What is a CellPhone GPS Signal Jammer?
A Cellphone GPS signal jammer is an electronic circuit that allows you to completely block the transmission and reception of any cellular signals, by creating some sort of interference (noise) in the same frequency bands as that of the mobile phone. Basically, a cellphone signal jammer is like an RF transmitter, that emits radio signals in a similar frequency range as that of GSM Communication. They are mainly used by the police and the military amidst any dangerous situation in order to stop network activity around the area such as Bomb diffusing, hostage rescue & paramilitary ops. So, In today’s tutorial, we are going to go over a step by step process on How To Make a Cellphone GPS Signal Jammer/Scrambler Using 555 Timer.
WARNING: Blocking, Scrambling, or Jamming Radio Signals is against the law in most countries. Check with your local law enforcement before using such devices.
NE555 Timer
NE555 is a high precision timer IC. The IC is capable of operating in three modes, astable, bistable & monostable. The IC possesses an oscillation frequency ranging from 670 to 680 Hz. Here, the NE555 timer acts under astable multivibrator mode. An astable multivibrator is a free-running square wave signal oscillator. With no external signal applied, the transistors alternately switch from cutoff to saturation state at a frequency that RC time constants of the coupling circuit determine. If these time constants are equal (R and C) then a free running square wave will generate with a frequency of 1/1.4 RxC.
Hardware Components
You will need the following parts to build this project:
| S.No | Component | Value | Qty |
|---|---|---|---|
| 1) | Timer IC | NE555 | 1 |
| 2) | Transistor | BC547, NPN | 1 |
| 3) | Trimmer Capacitor | 30pF | 1 |
| 4) | LED | 5mm, 3.5V | 1 |
| 5) | Enameled Copper Wire | 24 AWG | 1/2 meter |
| 6) | Capacitors | 4.7uF, 47pF, 4.7pF, 3.3pF, 2pF | 4 |
| 7) | Resistors | 82K, 10K, 5.6K, 6.8K, 1K, 220 Ohm | 6 |
| 8) | Soldering Iron | 45W – 65W | 1 |
| 9) | Soldering Wire with Flux | – | 1 |
| 10) | Veroboard | – | 1 |
| 11) | DC Battery | 9V | 1 |
| 12) | Battery Clip | – | 1 |
| 13) | Jumper Wires | – | As per need |
NE555 Pinout
Useful Steps
1) Solder the NE555 timer IC on the veroboard. After that, solder the toggle switch on the veroboard.
2) After that, solder the 30pF trimmer capacitor on the veroboard.
3) Solder the 4.7uF capacitor with pin 3 of the IC. After that, solder the +ve terminal of the LED with Vcc of the circuit and -ve with 1K resistor.
4) After that, solder all capacitors on the veroboard.
5) After that, solder the base terminal of the BC547 transistor with the -ve terminal of the 4.7uF capacitor transistor. Also, solder the collector and emitter pin of the transistor with the trimmer capacitor and the 2pF capacitor respectively.
6) After that, solder all the resistors on the veroboard.
8) Solder the two coils on the veroboard.
8) Create an aerial antenna for the jammer circuit by coiling a 4ft – 6ft piece of magnet wire.
9) After that solder the aerial antenna on the veroboard.
10) Connect battery clip between pin 1 and pin 8 of the IC.
11) Power up and test the circuit.
Working Explanation
For any cellphon jammer circuit there are three key elements
- RF Amplifier
- Voltage Controlled LC Oscillator
- Tuning Circuit
When the circuit is switched ON, the NE555 timer starts to generate a free-running square wave since it is connected in an astable multivibrator configuration. The output from the 555 timers then passes through a coupling capacitor( that blocks the DC component of the signal, allowing only AC to pass through), before serving as a control signal on the base of the BC547 transistor. Here, the transistor Q1, C3, C2, and R4 constitute the RF amplifier circuit. this amplifies the signal generated by the tuned circuit. The amplified signal is then given to the antenna through the C5 capacitor, C5 removes the DC component of the signal, allowing only the AC to be transmitted in the air.
Mobile Phones normally function in the frequency range of 450 MHz. To block this 450MHz frequency, we also need to generate a 450Mhz frequency with some noise which will act as a simple blocking signal. The tuned LC oscillator produces a very high frequency with min. damping. Then both inductor and capacitor of the tuned circuit will oscillate at its resonating frequency. Thus, blocking the 450 MHz cellphone signal.
Applications
- Generally functions in areas where the use of a cellular device is prohibited such as military installments & ATC testing sites.
- Also used in sensitive places such as mosques, bank vaults, prayer rooms, and examination halls where the use of cellphone is strictly prohibited.
See Also: How To Make An FM Radio Receiver Using LM386 Audio Amplifier IC | DIY | Power Inverter (200W) Using CD4047 Monostable/Astable Multivibrator IC | Pulse Width Modulation (PWM) Signal Generator Using LM358 Op-Amp IC
