SYV75-3, 5, 7, 9 ..., 75 ohm, polyethylene insulated solid coaxial cable. In recent years, some people call it "video cable", SYWV75-3, 5, 7, 9 ... 75 ohm, physical foamed polyethylene insulated coaxial cable. Some people call it "RF cable", It can be connected to RF connectors.

    The basic performance of coaxial cable:

    (1) SYV physical structure is 100% polyethylene insulation; SYWV is a physical foamed polyethylene insulated cable with a foaming rate of 70-80%;

    (2) Because of the dielectric loss, the SYV solid cable attenuation obviously exceeds the SYWV physical foaming cable; in the common engineering project cable of RF connector assembly, the current physical foaming cable is still the cable with the lowest transmission price at the most suitable price. The video, RF, and microwave bands are all test data listed by such vendors.

    (3) Coaxial cable of RF coaxial connector can be used in DC, RF, and microwave bands. According to "RF" / "Video" to distinguish cables, not only is it deficient, but also very easy to cause misunderstanding: it seems that video transmission can only select solid cables (select large attenuation, high price); from the perspective of engineering projects It is better to use the "solid core" and "foaming" cables to distinguish the categories;

    (4) The differences characteristics between high-profile (128) and low-grade (64) cable : According to experimental research in the laboratory, it is concluded that the "low resistance" of the high-profile cable shield plays a primary role in the frequency band of 200 kHz, so the low frequency The transmission attenuation is lower than the low braided cable. However, in the video, RF, and microwave bands above 200-300KHz, because the "high-frequency skin effect" plays a primary role, the high-knit cable has lost the "low-resistance" superiority, so the high-frequency attenuation of the two cable cores is the same.