Jump to content

One for Dave H.


Recommended Posts

Waterside Echo

Three of my neighbours are having trouble with the remote central locking on their cars. They live within 300 yards of each other, own different makes of car, but when parked outside their houses the cars will not remotely lock or unlock. This has only just started happening in the last week, and when the cars are moved further down the road everything works O K. Any ideas ? W/E.

Link to post
Share on other sites
  • Replies 56
  • Created
  • Last Reply

Top Posters In This Topic

  • DaveH

    28

  • hilldweller

    14

  • Waterside Echo

    6

  • Stuart0742

    4

hilldweller

Three of my neighbours are having trouble with the remote central locking on their cars. They live within 300 yards of each other, own different makes of car, but when parked outside their houses the cars will not remotely lock or unlock. This has only just started happening in the last week, and when the cars are moved further down the road everything works O K. Any ideas ? W/E.

I read an article some time ago about the lengths that the AA in London had to go to in order to unlock cars, they included towing cars several streets away before they could be opened. Nowadays most cars can be over-ridden with the normal key (if they have one).

The trouble is caused by local high powered transmissions (ham radio, CB, or taxi firm etc) which swamp the very primitive TRF front-ends of the remote control receivers. Because the transmissions are digitally encoded with lord knows how many changing digital bit lengths there is no need for high selectivity in the receiver. At least not until some herbert starts kicking out a few watts of RF. It doesn't even need to be at the same frequency at long as it's powerful enough. I should look around for some aerial that has just appeared.

I may be barking up the wrong tree (I usually do), but it is a known problem.

HD

Link to post
Share on other sites

Three of my neighbours are having trouble with the remote central locking on their cars. They live within 300 yards of each other, own different makes of car, but when parked outside their houses the cars will not remotely lock or unlock. This has only just started happening in the last week, and when the cars are moved further down the road everything works O K. Any ideas ? W/E.

I will leave Stuart0742 to answer that one.

His fleet of vehicles all seem to have remote locking devices, but my car is operated by a good old fashioned key.

I understand there is a device available, and in the hands of criminals which can intercept, record and playback, as it were, the signals from remote control door locks.

All a car thief has to do is be within range of you when you lock / unlock your car yourself.

His device will receive the same signal and store it.

When you are not around he can then use the stored signal on his device to unlock your car

Encrypting the signal is useless as it is the same signal, complete with any encrypted codes :o

Much more secure with a key

having said that, in this recent wet and icy weather there have been a number of occasions when I have been unable to get into my car (really secure then) due to ice in the locks :angry:

I am not sure how these "zappers" work or the type of beam they use.

Infra Red would not penetrate the car bodywork and radio would tend to have a longer range, multidirectional and much easier for a criminal to "hack"

Link to post
Share on other sites
hilldweller

I will leave Stuart0742 to answer that one.

His fleet of vehicles all seem to have remote locking devices, but my car is operated by a good old fashioned key.

I understand there is a device available, and in the hands of criminals which can intercept, record and playback, as it were, the signals from remote control door locks.

All a car thief has to do is be within range of you when you lock / unlock your car yourself.

His device will receive the same signal and store it.

When you are not around he can then use the stored signal on his device to unlock your car

Encrypting the signal is useless as it is the same signal, complete with any encrypted codes :o

Much more secure with a key

having said that, in this recent wet and icy weather there have been a number of occasions when I have been unable to get into my car (really secure then) due to ice in the locks :angry:

I am not sure how these "zappers" work or the type of beam they use.

Infra Red would not penetrate the car bodywork and radio would tend to have a longer range, multidirectional and much easier for a criminal to "hack"

The manufacturers have got around this by having the code change each time the button is pressed. The code changes according to a pre-arranged table of huge length (a psuedo-random number) stored in both the remote and the receiver. According to some details I saw the number doesn't repeat for several million numbers.

HD

Link to post
Share on other sites

I will leave Stuart0742 to answer that one.

His fleet of vehicles all seem to have remote locking devices, but my car is operated by a good old fashioned key.

I understand there is a device available, and in the hands of criminals which can intercept, record and playback, as it were, the signals from remote control door locks.

All a car thief has to do is be within range of you when you lock / unlock your car yourself.

His device will receive the same signal and store it.

When you are not around he can then use the stored signal on his device to unlock your car

Encrypting the signal is useless as it is the same signal, complete with any encrypted codes :o

Much more secure with a key

having said that, in this recent wet and icy weather there have been a number of occasions when I have been unable to get into my car (really secure then) due to ice in the locks :angry:

I am not sure how these "zappers" work or the type of beam they use.

Infra Red would not penetrate the car bodywork and radio would tend to have a longer range, multidirectional and much easier for a criminal to "hack"

All I know, is that if you hold the metal part of the key against your head it increases the distance they work over lol , its true even Top Gear have featured this.

Perhaps it fries your brain as well, I'm not sure, perhaps that's why I'm daft. lol

Link to post
Share on other sites

The trouble is caused by local high powered transmissions (ham radio, CB, or taxi firm etc) which swamp the very primitive TRF front-ends of the remote control receivers.

HD

I can't speak for CB radios and taxi firms as I never approved of illegal CB radio and have not worked for a taxi firm.

Illegal CB in the early 1980's craze caused all sorts of problems, but now the craze has passed and the CB users that are left are all properly licenced and using the allocated frequencies around 27MHz in the 11 metre band but with FM instead of AM the problem seems to have gone away.

For Amateur Radio which has always been controlled and licenced, the power used depends on the band. In some it was as little as 10W and was never more than about 150W, 40W being the norm. I am speaking of the HF bands in the short wave range. If a car zapper used 10W on these bands it would be possible to open a car door in Australia with a zapper in Sheffield!

Since my interest in short wave radio has declined I know the amateurs have done more and more on the VHF and UHF frequency bands, - which must have shortened their communications range a hell of a lot, - but also may be where it comes into conflict with short range very high frequency car door zappers.

To be fair, ham radio, CB and taxi firms are all licenced, sensible users these days and are not that likely to be the source of the problem.

Has someone recently set up an illegal pirate radio station in the neighbourhood?

One with a massive power output?

As Hilldweller said, - look around for a large aeriel which has recently appeared.

Link to post
Share on other sites
hilldweller

All I know, is that if you hold the metal part of the key against your head it increases the distance they work over lol , its true even Top Gear have featured this.

Perhaps it fries your brain as well, I'm not sure, perhaps that's why I'm daft. lol

My theory for this goes like this.

The tiny remote control is not large enough to hold an aerial resonant at the frequency it transmits on. Therefore it works at less than optimum efficiency.

When you place it against your body the signal capacitively couples to your body. Perhaps there is a part of your body of dimension more suited to radiate the signal. I shudder to think which bit but the optimum length of a half-wave dipole at around 400 Mhz is around 7.5 inches. Perhaps that's the distance between your ears !

Next time the missus tells you you're useless, tell her you're a very efficient parasitic radiating element.

HD

Link to post
Share on other sites

My theory for this goes like this.

The tiny remote control is not large enough to hold an aerial resonant at the frequency it transmits on. Therefore it works at less than optimum efficiency.

When you place it against your body the signal capacitively couples to your body. Perhaps there is a part of your body of dimension more suited to radiate the signal. I shudder to think which bit but the optimum length of a half-wave dipole at around 400 Mhz is around 7.5 inches. Perhaps that's the distance between your ears !

Next time the missus tells you you're useless, tell her you're a very efficient parasitic radiating element.

HD

Do they work at 400MHz?

A lot of stuff these days seems to work at around 2400Mhz (2.4Ghz)

At this much higher frequency the aeriel would be a lot shorter and probably would fit inside the zapper.

Link to post
Share on other sites
hilldweller

Do they work at 400MHz?

A lot of stuff these days seems to work at around 2400Mhz (2.4Ghz)

At this much higher frequency the aeriel would be a lot shorter and probably would fit inside the zapper.

I understand that most car "zappers" work at 418 or 432 Mhz although my german made garage door works at 868Mhz.

I think the 2400 Mhz band seems to be reserved for wireless security cameras / alarms and the boxes used for sending video signals around the home. It is also used for earlier versions of wireless broadband.

HD

Link to post
Share on other sites

I understand that most car "zappers" work at 418 or 432 Mhz although my german made garage door works at 868Mhz.

I think the 2400 Mhz band seems to be reserved for wireless security cameras / alarms and the boxes used for sending video signals around the home. It is also used for earlier versions of wireless broadband.

HD

OK, so to solve waterside's problem we need to be looking at what else, in a fairly local area could be using frequencies around 400MHZ at fairly high power, or alternatively, if its illegal stuff giving out a lot of RTI noise, working at another frequency but giving out unfiltered harmonics at about 400MHz.

Link to post
Share on other sites
hilldweller

OK, so to solve waterside's problem we need to be looking at what else, in a fairly local area could be using frequencies around 400MHZ at fairly high power, or alternatively, if its illegal stuff giving out a lot of RTI noise, working at another frequency but giving out unfiltered harmonics at about 400MHz.

As I understand the situation the receiver input stages are so rudimentry that any strong RF signal of virtually any frequency is capable of completely swamping the single Tuned Radio Frequency RF stage. I understand that mobile phone masts have been implicated with frequencies way above as well as AM and FM CB equipment. Perhaps a quick check with a scanner would help, somone might have one. It doesn't seem to matter what frequency or modulation type is involved if the signal is strong enough.

HD

Link to post
Share on other sites

As I understand the situation the receiver input stages are so rudimentry that any strong RF signal of virtually any frequency is capable of completely swamping the single Tuned Radio Frequency RF stage. I understand that mobile phone masts have been implicated with frequencies way above as well as AM and FM CB equipment. Perhaps a quick check with a scanner would help, somone might have one. It doesn't seem to matter what frequency or modulation type is involved if the signal is strong enough.

HD

Poor quality radio equipment controlling the security of your car :blink:

I stand by my original post in this thread and I am glad that my car security is controlled by a key. ;-)

Link to post
Share on other sites
Waterside Echo

Poor quality radio equipment controlling the security of your car :blink:

I stand by my original post in this thread and I am glad that my car security is controlled by a key. ;-)

Just had a walk round the block, a couple of C B masts have recently appeared so that could be the answer. Thankyou all. W/E.

Link to post
Share on other sites
hilldweller

Poor quality radio equipment controlling the security of your car :blink:

I stand by my original post in this thread and I am glad that my car security is controlled by a key. ;-)

Looking on the bright side, the code hopping multi-bit encoding means that no-one else can get in your car. The flip side is that if you park it in the wrong place YOU might not be able to get in your car. However if I unlock my car using the key it switches off the alarm and immobiliser, so no worries.

Years ago we went to look at a house located almost under a TV relay transmitter. As we pulled up the car radio started buzzing loudly and when we went to leave the electronically managed car engine wouldn't run properly until we were 50 yards down the road. We didn't buy the house.

25 years ago I shinned up a lattice mast to renew a damaged transmitter aerial and became aware that the side arms of my specs were burning the sides of my face. All our transmitters were isolated but the police mast a few yards away and level with me wasn't.

HD

Link to post
Share on other sites

As I understand the situation the receiver input stages are so rudimentry that any strong RF signal of virtually any frequency is capable of completely swamping the single Tuned Radio Frequency RF stage. I understand that mobile phone masts have been implicated with frequencies way above as well as AM and FM CB equipment. Perhaps a quick check with a scanner would help, somone might have one. It doesn't seem to matter what frequency or modulation type is involved if the signal is strong enough.

HD

OK so its likely to be the CB mast.

CB works on 27MHz and hilldweller says that one of the frequencies used by the zappers is 432MHz.

That means that :-

Either the car zapper receiver is responding to the 16th harmonic wave (which should be very weak anyway and should be filtered out)

Or, that TRF in the car really is useless.

What makes of car were they agian?

I bet they were expensive top of the range cars fitted with cheap tac security remote door locking. :o

Link to post
Share on other sites
Waterside Echo

OK so its likely to be the CB mast.

CB works on 27MHz and hilldweller says that one of the frequencies used by the zappers is 432MHz.

That means that :-

Either the car zapper receiver is responding to the 16th harmonic wave (which should be very weak anyway and should be filtered out)

Or, that TRF in the car really is useless.

What makes of car were they agian?

I bet they were expensive top of the range cars fitted with cheap tac security remote door locking. :o

BMW, Jaguar and Nissan. All 3 less than 2 years old. Mine no problem, Fiat, 15 years old. W/E.

Link to post
Share on other sites

BMW, Jaguar and Nissan. All 3 less than 2 years old. Mine no problem, Fiat, 15 years old. W/E.

I knew it, I knew it, I knew it lol lol lol

3 flash, expensive cars (often owned by arrogant show offs with poor driving skills and limited knowledge of the highway code) and all of them have got crap door locking systems in which the security of the vehicle is easily compromised.

BMW, highly over rated, and overpriced. :o

Nissan, started out as Datsun, got such a bad reputation that they changed the name to Nissan (after the hut! lol ), they didn't improve the car much though :angry:

..and as for Jaguar, - some of us can remember when this was a BRITISH car :rolleyes: , there wasn't much wrong with it then ;-)

Link to post
Share on other sites
Waterside Echo

I knew it, I knew it, I knew it lol lol lol

3 flash, expensive cars (often owned by arrogant show offs with poor driving skills and limited knowledge of the highway code) and all of them have got crap door locking systems in which the security of the vehicle is easily compromised.

BMW, highly over rated, and overpriced. :o

Nissan, started out as Datsun, got such a bad reputation that they changed the name to Nissan (after the hut! lol ), they didn't improve the car much though :angry:

..and as for Jaguar, - some of us can remember when this was a BRITISH car :rolleyes: , there wasn't much wrong with it then ;-)

Well said DaveH, my sentiments entirely. I will keep you updated and let you know the outcome. W/E.

Link to post
Share on other sites
  • 3 weeks later...
Waterside Echo

Well said DaveH, my sentiments entirely. I will keep you updated and let you know the outcome. W/E.

It turns out the culprit was a wireless operated burglar alarm. It was noticed the problems had only started after one of the neighbours in the vicinity went away, a week later on his return things went back to normal. W/E.

Link to post
Share on other sites

It turns out the culprit was a wireless operated burglar alarm. It was noticed the problems had only started after one of the neighbours in the vicinity went away, a week later on his return things went back to normal. W/E.

So not only do we know how to gain entry to cars fitted with wireless key zapper technology, -we also know the frequency needed to get past someones wireless burglar alarm :o

I am sure that these wireless devices are not as secure as we are lead to believe, - and that goes for wireless internet connection.

If wireless was secure then why was it used for general broadcasting rather than private conversions and why didn't the telephone become obsolete as soon as radio (wireless) had established itself?

Link to post
Share on other sites

It turns out the culprit was a wireless operated burglar alarm. It was noticed the problems had only started after one of the neighbours in the vicinity went away, a week later on his return things went back to normal. W/E.

Not as technical as wireless but a true story.

Late one dark winters evening a few years ago I was walking down to Stuart0742's house when all the street lights went off.

On arriving at Stuarts I told him what had happened to the street lights and he said it was the fault of a guy who lived up the street and that they would come back on again in a few minutes, which they did.

Half an hour later we both went out to go to the boozer and exactly the same thing happened again.

Stuart said, "That's the guy there in that garden, -it's his fault the lights keep going on and off!"

It turns out the guy in question was a heavy smoker and his wife was a non smoker. She didn't like her house smelling of fags so she made him smoke outside in the garden.

To make life a bit easier for himself smoking in the garden in the evenings he had installed a high intensity security light, - the type with a 500W halogen bulb, so that he could see in his garden at night.

Unfortunately, at the bottom of his garden was a small sub station used to provide the 410V 3 phase to power the street lights and this station had a photocell attached to it which controlled when the street lights came on and went off according to the ambient light level. The photocell was directly in line with his security light!!!

So, he comes out for a fag, his security light comes on, the photocell thinks its daylight and off go all the street lights in all the neighbouring streets.

When he's finished smoking and goes indoors the security light goes off, the photocell realises its dark and the street lights are restored.

So once again one mans use of technology interferes with the lives of many others in a negative way.

Link to post
Share on other sites

How about this then. We rented a car on a visit to the U.K. All was well untill on the second day, the thing wouldn't start, wouldn't even turn over. We called the rental company, who sent out a mechanic with tow truck to see if they could start it. After about 10 minutes fiddling around, the mechanic announced all was well. For a couple of days everything was fine, then, a day later the same thing happened. Again a repairman was sent to fix it. Five minutes later he announced all was o/k, and left the motor running. I turned it off, then tried to start it again to no avail.

It turned out, the security interlock device, built into the ignition key was being overridden, and it finally turned out that this was caused by having our cell phone plugged into the cigarette lighter. Somehow the signals got mixed up, preventing the ignition being enabled. The repairmen that looked at it must have seen the problem before, and kept quiet so they would recieve payment for the repair job.

Link to post
Share on other sites

How about this then. We rented a car on a visit to the U.K. All was well untill on the second day, the thing wouldn't start, wouldn't even turn over. We called the rental company, who sent out a mechanic with tow truck to see if they could start it. After about 10 minutes fiddling around, the mechanic announced all was well. For a couple of days everything was fine, then, a day later the same thing happened. Again a repairman was sent to fix it. Five minutes later he announced all was o/k, and left the motor running. I turned it off, then tried to start it again to no avail.

It turned out, the security interlock device, built into the ignition key was being overridden, and it finally turned out that this was caused by having our cell phone plugged into the cigarette lighter. Somehow the signals got mixed up, preventing the ignition being enabled. The repairmen that looked at it must have seen the problem before, and kept quiet so they would recieve payment for the repair job.

Sounds like a very similar problem to the original one with the zapper key locks.

Now if all these radio controlled and "wireless" communication devices didn't all use the same or very similar frequencies then things may be a bit better.

Link to post
Share on other sites
  • 2 weeks later...
hilldweller

Not as technical as wireless but a true story.

Late one dark winters evening a few years ago I was walking down to Stuart0742's house when all the street lights went off.

On arriving at Stuarts I told him what had happened to the street lights and he said it was the fault of a guy who lived up the street and that they would come back on again in a few minutes, which they did.

Half an hour later we both went out to go to the boozer and exactly the same thing happened again.

Stuart said, "That's the guy there in that garden, -it's his fault the lights keep going on and off!"

It turns out the guy in question was a heavy smoker and his wife was a non smoker. She didn't like her house smelling of fags so she made him smoke outside in the garden.

To make life a bit easier for himself smoking in the garden in the evenings he had installed a high intensity security light, - the type with a 500W halogen bulb, so that he could see in his garden at night.

Unfortunately, at the bottom of his garden was a small sub station used to provide the 410V 3 phase to power the street lights and this station had a photocell attached to it which controlled when the street lights came on and went off according to the ambient light level. The photocell was directly in line with his security light!!!

So, he comes out for a ***, his security light comes on, the photocell thinks its daylight and off go all the street lights in all the neighbouring streets.

When he's finished smoking and goes indoors the security light goes off, the photocell realises its dark and the street lights are restored.

So once again one mans use of technology interferes with the lives of many others in a negative way.

Years ago (too many to contemplate) I went to school with a lad who lived at the bottom of Langsett Avenue at Middlewood.

This was at the time when the gas-lamps were being replaced by low-pressure sodium lighting. A few weeks after the new lighting was installed my pals father received a huge electric bill.

He queried it and they swopped the meter but he found that it began to fly around again each evening. It soon became apparent that the next bill was going to be huge as well.

In a panic he switched the power off at the mains and they realised that not only was their house in darkness but the street lights had gone out as well. He switched back on the power and after a couple of minutes the street lamps came on again when they had cooled down enough to re-strike.

In triumph he contacted the YEB who told him it was impossible.

It turned out that they had fed the street lamps from an armoured cable buried on the edge of the pavement which fed power from his house to his large garage built further up the street.

It made front page news in the star.

HD

Link to post
Share on other sites

Join the conversation

You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...