Blog Editor’s Note: An interesting article about the inner workings of one of these devices. 

Written for hands-on technologists, but many others might find it interesting also.

Two notes:

  • The author mentions he did not investigate its effective range. Authorities in Europe have said that a device like this is effective for 100 meters or more.  Of course, its is not like they are UL certified, so performance likely varies.
  • The author also makes mention that it would be good if these didn’t get into general circulation. Too late. There are likely tens of thousands of them in use in the United States.  While no one in the U.S. has done any looking, that we know of, sampling in the EU detected about 50,000 jamming incidents and identified around 300 “families” of jamming devices.


If you spend enough time trolling eBay for interesting electronic devices to take apart, you’re bound to start seeing suggestions for some questionable gadgets. Which is how I recently became aware of these tiny GPS jammers that plug directly into an automotive 12 V outlet. Shipped to your door for under $10 USD, it seemed like a perfect device to rip open in the name of science.

Now, you might be wondering what legitimate uses such a device might have. Well, as far as I’m aware, there aren’t any. The only reason you’d want to jam GPS signals in and around a vehicle is if you’re trying to get away with something you shouldn’t be doing. Maybe you’re out driving a tracked company car and want to enjoy a quick two hour nap in a parking lot, or perhaps you’re looking to disable the integrated GPS on the car you just stole long enough for you to take it to the chop shop. You know, as one does.

But we won’t dwell on the potentially nefarious reasons that this device exists. Hackers have never been too choosy about the devices they investigate and experiment with, and there’s no reason we should start now. Instead, let’s take this piece of gray-area hardware for a test drive and see what makes it tick.