Introduction: How to Create Your Signal Jammer

Picture of 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

Picture of 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!

Picture of 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

Picture of 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!


shiaulteyr (author)2012-02-22

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).

astral_mage (author)shiaulteyr2013-11-24

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.

BearGrills (author)shiaulteyr2012-02-22

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

dongyanzhi (author)2017-06-28

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

Thank You, Bill

GaryK18 (author)dongyanzhi2017-10-29


Can you share part list.


jeseem212 (author)2017-07-20

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....

janie71 (author)2017-04-06

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

RyanW127 (author)2016-05-20

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

The Life Hacker (author)RyanW1272017-02-05


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

Camclub (author)RyanW1272017-02-05

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

JamesG33 (author)RyanW1272016-05-31

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

nayem96 (author)2017-02-14

please tell me need instrument

cedrickN (author)2016-07-08

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


gustavio101 (author)cedrickN2016-12-09

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.

Almany (author)2016-11-24

Hello if wifi can turn a cell phone into a device to see someone through wall--can same or other device be used to throw or transmit sounds through walls and make it sound like they originated in the room their sent to? Also can signal jammer block those sounds and eavesdropping also? Thank you for your reply!

hyland66 (author)2016-11-16

What did you use for your VCO

henrique12345 (author)hyland662016-11-18

Please do excuse me hyland66, I do not know anything from the jamming device and was not sure whether you were answering my question. If you were I am not familiarised with the term VCO.

henrique12345 (author)2016-11-12

henrique12345 (author)2016-11-12

can you please reply via email, I would really appreciate it

henrique12345 (author)2016-11-12

They say a mobile phone jammer is an instrument used to prevent cellular phones from receiving signals form base stations. So lets say I have a mobile phone jammer in my possession, is it possible for me to prevent someone who is next to me from MAKING A PHONE CALL?

Hope to hear from you soon?


Nash17Owen (author)2016-10-14

not bad

fastedi (author)2016-08-17

Actually project is simple but need some electronic hobbies skills . Critical two parts can be found mini circuits offical site and its dealersat

My question is if this device works at 900 MHz range(out of USA) ?anyone have idea?

FelicianoTech (author)2016-08-07

So where exactly would one find the circuit in the first picture as well as any other components needed to creat such a device?

CarlosP185 (author)2016-07-27

Good, I with a few friends of the college we need to do this object and I believe that with his serious help every easy mas.

Porfavor if it has e-mail write it and there we are in contact.


DivyamT (author)2016-06-05

Well can i place any amplifying electronic component or it should be respective to the rf mixer and sweeping oscillator. Pls kindly rply

johar.raza.7 (author)2015-04-21

Can you tell me HOW to increase the range of Jammer? Please send email at

JamesG33 (author)johar.raza.72016-05-31


EddyM4 (author)2015-08-07

Hi, I want to build a 40 meter cell phone jammer. how can i boost 10 meters to 40 meter? anyone help

JamesG33 (author)EddyM42016-05-31

Power and antenna length are a start. Possibly the speed of oscillation.

hphoobalan (author)2015-09-16

Sorry for asking cause i'm not an expert in electronics.

So can anyone tell me where can I get a sweeping oscillator?

JamesG33 (author)hphoobalan2016-05-31

Did you find out?

servicemarin (author)2015-10-11

In sweden we have about ten different frequencies used by cellphone providers. Does it mean that I need to construct 10 different jammers of this type to be sure that no signal can pass trough? Or is it enough with a couple of jammers? What exactly do I have to change for other frequencies?

JamesG33 (author)servicemarin2016-05-31

No, im thinking you might be able to put a knob that turns and selects the range your looking to jam. Search online

ChetanchowdaryM (author)2016-03-08

Can anyone please, suggest me the specifications or what kind of antenna used in this project. Please drop info on my mail

JamesG33 (author)ChetanchowdaryM2016-05-31

If you have a Redbox in your neighborhood, go and look at that antenna they use. Thats a 2.4Ghz antenna. That would be petfect... Probably the best. Its also a good antenna for many other projects, such as extending your home wifi signal up to almost half a mile from home. Im going to use antennas from my handheld Ham radios. Im sure your could also design your own antenna.

markusturku (author)2016-05-10

thank you. need this against darpa-styled neuro RF-implants and mind control

JamesG33 (author)markusturku2016-05-31

Another good reason could to bring back conversation at the dinner table.... Lol

heykene (author)2016-04-28

pls can i get the full circuit diagram , i need it for my final year project . here is my mail thank u

Doshman (author)2016-04-17

Anyway to get a schematic and component list

Jasxxx (author)2016-03-31

can you make me a jammer and send it too me? And set it for electronic harassment frequencies

mnazarulakram (author)2016-03-22

so it able to jam all entire network right . how about to jam only 3G/4G freq network

email me

RohitP38 (author)2016-03-12

please tell me all about, how to make this and what I need,

Kasper_Sky (author)2016-02-23

if anyone was successful in getting the circuit diagram can you please email it to me as well,

Very much appreciated!

Did you get the circuitry? I would like it too please!

DhruvT6 (author)2016-02-17


RickS17 (author)2016-02-08

hi - if anyone has a copy of the schematic, please send to me at

Thank you!

GamingGecko (author)2016-01-29

hey im wondering if the guy who made this is actually still monitoring this as im looking to make one

HasnatH1 (author)2016-01-26

can you please email me the things required for making the jammer in a list...

sorushm (author)2016-01-22

nice one! can you send me the circuit diagram please?

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