15-09-2017, 02:41 PM
This mobile tracker circuit can detect the use of a GSM mobile in restricted areas of mobile phones such as exam rooms and other "do not disturb" areas. You can detect the activity of the phone from a distance of eight meters or more. The sniffer continues to monitor the RF level in the area and gives a warning if the RF level increases due to mobile phone activity. If two identical units of this sniffer are placed in the room, the range can be extended to a radius of 15-16 meters. The circuit can detect all forms of mobile phone activity, even in silent mode.
Circuit diagram for the mobile sniffer
The mobile sniffer circuit is designed as a sensitive RF detector. RF signal diode 1N34 is the main element. Together with resistor R1 and capacitor C2, the diode picks up RF energy in the area. In standby mode, the output of the diode is about 0.6 millivolts, which rises to 60 millivolts when it receives high energy radiation from the mobile phone. Since the voltage level from the sensor diode is too weak, a three-stage amplification is provided to give the warning indication through the loudspeaker.
Following video is better to understand the mobile sniffer :
Circuit diagram for the mobile sniffer
The mobile sniffer circuit is designed as a sensitive RF detector. RF signal diode 1N34 is the main element. Together with resistor R1 and capacitor C2, the diode picks up RF energy in the area. In standby mode, the output of the diode is about 0.6 millivolts, which rises to 60 millivolts when it receives high energy radiation from the mobile phone. Since the voltage level from the sensor diode is too weak, a three-stage amplification is provided to give the warning indication through the loudspeaker.
Following video is better to understand the mobile sniffer :