to 0.7 seconds to acquire and register a target at an operational range of 800 metres.

Laser is used in Lidar type detectors (Lidar meaning Light Detection and Ranging). Now as you can see trying to detect a pulse of laser is pretty difficult.

Basics for a detector
Well we have seen that in order to counter all threats we need a detector that will cover X band, K band and the variations, and detect Laser. We also need to be able to switch off or reduce the sensitivity of X band in order that we do not get false alarms every time we drive past Boots and the doors open.

Most 5-band (detects all the above frequencies and Laser) detectors are basically the same. They have a radar sensor, and a visual warning. Some even have audible alarms. All are mounted facing forward and passively (they do not transmit any signal, a radio licence is required for a transmitter) receive signals.

The major difference between them is their range and filtering. Some have a good range but do not filter that effectively
, some are good at both and some neither.

One important piece of advice I can give is do not buy a 4 band as these will not find the new Ku band and therefore not detect mini Gatso cameras, and ensure that whatever detector you buy it will detect Laser.


Radar Detector in practise
Radio Shack 22-1654 (Does not have Ku)

Appearance
This little black box smaller than my palmtop (L12cm, W7.5cm, H3cm, all taken from the maximum points) has the receiver at one end, an LCD display at the other, with a volume adjustment to one side, the plug on the other and 3 function buttons giving a very discreet look.

How it works
The detector sits on the dashboard or clips to the sun visor with the receiver pointing forward. Receiving power from your cigarette lighter when it detects either radar or laser it alerts with a tone and visual signal.

This particular detector has built in suppression to prevent false alarms caused by other forms of radar transmitter such as jamming devices without reducing its sensitivity to actual speed detection radar signals.

Turn it on and the radar goes though a self-test; giving a tone and lights for each band and signal strength indication.

Next it is necessary to select the mode: Highway, maximum sensitivity across all bands, or City, the detector needs to receive a much stronger x band signal than say a door opener would give off before it activates.

Ok time for the test.

Drive one
We travel along a road I know to have a Gatso. I can see the camera and still nothing closer I slow down and pass through the camera at 30mph the detector beeps as we go past.

About 200 metres before the next camera the display lights under K band and the detector starts to chirp. By the time we reach the camera the tone is almost constant and then slowly fades as we pass the Gatso.

On my return home it finally clicks. Being the only car on the roa
d at the first camera, no signal had been transmitted by the Gatso. I prove this again on my second drive.

Drive two
The first camera does not show up on the detector until we are level. Rounding a bend though, at 50mph on a 50 limit the detector lights up and the alarm sounds. I slow to just under 50mph and about 500metres down the road, with a constant tone in my ear, is Mr Plod in a fluorescent jacket randomly bouncing his laser off passing vehicles (by the way according to legislation a police Officer can only use an instrument to verify his first impression that a vehicle was speeding, using a Laser gun indiscriminately is a breach of this legislation). (Do you know how many miles I had to drive to find one of these speed traps?)

Drive three
A nice Motorway at 70mph we approach a sweeping right hand curve and I know there is a camera located half way along it. Increasing to 80mph the Radio Shack detector beeps with plenty of time to slow down to 70mph safely and pass the camera. I try this at 90mph and again have plenty of time to slow down before passing the camera at 70mph.

At night time switch this to dark mode and the visual display dims or turns off although to be honest I did not find the small flashing lights a distraction.

The mute button allows the audible warning to be turned off relying only on the visual warning. I would not recommend this, as you are likely to be watching the display rather than the road.

I have since carried this in my vehicle and found that apart from the x band detecting every set of traffic lights and every automatically opening door that the detector does work all be it in a limited way. Unfortunately this is due to the detector being designed for the US market where the Police utilise different frequencies to ours.

Conclusion on the practise

Overall a good detector but originally built for the American market it will not pick up mini Gatso whic
h are the biggest threat to the driver at this time, being more popular than the Lidar detectors, particularly in Essex. The tone can become annoying and I did suffer with a few false alarms although not enough to make me ignore the tone.

Although I have to state at this point that Lord Percy road tested this as well and had very little success apart from being able to identify traffic lights!

I will be investing in a detector but the price range from around £100 to £500 leads you to ask what is good and what is not, bearing in mind that possibly in a year or two it will be necessary to purchase a more modern unit as new speed detection systems such as SVDD are introduced.

My recommendation would be to buy the detector that will suit your biggest threat and spend as little as you can in doing so. My recommendations based on talking to lots of people who have used them and reading lots of test articles are:

At the cheaper end of the market the Snooper 815 at £254 (inc VAT) from www.snooper.co.uk a good range but can be prone to false alarms in town.

Next comes the Snooper S5 at £349 (inc VAT) again from the above web site. This gives much better filtering than the 815 and better range.

My final recommendation, for those who cannot afford to be caught and therefore are willing to invest a little more, the Bel Euro 550 at £399 (inc VAT) is reputed to be the ultimate in detector. With good range and excellent filtering no tester has failed to recommend this product. Available from www.beldirect.co.uk

Personally I will order the Snooper 815. I have just got my first 3 points in 18 years of driving but as I do not do that many miles a year cannot justify the extra almost £200 fro the Bel product.

Finally

Remember the whole point is to drive safely and make sure you arrive at the end of your journey!

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