How far can the jammer reach?
The actual range of the jammer depends on its power and the local environment, which may include hills or walls of buildings that block interfering signals. The low-power jammer can block calls in a range of about 30 feet (9 m). Higher power units will create a cell-free area as large as a football field. The equipment used by law enforcement authorities can shut down services within 1 mile (1.6 km) from the equipment.
Mobile phones are full duplex devices, which means they use two independent frequencies, one for talking and one for listening at the same time. Some jammers only block one of the frequencies used by the phone, which has the effect of blocking both. The phone was tricked into thinking it had no service because it could only receive one of the frequencies.
To interfere with your phone, all you need is a device that broadcasts at the correct frequency. Although different cellular systems process signals differently, all cellular networks use radio signals that can be interrupted. GSM is used for digital cellular and PCS based systems. It uses 900 MHz and 1800 MHz bands in Europe and Asia, and 1900 MHz (sometimes called 1.9 GHz) bands in the United States. The jammer can broadcast on any frequency and is effective for AMPS, CDMA, TDMA, GSM, PCS, DCS, iDEN and Nextel systems. Older analog phones are just as vulnerable to interference as today's digital devices.
The jamming device suppresses the mobile phone by transmitting signals at the same frequency and high enough power to make the two signals collide and cancel each other. The mobile phone is designed to increase power when encountering low-level interference, so the signal jammers must identify and match the increased power of the mobile phone.
Less complex devices can only block a group of frequencies, while complex jammers can block multiple types of networks at the same time to prevent dual mode or the third mock examination mobile phones from automatically switching between different network types to find open signals. Some high-end devices will shield all frequencies at the same time, while others can tune to specific frequencies.
Do signal jammers block GPS? The GPS jammer can block all existing positioning methods Government agencies often buy users' GPS locations from tech companies How to block, disable and find your vehicle's GPS tracker Does the mobile phone jammer block GPS? Use of high powered jammers to disrupt aircraft during military operations The Pentagon has been mysteriously testing the shielding of GPS Beidou signal
Mortgage company installs GPS jammers to hide vehicles and security Desktop and handheld Jammers also work with car chargers Research that could lead to bomb detection and destruction of GPS jammers Employees who monitor in targeted and permanent ways can use jammers to fight back Remember to use Jammer when you lose your privacy under the GPS tracking suite Avoid tracking GSP jammers that should be shielded from GSM Use GPS jammers accordingly to counter GPS-tracking GPS navigation and GPS jammers are symbiotic