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Pacific Security Network News ]
As a wireless communication tool, the walkie-talkie has its own characteristics compared with the mobile phone. In one-to-one and one-to-many directional special communication, it has the characteristics of establishing rapid communication, especially the one-to-many feature that ordinary mobile phones cannot. Comparable. In the past, walkie-talkies were widely used in government departments such as military, public security, security, ambulance, and public utilities. With the development of the economy and the increasing demand for mobile communications, walkie-talkies began to be applied to taxi dispatch, security, property management, construction sites, and hotels. Waiting for civilian occasions. Through this shopping guide, you can learn about the precautions when purchasing a walkie-talkie/radio device.
Communication distance
The general communication distance within 2-3 km can be regarded as short-distance communication. For individual users, you can purchase a civilian walkie-talkie. For the unit user, you can purchase a small power walkie-talkie by applying. If you want to ensure the communication effect, you can choose a professional walkie-talkie. Need to communicate within the city, communication distance is within 3-10 km, you can consider buying a professional walkie-talkie. If it is farther away, it is better to use the base station to communicate with the handheld walkie-talkie, or the radio station and the radio station communication base station. We can use the car radio with a relatively large output power. If you need a longer distance or better communication quality, you can consider using a cluster walkie-talkie if you don't have a network. Because the radio intercom is supported by the radio network, the communication distance is relatively long, and the effective distance reaches 1530KM. This type of walkie-talkie requires network support, so once it is disconnected from the network, just like the mobile phone is off the net, even if the two sides of the call face to face, it cannot be called.
Transmit power
For radios, the amount of transmit power is critical. The same wireless device, the product with high transmission power and the price of the product with small transmission power are not small. Not only that, but the difference in transmission power also directly affects the data transmission stability of the wireless network. Therefore, paying attention to the transmission power of the selected device is also an important part in the process of selecting a wireless device. At present, the transmission power of the wireless network device is directly marked with the power value in the device specification, and some is the transmission power size by the distance of the transmission distance. Under normal circumstances, the wireless device's transmission power should be between 25mW and 50mW, or the transmission distance is between 50m and 200m. If you can't find the transmit power value on the device nameplate or in the manual, don't buy it at will-
Professional walkie talkie
Professional walkie-talkie refers to walkie-talkies with a transmit power of 4-5W and a frequency range of 136-174MHz or 400-480MHz. These walkie-talkies are usually between 3 and 8 kilometers away (depending on the specific environment). . It's relatively simple to operate because most professional walkie-talkies don't have a numeric keypad. There are only two knobs to control the channel count and power and volume switches. The shortcoming of the professional walkie-talkie is that it is relatively large and relatively heavy, but it is more prominent in preventing water ingress, anti-vibration, anti-drop and anti-aging, and the performance of the walkie-talkie is much more stable. The price of professional walkie-talkies is relatively high (500-2500 yuan), which is generally applied in construction engineering, property management, and factory workshops.
Commercial walkie-talkie
Commercial walkie-talkie refers to a walkie-talkie with a transmit power of 0.5-4W and a frequency range of 400-480MHz. The talker distance is between 800m and 8km (depending on the size of the intercom's transmit power and the specific environment) . The commercial walkie-talkie is light and beautiful in appearance. The walkie-talkie is attached to the waist through the belt clip of the walkie-talkie, and the hands can be liberated to improve work efficiency. The price of commercial walkie-talkies is relatively high compared to professional walkie-talkies, and is generally used in shopping malls, supermarkets, retail, factories, and manufacturing.
Civil walkie-talkie
The civilian walkie-talkie refers to a walkie-talkie with a transmit power of 0.5W and no more than 1W and a frequency range of 409MHz. The civilian walkie-talkie generally has a short talk distance (3 km of open space) is a wireless communication device that the state can approve without a license. The civilian walkie-talkie is small in size and diverse in color, and the price is generally as low as 300,600 yuan, which is more suitable for personal travel, tourism, and restaurant use.
Amateur walkie talkie
A walkie-talkie is a radio walkie-talkie designed and produced to meet the needs of amateur radio enthusiasts. This kind of walkie-talkie can also be called "playing machine". For this amateur personal radio service, each country has opened up a dedicated frequency band for use by amateur radio enthusiasts. China's frequency bands are 144-146MHZ and 430-440MHZ, which are also commonly used in countries around the world. Amateurs only need to buy their favorite models, apply for local radio network access licenses, you can talk to other people. This frequency band is also generally used in countries around the world.
Explosion-proof walkie-talkie
There are not many brands of explosion-proof walkie-talkies in many wireless walkie-talkie brands. Currently there are only three brands of (MOTOROLA) Motorola, (VertexStandard), and (HYT)-Huitton. Motorola's explosion-proof walkie-talkie has fought against China's eight-layer explosion-proof walkie-talkie market with its superior performance. Explosion-proof walkie-talkie refers to walkie-talkies that can work in flammable and explosive environments. For example: coal mine, liquefied gas filling company, oil depot, oil field, petroleum, gas station chemical, petrochemical, coal mine, mine, natural gas, chemical plant, flour Processing plants, linen processing plants, coal processing plants, fire protection.
Railway intercom
The railway intercom is undoubtedly a special intercom equipment tailored to the actual working needs of the railway and railway departments. The transmit power is 4-5W and the frequency range is selectable within 440470MHz. The front side of the railway intercom has generally 2-4 function buttons, which are used for the selection of different environment communication in the plain and ramp, and the switching between the station and the locomotive. Due to the large noise of the train, the audio output of the walkie-talkie is very high, and the walkie-talkie is compressed by voice, which makes the call sound more clear and crisp.
Police walkie talkie
The police intercom is a special equipment for the public security system. The frequency range of the police intercom is 350-370MHz and 370-390MHz. No one may steal or steal the frequency resources of the special walkie-talkie of the public security system in any way. The functions of the police intercom are many, and the general appearance is mostly in the keyboard type. When purchasing a walkie-talkie, we should pay attention to the range of the transmission frequency of the walkie-talkie (400-420MHz, 450-470MHz) to avoid unnecessary trouble.
Car radio
The working voltage of the car radio is 12.5V, and the current car voltage is divided into 12V and 24V. When the car radio is to work on a car with a voltage of 24V, it is necessary to install a transformer between the car and the intercom. The transmission power of the car radio is 25-50W, the power is large, and the signal is transmitted far. The car radio can only be fixed in one place, and it is not as convenient to use as a walkie-talkie. Car radios are generally used in the fleet.
Transfer station base station
The specific function of the relay station and the base station is to transmit the received wireless signal through internal processing and transmit it at a greater power, thus achieving the expansion of the wireless communication distance. It is simple to say that some transfer stations and base stations are a wireless communication signal generator. As your company's business grows and grows, the need for two-way communication is also expanding. Use the repeater and base station to enhance your communication capabilities. And through our powerful dispatching and forwarding stations, we can promote the coordination of system resources and broaden the communication range of walkie-talkies.
Ductile Cable Manhole Cover
Ductile cable manhole covers are a type of access cover that is specifically designed to provide a secure and durable solution for underground utility access points. These covers are made from ductile iron, which is a type of cast iron that has been treated with magnesium to enhance its strength and ductility.
Ductile iron is known for its excellent mechanical properties, including high tensile strength, impact resistance, and flexibility. These properties make it an ideal material for manufacturing manhole covers that can withstand heavy loads and harsh environmental conditions. Ductile cable manhole covers are specifically designed to accommodate cables and wires that pass through underground utility access points.
One of the key features of ductile cable manhole covers is their high load-bearing capacity. These covers are able to withstand heavy loads, such as vehicles driving over them, without experiencing any deformation or damage. This is crucial for ensuring the safety of pedestrians and vehicles, as well as preventing any disruption to the underground utilities.
In addition to their load-bearing capacity, ductile cable manhole covers also offer excellent resistance to corrosion and wear. The ductile iron material is highly resistant to rust and can withstand exposure to moisture, chemicals, and other corrosive agents. This ensures that the covers remain in good condition for an extended period of time, even in harsh environments.
Furthermore, ductile cable manhole covers are designed to be easy to install and maintain. They typically feature a hinged design, allowing for easy access to the underground utilities. This makes it convenient for utility workers to carry out inspections, repairs, and maintenance tasks without the need for specialized tools or equipment.
Another important aspect of ductile cable manhole covers is their anti-theft features. These covers are often equipped with locking mechanisms or tamper-proof features to prevent unauthorized access or theft. This is especially important in areas where the underground utilities are valuable or sensitive, such as power distribution networks or telecommunication infrastructure.
Moreover, ductile cable manhole covers are designed to be aesthetically pleasing. They often feature a smooth and sleek surface finish, which not only enhances their visual appeal but also prevents debris or water from accumulating on the cover. This helps to maintain a clean and tidy appearance in urban areas.
In conclusion, ductile cable manhole covers are a reliable and durable solution for underground utility access points. Their high load-bearing capacity, corrosion resistance, and anti-theft features make them an ideal choice for ensuring the safety and functionality of underground utilities. With their easy installation and maintenance, as well as their aesthetically pleasing design, ductile cable manhole covers are a practical and efficient solution for various infrastructure projects.
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