Cable TV line specifications, what is cable TV

75-5 is the entrance line, and 75-7 is the line used between outdoor units.

75-9 is the main line of the system.

75-12 is the backbone of the system.

P4 indicates that the outer conductor of the wire rod is double-layered, that is, two layers of metal mesh and two layers of tin foil. Those who do not mark this item are single-layered.

Most people will say this - read "bar" -5 coaxial -7 coaxial The difference is that -5 wire is the thinnest Because the attenuation signal is relatively large, it is used in the shortest place Generally it is in the corridor or the user's home -12 is the thickest Used in long-distance places Used between buildings -7 or more lines are generally rarely seen in residents When pulling the wire and bending it is very laborious P4 4 shielded wire P2 is a 2 shielded wire There are also single-shielded wires The kind produced a long time ago Many kinds But now P4 shields are the most When the signal is transmitted, it is least affected by the outside world, and the less the shielding layer, the worse the shielding effect.

The home use is generally 75-5 (rg6), the building is used 75-7 (rg11), and some satellite enthusiasts use 75-7. The model number you wrote SYWV75-12 is incorrect, it should be SYWY75-12This model is used on the trunk line.

The main difference between the several cables is that the attenuation is different for each model. The TV station should be calculated on the trunk line, how long, add an amplifier. In addition, when entering the house, it is necessary to ensure that the number of signals reaches is mostly the meaning of four shields.

The true writing of the national standard is SYWV-75-5, the four shields are SYWV-75-5S, and the self-supporting cable is SYWV-75-5Z

Cable TV is:

Cable TV is a system that uses coaxial cable as a medium to directly transmit TV and FM radio programs to user TV. As with radio broadcasting, many channels can be transmitted over a single cable using different frequencies without interfering with each other. A TV tuner, VCR or radio can select a channel from a mixed signal.

Cable television systems generally pay a monthly fee according to the number and content of the program. Digital cable TV also allows users to freely choose the channels they want to watch through some devices, such as set-top boxes.

The advantages of cable TV are:

2. More personalized programs: more than 100 professional TV programs are tailored for you.

3. More convenient viewing: The unique electronic program guide provides you with an electronic version of the TV program report.

4. Clearer image: The clarity of digital TV picture is comparable to that of digital TV. The accompaniment sound is more realistic.

5. More abundant channels: The digitization of cable TV has fully released the spectrum resources, and analog TV can only transmit about 50 sets. Cable digital TV can transmit more than hundreds of TV programs. <>

1. Trunk cable: its insulation outer diameter is generally 9mm or more of thick cable, which requires small loss of side branches and low requirements for flexibility.

2. Branch cable: its insulation outer diameter is generally 7mm or more of the medium and thick cable, which requires less loss of the beam and mainly requires good flexibility.

3. User wire and cable: Its insulation outer diameter is generally 5mm, and the loss and transportation requirements are not important, but the main requirement is good flexibility.

There is no difference, it is also a coaxial cable, but it is *** bad.

Cable TV transmits analog signals, which can be directly received and watched by television sets.

Cable digital TV transmits digital signals, and the TV cannot receive it directly, and needs to be watched through a set-top box or an all-in-one TV with a set-top box function.

Cable digital TV can achieve theoretical lossless picture quality, that is, what the TV picture in the cable room looks like, what does it look like to the user's home, but the analog signal of traditional cable TV cannot be realized.

There is also the billing process: After arrears, cable TV generally manually turns off the opening signal.

On the other hand, cable digital TV turns off the authorization of the IC card in the set-top box, rather than turning off the signal.

For users, these are basically the differences, and if you want to go into more depth, you can write a book.

The landlord's problem is too big to prepare.

The line used for both signals is the same... It's like saying that your water pipe, the water company can give you **tap water, or **Pepsi Cola...

Cable TV is an analog signal, which is generally transmitted by voltage, and TV restores images and sounds by analyzing the meaning of voltage.

Digital TV is an electrical pulse signal, and the TV analyzes the signal image by forming a 1,0 signal through the electrical pulse, so that it is less affected by the outside world and the image quality is better.

Digital TV is divided into wireless satellite digital TV and cable terrestrial digital TV. Wireless digital TV generally refers to satellite digital TV, which is the "pot cover" we usually see, and the set-top box used at home is terrestrial cable digital TV.

Absolutely! That's the installer who wants to make some extra money.。。。

The type is Hu L insulated outer diameter Sun erected.

mm) Cable outer diameter.

mm) insulation resistance.

mω.km) characteristic impedance.

Attenuation constant to do limb return loss dB 100m vhf dhf sywv-75-5

max) 5000 75±3 sywv-75-7max) 5000 75± sywv-75-9 5000 75± sywv-75-12 5000 75±2

TV connection line front, TV production line, CCTV line, section backup TV signal line Hui Ranpei.