Try this out and tell me if it's true?

bindi · 08-10-2005, 07:38 AM

I don't have keyless entry - so I don't know if it's true or not... anyone willing to try it out and tell me if it's another hoax?

Locked your keys in your car ???? Did you know this??

If you lock your keys in the car and the spare keys are at home, call someone on your (or someone else's) mobile phone.

Hold your phone about a foot from your car door and have the other person at your home press the unlock button of your key, holding it near the phone on their end. Your car doors will unlock. Saves someone from having to drive your keys to you.

Distance is no object you could be hundreds of miles away, and if you can reach someone who has the other "remote" for your car, you can unlock the doors (or the boot!).

Editor's Note* It works fine! We tried it out, and it unlocked our car over a mobile phone!)

Mike's Note* I locked the car, had my youngest daughter call me while I was far away from the car. I cliicked open into the phone and I could hear the car doors unlock through her phone.. My daughter confirmed that sure enough the doors opened.

MightyXR6Turbo · 08-10-2005, 09:27 AM

That kinda defies logic. How can a mobile phone, which is designed to capture and transmit sound, actually transmit radiowaves? It's a total load of bollocks.

LUXO_8 · 08-10-2005, 09:39 AM

certainly sounds like a load.....

Mike Gayner · 08-10-2005, 09:48 AM

It would probably work, depending on how mobiles modulate signals (anyone know the modulation method used?

RED_EL_XR8 · 08-10-2005, 11:55 AM

Quote:

Originally Posted by MightyEFGhia

How can a mobile phone, which is designed to capture and transmit sound, actually transmit radiowaves?

Heard of a carrier frequency? A mobile handset is a radio transceiver! The only things that transmit sound directly are a passive phone and a didgeridoo!

Some simple simple detective work would soon debunk the mobile / keypad myth. The mobile transmits modulated audio, so unless you have noise-making key-fobs you are plumb out of luck.

This on one is just a poorly conceived hoax that'd only trap only the very gullible.

Mike Gayner · 08-10-2005, 12:53 PM

Quote:

Originally Posted by RED_EL_XR8

This on one is just a poorly conceived hoax that'd only trap only the very gullible.

Meh I don't care I'm still going to try it :P

A mobile phone is nothing but a really fancy CB radio on a much higher frequency, so yeah they do radio waves.

paul7v7 · 08-10-2005, 01:13 PM

Quote:

Originally Posted by RED_EL_XR8

Some simple simple detective work would soon debunk the mobile / keypad myth. The mobile transmits modulated audio, so unless you have noise-making key-fobs you are plumb out of luck.

you so sure just modulated audio or just generalising once again?

in saying that i don't think the trick will work.

RED_EL_XR8 · 08-10-2005, 04:14 PM

Quote:

Originally Posted by paul7v7

you so sure just modulated audio or just generalising once again?

in saying that i don't think the trick will work.

Very much a generalisation, but anyone who has not grasped that the input source of any type of mobile telephone is audio only, will likely not be too clued up on modulation of digitised signal packets.

dogbreath_48 · 08-10-2005, 04:30 PM

Well i'm tipping remote locking doesn't work on an uper-high frequency sound, and even if it did, and the phones mic actually picked it up, and the recieving mobiles speaker could actually tramsmit that frequency, i doupt it would be loud enough for the car to 'hear' it.

-Stu

vztrt · 08-10-2005, 04:34 PM

Quote:

Originally Posted by dogbreath_48

Well i'm tipping remote locking doesn't work on an uper-high frequency sound, and even if it did, and the phones mic actually picked it up, and the recieving mobiles speaker could actually tramsmit that frequency, i doupt it would be loud enough for the car to 'hear' it.

-Stu

Mobile phones also filter alot of frequencies out that humans wouldn't hear to help clean up the sound before it's sampled by the ADC. If it did work I'd be very surprised.

PH47 · 08-10-2005, 05:03 PM

Why doesn't someone just try it? :P

I would but.. er.. 67's didn't come with remote central locking

Biggoggs · 08-10-2005, 05:11 PM

Quote:

A mobile phone is nothing but a really fancy CB radio on a much higher frequency, so yeah they do radio waves.

Mobile phones use around 900MHz (1800 if GSM2), remote entry seems to use 300-400MHz. On top of that, as someone else has pointed out, mobile phones modulate sound, usually between 20-20,000Hz. On top of that again, your phone uses 14kbps GSM audio encoding, which clips, compresses, and packets audio through different GSM cells.

Unless your keychain uses sound to unlock the car (lol), it has the same effect as waving a photograph in front of your mobile phone to send a picture, interference aside.

Quote:

Mike's Note* I locked the car, had my youngest daughter call me while I was far away from the car. I cliicked open into the phone and I could hear the car doors unlock through her phone.. My daughter confirmed that sure enough the doors opened.

How far away exactly?

vztrt · 08-10-2005, 05:23 PM

Quote:

Originally Posted by Mike Gayner

Meh I don't care I'm still going to try it :P

A mobile phone is nothing but a really fancy CB radio on a much higher frequency, so yeah they do radio waves.

Your right because the old two way radio engineers (that had a system for emergancy radio and telstra employees) became the mobile phone engineers. It's just mobile phones do alot more than the old two ways of the 70's

MightyXR6Turbo · 08-10-2005, 05:38 PM

Quote:

Originally Posted by RED_EL_XR8

Heard of a carrier frequency? A mobile handset is a radio transceiver! The only things that transmit sound directly are a passive phone and a didgeridoo!

Yeah, I am aware of that, all that i was saying is that a mobile phone is designed to capture sound, turn it into radio waves and transmit it away, it isn't designed to be a repeater system for key fobs. We agree that the whole thing is stupid, but I wasn't saying that all a phone does is transmits vibrations to make noise at a point on the other side like talking into a cup with a piece of string attached to another cup.

Kryton · 08-10-2005, 06:08 PM

would someone just try it.

donno · 08-10-2005, 06:16 PM

I've done signal processing at uni, and there is no way in hell that it would work... Period. For a signal to travel along a carrier, it first has to be modulated, which is done by alot of electronics. There is no chance in hell this could just happen in thin air. Secondly, the mobile call goes to a tower, into the system, which firstly demodulates the signal, then runs it through low and high pass filters to get rid of noise, then re-modulates it where it travels along phone lines to other towers, which then demodulate it, clean it again with said filters, and remodulate the signal to be picked up by the mobile. I'll believe it when boy george is proven to be straight.

Fairlane · 08-10-2005, 07:10 PM

Well boy george aint straight, but he is high on drugs.

I cant see how in a million years this could work.

myxr6 · 08-10-2005, 07:16 PM

Audio baseband is 300hz to 3000hz , so i assume the phone would filter out the rest.Thats why when you hear music over a phone it sounds tinny.

Aussie Falcon · 08-10-2005, 07:44 PM

It's false according to http://www.snopes.com/autos/techno/keyless.asp

MO · 08-10-2005, 08:09 PM

If anyone cares to check there was a thread on this a while back!!!!!!!!

bindi · 08-10-2005, 08:10 PM

Quote:

Originally Posted by davway

would someone just try it.

I agree. If I had central locking, I would bloody well TRY it.

That is why I asked in the friggin thread title - Try this out and tell me if it's true?

I don't want theory, I wanna see if it works. That's all!!!

big_pete · 08-10-2005, 08:19 PM

haha, this thread is hi-larious!!!!

Damo · 08-10-2005, 08:36 PM

yeah i tried it, works a treat. Also when my car hits 88 mph it can travel back in time.

:

Kapn_Kiwi · 08-10-2005, 08:39 PM

Quote:

Originally Posted by Damo

yeah i tried it, works a treat. Also when my car hits 88 mph it can travel back in time.

:

I've been watching that all weekend. ONE POINT TWENTY ONE JIGAWATTS!

gtfpv · 08-10-2005, 08:46 PM

amazing how no one has actually tried it.

mcflux · 08-10-2005, 08:51 PM

Oldskool TV remotes used to use high frequency sound for changing the channel, volume, on/off, etc.

But I think that was when the first "wireless" remotes came out (70s>=?).

EL_futuraistic · 08-10-2005, 09:07 PM

ahhh Horse Harry

richo77 · 09-10-2005, 05:37 PM

Okay heres one that works and I would love to hear an explanation from the more educated out there as to how it works..

Get your smartlock control and walk as far away from the car as it takes for it to not activate/deactivate the locks.

Then walk a bit further back just for good measure.

Now hold the control next to your throat and press the button and it will work!! :Up_to_som

donno · 09-10-2005, 06:02 PM

Possibly because when you unlock your car, the hold the keys by your waist. As you move further back, the angle of incidence to the receiver decreases, and the signal has to travel through the door, most likely a denser medium than glass. When you go to put it at your throat, the angle of incidence is increased, hence the signal is passed though the less dense material, hence it dissapates less over distance. If you held your arm up high you'd get the same effect (I know, I've tried this).

GeoNazi · 08-06-2009, 03:13 PM

I have tried this IT DOESN'T WORK!!!