How to Create Your Signal Jammer





Introduction: How to Create Your Signal Jammer

For a long-long time many people were looking for this cool recipe of making something interesting for yourself. And I was one of them until last days. In my quest I came across the Jammer Store blog post called How To Make Your Cell Phone Jammer: DIY Guide. It inspired me to make something like that by myself.

All necessary info, schemes and pictures are there, so I tried. The result is represented in this humble guide for you.

Step 1: The Basics

This signal jammer uses 800MHz frequency to operate because many cell phones are working on the same frequency. So I chose the sweeping oscillator as my VCO. It is really efficient yet may be difficult to use if you are beginner without some semi-professional RF-testing tools.

The clock oscillator (45MHz) is driving a local oscillator port as my noise source and is located on the mixer of the mini circuit. To equate the impedance of a clock oscillator with the mixer there is an impedance matching network. Local oscillator signal goes through this network and impedance is matched.

The 800MHz antenna from the old cell phone is connected to the RF input (mixer port). The RF output then goes to the amplifier located on the mini circuit. The amplifier will increase produced output by 15-16dbm of pure power. The empowered signal is going to another old phone antenna.

Step 2: Your Jammer Works!

GSM800 cell phones have their frequencies separated by 45MHz exactly. So when any cell phone tries to make a call - it becomes blocked by itself! The phone talker will hear its own voice.

You can also keep in mind that this cell phone signal jammer can block all cell-based trackers which use your car GPS to track you down and record the data. Even IEDs are probably could be jammed, at least those ones controlled by cell signals.

Step 3: Pics and Notes

I used 600MHz mixer but it works nice due to some electronic interferences.
The amplifier is really a must for this device even considering its power consumption.
The case is made from aluminium box for better heat loss.
UHF connectors were attached to the mini circuit because they are perfect for antennas to fasten.
Voltage regulator is required for the nine volts battery to convert voltage.
The battery located inside and separated from other details using foamed plastic.
Do not forget to place the power switch (it may seem obvious yet it is easy to forget).
The antennas from my old Motorola cell phone but you can use other models.

Well, this is probably all. Now go and make some cool stuff!



    • Creative Misuse Contest

      Creative Misuse Contest
    • Oil Contest

      Oil Contest
    • Clocks Contest

      Clocks Contest

    184 Discussions

    Swapping out the sweeping oscillator with one from the phone itself, an old router - if you're interested in those bands - and other electronics (such as old RC toys, which makes those crack-of-dawn RC plane enthusiasts quite down nicely) should work with this design too. That is, in theory at least. Great project to experiment with though!! Good work!

    Just on the IED topic there - we used to use a similar device in Afghanistan when the opportunity presented itself and I know that many Police agencies have them in their arsenal - where they provide, I'm sure, much more use than they did for us! (By the time you find out it's a cellular triggered device, you're probably already picking up what's left of it after it went off the day before! Not to mention, setting the phone's alarm as a backup/failsafe is immune to jamming - as are grenades).

    2 replies

    and i hate to say / type this. depending on the phone. the alarms wil still go off even if its in stand by mode. then depending on the phones battery, it can be in stand by for up to a week. if u want it to last longer put in a small solar panel.

    Thank you for nice words and advices! It is pleasant to know that similar devices are saving lives out there :)


    can you post the schematic?


    Question 5 weeks ago

    Did anyone get the schematic?


    Question 2 months ago

    Range of this jammer?

    It's a really informative information.. thanks to sharing with us.

    Hello,dear Bill. Thanks you for excellent works. Can i share the the parts list , instructions or need instrument please???

    Thank You, Bill

    1 reply


    Can you share part list.


    can you pls explain me how did you embed the 50ohm microstrip line iam sorry if my question is wrong this is probably my first electronic project and iam at extreme basics can you just help me in that part.. pls

    eager for you response....

    I'm afraid I'm all thumbs. Is there anyone out there that can make me a tv signal jammer?

    I would love it if you could email me the full details of this project. Parts needed and circuit diagram? Email is

    4 replies

    Im with camclub. Parts list and instructions would he much appreciates if you could help? Im sure i can help you out with whatever. One hand washes the other

    If you got the parts list and or instructions do mind sharing them with me please???
    Thank You, Bill

    Hey, I was wondering if you ever found a circuit diagram and parts lists? Either for this particular design or possibly a different one online. Ive been looking online for an easy to understand project with clear(er) instructions but have not yet. Im thinking once I do teach myself how to do this that I will put out a better instructable, with step by step and explanations of the how and whys. Any help from you would be appreciated. Thanks

    please tell me need instrument

    Can this block 3g and 4g phones and can stop like wifi and Bluetooth and mobile data?


    1 reply

    All those things run on a wireless frequency as well, so the answer is yes. Bluetooth for example uses 2,45 GHz. But it's also common with automatic frequency switching which is made to prevent jamming from other devices.

    But 3g shouldn't be any problems, you could block all these signals with one device.