Interesting article in the local rag:
new.edp24.co.uk/content/news/story.aspx?brand=EDPO...0
How do you make these links short? Apologies!
Anyway, report is about cars going past a local radar station then cutting out/electrical problems...
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runboy - copy the link to the clipboard, go to www.tinyurl.com, paste it into the "Enter a long URL to make tiny" box and bingo! If you're using IE, it copies the short link to your clipboad. If not, highlight the new link on screen and copy it via control-c.
HTH,
CM
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"The spokeswoman also pointed out it was the responsibility of car makers to protect vehicle electrical systems"
That sounds like an admission, to me. Not quite sure how you protect against pulsed and tightly focussed microwave transmissions at close range. If they're coming at you near ground level, they're not being aimed right, and it's not just your car you need to worry about!
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First discovered by Audi on the M1 next to the MF transmitter at Rugby. Theirr cars always broke down there.
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TourVanMan TM < Ex RF >
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First discovered by Audi on the M1 next to the MF transmitter at Rugby. Theirr cars always broke down there.
What's the excuse for their car breaking down elsewhere? ;)
Name-change time: NoWheels + Almera = NowWheels
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What's wrong with 'local paper'? I don't slag off your trade...
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Many will know that aerials have special dimensions so that they tune up and respond to certain radio/TV frequencies-- your TV aerial, for instance.
The radar/microwave people know, in their world, that they can use metal and other cavities to do similar.
What is largely over-looked by the non-microwave electronics designer, who rarely has much in the way of microwave knowledge, is the ability of the metal boxes, used to house their electronics, to tune up (resonate) and play havoc with the behavior of their electronics under certain, usually rare, circumstances. I have seen it happen and taken precautions that stopped it.
How many designs have taken that aspect into account? Any?
I don't know whether this is a cause in this particular case. But clearly the signal is getting into the electronics and over-riding the wanted signals.
Radar can emit a very powerful many-kilowatt signal and at that power can get into most things. Perhaps the radar should be mounted higher up so the main beam does not hit ground level until further away.
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Err... isn't it more likely to generate a resonance within the electrical ciruits of the car and not the metal boxes? Can't see how you could induce any resonance in a metal box from EM radiation.
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The box could act as a resonant cavity - but would need a way to get from said cavity into the car electronics and it could be quite hard to find the coupling mechanism involved (inductive, re-radiation, capacitive etc. )
Chris Muriel, Manchester
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"and it could be quite hard to find the coupling mechanism involved (inductive, re-radiation, capacitive etc. )"
Your making my point about lack of knowledge.
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Your making my point about lack of knowledge.
Oh my good god, irony overload.
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I thought it was an overload of microwaves?
At trimingham (a Type 93) approx 1.1Megawatts (peak) of overload.
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TourVanMan TM < Ex RF >
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I think I'd be more worried about the effects on people who are walking or driving past this thing.
Non-Ionising Radiation??!!! Don't bet on it!
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To be honest, my feelings are that the powerful microwave transmitters simply overpower any other microwave signal in the area. (IIRC most keyfobs work on the microwave frequency, and there's always a possibility that an inductive circuit is used to verify that the key is genuine when it's in the ignition.
I think it's more a case of not being able to see a torch beam on a sunny day, rather than the sun breaking the torch. :-)
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Think about what happens when you put your mobile next to the radio and send a text.
Then imagine that many many times more powerful, with sensitive, sophisticated electronics in range.
I wouldn't want to drive my Pug past there, French electrics being what they (apparently) are...
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That's because a radio is specifically designed to pick up radio signals and is full of inductors and capacitors which tend to pick up high frequencies quite easily.
I could argue your point the other way. I'm sitting here with my phone sitting on my laptop while on hold and on speakerphone. Signal is poor so phone will be transmitting at maximum power.
See? No problem whatsoev---!!@#@!#@ ERROR CONNECTION LOST
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Most keyfobs use 433.820 MHz or thereabouts.
This is UHF (just below your TV channels) and I wouldn't class it as microwave.
However, since keyfob transponders are designed for tiny size and low cost, their transmitters and receivers aren't likely to be exceptionally well filtered - for the techies I believe that often a super regenerative receiver is used as a superhet would cost too much).
Chris Muriel, Manchester
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My mistake. Thanks for the correction, Chris.
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Most keyfobs use 433.820 MHz or thereabouts.
That well know 'pyramid' that used to be golf balls in North Yorkshire isn't far from that. Certainly stopped my electric windows working when I parked next to it.
www.subbrit.org.uk/rsg/sites/f/fylingdales/
"all three BMEWS radars operate in the 420 - 450 MHz frequency band."
Martin
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"Non-Ionising Radiation??!!! Don't bet on it!"
Don't forget the heating effect. A military radar transmitter (or civil one, come to that) can fry you if you get close enough...
As I suggested earlier, this thing shouldn't be aiming anywhere near ground level. I am typing this 100 yards from a factory that makes and tests airfield and other radar sets, and although there are houses even closer, there is virtually no interference. There would be Hell to pay if there was!
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You have to bear in mind this is not your average radar and as well as being aimed high, will be aimed low to catch "under the radar" raiders with the background clutter being computer enhanced to spot moving targets.
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TourVanMan TM < Ex RF >
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On a biking tour to France a few years back, two of our party had their bikes inadvertantly immobilised/alarms screaming when we got to the top of the Puy de Dome.
A rather large radio transmitter on the peak was the culprit; once they wheeled them back down the hill a kilometer or so the bikes were fine.
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You have to bear in mind this is not your average radar and as well as being aimed high, will be aimed low to catch "under the radar" raiders with the background clutter being computer enhanced to spot moving targets.
So I you are dricing at over 300mph, chances are they'll mistake you for a low-flying MiG and blast you with surface-to-air missiles. And then you'll be lamenting the loss of the good old days of speed camras ;)
Name-change time: NoWheels + Almera = NowWheels
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>will be aimed low to catch "under the radar" raiders
Or speed cameras, come to that. This from the ACPO guidelines...
"When selecting a casualty reduction site, treat with extra caution places with view of: high voltage overhead lines, transmitting masts or tower, airports or harbours, and any other place where high power radar transmitters may be expected to operate.
Never point a speedmeter at a civil or military aircraft, vessel or armoured vehicle. Many military aircraft, vehicles or vessels have target acquisition detectors, some of which initiate automatic counter measures."
Nice mental cartoon of cop with hairdryer hotly pursued by missile...
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IIRC that has already come close to happening.
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Urban myth
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TourVanMan TM < Ex RF >
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