The video cable is an important part of the video system in the TV broadcast control room. The quality of the production directly affects the technical indicators of the video channel. The poor quality video cable may cause the signal to be reversed, the signal is seriously attenuated, the equipment is out of sync, and even the signal is interrupted. In the video system, except for a small number of control signal lines, the program signal, synchronization signal, keying signal and other signals are all transmitted by the video line, so the problem of the video line is one of the common failure sources of equipment and system failures.
In the process of making a video cable, first of all, the correct video cable and connector must be selected. When choosing a cable, you should first pay attention to its nominal impedance. There is a cable with a characteristic impedance of 50Ω that is very close to the video cable in appearance and must not be confused. In addition, attention should be paid to whether the cable or connector is oxidized. The cable or connector should be scrapped or treated as appropriate. Otherwise, the oxide will cause solder joints to be soldered, resulting in serious signal attenuation or even interruption. Some manufacturers cut corners in the market, and the video cables produced do not meet the specifications, such as: sparse shielding layer, non-standard wire diameter, etc., pay attention when purchasing. In the selection of the connector, try to meet the needs of the equipment, avoid using the converter, and the specifications should be used according to the specifications of the cable.
Secondly, good crimping quality or welding quality must be guaranteed. The use of crimping joints has strict requirements on the wire diameter of each layer of the cable and the crimping process. It is easier to make on the surface, but if you are not careful, it may be virtual connection. , You should try to avoid using this type of connector. When you have to use it, it is best to weld it after crimping. At the same time, avoid applying force on the cable when unplugging. Relatively speaking, the welding-type joints have lower process requirements, but it is still necessary to pay attention to the specifications of the joints and the cable specifications. The welding requirements are the same as those for welding ordinary electronic circuit boards. .
Finally, it must be checked for open or short circuits. Whenever a video cable is made, no matter what connector it is and how long it is, it must be checked with a multimeter to make sure that there is no open circuit or short circuit before it is completed.
