With the development of urban construction, high-rise buildings, basements, etc. continue to emerge. Based on the shadow effect of wireless transmission, signal blind spots for mobile phone communication will be formed behind high-rise buildings or in middle floors and basements. In addition, during the construction of cellular mobile communication base stations, the main lobe of the antenna radiation field pattern has a large down-tilt angle to avoid interference from adjacent cells, so that the upper and middle parts of high-rise buildings generally cannot receive signals effectively. For this, How Make A Cell Phone Jammer came into being. However, since cell phone jammer is added to the original communication system, if the equipment index is not up to standard, it will interfere with the original communication system. Some mobile phone users tend to buy cheap but substandard "three no" products from the Internet. These products do not have network access licenses, have poor filtering effects, and occupy the center frequency for a long time, which will seriously interfere with the base stations of nearby operators and cause frequent disconnection of surrounding mobile phone users. "Because of the poor quality of the self-installed repeater and the irregular installation, although the mobile phone users can see the full cell phone signal, they can't actually get through. When the amplified signal of a repeater interferes with normal communication, For the convenience of communication, other nearby mobile phone users will also install repeaters without permission to expand their signals, which will eventually lead to a vicious circle of mutual interference."
The outdoor antennas of mobile phone signal jammers are often set up on the top floors of high-rise buildings. Due to irregular installation and poor lightning protection performance indicators, it is easy to cause lightning strikes in thunderstorms, causing equipment short-circuits and eventually fires. Moreover, such equipment usually has poor emission indicators and large stray signals. The electromagnetic radiation emitted by antennas installed indoors seriously exceeds the standard. How Make A Cell Phone Jammer Will it bring a great threat to human health? In addition, my country has entered the era of high-speed rail. The frequency band used by the base station of the train control system along the high-speed rail line is very close to the frequency band of the mobile company. If a mobile phone signal jammer is installed within 5 kilometers of the railway line, it is likely to cause blocking interference and threaten the train operation. Safety. Therefore, a relevant person from Shanghai Mobile told reporters: "When users find blind spots on mobile phones, they can call 10086 to report, and do not install and use mobile phone signal jammers without permission."