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.


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!<br><br>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).
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 :)
<p>not bad</p>
<p>Actually project is simple but need some electronic hobbies skills . Critical two parts can be found mini circuits offical site and its dealersat</p><p> <a href="" rel="nofollow"></a></p><p>My question is if this device works at 900 MHz range(out of USA) ?anyone have idea?</p>
So where exactly would one find the circuit in the first picture as well as any other components needed to creat such a device?
<p>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.</p><p>Porfavor if it has e-mail write it and there we are in contact.</p><p>Regards</p>
Can this block 3g and 4g phones and can stop like wifi and Bluetooth and mobile data? <br><br>Thanks
Well can i place any amplifying electronic component or it should be respective to the rf mixer and sweeping oscillator. Pls kindly rply
<p>Can you tell me HOW to increase the range of Jammer? Please send email at joharraza999@gmail.com.</p>
<p>Hi, I want to build a 40 meter cell phone jammer. how can i boost 10 meters to 40 meter? anyone help</p>
Power and antenna length are a start. Possibly the speed of oscillation.
<p>Sorry for asking cause i'm not an expert in electronics.</p><p>So can anyone tell me where can I get a sweeping oscillator?</p>
Did you find out?
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?
No, im thinking you might be able to put a knob that turns and selects the range your looking to jam. Search online
<p>Can anyone please, suggest me the specifications or what kind of antenna used in this project. Please drop info on my mail :-mchetan133@gmail.com</p>
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.
<p>thank you. need this against darpa-styled neuro RF-implants and mind control</p>
Another good reason could to bring back conversation at the dinner table.... Lol
I would love it if you could email me the full details of this project. Parts needed and circuit diagram? Email is ryanweigelt@gmail.com
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
<p>pls can i get the full circuit diagram , i need it for my final year project . here is my mail sergrod98@gmail.com. thank u</p>
Anyway to get a schematic and component list
<p>can you make me a jammer and send it too me? And set it for electronic harassment frequencies</p><p>jsmnbabic@live.com.au</p>
<p>so it able to jam all entire network right . how about to jam only 3G/4G freq network</p><p>email me mnazarulakram@gmail.com</p>
please tell me all about, how to make this and what I need, <br>rohitpachauri115@gmail.com<br>
<p>if anyone was successful in getting the circuit diagram can you please email it to me as well, support@allentownbitcoins.com</p><p>Very much appreciated!</p>
<p>Did you get the circuitry? I would like it too please! </p><p>kittensarefluffy135@gmail.com</p>
<p>CIRCUIT DIAGRAM PLEASE</p><p>dhruvtyagi01@gmail.com</p>
<p>hi - if anyone has a copy of the schematic, please send to me at flashmaster67@gmail.com</p><p>Thank you!</p>
<p>hey im wondering if the guy who made this is actually still monitoring this as im looking to make one</p>
<p>can you please email me the things required for making the jammer in a list...</p><p>hasib1220@gmail.com</p>
<p>nice one! can you send me the circuit diagram please?</p><p>sorush.moradisani@gmail.com</p>
Can u please send the diagram to <br>Hackeragha5555@gmail.com<br>
<p>I'd love to have the circuit diagram too. Send it to sergrod98@gmail.com</p>
<p>circuit diagram Plz</p><p>tracert1543@gmail.com</p>
<p>I'd love to have the circuit diagram too! davidex720@gmail.com</p>
<p>Can I plz get the circuit diagram of the jammer?</p><p>Plz mail me on onaik116@gmail.com</p><p>Waiting for a good reply.</p>
<p>I'd love to have the circuit diagram too! davidex720@gmail.com</p>
Also if will it cause interference if i place the antennas closer together?
Question, will the also jam the data on GSM800 phones?
<p>Cell Phone/Signal Jammers are illegal. <a href="https://transition.fcc.gov/eb/jammerenforcement/jamfaq.pdf" rel="nofollow">https://transition.fcc.gov/eb/jammerenforcement/ja...</a><br>If you get caught you can end up in jail...</p>
<p>How would one be able to adjust this design to jam other frequencies? Specifically lower frequency or ELF?</p>
<p>pls mail me rajgopal.009@gmail.com</p>
<p>i need both the ckt under one board</p>

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