Instructables

Is it possible to hack an AM transmitter that transmits at about 1500KHZ to be used as a cellphone jammer?

I know that the band for cell phones is between about 800-1990MHZ and I was wondering if it would be possible to hack an AM transmitter or for that matter an FM ipod type transmitter into the cell phone range like KipKay did in his instructable with a reciever so that if you transmit noise it would disrupt the cell phone call and make them hang up. This is just an idea I had that would be the alternative to creating a jammer like the Wave Bubble made by Lady Ada that would be a lot easier and cheaper. This is not intended for bad purposes, its just for fun. I might not even make it but I am still wondering if it would work.

smiot.hi55 years ago
I could tell you this is illegal and to go away, but that's your job. Receivers work in a totally different way, you couldn't do the same thing on the transmitter. So. On to making the jammer.

If your transmitter cannot change frequencies, then it probably is a crystal transmitter. The easiest thing to do would be just replace the crystal! It should be in a silver box. Go buy a new crystal (frequency is covered later).

If it isn't, you'd be better off building your own new one. Follow these directions and replace the crystal with one whose frequency is going to be discussed below.

So. You want to jam cellphones. GSM, or 2G, has 4 bands. The band is not between 800 and 1990Mhz. The four bands are 850, 900, 1800, and 1900mhz. Above these are a few MHZ of area that is used. You'd need to make 4 transmitters to cover each band.

Phones are smarter than your average radio. They use a system called trunking. You won't be able to target a specific call, and it won't work on some carriers.

Easier than wavebubble:
http://www.instructables.com/id/RF-Jammer/
beak90 (author)  smiot.hi55 years ago
Thanks! I'll check to see if its a crystal transmitter. And I realize that there are 4 bands but those four are approximately between 800 and 1990. And I wouldn't need 4 different transmitters because each of those bands are for specific things. 870-894MHz is for rural parts of the US. 925-960MHz is the most common frequency in Europe. 1805-1880MHz is another band used in Europe. 1930-1990MHz is the most common band used in the US and its what I would make it on. Just putting a crystal in might not work because I would somehow have to sweep each band, because each band has a range that they use, not just one frequency. And I realize that this would only work on gsm carriers such as AT&T or T-Mobile. And just to reiterate, I AM NOT GOING TO BUILD THIS. IT IS JUST FOR SELF EDUCATIONAL PURPOSES.