TV receiving antenna selection requirements: Should be based on different receiving channels, Digital TV Antenna field strength, receiving environment and the size of the common antenna TV system facilities to choose the antenna to meet the receiving TV images clear, colorful requirements, and product certification.
All kinds of iron should be fully galvanized. Can not be galvanized, anti-corrosion treatment should be carried out. Such as the use of 8 # wire and wire rope and a variety of iron pipe, angle steel, channel steel, flat iron, round steel, 14 # tie line, wire cards, flower baskets, pull rings, etc. should be galvanized. A variety of machine screws, metal up tube bolts, wood screws, washers, spring mats, etc. should be galvanized.
User box (also known as the junction box or terminal box) is the system and user TV port, the user box is divided into outdressed and concealed, concealed box and plastic box and tin two, outfit generally use plastic box , The box should not be damaged deformation, jack impedance must match the TV impedance, Digital TV Antenna box and cover the same color, and product certification.
Parallel flat feeder (ie, 300Ω flat feeder) is simple in construction, low in cost and easy to connect with the equivalent dipole antenna, so it is widely used in very high frequency range. It is suitable for TV and shared antenna TV socket, and product certification.
Coaxial cable feeder. It is composed of coaxial inner and outer conductors, the inner conductor is a solid core conductor, the outer conductor is a metal mesh, the inner and outer conductors are padded with polyethylene high frequency dielectric material, and the outermost layer is polyvinyl chloride protective layer. Digital TV Antenna Characteristic impedance 50Ω; 75Ω; 100Ω three, the choice should pay attention to impedance requirements, and product certification.
Dispenser: usually two points, three points, four and six points, such as distributor, the choice should be selected according to design requirements, and product certification.
Should be based on the design requirements, select the appropriate type and performance of the antenna amplifier, mixer, channel converter, splitter, trunk amplifier, Digital TV Antenna branch (distribution) amplifier, line amplifiers, chassis, cabinets and so on. Should check the appearance of the instrument is intact, the machine is complete parts, and then power test to check the work is normal. Product brochures and technical information is complete, and product certification.
The height of antenna from the ground or roof should not be less than one wavelength. Should consider the radio wave propagation process, Digital TV Antenna not only reflection, should also consider the phenomenon of refraction due to the heterogeneity of the air media should be properly adjusted horizontal position and height, to receive the best signal quality prevail.
Choose the strongest antenna direction. The receiving antenna is generally the maximum receiving direction aligned television tower. But sometimes in order to avoid the interference source or because there is obstruction in front, according to the actual situation, the maximum receiving antenna receiving direction slightly offset some, Digital TV Antenna and even receive the reflected wave.
Antenna base (base) should be with the civil construction, construction, when making the roof, make the embedded bolts or floor bolts. Embedded bolts should not be less than φ25 × 250mm; grounding down bar diameter should not be less than φ8mm; connecting plate thickness should not be less than 6mm; base height should not be less than 200mm; cement mortar will be the base plane, elevation Wiped flush. At the same time, Digital TV Antenna a good anchor is embedded. The angle between the three points is at 120 °. Digital TV Antenna The pull ring is made of galvanized round steel with the diameter of φ8mm or more. The bottom is welded with the structural steel bar. The welding length is 6 times of the round steel diameter, Skin, and smooth with cement mortar.
Post time: Sep-25-2018