Wireless car key has more range when you hold it to your head

Have you forgotten to lock your car and are already too far away? You can use a simple trick to increase the range of your wireless car key – by holding it to your head. We'll explain to you why that is.

Did I really lock my car? Many people have this question running through their minds as they walk away from their vehicle. Fortunately, these days you don't have to go all the way back, you can simply lock it afterwards using a wireless car key. Unless they are already too far away.

But even then she offers a simple trick to increase the range of the radio signal: you can simply hold the car key to your head.

Trick: This is how you extend the range of your wireless car key

Wireless car keys contain a transmitter that emits radio waves. When locking and unlocking, they reach a control unit that controls the vehicle doors. For European cars the frequency is around 434 megahertz. This corresponds to a range of approximately one meter.

The further owners move away from their cars, the weaker the signal becomes and the chance of locking the vehicle from further away decreases. However, if you hold your key to your head, you can extend the range of the signal by 20 times.

In a YouTube video, physicist Roger Bowley from the University of Nottingham explains how this works: The human head is full of water. This liquid acts as an amplifier for the electromagnetic waves emitted by the remote key. They cause the water molecules in the head, which are electrical dipoles, to vibrate. So if you and the car key are close to each other, they will oscillate in the same phase and the signal will be amplified.

This way you can extend the range of your key even further

What already works very well with water in your head works even better with a water bottle. There is also another trick that can be used to increase the range of a wireless car key: using metal.

If you hold your car key against a metal object, such as a light pole, you can use it as an antenna. Anyone who happens to have a copper cable with them will get a similar effect. Wrapped around the key, it increases the range of the signal. The same can be done with a metal rod.

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