Views:5 Author:Site Editor Publish Time: 2021-07-07 Origin:Site
The clock radio is the receiver of radio broadcasting. The weak signal of high frequency modulation input by the receiving antenna is converted into audio signal through method, frequency conversion and detection. According to different needs, the radio can be combined with different components and wiring methods. Earlier radios used electronic tubes, but now transistors and integrated circuits are commonly used.
A regenerative radio with a simple circuit only needs a transistor, while a superheterodyne AM FM radio with a complicated circuit often uses a variety of integrated circuits.
The city is a reinforced concrete structure, plus the shielding effect of the steel bar in the ceiling and floor, so the signal is not very good. The clock radio receives FM and short-wave signals. It uses the attached whip antenna. You can drag a flexible wire indoors, scrape one end and connect it to the antenna to enhance the signal. If possible, drag the other end of the wire to outside the window better.
Cable TV in many cities will include several sets of FM programs. If you connect the radio antenna to the TV’s broadcast FM jack, the signal will be very good, but the working frequency is different from that of the radio.
In the mid-wave band, the clock radio uses the built-in magnetic rod antenna, which is directional, and you can adjust the direction to find the best signal position. It is also possible to wind the flexible wire around the radio shell a few times to improve the reception of the medium wave, but in this way the directionality of the medium wave station is lost.
In FM FM radio, the modulation method in which the carrier frequency is changed according to the modulation signal is called FM. The change of the modulated wave frequency is determined by the size of the modulation signal, and the period of change is determined by the frequency of the modulation signal. The amplitude of the modulated wave remains unchanged. The waveform of the FM wave is like a spring that is compressed unevenly. The FM wave is represented by the English letter FM.