The main environmental factors include the path, density of trees, environmental electromagnetic interference, buildings, weather conditions and topographic differences. These factors and other parameters directly affect the field strength and coverage of the signal.
1) The battery is low, when the battery is low, the call quality will deteriorate. Serious, there will be noise, affecting the normal call.
2) Antenna matching, the antenna frequency band and the machine band are inconsistent, antenna impedance mismatch, will seriously affect the call distance. For the user, when changing the antenna, pay attention to tightening the antenna. In addition, you should not use the antenna not provided by the manufacturer or the antenna that does not conform to the frequency of the machine.
3) The quality of the sound depends mainly on the pre-emphasis and de-emphasis circuit, there are more advanced voice processing circuit "voice companding circuit and the application of low-level expansion circuit," which has a good effect on fidelity voice.
4) The factors that affect the intercom call distance and effect are also related to the seasons, the summer is better than the winter.