FM Radio jammer
Description.
Circuit shown here can be used to jam FM radios in its vicinity. The circuit is nothing but a classic single transistor oscillator operating in the VHF region. Working principle of the circuit is very simple and straight forward. Powerful VHF oscillations from the circuit will interfere with the FM signals to nullify it. Jammer circuits like this are illegal in many countries and you must assemble this circuit on your own responsibility. This circuit is intended only for fun and i request you not to misuse it.
Circuit diagram.
Notes.
- For L1 make 6 turns of 16AWG enamelled copper wire on a 9mm plastic former.
- The circuit can be powered using a 9V PP3 battery.
- For extended range, use an antenna.
- A 30cm long wire connected anywhere on the coil will do for the antenna.
- For better performance, assemble the circuit on a good PCB.
The legality of the circuit depends on how and where you use it. It is basically a CW generator so a radio will just pick up silence. It differs little from the little transmitters that allow a CD player to be picked up on a nearby radio. There’s just no input where a mic or CD player could be attached. In most jurisdictions, the limiting factor is SWR. So if it can only be picked up for a few meters, the legality would depend on how you use it. If you’re only interfering with your own radio, it should be alright in most places. If you’re intentionally interfering with other peoples’ radios, then it’s illegal almost everywhere.
[...] Notes. For L1 make 6 turns of 16AWG enamelled copper wire on a 9mm plastic former.The circuit can be powered using a 9V PP3 battery.For extended range, use an antenna.A 30cm long wire connected anywhere on the coil will do for the antenna.For better performance, assemble the circuit on a good PCB. Link – circuitstoday [...]
Can Anyone tell me the value of INDUCTOR in henry?or any other compatible inductor..
what if you doubles all the capacitors Uf’s and transistors current will the wireless range change
Hi Bryce by reducing emitter resistance and providing heat sink to 2N2222 and increasing the supply to 12volt you can achieve your requirement. you can replace 2N2222 with 2N2219 for better power desipation
would the fm radio jammer work without the resistors
what is the wireless range of the fm radio jammer
does the circuit parts have to be exsactly right (I cant be a ohm or a uF off)
would 3.9 k=3k and 900 ohms
Hi without emitter resistance the transistor will blow of. Resistance can be a near preferred value. THE JAMMER CAN WORK WITHIN A SMALL COMPOUND ONLY.
why is nt his circuit working when I tested it help me
Hi Bryce what capacitor value you have used for C2. It can be upto 10PF ceramic disc, L1 should be 6 to 9mm dia air core with 18SWG super enameled copper wire close wound 5 to 6 turns. set the trimmer C1 at the center.
once the circuit is assembled keep it close to an FM radio tuned to around 100MHz. now switch on the jammer, with a plastic tool expand the coil axially till a blank carrier is heard in the radio. now your FM radio jammer is ready.
DOES THE RADIO HAE TO BE ON A CERTAIN STATION
does the L1 have to be 16 awg
Hi Bryce super enamelled copper wire of 1mm dia is well suited. (16 to 18 AWG)
If you want to jam that station tune in and jam with jammer.
could I use any varaible capacitor or does it have to be a varaible capacitor that is 6-35 pt
Hi Bryce it has to be in the range of 3 to 35PF. you can use FM tuner variable capacitor also.
does the L1 have to be a 16 awg wire plastic former just give me a staight up answer.
No former self supporting coil, 16 to 18AWG any one can be used.
what is the wireless range for this circuit
Hi Bryce within the house only.(less than 100 feet)
How can i increase power? Adding another transistor as Rf amplifier?
what if I connected a fm transmitter to the fm radio jammer would the wireless range change
i think the configuration of two transistor is momething like that:http://english.cxem.net/radiomic/bug29.php
T2+T3 do the job for increasing power. I don’t know L2 what is used for!
Hi Gino L2 is the Tank coil to match antenna. you can use the one similar to L1 and tune it for the maximum radiated power
how many uh does the L1 have
would you have to adjust the Fm radio jammmer’s varaible capacitor every time you changed the station on the radio
Hi Bryce yes. but if you want to only jam a particular broadcast tune only to that.
very use fuul
hai friends if want ask any doubt contact the emailid arivueee@gmail.com
Hi.
And if i want to block the whole fm band 88-108mhz.How will i to do?
hi can u please give me value of L1 in henry?so that i can directly use inductor having that value?
Hi Dishant it is in uH, not readily available and easy to wind air core 8 t0 10 mm id, 6 turns wound with 16 to 18 gauge wire with a gap between each winding of wire thickness.