Received email that if your car door is locked and you lose (misplace) your keys and remote, call home via cell phone, have someone push the "unlock" on the other remote near a phone while you hold the cell phone next to the car. This is suppose to unlock the door, however isn't there a difference with radio waves and sound waves?
This will only work if you simultaneously place one foot in a bucket of water while wearing an aluminum-foil beanie cap on your head... to amplify the signal. Trust me.
Hairy Houdini
Posted: Thu Oct 14, 2004 | 10:52 AM
A-man, I tried it. All I got was a wet sneaker and an empty foil roll. Perhaps I should have chanted "Open, seza me"
ryan
in stlouis
Posted: Mon Feb 28, 2005 | 05:06 PM
it does work, use two cell phones, why would you use a house phone?!?! The signal piggy backs through as interference on the cell signal.... I use it many times, and it is fun.
ryan,
Who said they use / used a house phone? The article said... "Call home via a cell" not to use the house phone. That wasn't given as direction. It's just probably assumed that you'd be able to use the house phone... besides did you check the snopes link above???
Jake
in Canada
Posted: Mon Apr 04, 2005 | 12:57 PM
I tried it with a house phone, and my cell phone. it worked :D
Dave
in Florida
Posted: Thu Jun 02, 2005 | 09:03 PM
Hi all,
Ok, a little Science.
When you push that little button on your remote car door opener, you are transmitting a coded RADIO FREQUENCY. That signal is received in the vehicle and if the code sequence matches that stored on a chip, your door unlocks.
The Telephone, be it Cell phone or Landline, detects SOUND energy in the vicinity of the mouthpiece and reproduces Sound energy at the other end NOT a Radio Frequency. Hence this idea has no possibility of working.
Dave
If this worked, all you would need to do to break into someone's car is to record the sound of them unlocking the car with their key button thing, and then play it back at a later time near their car. It sounds like a much stupider concept when put that way, does it not?
According to "ryan" and "jake" it works. These guys must be fun to know... just imagine the shit you could lay on them!
FISHPRO200HP
in FT. LAUDERDALE
Posted: Tue Jul 12, 2005 | 12:37 PM
i did not believe it would work, so i tried it and it did work from cell to cell but i could not get it to work from a landline.
try it it is cool
Dave
in Florida
Posted: Tue Jul 12, 2005 | 12:45 PM
Absurd, how far away was the Cell Phone from the car?
No doubt, well within range of the RKE device. Some will work up to 300 feet away. The science is clear, no violations of the laws of physics allowed.
David B. Member
Posted: Tue Jul 12, 2005 | 01:36 PM
I'll believe this when I see it, but 'Dave' is a bit off the mark with his science.
While it is true that the first and last stages of a cell-call are sound waves, everything else is purely an electromagnetic signal.
Two stories: -
1) Some people I worked with could never understand how I'd dig in a coat pocket, bag or under a sheaf of papers and pick up my cellphone just before it started ringing. My explanation that I could feel the calls coming just made then more uneasy. The fact that I spent most of my days plugged into my Walkman listening to Radio 4 never seemed to tip them off. Whenever the phone was being 'polled' prior to the call being connected a distinctive 'clicky-clicky-click' of radio interference sounded in my ear, giving me 2 seconds to find the phone before the ringing started.
2) Back in the days of analogue cellphones (remember them), I discovered that the cheapo cellphones my employer was providing gave a rough, but audible, reproduction of any sound file played on my AlphaStation (to a range of about 2m) despite the fact that there were no speakers plugged in. Consequently, I could cause someone on the phone to hear "You're dethpicable! (Daffy)", "Waa-hoo-hoo-hoo! (Goofy), or my personal favourite 'Ni! (Monty Python)' by remotely scheduling sounds to their workstations while they were on their cellphones. That no-one else could hear these sounds was great for making people doubt their sanity. Oh, the one where my boss got into an argument with his wife because he was sure he could hear their baby crying... Priceless.
'So what?' I hear you cry. Well, it demonstrates that (1) cellphones can electromagnetically influence other electronic devices, and (2) other electronic devices can influence (at least some) cellphones. The potential is there for a simple signal of low enough bandwidth and high enough redundancy to be piggy-backed onto a cellphone call. The sound/radio distinction is not really relevant in this case.
But like I said, I'll believe it when I see it, done double-blind, at TRL , with James Randi in attendance.
David B. Member
Posted: Tue Jul 12, 2005 | 01:37 PM
The science is clear, no violations of the laws of physics allowed.
Radio interference from a cell phone is a well known fact. Your cell basically screams 'Here I am!' when being polled for an incoming call. There are plenty of devices you can buy that light up or otherwise notify you when a nearby cell phone does this.
On the other hand, I don't believe that a cell phone network can transmit the radio signal accross their networks like this. It would involve the radio signal being picked up by the sound only microphone, being sent accross the network, and being transmitted by the sound only speaker at the other end. The phones operate by radio waves of course, but they are not designed to send external radio signals this way. In fact, I'm fairly sure that there are filters to remove extraneous electrical noise caused by interference, whether natural or man made. Your phone may cause interference or be affected by it, but it shouldn't transmit across the network to another phone. Especially a digital network.
David B. Member
Posted: Tue Jul 12, 2005 | 02:32 PM
It would depend on where the interference is having its effect. If it were, hypothetically, having an effect on any stage prior to the encoding and modulation of the signal into the 950+ Mhz range, then there is little the phone can do to distinguish between the interference and the signal.
The 'sound only' microphone is the smallest stage of the process, and although the digital encoding of the signal is only intended to cover the 20-20000Hz range, that does not mean a 400Mhz key-fob can't piggyback on it, as the actual frequency of the bit-pattern the fob sends is usually much lower.
It very probably is technically impossible, and I'd want to see a very convincing demonstration before I'd believe it (my remote is IR, so I can't do the "fool's errand" myself, for the sake of the board of course). But technically impossible (or more correctly, implausible) is not the same as scientifically impossible.
Dave
in Florida
Posted: Tue Jul 12, 2005 | 03:05 PM
Hi Boys and Girls,
Ok! I suppose we could hypothesize a Sporadic E bounce of a fourth order sub-harmonic generated by a Spread Spectrum microwave transmission in Rangoon!!! In 30 years at NSA I saw and wasted lots of time analyzing all sorts of bizarre EMF phenomena. I could quote Kotelnikov/Nyquist and demonstrate by numerous routes why this won't work. If anyone can't believe the theory, go outside and collect data. Just make sure that the Originating Cell phone/RKE device is well outside it's operating range from the target vehicle.
Dave
David B.
in Reading, England.
Posted: Wed Jul 13, 2005 | 06:24 AM
The fact that it doesn't work, which I don't dispute (although except for HH - who might have been joking - no-one has come forward to say they've tried it and it doesn't work), does not mean it breaks the laws of physics, is scientifically impossible, or has been forbidden by God.
As cellphones operate at 950+ Mhz, and key fobs at ~400 MHz, the Kotelnikov-Nyquist-Shannon inequality still holds. But I don't believe hi-fidelity reproduction is a reasonable mechanism for the proposed effect, and neither is 'sporadic E bounce' as that would not require the agency of a cell-phone.
If anyone can't believe the theory, go outside and collect data.
Too right! Although it's unfortunate that the only people who so far have claimed to have done so have been roundly ridiculed because they didn't report the 'right' results.
David said: As cellphones operate at 950+ Mhz, and key fobs at ~400 MHz, the Kotelnikov-Nyquist-Shannon inequality still holds. But I don't believe hi-fidelity reproduction is a reasonable mechanism for the proposed effect, and neither is 'sporadic E bounce' as that would not require the agency of a cell-phone.
Personally, I like "sporadic E bounce"...
Dave
in Florida
Posted: Wed Jul 13, 2005 | 09:00 AM
Hi all,
Well of course I was joking a bit and simply trying to say that there are all sorts of issues of mismatches in Frequency, Modulation, Filtering and subtle issue of Clocking.
Consider the Modulation issue to start with. RKE's of Japanese origin use Amplitude Shift Keying, while those of US origin use FSK. Modern Cell phones depending on type are using TDMA or CDMA on top of FM or in the digital domain Mixed Phase and amplitude techniques.
Now what we have to believe is that the Cell phone antenna resonates to some degree to the 400Mhz RKE and then, tell me what the Cell phone
Demodulator does with the ASK or FSK signal it now sees? It no doubt detects some modulation component or maybe it does not, just consider the issues, how many things would have to fall into place to make this work! additionally, the clock rates are so different between the RKE and the Digital speech encoder of the cell phone, now we introduce multiple sampling issues which are data rate asynchronous!!!
Not likely, but again I say Go out and collect some data.
Dave
