A cellphone jammer is an electronic device used to block or interfere with the normal cellphone signals. Cellphones are wireless communication devices that use radio signals, they can be easily interfered or jammed, here is a brief description given on how to build a cellphone jammer of your own, to play around by interrupting signals. This is for theoretical purposes only and could result in apprehension or fine if caught using it. The jammers can be designed to any frequency and are effective against iDEN, AMPS, Nextel Systems, CDMA, TDMA, GSM, PCS and DCS.
Difficulty level: Moderately challenging
Time required: It depends upon an individual’s experience who is working on the project. For an average experienced person, it would take a couple of hours or even less.
(De) Solder braid
Small flash light
Estimate cost: $25 for printed circuit board and $100 for other parts.
1 - Gather all the resources required in one clean and dry place. Take a printout of the circuit design and go through it thoroughly and understand the working. Before starting the next step check all the components for their proper working using a multimeter and oscilloscope.
2 - Take the printed circuit board and start soldering all the electronic components from one end using the soldering iron and soldering lead. Be careful, do not overheat any electronic component as it may damage them. Use flux where ever necessary.
3 – Check using the microscope for flaws in the soldering and use the De solder braid to remove the existing solder and re-solder. Once the solder of the electronic components is done, clean the PCB using the thinner and a brush.
4 – Connect the battery to its terminals through a switch and connect the oscilloscope terminals to the antenna’s terminals across the ground. Turn on the switch and the oscilloscope. Check for the frequency of the signals emitted by the antenna. If it is not equal to 800MHz then fine tune the circuit till the desired frequency is obtained.
5 – Once the tuning and the test are done, remove the battery and take the aluminum box and fix all the components in it. Close the cover of the box and connect the antennas.
6 – The signals sent by the chips in the PCB are transmitted through the antenna and will be effective only in the range of 20-25 feet. Test using a cellphone try to make a call. The phone will display a error message saying out of coverage area or connection error.
Frequently asked questions:
Q: How to solder the ICs?
A: Usually the ICs are soldered using a machine but can also be done using a soldering iron with a fine tip.
Q: How to apply the flux?
A: Flux should not be applied directly to the component. Take the soldering iron and just touch the surface of the flux and continue with the soldering.
1 – Do not use too much of lead to solder. Even little amount of soldering lead will be enough.
2 – Use a sprayer to spray the thinner to clean the surface after the soldering is done.
3- For maximum results use the jammer where there are no obstacles like walls etc.
4 - Place the antennas in opposite direction to ensure maximum range.