In the self driving activities, especially in the fleet, each vehicle should be equipped with walkie talkies, which can inform each other of the road conditions and vehicle conditions during driving, so as to facilitate mutual help and coordination. In the long-distance journey, they can also remind each other and talk to each other, so as to maintain a good driving state and atmosphere, and avoid the possible adverse consequences caused by long-term driving or fatigue driving. Communication distance is the most important factor to be considered in the selection of walkie talkies for motorcades, because when motorcades are driving, the front and rear cars will be pulled apart for a long distance, less than 1 km, more than 3 or 5 km. Therefore, the team should choose a higher power walkie talkie, such as a professional walkie talkie, which can inform teammates of the location information at any time. But if there are many vehicles in the team and the car is pulled far away, the hand-held walkie talkie will not be able to do its job. The professional car radio is more suitable for the team to connect.
In outdoor travel, the function of walkie talkie is incomparable with that of mobile phone. The reason is that when a walkie talkie is talking, other walkie talkies in the same communication group can receive it. But mobile phone has no such effect, especially in outdoor, there is often no mobile phone signal, and walkie talkie can talk directly without any network, that is why the users choose walkie talkies instead of mobile phone in external activities. Then,how to choose the right walkie talkie?
The commonly used walkie talkies are divided into frequency bands, generally working in vhf16mhz ~ 174mhz (also known as V segment), uhf400mhz ~ 470MHz (also known as u segment), and 350MHz. Segment V and segment u are generally used for civil service stations. According to the shape, it can be divided into vehicle station, hand-held station, base station and relay station. Power: the power of car station is generally 25W, and that of hand station is usually between 0.5W and 5W. At present, the power of FRS license free walkie talkie on the market is 2W, and that of PMR446 license free walkie talkie is 0.5W (the sea level can reach 3km).
Using walkie talkies, we are most concerned about the communication distance. "Very high frequency" (VHF) and "ultra high frequency" (UHF) radio waves are mainly transmitted in a straight line, so it is suitable for short-range communication. In the urban environment, the communication distance of the hand station (original antenna) with output power of 3W is about 3km, and the communication distance of the 25 W car station with car antenna is about 10-20km Path, density of trees, electromagnetic interference of environment, buildings, weather conditions and terrain differences, these factors and other parameters directly affect the field strength and coverage of the signal, so that the call distance is affected to a certain extent.
Generally, the walkie talkie with push-button frequency modulation is more suitable for car riders. Although the operation is troublesome, it can be seamlessly connected with any brand of walkie talkie, which is very practical. When traveling, the frequency can be set at will, and the frequency can be changed at will to avoid the frequency commonly used by others, so-called string frequency. This kind radio is characterized by small size, with display screen, intuitive, beautiful and fashionable. The disadvantage is that the power endurance is slightly poor, and the anti Strike ability is slightly poor. The handsets of different styles and brands can also use FM to keep each other talking. The only thing is that the handsets should be FM on the computer.
For long-distance self-driving, there are some products that are indispensable, a car charger, a cigarette lighter at one end, and a charger at the other. Because in the process of self-driving tour, the use rate of the hand held walkie talkie is quite high. With this line, you can ensure that your hand held walkie talkie will not lose you and the lead car, cruise car, escort car, etc. due to power failure. Connection. Imagine if you can’t receive the command from the commander while you are on the move, you will become deaf, lost in confusion, and even grow in fear. This line, you must have.
The hand microphone is another must-have item for you. One end is the earphone jack of the hand held radio, and the other is clasped in your hand. Note that the hand microphone and the earphone jack are double, one thick and one thin. The so-called one way out one way in, hand held radio is two-way communication. The role of the hand microphone is to liberate your hand holding the steering wheel. If you hold the steering wheel with one hand and hold the hand with one hand while driving the vehicle, it will be a very dangerous thing. The matching mic looks important.
Another optional component is the car antenna, which was originally used on the car radio station. Now it is also commonly used on the hanhheld radio. If you have more than 20 self driving vehicles or more turning mountain roads on the road, the antenna is essential, because the walkie talkie is a straight-line transmission, and the acceptance ability is greatly reduced in case of obstacles or distance extension. This antenna can improve your hand held radio by 3-5 times, It is recommended to select the clamp seat instead of the suction cup seat because the suction cup seat is easy to dump and scratch the car paint when opening the trunk cover, while the clamp seat is light, beautiful and stable. After the antenna is unscrewed, there is a screw seat which looks like a camera. People dare not move your car easily.
As for the selection and purchase of hand held radio, they are mainly practical and do not pursue too many functions. They mainly focus on the smooth voice transmission and long distance. The transmission power of early hand held radio is mostly 3-5 watts. In recent years, the transmission power of many hand held radio has increased up to 10 watts. In theory, the larger the transmission power is, the longer the transmission distance is. It is recommended to choose the handsets with high transmission power.