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Mobile phone signals shielding device is mainly for domestic college entrance examination, adult the university entrance exam, self-study exam and all kinds of colleges and universities in the process of examination, some students use mobile phone to cheat the status quo, and at the same time combined with all kinds of intermediate and senior high school students use mobile phones in the present situation of the class time loose hair message, as well as government agencies, enterprises of all kinds of big small and medium-sized conference room, concert halls, theaters and other places of serious and noisy in the mobile phone brings trouble.
According to the actual situation of mobile phone signal interference, it can be in the radius of 1-20 meters (1-200 square meters) partition GSM/DCS/CDMA/PHS/3G(td-scdma /CDMA2000/WCDMA)/4G mobile phone signal, 2.4GWIFI wireless signal, so that the mobile phone can not play and receive, but will not interfere with other electronic teaching equipment work, mobile phone can return to normal use from the partition range.

Working principle of mobile phone signal shielding device:
Within a certain frequency range, mobile phones and base stations are connected by radio waves to transmit data and sound at a certain baud rate and modulation. Mobile phone signal blocker in the process of work at a certain speed forward channel low-end frequency to high-end scanning. This scanning speed can form garble interference in the signal received by the mobile phone, and the mobile phone cannot detect the normal data sent from the base station, so that the mobile phone cannot establish a connection with the base station. Mobile phone performance for search network, no signal, no service system and other phenomena.

Use method of mobile phone signal jammer:
Remove the phone signal jammer host from the packaging box. The surface temperature of this product can reach 50℃, so please stay away from low-heat-resistant objects. Area selection need to cut off the phone signal, the mobile phone signal jammer in the area of the desktop or on the wall, the recommended installation height (1.5-2.0 meters), power supply 5 v output of receiving host first, and then insert the power supply of the ac input into the mains socket, and then open the power switch, the power indicator according to begin to work on the work.
After the equipment is connected, press the power switch to cut off the device to work. At this time, all mobile phones on the scene are in the search network state, losing the base station signal. No telephone contact could be established between the main caller.
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Note for cell phone signal blocker
1. The effective coverage area of mobile phone blocker is a circular area centered on the signal shielding device, so pay attention to the correct placement of mobile phone signal shielding device to avoid shielding dead Angle.
2. The mobile phone blocker should be placed in a well-ventilated place to avoid large objects and strong electromagnetic source of strong heat source, so as to ensure the shielding effect and stable operation for a long time.
3. When the mobile phone blocker is working, do not stack other articles on it and remove the antenna, so as not to affect the shielding effect and damage the machine.
4. When the site area is larger than the effective shielding range, it is recommended to install multiple mobile phone shielding devices in a cellular manner to ensure the shielding effect.
https://www.jammer-mart.com/phone-blockers-jammers.html