What factors affect the radio distance

Many walkie-talkie users may have this question: Why is the communication distance marked on the walkie-talkie different from the actual callable distance? This is because the walkie-talkie is often affected by the surrounding environment, its own accessories, etc. in the actual use process, which reduces the communication distance. Then, let's take a closer look at several important factors that affect the distance and effect of the radio:

The communication distance of the two-way radio depends on the antenna gain, height, transmitter output power, receiver sensitivity, electromagnetic environment, and obstacle-free factors.

1. System parameters:

1) The stronger the output power of the transmitter, the greater the coverage of the transmitted signal and the farther the communication distance. However, the transmission power should not be too large. If the transmission power is too large, it not only consumes power and affects the life of the power amplifier components, but also has strong interference, affects the communication effect of others, and also produces radiation pollution.
2) The higher the receiving sensitivity of the communication device, the longer the communication distance.
3) The gain of the antenna. When the antenna is matched with the radio, usually, the height of the antenna increases, and the receiving or transmitting ability increases. The antennas used in handheld walkie-talkies are generally helical antennas, whose bandwidth and gain are smaller than other types of antennas and are more susceptible to human influence.

2. Environmental factors:

Environmental factors mainly include paths, density of trees, electromagnetic interference of the environment, buildings, weather conditions and terrain differences. These factors and other parameters directly affect the field strength and coverage of the signal.

3. Other influencing factors:

1) The battery power is insufficient. When the battery power is insufficient, the call quality will deteriorate. In severe cases, noise will appear, affecting normal calls.
2) Antenna matching, the frequency band of the antenna is inconsistent with the frequency band of the radio, and the impedance of the antenna does not match, which will seriously affect the call distance. For users, pay attention to tighten the antenna when changing the antenna. In addition, you can't use an antenna that is not provided by the manufacturer or an antenna that does not meet the frequency of the radio.

4. The quality of the sound

It mainly depends on the pre-emphasis and de-emphasis circuits. At present, there are more advanced voice processing circuits "application of voice companding circuit and low-level expansion circuit", which has a good effect on fidelity voice.

5. Safety precautions for the use of the radio and routine maintenance of the radio

1) When the walkie-talkie is launching, keep the walkie-talkie in a vertical position, and keep the distance between the microphone and the mouth 2.5-5 cm. When launching, the intercom is at least 2.5 cm away from the head or body. If the handheld radio is carried on the body, the antenna is at least 2.5 cm away from the human body when transmitting.

2) Do not perform multiple power-on and power-off actions during use, and at the same time adjust the volume to a volume suitable for your hearing.

3) On cars with airbags, do not place the radio within the range that may be involved when the airbags are deployed. If the walkie-talkie is in the area that may be involved when the airbag is deployed, once the airbag is rapidly deployed, the walkie-talkie may injure people in the vehicle with a great impact.

4) In a potentially explosive atmosphere or occasion, unless the radio is specially certified, the radio must be turned off. In a potentially explosive atmosphere, electric sparks can cause an explosion or fire.

5) Do not replace or charge the battery in a potentially explosive atmosphere. Installing and removing the battery may cause contact sparks and explosion.

6) Before approaching the blasting area and the area where the detonator is located, the walkie-talkie must be turned off to avoid possible explosion.

7) After long-term use of the radio, press the key, the control knob and the cabinet are easily dirty. Please remove the control knob from the radio and clean the cabinet with neutral detergent (do not use strong corrosive chemicals) and a damp cloth. The use of chemicals such as detergents, alcohol, sprays, or petroleum preparations may cause damage to the surface and housing of the radio.

8). Handle the walkie-talkie lightly and never move the walkie-talkie with the antenna.

9). If the accessory is not applicable, please put on the dust cover (if equipped).