Keywords: FM antenna, eight wood antenna
The antenna is a tool for the receiver capture signal. Most of the antenna used for remote frequency modulation broadcast received uses the eight-way antenna. The number of units of the eight-timber antenna affects the receiving range. The more the number of cells is, the more the direction is sharp, the higher the gain. The farther distance. China's FM broadcast band is 87.5-108MHz, and the center frequency of the TV five channels is 88MHz, so the five-channel antenna is basically suitable for remote frequency band broadcast reception. The enthusiast can buy five channel TV antennas, require high The enthusiasts can use the five-channel TV antennas and use it. I recommend using five units well, it has a higher gain, and the size is not large. The ordinary five-channel five units eight wooden antennas are only more than ten yuan, after purchasing Change the most cost-effective.
The following is some processing methods using antennas: 1. Matching problems of antenna, the general antenna output is 300 Euro, and the cable is more than 75 euros, the impedance is different, otherwise the high frequency signal is difficult to transmit. Antenna match Most of the transformers and U-shaped half-wave rings, transformer matches are more complex, line and magnetic selection directly affect match coefficients. The U-type half-wave ring is only a 75 Euro cable. I feel that the U-type half-wave ring is better. 2. The debugging problem of the antenna is not the effect of the tilt rod, it is necessary to make debugging. First, we must first determine The direction of the receiving radio (because the antenna is a directional antenna), the direction of the antenna primer is aligned in the radio direction. Use the receiver testing radio, then find a weakest signal to adjust the height of the antenna, find the strongest signal. After the location, the antenna will be fixed. 3. The problem that should be paid attention to using antenna amplifier. At present, the antenna amplifier on the market is more than two 9018 combinations. Since the 9018 work noise is large, "fever" is best to change 9018 to C3358 or C3355 low noise. If an unknown digital sound (audio pulse) occurs in multiple frequency points when using the amplifier, the harmonic regeneration caused by the paging radiometer is due to the filter problem of the antenna amplifier. It is best to add a BPF (88-108 MHz filter) at the input terminal to be removed from the old FM radio (shape such as TV 6.5MHz filter). Can also be added to the coupling capacitor of the first magnitude 5-45P capacitance. 4. The antenna and cable should pay attention to the rust, the antenna is generally erected in the roof. After the sun is blown, the antenna interface is easy to rust, which will affect the transmission of the signal and the matching of the antenna, so that the reception effect If the antenna amplifier is extremely easy to make the amplifier self-excitement, it is best to apply the interface to anti-rust paint when the antenna is installed. 5. Try to pull it straight to the cable installation, it is best to enter the house. Enjoy a socket in the house, can be unplugged soon when thundering. 6. When the antenna is settled, attention should be paid attention to lightning protection. The high-rise buildings generally have lightning rods. The radiocarns are the hostewheel of 45 degrees with needle tip, The antenna should be safe in this space. 7. The maintenance of the antenna, because the antenna is blown, sun, rain will be oxidized after the rain, there is time to wash an antenna once a year, I am another payment for one year Antenna. All interfaces of the cable should be washed with 95% alcohol cleaning. 8. The reflectors of the antenna cannot be turned on with the bracket, and the plastic is separated! 9. Most of the radio is 300 o'clock You can disconnect the 300-75 Euro matching of the radio to 75 Euro interface. A FM receiving system is not a good antenna, and the advanced cable has a good reception effect. But to be on the antenna, cable With each other with each other. Just like our audio, the sound source, power amplifier, wire, and speakers match each other. I have a good effect. I When choosing a receiver, it should be noted that many radios on the market are not suitable for remote frequency modulation reception. The ordinary micro radio is mainly designed to receive local and neighboring radio, which spends less work in tuning. Frequency processing is not good, it mainly flowers in the shape design. Ordinary radiop I think the hand is better than the tone, the current domestic ordinary number of adjustments are mainly designed in its function, not to seek it. High sensitivity, hand-tune radio is the mature product of China's national industries, obviously ordinary hand-conditioned tone than the tone. However, some domestic digital tones are still good, but it has been better than some imported products. In my use It is found that the car foucher receiver is quite good. Whether it is hand-tune or a tone, its sensitivity and adjacent frequency processing are very good, and the medium intensity signal is completely separated at 0.2MHz, mainly it uses an integrated tunator, One tuner is not like ordinary tuning, and the center and stereo demodulation is designed on the same board, but from professional manufacturers, it is better, regardless of technology or technology. When using Walkmen, I think hand-tune It is very good than the tone, such as Panasonic, Aihua, Sony's radio function is excellent.
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