1. Classification of walkie-talkies According to the type of communication terminal, walkie-talkies can be divided into three categories: hand-held walkie-talkies, car-carried walkie-talkies (base stations), and relay stations (repeater stations).
2, frequency range. In the selection of walkie-talkies, the first thing you should know is whether the walkie-talkie has the national radio management department of the network standard.
Secondly, you should know the frequency of the walkie-talkie, such as the national regulations for civilian walkie-talkie frequency range of 400 ~ 420Mhz. 3, the transmitter power.
Transmitting power is an important indicator of the walkie-talkie, it determines the distance of the walkie-talkie, the use of time and whether it will cause interference to other communication equipment, so when you buy a walkie-talkie, you should understand the transmitting power of the walkie-talkie according to the actual demand. Generally, the transmit power of civilian walkie-talkie is about 1W, and the transmit power of commercial walkie-talkie and professional walkie-talkie is about 4W.
(National regulations handheld walkie-talkie transmitter power shall not exceed 5W). 4, frequency range.
In the selection of walkie-talkies, first of all, you should know whether the walkie-talkie has a national radio management department of the network license. Secondly, you should understand the frequency of the work of the walkie-talkie, such as the national regulations for the use of civilian walkie-talkie frequency range of 400 ~ 420Mhz.
2. Walkie-talkie and some general knowledge of the radio
1, the frequency band can not be changed, the determination of the radio frequency band is initially generated by the crystal oscillator, the frequency of this crystal oscillator is a certain. The crystal output frequency and then a series of complex work through the circuit, and ultimately produce the operating frequency.
So 450-470 walkie-talkie can not be adjusted to 430.
2, the frequency band is the crystal oscillator and transmitter circuit **** with the decision. The antenna can not determine its frequency band, the length of the antenna must be determined by the transmitter band, too short, too long will lead to transmit power can not be completely launched from the antenna, resulting in the antenna tuner temperature is too high, and finally lead to burn out.
3, the frequency band of the walkie-talkie is a special band, according to the national law of the frequency band, and the radio use frequency band is staggered. So it doesn't work.
3. Who gives the basics of the walkie-talkie
Walkie-talkies are mainly used in what areas? Walkie-talkies are mainly used in public security, civil aviation, transportation, water conservancy, railroads, manufacturing, construction, service and other industries, for contact between group members and command and control scheduling, in order to improve the efficiency of communication and to improve the handling of emergencies and rapid response capability.
With the walkie-talkie into the civilian market, people traveling, shopping also began to use more and more walkie-talkie. How far is the intercom distance? Conventional walkie-talkies can talk up to 8-10 kilometers in open space, 3-5 kilometers in urban areas, and relatively shorter distances in cases where there are tall buildings or mountains in the way.
When there is network support, the intercom distance can reach tens of kilometers. Networking is the use of a repeater (also known as a base station or relay station), which automatically receives the transmitted signals from the walkie-talkie, and amplifies and forwards them.
Networking can expand the intercom communication coverage, extend the call distance, open space up to 10-20 kilometers (handheld radios) or 30-50 kilometers (car radios), the building can be covered in the basement, underground parking plant, fire escapes and other shielding is serious, usually known as the dead zone of the region. What are the safety precautions during the use of walkie-talkies? 1. In cars with airbags, do not put the walkie-talkie in the range that may be involved when the airbag is deployed.
If the walkie-talkie is in the area that may be involved in the deployment of the airbag, the walkie-talkie may injure the occupants of the vehicle with the tremendous impact once the airbag rapidly deploys; 2. In potentially explosive atmospheres or situations, the walkie-talkie must be turned off, unless the walkie-talkie is a specially certified explosion-proof type of walkie-talkie. In potentially explosive atmospheres, electrical sparks can cause explosions or fires; 3. Do not change or charge the battery in potentially explosive atmospheres.
Installing and removing batteries can cause contact sparks and result in an explosion; 4. Turn off your walkie-talkie before approaching blasting areas and areas where detonators are located to avoid a possible explosion. How to maintain the walkie-talkie? 1. After long-term use of the walkie-talkie, the pushbutton, control knob and case are easily dirty, please remove the control knob from the walkie-talkie, and clean the case with neutral detergent (do not use strong corrosive chemicals) and a damp cloth.
The use of chemicals such as detergents, alcohol, sprays, or petroleum-based agents can cause damage to the surface and case of the intercom; 2. Hold the intercom gently and do not move it with the hand-held antenna; 3. When not using accessories such as the headset, close the dust cover (if equipped). What factors affect the walkie-talkie call distance and effect 1. system parameters: 1) the stronger the transmitter output power, the greater the coverage of the transmitted signal, the greater the communication distance.
But the transmitter power can not be too large, the transmitter power is too large, not only power consumption, affecting the life of the amplifier components, and strong interference, affecting the effect of other people's calls, but also produce radiation pollution. The radio regulatory agencies of various countries have clearly defined the transmission power of communication equipment.
2) The higher the receiver sensitivity of the communication machine, the farther the communication distance. 3) The gain of the antenna, when the antenna is matched with the machine, usually, the height of the antenna increases, the receiving or transmitting ability is enhanced.
The antenna used for handheld walkie-talkie is generally a spiral antenna, its bandwidth and gain is smaller than other kinds of antennas, and it is more likely to be affected by the human body. 2. Environmental factors: environmental factors are mainly paths, the density of trees, the environment of electromagnetic interference, buildings, weather conditions and terrain differences.
These factors and some other parameters directly affect the signal field strength and coverage. 3. Other influencing factors: 1) Low battery, when the battery is low, the call quality will deteriorate.
In severe cases, noise will appear, affecting normal calls. 2) Antenna matching, the frequency band of the antenna is not consistent with the frequency band of the machine, and the antenna impedance is not matched, all of which will seriously affect the call distance.
For the user, pay attention to tighten the antenna when changing the antenna, in addition, you can not just use the antenna that is not provided by the manufacturer, and you can not use the antenna that does not match the frequency of the machine. What is a public walkie-talkie? Public walkie-talkie refers to: transmitting power is not greater than 0.5W, working in the specified frequency of the wireless walkie-talkie, its radio transmitting frequency, power and other radio frequency technical indicators must meet the following requirements: 1, the operating frequency (.9000;409. Unit: MHz): 409.7500, 409.7625, 409.7750, 409.7875, 409.8000, 409.8125, 409.8250, 409.8375, 409.8500, 409.8625, 409.8750, 409.8875, 4099125, 409.9250, 409.9375, 409.9500, 409.9625, 409.9750, 409.9875; 2, Modulation Mode: F3E; 3. Effective Transmit Power (EIRP): Comments 0 0 0.
4. What are the terms related to walkie-talkies
Term MONITOR A method of listening used to receive weak signals.
By pressing a dedicated key to force on the receiving signal channel, the operator uses his ears to recognize the weak sound in the speaker to achieve the purpose of listening. Scanning (SCAN) A listening method used to hear calls on all channels.
By pressing the dedicated key, the receiving circuit receives the signals in a certain order, channel by channel, for a certain period of time to hear the signals in the channel. If the reception time of each channel is 100ms, then ten channels can be scanned over per second, i.e. the scanning speed is 10ch/s .
Priority Channel Scan function (Priority Channel Scan) Prioritizes the scanning of the set priority channel during the scanning process. Delete/Add Scan Channel Deletes or adds a channel from or to the scan list.
5. Who gives the basics of walkie-talkies
In what areas are walkie-talkies mainly used? Walkie-talkies are mainly used in public security, civil aviation, transportation, water conservancy, railroads, manufacturing, construction, service and other industries, for contact and command and scheduling between members of the group, in order to improve the communication efficiency and improve the ability to deal with emergencies and rapid response.
With the walkie-talkie into the civilian market, people traveling, shopping also began to use more and more walkie-talkie. How far is the intercom distance? Conventional walkie-talkies can talk up to 8-10 kilometers in open space, 3-5 kilometers in urban areas, and relatively shorter distances in cases where there are tall buildings or mountains in the way.
When there is network support, the intercom distance can reach tens of kilometers. Networking is the use of a repeater (also known as a base station or relay station), which automatically receives the transmitted signals from the walkie-talkie, and amplifies and forwards them.
Networking can expand the intercom communication coverage, extend the call distance, open space up to 10-20 kilometers (handheld radios) or 30-50 kilometers (car radios), the building can be covered in the basement, underground parking plant, fire escapes and other shielding is serious, usually known as the dead zone of the region. What are the safety precautions in the use of walkie-talkies? 1. In cars with airbags, do not put the walkie-talkie in the range that may be involved when the airbag is deployed.
If the walkie-talkie is in the area that may be involved in the deployment of the airbag, the walkie-talkie may injure the occupants of the vehicle with the tremendous impact once the airbag rapidly deploys; 2. In potentially explosive atmospheres or situations, the walkie-talkie must be turned off, unless the walkie-talkie is a specially certified explosion-proof type of walkie-talkie. In potentially explosive atmospheres, electrical sparks can cause explosions or fires; 3. Do not change or charge the battery in potentially explosive atmospheres.
Installing and removing batteries can cause contact sparks and result in an explosion; 4. Turn off your walkie-talkie before approaching blasting areas and areas where detonators are located to avoid a possible explosion. How to maintain the walkie-talkie? 1. After long-term use of the walkie-talkie, the pushbutton, control knob and case are easily dirty, please remove the control knob from the walkie-talkie, and clean the case with neutral detergent (do not use strong corrosive chemicals) and a damp cloth.
Using chemicals such as stain remover, alcohol, sprays, or petroleum agents can cause damage to the surface and case of the intercom; 2. Hold the intercom gently and do not move it with the hand-held antenna; 3. When not using accessories such as the headset, close the dust cover (if equipped). What factors affect the walkie-talkie call distance and effect 1. system parameters: 1) the stronger the transmitter output power, the greater the coverage of the transmitted signal, the greater the communication distance.
But the transmitter power can not be too large, the transmitter power is too large, not only power consumption, affecting the life of the amplifier components, and strong interference, affecting the effect of other people's calls, but also produce radiation pollution. The radio regulatory agencies of various countries have clearly defined the transmission power of communication equipment.
2) The higher the receiver sensitivity of the communication machine, the farther the communication distance. 3) The gain of the antenna, when the antenna is matched with the machine, usually, the height of the antenna increases, the receiving or transmitting ability is enhanced.
The antenna used for handheld walkie-talkie is generally a spiral antenna, its bandwidth and gain is smaller than other kinds of antennas, and it is more likely to be affected by the human body. 2. Environmental factors: environmental factors are mainly paths, the density of trees, the environment of electromagnetic interference, buildings, weather conditions and terrain differences.
These factors and some other parameters directly affect the signal field strength and coverage. 3. Other influencing factors: 1) Low battery, when the battery is low, the call quality will deteriorate.
In severe cases, noise will appear, affecting normal calls. 2) Antenna matching, the frequency band of the antenna is not consistent with the frequency band of the machine, and the antenna impedance is not matched, all of which will seriously affect the call distance.
For the user, pay attention to tighten the antenna when changing the antenna, in addition, you can not just use the antenna that is not provided by the manufacturer, and you can not use the antenna that does not match the frequency of the machine. What is a public walkie-talkie? Public walkie-talkie refers to: transmitting power is not greater than 0.5W, working in the specified frequency of the wireless walkie-talkie, its radio transmitting frequency, power and other radio frequency technical indicators must meet the following requirements: 1, the operating frequency (.9000; 409. Unit: MHz): 409.7500, 409.7625, 409.7750, 409.7875, 409.8000, 409.8125, 409.8250, 409.8375, 409.8500, 409.8625, 409.8750, 409.8875, 4099125, 409.9250, 409.9375, 409.9500, 409.9625, 409.9750, 409.9875; 2, Modulation Mode: F3E; 3, Effective transmit power (EIRP): < 0.5W; 4, Transmit frequency tolerance: <+5ppm; 5, Transmitter stray radiation: <50uW; 6, Receiver stray radiation: <20nW; 7, Channel spacing: 12.50kHz.
Electromagnetic interference of walkie-talkie, electromagnetic compatibility In order to avoid the electromagnetic interference To avoid problems caused by electromagnetic interference and/or electromagnetic compatibility, turn off the walkie-talkie in places where the "Turn off walkie-talkie" sign is posted. For example, in hospitals or other places where healthcare medical equipment is used.
You should also turn off your walkie-talkie when traveling on an airplane, if required. Precautions for use of walkie-talkie batteries 1. Use original or approved batteries from Wilwood; 2. All batteries may cause damage or personal injury if a metal conductor, such as jewelry, keys, or beadwork, touches the battery's *** electrodes.
Please be careful with charged batteries, especially when carrying them in a pocket, wallet, or other metal container; 3. Charging should be done in an environment of 5~40 degrees Celsius. If the temperature exceeds this range, the battery life is affected and there is a risk of undercharging the rated capacity.
Do I have to pay to talk on a walkie-talkie? You don't have to pay to talk on a regular walkie-talkie. No matter how often you use it, you only pay a few dollars per year for each walkie-talkie, or nothing if you use a public walkie-talkie.
Precautions for the use of walkie-talkie antennas 1. Use only WEIERWEI's original or approved antennas. Unrecognized antennas, modified or added accessories may damage the walkie-talkie or violate the regulations of the Radio Regulations of the Ministry of Information Industry; 2.
When transmitting, if the damaged antenna touches the skin, it may cause please slight burns.