1. Prepare mobile phones with multiple frequency bands, turn on the cell phone jammer, hold each mobile phone, and set the effective shield radius of the jamming device and the shield distance in multiple directions from the installation position of the jamming device. Test from near to far.
2. When checking if the mobile phone is shielded, the signal grid number of the mobile phone may be incorrect and does not represent the current communication status of the mobile phone, so the signal grid number of the mobile phone should be used. You need to be careful, not just check. At this time, don't come to a conclusion too early. , Said that this shield device is ineffective. Instead, you need to dial your cell phone intermittently. Try dialing a local toll-free number or a fixed land line number. If the call fails, it is still considered to be within the shield range. Otherwise, the shield range is out of range.
3. To test if a particular point is within the shield range, hold the phone in this position for at least 30 minutes to see if the phone is shielded.
4. When calling from an unshielded area to a shielded area, you often walk a considerable distance to the shielded area before your cell phone is completely shielded. This is because dialing a mobile phone does not interfere with the mobile phone itself. This type of anti-interference feature allows the cell phone to adjust its transmit power, this time ensuring a normal call. Therefore, it is generally not advisable to run dynamic tests in the invocation state, but it is advisable to run static tests at various points.