Nice. But who uses fm radio anymore?

I saw this same mod on afrotechmods a while ago. http://www.afrotechmods.com/cheap/jammer/jammer.htm
i hope he’s receiving due credit.

Thats the same URL linked to in the article.

I’m gonna probably post my hack soon. Pretty easy to do, uses old keyboard (Linux for control – recommended;))

Can something similar be done with the AM band? I dont particularily like the chinese music my neighbors blair at 7am to 9am daily. -_- wish they would use headphones.

Isn’t this one: http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=602085&e_categoryid=437&e_pcodeid=69507 ? If not, sorry.

I don’t know about crystals much more then how to solder them when needed, but couldn’t you use the next closest above the range needed like you can for resisters or capacitors?

John, most crystals arn’t that big. If anything, you should be able to find one that you can fit with two cell batteries inside a relatively fat pen.

So under this method would a 2.4 GHz oscillator disrupt 802.11 signals?

Dewey, and cordless phones, and cell phones, and microwaves (Maybe) etc.

Ya should check Ladyada’s site http://www.ladyada.net for her Wave Bubble project. It blocks all radio frequencies.

where? all i could find was the gamegrrrl that she made

the oscillator he used from from a 90′s circuit board. will a brand new oscillator have the same effect of jamming all of FM? the ones im looking at are supposed to be very accurate and stable.

Hi there
To answer some of your questions,
No you can’t use the next closest in the range like with Rs and Cs. Unless it is _really_ close like 98-102Mhz or something.
You can power it with a simple 3.3V lithium (coin battery) cell.
Yes the same principle can be used to jam 802.11x. However, you will never find a crystal that oscillates at 2.4Ghz so the project will be much more complicated.

I was thinking the same thing John. This would be an awesome hack for an altoid box. This one: http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=602085&e_categoryid=437&e_pcodeid=69507 looks good, but is anyone positive? I don’t want to buy the wrong part.

I havnt really ever replied but ive been here for awhile, i have to say I love hackaday and this crap is neat all of it, the jammer and ring are markable new ones, usb batter, infrared camera, hell more than i can name

when i was reseaching jammers and related trouble-makin’ stuff i was refered to this nifty article that explains the theory behind ‘all channel FM transmitting”: http://www.tinaja.com/glib/muse91.pdf

of course, extending the math to this situation: a 100.0000MHz crystal will indeed have a first harmonic at 100.0000MHz and therefore certainly jam any station transmitting at that frequency…but it would be really really weird for such a high precision crystal to have harmonics/variations that extend from 88 -> 108MHz. so, while i think its a very nifty hack, i’m curious as to whether/how it jams the entire broadcast band…

At ladyada.

It could be the harmonic rich square wave put in the simple wire antenna somehow is distorted, making the band of noise wider. I also see no decoupling at all, so the wave coming out of it could very well be very distorted with not well defined edges (different harmonics).

Well you could verify it by using the same setup, with decoupling and without. And then you check the output with a spectrum analyser. Not that i have such equipment lying at home, but at work we develop products that need to be compliant with CE EMC emissions, so i could make a small setup and measure it.

As someone said before, does anyone have any ideas what one of these would be used for in commercial products? (what could i possibly own that has a 100mhz crystal oscillator in it?)

Ya,
This seems like a good beginner hack for me to try as my first hack. I too am wondering what commercial things have the 100mhz crystals in them.

The Wave Bubble/Air Fresh project from LadyAda.net:
http://www.ladyada.net/techproj/freshair/index.html

Somewhere an FCC chairman is feeling a great disturbance in the force.

Well, apply the same concept but get a 2.4 Ghz oscillator and your set. Good luck finding one :P.

I dont know if u under stood me right joe, i was just saying if he got those hack ideas from make, then he should say that he got found out from make. I actually dont care but its sorta lame when u find 2 articles in a role the day after the make article was posted. If your gonna do that try to diperse it more.

I think I found a 2.4 GHz op. Please goto the link below for a diagram (http://www.2sale.info/images/design.JPG) . Please let me know if this will work. Thanks

http://www.2sale.info/images/design.JPG

afroman’s been on hackaday before. I seen his site before I been to hackaday as well. There is such thing as coincidence, enfusion. And justin, “hackers” like you are the reason hacker is seen as a bad thing.

Now, would a 100mhz crystal in the 486′s be from the bus or processor?

http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=656270&e_categoryid=434&e_pcodeid=54924

2.4ghz crystal from mouser ???

anyone know where to find one let me know what link to get one heck I’ll get you one also would like to try this out looks cool thanks.

Afroman’s site has been hackadotted! (alright, it’s running fine). Anyway, my two cents:

If you put a signal through the oscillator, you may be able to broadcast in a limited range with that thing. Also a fun thing to have around if you live near an FCC office and are extremely bored.

Do you really think that anyone would have any idea what was going on? Its called a senior prank bub, im sorry that i give you a bad name because i know so many people pay attention to the hacker “underworld”. So chill, its all in good fun, its not like im hurting anyone, its better than releasing thousands of crickets in the library.

http://www.minicircuits.com/oscillat.shtml

These are the suppliers from the FreshAir project. They have a wide range and in frequencies from R/C to FM to WiFi.

I don’t have the background to know how to read the spec sheets, but I’m fairly sure that these are the correct components.

Could someone who knows better please enlighten us as to how these buggers actually work??

trimbandit: like what ttm asked will the one at jameco work on 3.3v will for sure pick some up I have 3.3v laying all over the place :)…. thanks

I once put together a Ramsey’s FM10 FM transmitter kit and I found that even though it was set to 102.7, I could hear the signal all over the FM band, even when the antenna wasn’t attached. This is why a good filter for your transmitter is essential. and also why an unfiltered signal causes noise all over the band.

Can you make a am jammer?

The instructions pretty much stink on the link. Can anybody please tell an idiot with no tech-hacking knowledge how to attach the battery and antenna? Thanks in advance.

A few years ago I started pondering a cellphone jammer, using similar techniques… but discovered that a jammer could easily kill a pacemaker. Please be careful folks.

ghastly_1

I converted a Sony Shortband Handheld Radio
into a Variable Frequency Modulated over-
ride device one time.With this Circuit though
the Receiver would have to be within 5 feet
if not closer, because it is only operating
at about 2-4 WATTS.

To keep it simple but powerful add some Heavy Duty Transistors from a TV or even Substation
to amplify the Signal.Even the shitty Commercial
AM/FM Stations operate at about 50mW.Thats why
you can pick up stations for up to 100 Miles on
a weak car stereo.If you raised the Potential
Difference with a Heavy Duty 9v Battery, and the
above mentioned Transistors you could probly
get 10-35 Watts, and with a simple 25G copper
wire antenna that could get you up to a 1 Mile
circumfierance of listeners.

I would use a 555 IC and some Variable Capacitors so I could adjust it from
1HZ to up to UHF.You could combine Analog
and Frequency Modulation and overide there
Local TV viewing to with some simple A/V
jacks from you’re TV/SAT reciever.

To really fuck them in there Transportation
use a Copper wound Iron core and a TV
Transformer, and EMP Bomb there cars ECM
CPU.

Will any one post a confirmed link to a working 100MHz crystal plz. Thanks guys/gals.

Roostoo: I cant get the one from jameco to work at all! Is the wiring scheme the same as the example on the post? I also have a 3v battery, but it may need a full 5v to work. Also, how do you connect the battery to the device? i wrapped copper wire around it and just connected it to the pin sticking out. One more thing – the ground, what does it need to ground to? Does it just touch some other metal object?

The ground goes to the negative part of the battery (underneath the button). 3v-5v goes to top of battery. The the antenna wire just hangs off and goes to nowhere

wouldnt part nimber JTOS-150 from http://www.minicircuits.com/dg03-228.pdf block out everything on the fm band. it says the frequency is 75-150 mhz ?

i don’t get why everybody’s going crazy and trying to find this certain rare crystal

why not throw together a resistor/capacitor oscillator with stuff that everybody has?
its not as precise, of course, but that might be good. also, if you used a pot or a varactor, you could just turn a knob on your jammer until the house next door becomes quiet

think 2 AAA (those are 1.5v each) batteries would work for a 5v oscillator?

People keep mentioning simpler/cheaper designs but yet they don’t back up there posts with any links or how to’s.

got my chip today by mouser and it looks nothing like the pick has no leg to solder to just pads guess they send me the wrong chip don’t get the one from the uper link from mouser does not work or look like the one in the pick

trimbandit: hey got the one from mouser did not work could you help me out your around jameco could you pick me one up and send it to me they want $10shipping just to get one from them please let me know would like to try this out thanks just lost out on the one from mouser :(

ati: you got what you ordered, on mouser there types. the pads are mostly for flat connections, its the same thing as the legs so it should work aswell.

phuct: careful with 2.4ghz, i think it might mess up pace makers, but post what happens when you get it wired.

I bought one from Jameco and it works.. on the 99.1-100.3 band how can I posibly get a dirtier signal

So do the ones from mouser not work, because I ordered a few of them :(

Can you double them up like put 2 50mhz Crystal Oscillators together or a string of 30mhz?