I Don’t Think This Will Work

I received this e-mail from a co-worker this morning. I don’t think it will work, so I’d like to do a test – Jon is particularly good at locking his keys in his car (he managed to do so on Saturday, while driving it, which is quite impressive), so perhaps he’d try this out for me:

> Apparently this works. Good to remember
>
> This only works if your car has remote controlled locks. Also
> you need a CELL PHONE handy at your car.
> Ever lock your keys in the car? If you lock your keys in the
> car and the spare keys (remote) are home, call someone at home on
> your
> cell phone.
> Hold your cell phone about a foot from your car door and have
> the other person at your home press the unlock button on the remote,
> holding it near the phone on their end.
> Your car will unlock. Saves someone from having to drive your
> keys to you. Distance is no object. You could be hundreds of miles
> away,
> you can reach someone who has the other “remote” for your car,
> you can unlock the doors (or the trunk!)
>
> Editor’s Note: * It works fine! We tried it out and it
> unlocked our car over a cell phone!)

I think this is a hoax – as I understand it, these remote central locking devices send a radio signal, not an audio signal (capable of being carried over a telephone). And before anybody suggests ultrasonic, remember that telephones – and particularly mobile telephones – have a low dynamic range, designed to cater for the human voice (ever noticed how shit music sounds over a mobile phone): this is the same reason that conventional modems can’t be used on a mobile. But now I’m curious, so somebody try it and tell me what happens.