The antenna amplifier is actually an ultra-large high-frequency band amplifier. The receiving channels, frequency ranges and overall gain of various types of antenna amplifiers are different. When using an antenna amplifier, you should generally pay attention to the following issues:
(1) Pay attention to the installation position. The antenna amplifier usually consists of two parts: the amplification part and the power supply. When the antenna feeder is short (generally refers to the use of indoor antenna), the antenna amplifier can be placed next to the TV; when the antenna is erected higher and the feeder is longer, the two parts should be placed separately, and the enlarged part is sealed by a waterproof box Finally, it is best to install it at the end of the support rod 1-1.5m away from the antenna vibrator, and the power supply part can be placed near the TV, which can improve the signal-to-noise ratio of the TV signal.
(2) The channel must match. Antenna amplifiers are generally divided into two categories: VHF and UHF. The VHF type can amplify TV signals from channels 1 to 12, and the UHF type can amplify TV signals from channels 13 to 68. When used, the antenna amplifier should match the TV channel to be received.
(3) Pay attention to impedance matching. The output impedance of the antenna amplifier and the antenna output terminal and the input impedance of the TV should match. The feeder line should not be too long, that is to say, the antenna should not be set too high or too far away. Otherwise, although an antenna amplifier is added to the TV, the amplified signal will be severely attenuated in the process of being sent to the TV, resulting in little improvement in the reception effect. In addition, the input and output feeders of the antenna amplifier cannot overlap, nor can they be too close to avoid feedback or interference.
(4) The gain must be selected. The gain of various types of antenna amplifiers is different, and there are generally high and low points. The high-gain antenna amplifier usually has a gain of 30-60dB, and it can receive TV programs hundreds of kilometers away with the multi-channel Yagi antenna. The low-gain antenna amplifier has a gain of 20-4OdB and can receive programs dozens of kilometers away. Proper selection should be made when selecting, but the higher the gain, the better.
(5) Check the installation effect. If the image received by the indoor large line is poor, but the good effect can be obtained when the outdoor antenna is installed, the indoor antenna can still be used after the amplifier is used. If the viewing effect of the TV does not change significantly after installing the antenna amplifier, or the viewing effect is worse than before, it is caused by an installation error, and it should be corrected after careful inspection.
(6) Have a good antenna and lightning protection equipment. For example, users of TV sets using outdoor antennas need to install antenna amplifiers. They must have good multi-unit antennas to cooperate with them, and lightning protection equipment must be installed to prevent lightning strikes.
(7) In terms of brand selection, European amplifier technology has always been leading the entire industry. Several major brands such as: Antiference, Johansson, Commtel, Fringe, Global, Labgear, Nikkai, OneforAll, Optima, Paragon, Philex, Proception, Televes, Triax , Vision, Wolsey, etc. have always been the first choice of many TV enthusiasts, but in fact, many of these products are manufactured or even developed in China. Therefore, in this field, the domestic R&D level and process standards are relatively close to those of the international ones. Several well-known domestic brands include Jefferson (Jiehexing), Polecoz (Bo Ligao), Zinwell (MHz), Gecen (Jiaxin), SMT, Seebest (Seebest), Masda (MasterCard) and aerospace and first-class all It is a relatively well-known RF electronics manufacturer in the industry. Many foreign brands are manufactured and developed in these factories.
