Mobile phone signal blocking bag jammers have different effects on different people’s phones
Simply put, a mobile phone signal blocking bag jammer is a jammer that makes the radio, mobile phone, Bluetooth, and WiFi signal bands within a certain distance all noise, so electronic devices such as mobile phones and radios lose communication signals. It's as if you are in a very noisy vegetable market, and others can't understand what you are saying, and you can't understand what others are saying. Listening and speaking are useless. The effective distance of mobile cell phone jammer used in schools and examination rooms is generally within 200 meters. And usually many units are installed, repeated coverage, and strengthened shielding. If you want to hold up a larger "shielding umbrella", you need more professional equipment. Usually you will drive a signal shielding car. Be careful: The original signal jammer was designed to fight crime and serve law enforcement agencies and the military. So in fact, buying signal shielding on your own is also suspected of breaking the law. Signal jammers in the hands of criminals may cause serious consequences. .
I don’t understand the phone shielding, but the metal detector is definitely useful. The high-power design of a mobile phone jammer can definitely interfere with the receiver. But I would like to ask, directly on the high-power fixed-frequency sinusoidal electromagnetic wave to transmit Morse code (on-off-on), the examinee has been trained to decode on the spot, will the receiver be interfered. . I think the general signal transmission is very precise and easy to be disturbed, but can this simple and rude type be disturbed? What's more is to find the examination room and send the answer with infrared rays on the opposite floor. I don’t know if there is such a case, I think This can only check whether the candidate has headphones. . . But the metal detector passed my ear for the first time during the college entrance examination.
The mobile phone signal blocking bag jammers on the market are all full frequency bands, which can shield all the 2G 3G 4G signals, 2.4G WIFI signals and Bluetooth signals under the three operators of China Mobile, China Unicom and China Telecom. The signal wifi jammer is turned on during the college entrance examination to prevent candidates from bringing their mobile phones to cheat. Of course, it is useful. Basically, the mobile phone jammer can handle the 2G 3G 4G signals and 2.4G WIFI signals of all China Mobile, China Unicom and Telecom mobile phones during working hours. Block them all. The working principle of the mobile phone signal jammer is that the frequency emitted by the mobile phone jammer interferes with the normal frequency of the mobile phone receiving the base station, making the mobile phone unable to connect with the base station, and thus unable to make calls, receive and send text messages and surf the Internet normally.