Cell phone jammer circuit | cell phone jammer schematics plans
Your friend was absolutely right. Those “code grabbers” really exist. To understand how they do work and what the means of protection are, we should clarify how your car alarm works. The process of disarming a car alarm looks like that: your trinket sends waves on the specified frequency (315/868/433 MHz). The receiver mounted in your car alarm receives those waves that carry a specific code, which unlocks your car.
Thieves use those code grabbers to intercept those signals that your trinket sends and then they just have to crack that opening code. It is not really complicated and that is the main reason of that that car hijackers just love this technique. Another reason for this is in that that they can avoid suspicious activity like picking the lock or cracking a window so the chances to get caught are lower.
The best way for protection will be using a remote control jammer that works with a needed frequency to make sure that thieves will have no possibility to use a code grabber. The hardest thing in protecting your property is to find out what frequencies are used by your car alarm. As I’ve already written they can be different. Generally the most common frequency for USA is 315 MHz, but it is not 100%. So you may try a 315 MHz jamming device but if your car alarm is manufactured in Japan or somewhere else it will not probably work. The best solution will be using a universal all frequency remote control jammer that covers all those remote frequencies: 315, 868 and 433 MHz.
Jammer-Store thanks you for your question! Keep your car safe!
P.S. You may find some info on remote control jamming devices right here.