GSM phone "jammer"

[solvarg]

Iwould like to build a device that could jam, break a GSM call. A short range 2-4m RF transmitter able to disturb (break up) a phone call.
Any one seen a thing like this?
Any one has an idea on how to design one?


Thanks!

 

[ME]

Are you aware that such a jammer is illegal in most countries?
Regrds - ME

 

[flatulent]

other methods

A fully legal method would be to shout out "Diarrhea of the mouth indicates constipations of the brain." as you point to the person on the phone.

 

[E-design]

Iwould like to build a device that could jam, break a GSM call. A short range 2-4m RF transmitter able to disturb (break up) a phone call.
Any one seen a thing like this?
Any one has an idea on how to design one?


Thanks!

Very easy. You need a VCO that you sweep with a sawtooth around the center frequency of the GSM phone's receive frequency. You can add a small amp on the VCO output to buffer and give a bit of amplification. The VCO is swept at a few KHz with enough amplitude to cover the GSM receive frequency bandwidth.

I was involved in the prototype design of a dual-band unit for a government agency in Brazil and our unit could block and terminate any phone call in a 70m radius.

As the previous member said, this device is illegal in a lot of counties and I am only aware of about 8 that allows the use of this in restaurants and theatres.

E

 

[solvarg]

Just an tout

I need a schematic, anyone?
Would I be possible to use an old scraped GSM phone? I that case have anyone seen a phone schematic lying around?

 

[tanveerriaz]

h**p://gbppr.dyndns.org/PROJ/mil/celljam/index.html