Units used by law enforcement can shut down service up to 1 mile (1.6 km) from the device. Higher-powered units create a cell-free zone as large as a football field. Low-powered jammers block calls in a range of about 30 feet (9 m). The actual range of the jammer depends on its power and the local environment, which may include hills or walls of a building that block the jamming signal. Old-fashioned analog cell phones and today's digital devices are equally susceptible to jamming.
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Jammers can broadcast on any frequency and are effective against AMPS, CDMA, TDMA, GSM, PCS, DCS, iDEN and Nextel systems. GSM, used in digital cellular and PCS-based systems, operates in the 900-MHz and 1800-MHz bands in Europe and Asia and in the 1900-MHz (sometimes referred to as 1.9-GHz) band in the United States. Although different cellular systems process signals differently, all cell-phone networks use radio signals that can be interrupted. To jam a cell phone, all you need is a device that broadcasts on the correct frequencies. Some of the high-end devices block all frequencies at once, and others can be tuned to specific frequencies. People will not use jammers everywhere, but they use in selected places and highly confidential meetings, gathering etc.Less complex devices block only one group of frequencies, while sophisticated jammers can block several types of networks at once to head off dual-mode or tri-mode phones that automatically switch among different network types to find an open signal. Normally jammers are used in government offices in some countries, but jammers are mainly used by military, navy, air force and entire defense systems. The formula is F= 1/ (2*pi*sqrt (L*C)).ĭo you know How TV Remote Control Jammer Works? Applications of Jammer Circuits:
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Jammer circuit produces the high-frequency signal which will confuse the receiver of the particular system from receiving the signal, even though circuit is working properly, user of the system feels that circuit is not working properly. High-frequency signals are not capable to block those signals from reaching the devices, so we need very high frequency signals to block the actual signals from reaching the devices, so jammers are used for blocking the signals.
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In olden days while we were using analog signal for communication, the jamming circuit was very easy just by producing the high frequency noise signals, but today trend is completely changed in such a way that use of digital devices taken place from analog devices.