Weak current the inner conductor of the cable material basically has two kinds: pure copper and copper clad aluminum materials. Copper clad aluminum English is: CladAluminum cooper, so the Copper clad aluminum conductor also often referred to as: CCA conductor. Copper clad aluminum composite wire first launched in 30 s of the last century by the German, then in Britain, the United States, France and other countries to promote, widely used in various fields.

　　In 1968, the United States, CATV cable started trial copper clad aluminum wire, consumption quantity of 30000 tons a year, according to the understanding of American states have now with copper clad aluminum (steel) cable instead of the pure copper cable. In recent years, China's copper clad aluminum CATV cable also began to be a large number of use and in 2000 formulated the industry standard SJ/T11223-2000, vigorously to promote the use of copper clad aluminum cables. At present, Shanghai, guangzhou, zhejiang, liaoning and other places of cable television has been widely used copper clad aluminum cable, responded well. Copper clad aluminum in the aluminum or aluminum/steel alloy copper core material surface with pericardium, by drawing, copper layer thickness above 0.55 mm. Due to the high frequency signal transmission on the conductor with the characteristics of the skin effect, cable TV signal in the 0.008 mm above the surface of the copper layer, copper clad aluminum inner conductor can completely meet the requirements of signal transmission, the transmission properties of the signal is consistent with the same diameter copper body. Copper clad aluminum and pure copper can be compared the following four aspects:

　　Because poor than copper, the conductivity of aluminium made of copper clad aluminum conductor dc resistance than pure copper conductor, this presence of influence mainly to see if the cable is with power supply, such as supplies power to the amplifier, if be used to power supply, copper clad aluminum conductor will lead to additional power consumption, voltage lower more. When more than 5 MHZ frequency, at this time of ac resistance attenuation under the two different conductor has no significant difference between the two.

　　Of course, this is mainly because the skin effect of high frequency current, the higher the frequency, the flow of electric current is more close to the conductor surface, on the surface of copper clad aluminum conductor in pure copper material, at some point when the frequency is high, the current to flow in copper plating quality inside. In the case of 5 MHZ, the current flow in the 0.025 mm thickness of near surface, the thickness of copper and copper clad aluminum conductor thickness is about twice as many than that. For coaxial cable, because the signal transmission is above 5 MHZ, so the copper clad aluminum conductor and pure copper conductor transmission effect is the same. In the actual test the attenuation of the cable to prove it.

Copper clad aluminum conductor is pure copper, in the process of production easier for straightening processing, thus to some extent, can say with copper clad aluminum cable than in pure copper conductor cable good return loss index.

　　Pure copper conductor strength, elongation, larger than the copper clad aluminum conductor is pure copper in mechanical performance is better than copper clad aluminum. From the perspective of cable design, pure copper conductors than copper clad aluminum conductor mechanical strength good advantages, in the process of practical application does not necessarily need to. Copper clad aluminum conductor, much lighter than pure copper, so copper clad aluminum cable on the overall weight is lighter than pure copper conductor cable, this will give the transport of the cable and cable erection construction convenient. Other than pure copper soft copper clad aluminum, copper clad aluminum conductor cable production in terms of flexible cable is better than pure copper.

　　Use copper clad aluminum can reduce network failure, avoid network personnel in the maintenance of "cut core in winter, summer cut skin" (aluminum or aluminum tube with longitudinal bag products). Due to the copper aluminum inner conductor and outer conductor of the cable thermal expansion coefficient is large, in the hot summer, aluminum outer conductor for large, copper inner conductor relative retraction, not fully come into contact with the elastic contact within F head block; Outside in the cold winter, aluminum conductor shrinkage is larger, the shield falls off. When in the coaxial cable with copper clad aluminum conductor, it differ with aluminum outer conductor thermal expansion coefficient is small, the temperature changes, greatly reduced the cable core pulling fault, improve the quality of the network transmission.

　　Copper clad aluminum conductor are sold by weight, of pure copper conductor is sold by weight, the price of copper clad aluminum conductor is more expensive than the same weight of pure copper conductor. But the same weight of copper clad aluminum conductor length is much longer than pure copper, and is calculated on the length of the cable. Same weight copper clad aluminum wire is 2.5 times that of the copper wire length, the price is just more than a few hundred yuan per ton. Comprehensive, copper clad aluminum would be advantage. Because of the copper clad aluminum cable comparatively light, and the transportation cost of the cable, erectness cost will be reduced, can bring certain convenience to construction.

　　To sum up, copper clad aluminum conductor overall performance is better than pure copper conductor, it can be easy to maintain and can save the cost of the user. Have professionals said: wire and cable industry with copper clad aluminum wire is also a way to reduce the enterprise pressure, a layer of menstruation drawn aluminum outer package of double wire, because with a small specific gravity, transmission performance is good wait for an advantage, especially suitable for the inner conductor of the coaxial cable of the radio frequency