Main electrical parameters

(1) the surface characteristic impedance of the coaxial cable of the coaxial cable of the characteristic impedance to an average of 50 + 2 Ω, along the impedance of the coaxial cable of the single periodic changes as sine wave, center average + / - 3 Ω, its length is less than 2 meters.

(2) coaxial cable attenuation generally refers to the attenuation value of 500 meters long cable segment. When measured with 10MHz sine wave, its value does not exceed 8.5db(17db/ km); When measured with a 5MHz sine wave, it is no more than 6.0db(12db/ km).

(3) the minimum transmission speed required for coaxial cable is 0.77c (C is the speed of light).

(4) the center of the coaxial cable of the dc circuit resistance cable conductor resistance and the resistance of the shield of the sum is no more than 10 milliohm/m (measured in 20 ℃).

Physical parameters

Coaxial cable is composed of a shield layer consisting of a central conductor, an insulating material layer, a mesh fabric, and an external insulating material layer.

Coaxial cables are flexible enough to support a bending radius of 254mm(10in). The central conductor is a solid copper wire with a diameter of 2.17mm plus or minus 0.013mm. The insulation material must meet the electrical parameters of coaxial cable. The shielding layer is composed of metal bands or thin plates that meet the transmission impedance and ECM specification. The inner diameter of the shielding layer is 6.15mm and the outer diameter is 8.28mm. The outer isolation material is usually PVC or similar material.

The main parameters of the test

(1) opening of conductor or shield layer.

(2) short circuit between conductor and shielding layer.

(3) conductor grounding.

(4) short circuit between the shielding joints.