Multi core coaxial cable video cable SYV-75-5-41_安徽中盛电气集团有限公司官方网站

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产品名称：Multi core coaxial cable video cable SYV-75-5-41
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添加时间：2025-03-25 15:53:39
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介绍：

SYV-75-5-41，SYV是实芯聚乙烯绝缘聚氯乙烯护套射频同轴电缆，其中75的意思是导体的电阻为75欧姆，5是指电缆的绝缘zui大外径为5mm(标准要求4.8±0.2mm).，41为产品代号。(引用标准GB/T14864-1993 实芯聚乙烯绝缘射频电缆) 视频线又根据材质的不同分为SYV和SYWV两种

SYV-75-5-41, SYV is a solid core polyethylene insulated PVC sheathed RF coaxial cable, where 75 means the resistance of the conductor is 75 ohms, and 5 refers to the insulation of the cable with a maximum outer diameter of 5mm (standard requirement 4.8 ± 0.2mm), 41 is the product code. (Reference standard GB/T14864-1993 Solid core polyethylene insulated RF cable) Video cables are divided into SYV and SYWV according to different materials

SYV

syv 指实心聚乙烯绝缘的同轴电缆，国标代号是射频电缆——又叫“视频电缆”

Syv refers to coaxial cables with solid polyethylene insulation, and the national standard code is RF cable - also known as "video cable"

一般所指的视频线为电视有线，也可用作安防领域的监控摄像头用线。

The video cable generally refers to television cable, which can also be used as a cable for surveillance cameras in the field of security.

下面是一般视频线的参数

Here are the parameters of a typical video cable

75代表抗阻性,后面的3和5代表它的绝缘外径(3mm/5mm)

75 represents resistance, followed by 3 and 5 representing its insulation outer diameter (3mm/5mm)

SYV中S---同轴射频电缆,Y---聚乙烯,V---聚氯乙烯.

SYV S-coaxial RF cable, Y-polyethylene, V-polyvinyl chloride

SYV75-3传输在300米之内效果好.

SYV75-3 has good transmission performance within 300 meters

SYV75-5传输在800米内效果更好.

The transmission effect of SYV75-5 is better within 800 meters

75-3 传输距离 100米

75-3 transmission distance of 100 meters

75-5 传输距离 300米

75-5 transmission distance of 300 meters

75-7 传输距离 500--800米

75-7 transmission distance 500-800 meters

75-9 传输距离 1000---1500米

75-9 transmission distance 1000-1500 meters

75-12 传输距离 2000----3500米

75-12 transmission distance 2000-3500 meters

75代表电阻, -3代表线径

75 represents resistance, -3 represents wire diameter

SYWV

sywv 指聚乙烯物理发泡绝缘的同轴电缆，国标代号是射频电缆

Sywv refers to coaxial cables with polyethylene physical foam insulation, and the national standard code is RF cable

SYV与SYWV的相同点

Similarities between SYV and SYWV

1. 特性阻抗一样——75欧姆；

1. Same characteristic impedance -75 ohms;

2. 外层护套，屏蔽层结构，绝缘层外径，编数选择，材质选择，屏蔽层数等基本相同。

2. The outer sheath, shielding layer structure, insulation layer outer diameter, number selection, material selection, shielding layers, etc. are basically the same.

SYV与SYWV的不同点

Differences between SYV and SYWV

1. 绝缘层物理特性不同：syv是100%聚乙烯填充，介电常数ε=2.2-2.4左右；而sywv也是聚乙烯填充，但充有80%的氮气气泡，聚乙烯只含有20%，宏观平均介电常数ε=1.4左右；ε=εǎ?jε",其中，ε"为损耗项，空气的ε"基本为“0”，这一工艺成就于90年代，它有效降低了同轴电缆的介电损耗；

1. The physical properties of the insulation layer are different: Syv is filled with 100% polyethylene, with a dielectric constant of approximately 2.2-2.4; And Sywv is also filled with polyethylene, but filled with 80% nitrogen gas bubbles, polyethylene only contains 20%, and the macroscopic average dielectric constant ε is about 1.4; ε=εǎ? J ε ", where ε" is the loss term, and the ε "of air is basically" 0 ". This process was achieved in the 1990s and effectively reduced the dielectric loss of coaxial cables;

2. 芯线直径不同：以75-5为例，由于-5电缆结构标准规定，绝缘层外径（即屏蔽层内径）是4.8mm,不能改变，为了保证75欧姆的特性阻抗，而特性阻抗只与内外导体直径比和绝缘层的介电常数ε大小有关，ε大芯线细，ε小芯线粗，芯线直径：syv是0.78-0.8mm, sywv是1.0mm; 芯线结构形式都可以是单股或多股；这一区别，导致了芯线电阻的不同。如实测天成、爱普syv75-5电缆，1000米芯线直流电阻39Ω，典型sywv75-5电缆, 1000米芯线直流电阻19-20Ω;

2. Different core wire diameters: Taking 75-5 as an example, due to the -5 cable structure standard, the outer diameter of the insulation layer (i.e. the inner diameter of the shielding layer) is 4.8mm and cannot be changed. In order to ensure a characteristic impedance of 75 ohms, which is only related to the ratio of the inner and outer conductor diameters and the dielectric constant ε of the insulation layer, the larger ε core wire is thinner, the smaller ε core wire is thicker, and the core wire diameter: syv is 0.78-0.8mm, Sywv is 1.0mm; The core wire structure can be single or multiple strands; This difference leads to different core wire resistances. True testing of Tiancheng and Aipu SyV75-5 cables shows a DC resistance of 39 Ω for a 1000 meter core wire, while a typical SyWV75-5 cable has a DC resistance of 19-20 Ω for a 1000 meter core wire;

3. 上述两项根本区别，决定了两种电缆的传输特性——传输衰减不同，syv电缆是早期的同轴电缆，在几十上百年时间里一直用它传输，包括传输射频信号；但后来当sywv出现后，射频以上波段就很少应用syv了。因为高频衰减差别太大了；慢慢的syv就基本上主要用在监控视频传输上了，也就把这种射频电缆的 “元老”，改称为“视频电缆”了。但这不等于说：syv“视频电缆”的视频传输特性比sywv好，实际刚好相反，sywv的视频传输特性也优于syv电缆。这方面的误解很普遍，且我国南方比北方的误解要严重，认为传输视频信号， “须用视频电缆”。实测1000米电缆视频传输性能，sywv75-5/64编电缆：0.5m—5.15db,6m—19.12db;国标syv75-5/96编电缆：0.5m—6.43db,6m—21.76db（相同编网结构电缆衰减比发泡电缆大3db——即大1.4倍以上），有一个还挺有名的厂家产品，syv75-5/128编电缆，6m—25.22db，衰减比发泡电缆大6db以上——即大2倍多）；

3. The two fundamental differences mentioned above determine the transmission characteristics of the two types of cables - transmission attenuation is different. Syv cable is an early coaxial cable that has been used for transmission, including RF signals, for decades or even centuries; But later on, when SywV appeared, Syv was rarely used in the RF and above bands. Because the difference in high-frequency attenuation is too large; Gradually, Syv was mainly used for monitoring video transmission, and the "veterans" of this RF cable were renamed as "video cables". But this does not mean that the video transmission characteristics of syv "video cable" are better than those of sywv. In fact, the opposite is true, and the video transmission characteristics of sywv are also better than those of syv cable. Misunderstandings in this regard are common, and more severe in southern China than in northern China, where it is believed that transmitting video signals requires the use of video cables. Tested video transmission performance of 1000 meter cable, sywv75-5/64 cable: 0.5m-5.15db, 6m -19.12db; National standard syv75-5/96 braided cable: 0.5m-6.43db, 6m -21.76db (the attenuation of cables with the same braided network structure is 3db greater than that of foam cables - that is, more than 1.4 times greater). There is a well-known manufacturer's product, syv75-5/128 braided cable, 6m -25.22db, with attenuation more than 6dB greater than that of foam cables - that is, more than 2 times greater);

4. 关于高编电缆，一般指96-128编以上的电缆。高编电缆明显特点是：屏蔽层的直流电阻小，200khz以下的低频衰减少，对抑制低频干扰有利，实测表明，200khz-6mhz频率，由于“趋肤效应”，128编和64编衰减一样。（高频电流只在芯线外表面，屏蔽层内表面层流动）。从频率失真（高低频衰减差异）看，高编电缆反而严重。频率失真直接影响就是视频信号的各种频率成分的正常比例失真，直接影响到图像失真；

4. Regarding high-grade cables, they generally refer to cables with a rating of 96-128 or higher. The obvious characteristics of high-grade cables are: the DC resistance of the shielding layer is small, and the low-frequency attenuation below 200kHz is reduced, which is beneficial for suppressing low-frequency interference. Tests have shown that at frequencies of 200kHz-6mHz, due to the "skin effect", the attenuation of 128 and 64 series cables is the same. High frequency current only flows on the outer surface of the core wire and on the inner surface layer of the shielding layer. From the perspective of frequency distortion (difference in attenuation between high and low frequencies), high-density cables are actually more severe. The direct impact of frequency distortion is the distortion of the normal proportion of various frequency components in the video signal, which directly affects image distortion;

5. 铜包钢芯线：这是sywv电缆的一种，用于有线电视46mhz以上的射频传输，由于“趋肤效应”，电流只在钢丝外面的铜皮里流动，衰减特性和纯铜芯线一样，可抗拉强度却远高于铜线；但这种电缆用于视频传输不行，0-200khz低频衰减太大；

5. Copper clad steel core wire: This is a type of sywv cable used for RF transmission above 46MHz in cable television. Due to the "skin effect", current only flows in the copper skin outside the steel wire, with attenuation characteristics similar to pure copper core wire, but with much higher tensile strength than copper wire; But this type of cable is not suitable for video transmission, as the low-frequency attenuation from 0-200kHz is too large;

6. sywv电缆视频射频传输特性都优异，而且由于有巨大的有线电视市场的支撑，产量很大，价格也有优势；

Sywv cable has excellent RF transmission characteristics for video, and due to the support of the huge cable TV market, it has a large production volume and price advantages;

7. 关于视频线和射频线的问题，既有误解，也有误导，论坛里的激烈争论就是例证。但大家都应该尊重实践：用1000米75-5电缆，传输一个彩色摄像机的信号，末端送给监视器，监视器环路输出给示波器，测量“色同步头” 的幅度，原信号是0.3v,进行比较，电缆越长，两种差别越大，越容易比较。

Regarding the issue of video cables and RF cables, there are both misunderstandings and misleading, as evidenced by the intense debate on the forum. But everyone should respect practice: using a 1000 meter 75-5 cable to transmit a signal from a color camera, the end is sent to a monitor, and the monitor loop outputs to an oscilloscope to measure the amplitude of the "color sync head". The original signal is 0.3v, and for comparison, the longer the cable, the greater the difference between the two, making it easier to compare.