Then after my actual test, the 0.5W walkie-talkie is about 500 meters in the urban area, so it is impossible to go any further. Even the 5W Gymboree I am using now is about 1 km.
The watch walkie-talkie mentioned by the landlord is sold on many treasures, and it is really cheap. If the landlord uses it for a spring outing, or it is very convenient to play in the same community.
If you have higher requirements, you can buy professional machines. For example, the common power of Beifeng 5 1 18 is 2.5W, and the distance is much more than 0.5w. The price of one is also around 150.
Then the distance and power of the walkie-talkie are related, and the importance of the antenna.
The above is a simple explanation.
The following is a professional explanation:
The walkie-talkie discussed in this paper covers a wide range. Here, we call radio communication equipment working in ultrashort wave band (VHF30~300MHZ, UHF300~3000MHZ) radio interphone. In fact, according to the relevant national standards, it should be called ultrashort wave FM wireless phone. People usually refer to the hand-held wireless telephone with small power and volume as "walkie-talkie". In the past, some people called it "walkie-talkie" and "walkie-talkie", while high-power and high-volume wireless phones that can be installed on cars (ships) or used fixedly are also called "radio stations", such as vehicle-mounted platforms (vehicle-mounted platforms) and offshore platforms. . q
The walkie-talkie is the earliest wireless mobile communication equipment used by human beings, and it began to be used as early as the 1930s. 1936, Motorola Company of the United States developed the first mobile radio communication product-"patrol" AM vehicle-mounted radio receiver, and then in 1940, the first hand-held two-way radio AM walkie-talkie with a weight of 2.2kg was developed for US Army signalmen, with a communication distance of1.6 km ../kloc- Its shape is called "brick" and its size is similar to that of early mobile phones. After nearly 3/4 centuries of development, the application of walkie-talkies has become very common, from specialized fields to ordinary consumption, from military to civilian use. It is not only a professional wireless communication tool in mobile communication, but also a consumer tool with the characteristics of consumer products that can meet people's daily needs. As the name implies, mobile communication means that one party and the other party communicate on the move. Including mobile users to mobile users, mobile users to fixed users, and of course fixed users to fixed users. Wireless walkie-talkie is an important branch of mobile communication. It is a kind of wireless terminal equipment, which can be used for mobile point-to-multipoint communication. It allows many people to communicate with each other at the same time, so that many people can hear the same person at the same time, but only one person can speak at the same time. This communication mode has the characteristics different from other communication modes: instant communication, instant response, economy and practicality, low operating cost, no call fee, economy and convenience, and also has the functions of group call broadcasting, system call and confidential call. In dealing with emergencies, it plays an irreplaceable role in dispatching and commanding. Radio walkie-talkies and other wireless communication tools (such as mobile phones) have different market positioning and are difficult to replace each other. The walkie-talkie is by no means an outdated product. It will take a long time. With the development of economy and social progress, people pay more attention to their own safety, work efficiency and quality of life, and the demand for radios will also increase day by day. The widespread use of public walkie-talkies has promoted wireless walkie-talkies to become a communication tool that people like and rely on, just like wired telephones.
First, from the way of use, hand-held, car (ship, machine) loading, fixed, forwarding.
Handheld wireless walkie-talkie W|
This is a small size, light weight and low power consumption wireless walkie-talkie, suitable for hand-held or bagged, convenient for individuals to carry around, and can also communicate when traveling. Generally, its power does not exceed 5W in VHF band and 4W in UHF band. But there are also a few models whose power VHF is 6W and UHF is 5W, such as IC-T7H(VHF) is 6W. In an open area without obstacles, the communication distance can generally reach 5 kilometers. With the support of wireless communication network, the communication distance through the turntable can reach more than 10 km. This machine is suitable for close communication of mobile personnel in various occasions. In the wireless telephone series, the number and types of hand-held radios are the largest, accounting for more than 80%. From the high-end hand-held walkie-talkie produced by Motorola to the domestic low-end hand-held walkie-talkie with a price difference of about 100 yuan, it is estimated that this kind of walkie-talkie sells more than one million sets in China every year, which has great market potential. } G & lt`=
Amateur radio interphone
A radio walkie-talkie specially designed and produced to meet the needs of radio enthusiasts. This kind of walkie-talkie can also be called "playing computer". In view of this amateur personal radio service, all countries have opened up special frequency bands for amateur radio sports enthusiasts to use. China's open frequency bands are 144~ 146MHZ and 430~440MHZ, which are basically the same in the world. The Radio Frequency Planning of People's Republic of China (PRC) issued by national radio administration bureau, Ministry of Information Industry, in 20061October 5438+0 specifically explained amateur radio enthusiasts and amateur services. "Amateur service: a radio communication service for self-training, mutual communication and technical research for amateur radio enthusiasts. Amateur radio enthusiasts refer to people who are officially approved and interested in radio technology. Their interests are purely personal hobbies and do not involve profit. " U}
Because of the limited frequency range of radio interphone, the environmental conditions and requirements used are different from those of professional interphone. The main features of amateur machine are small size, complete functions, frequency scanning, direct setting of frequency on the panel and display of frequency points on the panel. Its technical index, equipment stability, frequency stability, reliability and working environment are also worse than those of professional radio stations. The direct result is that the cost of amateur machines is also lower to meet the needs of individual purchases. At present, most of the amateur machines used in China are imported equipment. Except for Motorola's two hand-held walkie-talkies AP50 and AP 10, which entered the domestic market in the mid-1990s, and Taiwan Province ADI's AR- 146/446 car platform and S- 145/450 handset, these devices are all made in Japan. These amateur car owners are: TH22A/42A hand-held walkie-talkie of Jianwu Company of Japan, TM26 1/46 1 car platform of Tron Company of Japan, DR 130/430, DR 135/435 car platform. Handheld walkie-talkies such as FTC2008/7008 and VX 150 from Yaekju Company of Japan, IC IC-)2 100H car platform from ICOM Company of Japan, and C 150/450 handheld walkie-talkie from marantz Company of Japan, etc. 8k~%S
Amateur machines generally have a feature, with a wide working range and frequency, and can work in the full range of V and U segments. V segment 136~ 174MHZ, and u segment 400~470MHZ. However, its technical indicators are only guaranteed in amateur frequency bands. For example, the actual working range of the DR435TG amateur machine of Japan Telong Company is 136~ 173.995MHZ, but its technical index can only be guaranteed in the amateur frequency band of 144~ 147.995MHZ. Similarly, the technical index of the DR435TA professional machine is/kloc-. If you want to use it in other frequency bands, you'd better re-debug, especially the power, otherwise the power will drop a lot. Because the price of amateur machines is lower, some professional users also choose amateur machines as their own models. At this time, it is best to ask an experienced engineer to re-debug it to ensure the performance index in the working frequency band. *F
D6 professional radio station
Most users of professional radio are used for the professional business of group teams. Therefore, the characteristics of professional walkie-talkies are simple and practical. A variety of communication interfaces are reserved in the design for users to carry out secondary development. Most of its frequency report settings are programmed by computer, and users can't change the frequency. Its panel only shows the number of channels, not the frequency points directly, so it has good frequency confidentiality, high stability and is not easy to run. In the long-term work, it has high stability and reliability, and the working temperature range is wide, generally from -30 degrees to +60 degrees. When the professional machine works in VHF band, it belongs to part of V high band (148~ 174MHZ) and V low band (136~ 160MHZ). The other part is the whole section (136~ 174MHZ). But in UHF band, most of them are divided into U high band (450~470MHZ) and U low band (400~430MHZ), and a few are U full band (400~470MHZ). The performance, reliability and stability of professional machines are higher than those of amateur machines, and the price is naturally higher than that of amateur machines, and some are even much higher. Except some domestic professional machines, most of them are imported models. The models produced by Motorola are almost all professional machines. The representative products are GP88, GP88S, GP2000, GP328/338 hand-held walkie-talkies, GM950, GH300, GM338/398 car-mounted platforms, T2000 series car-mounted platforms of Daji Company in New Zealand, KG series car-mounted platforms and handsets of KYODO Company in Japan, and Jianwu Company in Japan. F-series hand-held walkie-talkie and vehicle platform of ICOM company in Japan. Many models of hand-held walkie-talkies produced in China are carried out according to the design standards of professional machines, and few models really reach the level of professional machines. The gap is not only in the design technology, but also in the quality of components, the level of manufacturing technology and assembly technology, the processing quality of parts, the selection of materials (such as the plastic of chassis), especially the environmental test of products. As a professional machine, it must pass strict environmental tests according to standards. Many imported machines are tested according to the US military standards MIL-STD8 10C, D, E, and MIL-STD8 10 is the performance standard of products recognized by the US military in harsh environment. Its tests include low pressure, high temperature, low temperature, instantaneous temperature, sun exposure, sun protection, moisture prevention, salt spray, dust prevention, shock prevention and impact prevention. MIL-STD8 10E is an upgraded version of Advantages 0C and 8 10D. Some imported models are tested according to the European ETIS standard. Motorola's walkie-talkies have to undergo "accelerated aging test" before leaving the factory, that is, they simulate five years of actual bad use and meet the impact, shock, dust, moisture and IPX4 sealing tests of ELA-3 16B standards. In this respect, it is obvious that there is a big gap between domestic machines. Some lack conventional testing conditions, some have low testing standards, and some have no such testing awareness at all. Amateur machines will certainly not make much effort in this respect. The quality gap between professional and amateur machines is also obvious. For example, the working temperature of a professional machine reaches -30 degrees, while that of an amateur machine generally only reaches-10 degrees. It is not difficult for us to understand the price difference between professional machines and amateur machines, domestic machines and imported machines, professional machines and professional machines, brand machines and non-brand machines. p[p@
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Five, from the communication business can be divided into public walkie-talkies, digital walkie-talkies, police walkie-talkies, aviation walkie-talkies and marine walkie-talkies.
Public radio intercom
Public interphone, commonly known as civil interphone. This refers to the walkie-talkie that can only work on the radio frequency designated by the government radio management department for public use. In essence, it belongs to the category of personal business communication, and it is a short-distance radio communication service for individual families or small groups. Anyone can choose to use the public walkie-talkie without approval, frequency occupation fee and call charge. However, this kind of public walkie-talkie has clear regulations on frequency, power and technical indicators. At present, China is formulating the national standard "Technical Specification and Measurement Method of 400MHz Public Intercom". It is reported that the national standard of public walkie-talkie in China refers to the 95th part of American FCC standard 47 crr- Personal Radio Service, including seven aspects. Comparatively speaking, China's public walkie-talkie is equivalent to its second content-family radio service (FRS), so the standard of public walkie-talkie in China is mainly formulated with reference to the relevant standard "FRS" in the United States. Europe also has corresponding standards for public walkie-talkies. Although the standards of different countries are different, one thing is the same, that is, the level does not exceed 0.5W In terms of frequency, there are great differences. Each country or region stipulates or implements its own frequency and channel number. The number of open channels in China is 20, and the frequency range is 409.750 to 409.9875 MHz. The United States has 14 frequency points, which are divided into two groups of 462MHz and 467MHz, with 7 frequency points in each group; There are also 14 frequency points in Taiwan Province province, ranging from 446.00625 MHz to 446.09375 MHz. There are 80 open frequency points in Thailand, ranging from 245.000 MHz to 245.7375 MHz. It is understood that Japan and South Korea adopt the public frequency stipulated by the United States. In addition, as a public walkie-talkie, national technical specifications stipulate that the front panel of walkie-talkie cannot be equipped with programming operation function to prevent users from arbitrarily expanding the frequency range and modifying working parameters. According to the regulations, the public walkie-talkie can only display the number of channels, not its working frequency. At the same time, it is also stipulated that public walkie-talkies can use infrasound technology (CTCSS) below 300HZ, commonly known as anti-jamming code or dedicated line, to prevent interference from the same frequency walkie-talkies. o++ 1
According to the Regulations on Radio Management in People's Republic of China (PRC), Regulations on the Administration of Imported Radio Transmitting Equipment and Regulations on the Administration of Production of Radio Transmitting Equipment, public walkie-talkies sold in the domestic market, whether imported or made in China, must be tested by the National Radio Testing Center, meet the relevant national management regulations and technical standards, and obtain the type approval certificate of radio transmitting equipment issued by the Radio Administration of the Ministry of Information Industry. According to statistics, nearly 60 models of public walkie-talkies from nearly 30 manufacturers have been approved. But there are still many manufacturers to do this work, most of which are domestic machines. aK 1！
China public intercom standard frequency point
Channel123455678910m
Frequency (MHz) 409.7500 409.7625 409.7750 409.7875 409.8000 409.8125 409.8250 409.8375 409.8500 409.8625m =% _ l.
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Channel112131415171819/kloc-0.
Frequency (MHz) 409.8750 409.8875 409.9000 409.9125 409.9250 409.975 409.9500 409.9875% @ en]
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American public intercom standard frequency point a
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Channel 1 2 3 4 5 6 7 s
Frequency (MHz) 462.5625 462.5875 462.438+025 462.675 462.625 462.738+025 J'&; ! u:
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8 Channel 9101121314! %[
Frequency (MHz) 467.5625 467.5875 467.438+025 467.675 467.625 467.025 MPa. 596366
European public intercom standard frequency \/
Channel 1 2 3 4 5 6 7 8 _dTcQ=
Frequency (MHz) 446.00625 446.01875 446.03125 446.04375 446.0878+025 446.075 up {o @
Taiwan Province province public walkie-talkie standard frequency u? (6)
Channel12345675l &; ~B
Frequency (megahertz) 36838+0255540486
Police walkie-talkie KKF>；;
The police walkie-talkie is a walkie-talkie specially designed for wireless communication in eight departments: public security, prosecution, court, justice, security, customs, army and armed police. In order to ensure the safety of the communication services of the above special departments, the national radio management department has specially planned several groups of frequencies for its use, with the frequency range of 350~390MHz, of which 350 ~ 390 MHz ~ 370 MHz is mainly used for public security systems. This part of the frequency is called the low end of 350MHz in the line. 370MHz~390MHz is used by other departments, and this frequency is called 350MHz high end. This kind of walkie-talkie is collectively called 350MHz police walkie-talkie. Due to the particularity of policing, its working environment, requirements and the nature of its communication business are still different from other ordinary walkie-talkies. In addition to good reliability and durability, police walkie-talkies also require powerful functions, superior performance, firmness and durability, shock and collision prevention, light weight, convenient use, large battery capacity and long standby time. Some departments also have special requirements, such as communication security technology. g
Police walkie-talkies are divided into conventional communication and trunking communication. In conventional communication, it is divided into private communication network and non-network use. In trunking communication, it can be divided into trunking system with MPT 1327 signaling and trunking system with other standards. The public security system uses the largest number of police walkie-talkies. When using the police walkie-talkie in the public security system, it must pass the walkie-talkie network access test of the Ministry of Public Security, which meets the requirements of the Police Automation Level Specification of the Public Security Mobile Communication Network, such as CPSX numbering scheme, dynamic reorganization function, alarm function, single button start and so on. The trunking intercom shall conform to the signaling standard of MPT 1327, and be applicable to the dialing modes of CPS-X and MPT 1343 of the Ministry of Public Security. Trunk walkie-talkie should not only be used in trunking system, but also be able to switch to conventional channel mode conveniently, that is, it has off-network function. Offline refers to direct communication with other mobile stations by offline function (temporarily leaving the trunking system) in the case of short-distance simplex communication or beyond the coverage of the system. Answer! :\
As early as ten years ago, the 350MHz police walkie-talkie made in Japan entered the public security system and the armed police department. FG809 hand-held walkie-talkie, FG808 vehicle-mounted platform and other products of KG series, such as KG 105 vehicle-mounted platform, KG 107 vehicle-mounted platform, KG 109 hand-held walkie-talkie, KG 106 duplex vehicle-mounted platform and KG/KLOC-0. TK series police walkie-talkies of Jianwu Company of Japan, which are all produced by ICOM Company of Japan Co., Ltd., such as TK348 handheld walkie-talkie, TK808 car radio and TKR820 relay radio, were adopted by public security system earlier. The police walkie-talkie uses the products of Japanese Jianwu company and American Motorola company, which have a large number, great influence, complete specifications and many varieties. In the past ten years, Jianwu Company has developed many series products according to the China police walkie-talkie market, occupying a large market share. Handheld walkie-talkies are TK348, TK388, TK3 107 and TK388G, vehicle-mounted stations are TK808, TK868 and TK868G, and relay stations are TK820, TK828 and TK850. In contrast, Motorola entered the police walkie-talkie market late, and GP68-8 police walkie-talkie was launched in the domestic market in August 1997. However, with its strong strength and unique design, strong promotion and well-known brands, after the North American-style police walkie-talkies entered the China market, they developed hand-held police walkie-talkies, such as GP68-8, GP300, GP328/338, GP2000 and HTP700, and police vehicle-mounted equipment such as GM300, GM950, MTH700 and GB300, which became the strong brands in today's police walkie-talkies. Marantz brand HX260, HX290 hand-held walkie-talkie, GX 1608 car-mounted walkie-talkie and DR330 car-mounted walkie-talkie of Japan Telitong Company occupy most of the police walkie-talkies. T2000 series vehicle platform and T800 relay platform of New Zealand Daji Company; The KG5 10-40A relay station introduced by Japanese cooperation company in recent years is also widely used in police systems. Domestic police walkie-talkies represented by Shenzhen Haoyitong Company have made great progress in recent years and become an indispensable domestic brand in police walkie-talkies. Their products have been recognized by domestic public security users and exported abroad. There are two main reasons for domestic police walkie-talkies. One is TC338, TC388 and TC 668 S produced by Haoyitong; The other is PT388, PT3588 and PT3288 produced by Shenzhen Kelixun Company. At present, domestic police walkie-talkies are divided into two categories: those that conform to MPT 1327 signaling and those that do not. American motorcycle roller company produces PTX600, PTX700 and MTX960 (the first Chinese interface police walkie-talkie) MPT trunking hand-held walkie-talkies: MTS2000, LTS2000, PTS700, PTS760, MHX638 and MTX838. There are also MCX600E and MPT cluster vehicle-mounted machines. MCS2000, LCS2000, MAX638, MAXTRAC888, MAXTRACLS cluster vehicle-mounted machines.