Cable according to the different inner conductor, there are two main types, one is pure copper material, one is copper clad aluminum material. Copper clad aluminum in English is: Copper Clad Aluminum, copper clad aluminum conductor is also often referred to as: CCA conductor. Copper Clad Aluminum composite wire first introduced by Germany in the 1930s, then in the United Kingdom, the United States, France and other countries to promote, is widely used in various fields. As early as 1968, the CATV cable in the United States started trial copper clad aluminum wire, which consumed 30,000 tons / year. Now the Americas have replaced copper cables with copper-clad aluminum (steel) cables. In recent years, China's copper clad aluminum CATV cable has also begun to be widely used. Countries in 2000 set an industry standard - SJ / T11223-2000, to promote the use of copper clad aluminum cables. At present, Shanghai, Guangzhou, Zhejiang, Liaoning and other places of cable television has generally adopted the copper clad aluminum cable, the reaction is good. Copper clad aluminum is in the aluminum or aluminum / steel alloy core surface concentric clad copper layer, drawn by the copper layer thickness of 0.55mm or more. Because the high-frequency signal is transmitted on the conductor with the skin effect, the cable signal is transmitted on the surface of the copper layer over 0.008mm. The inner conductor of the copper clad aluminum can fully meet the signal transmission requirements. The transmission characteristic of the signal is the same as that of the copper with the same diameter Body consistent. Copper clad aluminum and copper can be compared in the following three areas: Mechanical characteristics: Pure copper conductor strength, elongation than copper clad aluminum conductor, that is pure copper mechanical properties better than copper clad aluminum. From the cable design point of view, pure copper conductor copper clad aluminum conductor mechanical strength advantages, in the actual application process is not necessarily required. Copper clad aluminum conductor is much lighter than pure copper, so the overall weight of copper clad aluminum cable lighter than copper conductor cable, which will give the cable transport and cable construction erection convenience. In addition, copper clad aluminum softer than pure copper, copper clad aluminum conductor cable production in terms of softness than pure copper cable a little better. Electrical performance: Because of the poor conductivity of copper than copper, making the copper clad aluminum conductor DC resistance than pure copper conductor, which has no effect on the main 2014 exam sprint comprehensive review guide Beijing area test Guangdong area test questions in Jiangsu Province to see whether the cable will be Powering the amplifier, such as powering the amplifier, will result in additional power consumption and voltage reduction if used to power the copper clad aluminum conductor. At frequencies above 5 MHz, the AC resistance decay at this time is not significantly different between these two different conductors. Of course, this is mainly due to the skin effect of high-frequency current. The higher the frequency, the closer the current flows to the conductor surface. In fact, pure copper material is applied to the surface of the copper clad aluminum conductor. When the frequency is high, Inside the copper material has flowed. At 5 MHz, the current flows in a thickness of about 0.025 mm at the near surface, whereas the copper layer thickness of the copper-clad aluminum conductor is about twice as thick as this thickness. For coaxial cable, because the transmission signal is above 5MHz, copper clad aluminum conductor and copper conductor transmission effect is the same. At the actual test cable attenuation can prove this. Copper Clad Aluminum than pure copper conductor, easy to straighten in the production process, so to some extent can be said that the use of copper clad aluminum cable with copper conductor return loss index better. Economy: Copper-clad aluminum conductor is sold by weight, pure copper conductor is also sold by weight, the price of copper clad aluminum conductor than the same weight of pure copper conductor more expensive. However, the same weight of copper clad aluminum conductors longer than the length of copper, while the cable is calculated by length. The same weight of copper clad aluminum wire is 2.5 times the length of copper, the price is only a few hundred dollars per ton. Put it down, copper clad aluminum is very advantageous. As the copper clad aluminum cable is relatively light, the cable transportation costs, installation and installation costs will be reduced, will bring some convenience to the construction. Easy to maintain: The use of copper clad aluminum can reduce network failures, to avoid the network staff in the maintenance of "winter shear core, summer shearing" (aluminum tape or aluminum tube products). Due to the large difference between the thermal expansion coefficient of the copper inner conductor and the outer conductor of aluminum in the cable, in the hot summer season, the aluminum outer conductor expands more and the inner copper conductor retracts relatively and can not fully contact with the elastic contact piece in the F head seat. In winter, the aluminum outer conductor contracts more, causing the shield to come off. When the coaxial cable copper clad aluminum conductor, it and the aluminum conductor thermal expansion coefficient difference is small, the temperature changes, the cable core pulling greatly reduced the fault and improve the quality of network transmission. Overall, the overall performance of copper clad aluminum conductor copper conductors better than it will save users costs. The industry believes that the wire and cable industry using copper clad aluminum is also a good way to ease the pressure on the current business. The bimetallic wire drawn from the outer layer of the aluminum wire has the advantages of small specific gravity and good transmission performance and is particularly suitable for the inner conductor of a radio frequency coaxial cable. Compared with the pure copper wire, the density is About 40% of copper. The transmission characteristics better than pure copper wire, is the best RF coaxial cable branch line conductor. Bentonite Inorganic Clay,Water Borne Emulsion Paints,Water Borne Bentonite Clay,Bentonite Performance Minerals CHANGXING GUANGDA NEW MATERIALS CO.,LTD. , https://www.gdbentonite.com