In recent years, in various national examinations, cases of cheating in examinations using mobile phones have occurred from time to time, which has seriously affected the fairness and impartiality of examinations. Therefore, the state stipulates that mobile phone jammers should be equipped during important examinations to create a fair atmosphere for candidates. Then, when the mobile phone jammer is turned on, why do some mobile phones still display signals?

There are several situations when the mobile phone has a signal.

1. The mobile phone displays a signal, and when the mobile phone makes a call, if the mobile phone can connect the phone normally, and the call quality is relatively high and is not affected, this situation indicates that there is no effective interference in the mobile phone jammer area. If the mobile phone is close to the mobile phone jammer, there is no signal, indicating that there is a base station or signal amplification in your location, and then it indicates that the mobile phone jammer you are currently using cannot meet your on-site interference requirements, Some high-power mobile phone jammers can be added.

2. The mobile phone displays a signal, but the mobile phone call quality is relatively poor. If this is the case, it indicates that the interference effect of the mobile phone jammer on the mobile phone is in a critical state, with interference effect, but the interference range is unstable. This situation may be that the signal strength from the base station to the use site varies from high to low, as well as some mobile phones with strong anti-interference.

3. The mobile phone displays a signal. In fact, the signal is false. The mobile phone cannot call normally or access the Internet. When making a call, the mobile phone will suddenly display no signal or restrict the service. At this time, it can be determined that the signal displayed on the mobile phone is a false signal, but in fact, the mobile phone is disturbed.

The size of the interference range of the mobile phone jammer depends on the strength of the mobile phone signal where the user is located. Where the mobile phone signal is strong, the interference distance of the mobile phone jammer will be shortened, and where the mobile phone signal is weak, the interference distance of the mobile phone jammer will be far.