How to make the radio receive more programs

Tools Raw material: radio.

1. First press and hold the ON mode button (power button) on the radio for 3 seconds, and the default is Bluetooth mode after powering on.

2. Press the ON mode button on the radio again to convert the mode to radio mode.

<>4. Press the previous song button to switch channels, which is to listen to the previous channel.

5. Press a song button to switch channels, which is to listen to the next channel.

1. You can move the coil on the magnetic rod back and forth to enhance the receiving signal of the radio.

2. Superheterodyne radios need accurate and fine adjustment, intermediate frequency, frequency coverage, and high and low segment unified adjustment.

3. By flipping the band switch on the radio, the frequency of the carrier wave changes with the volume of the sound.

Unlike FM, which is only an electromagnetic wave modulation method, its reception principle is the same. Both signal electromagnetic waves and local oscillator electromagnetic waves pass through the mixer to obtain the difference frequency (that is, the intermediate frequency), and then amplify and detect the intermediate frequency to obtain the audio signal, and then amplify the audio signal and sound through the earphones or speakers. Superheterodyne means that the local oscillator frequency is one intermediate frequency higher than the signal frequency, and if the local oscillator frequency is one intermediate frequency lower than the signal frequency, it is called superinternal difference.

2.As mentioned earlier, AM and FM are just different in terms of electromagnetic wave modulation, and the reception principle is the same. They all receive high-frequency signals, amplify them (some radios do not amplify them), and enter the mixer together with the local oscillator signal, and then get the intermediate frequency signal (the general radio intermediate frequency am is 450 or 455kHz, FM is.

Then amplify the IF signal (which is very important and has a vital role in the sensitivity of the radio), the modulation of the IF signal and the high-frequency signal are the same, and the carrier signal is also the same, but the frequency changes from high frequency to IF frequency. The audio signal is obtained by detecting the IF signal (AM is the detection and FM is the frequency discrimination). The audio signal can be amplified by headphones or speakers.

3.During the day, due to the noisy environment, there is more interference, which affects the reception of AM and FM only by electromagnetic wave modulation The environment is relatively quiet at night, so the radio receives more radio stations at night

Not long ago, the author bought a Desheng brand R9700 type 12-band radio, which has the function of TV sound chain and the effect is not bad. It uses short-wave secondary frequency conversion reception technology, which is commonly used in military and civilian communications, such as short-wave receivers and cellular mobile**, in order to improve reception sensitivity, selectivity and anti-interference capabilities. The radio is very creative in terms of chassis style and workmanship, and it is very detailed, which can be compared with famous brands such as S0NY.

From this, the author also sees the hope of domestic electronic products!

Also included in the included item is a shortwave external antenna to improve shortwave radio. Inspired by this, the author connected the middle terminal of the TV or FM hole of cable TV with a radio rod antenna with a piece of wire, and achieved good results. In the past, the TV sound band could only receive two or three local stations, and it was a radio station, but now after being connected to the cable TV system, it can receive many cable TV programs, such as Beijing TV, Shanghai TV, **8 sets, **5 sets, **3 sets can receive good results.

Fortunately, the radio effect of shortwave programs has also been significantly improved after the installation of the line, and the listening to shortwave programs is much clearer than before. Give it a try! The non-shed bridge is often simple, but it is very practical!

It should be noted that the connection should be reliable and tight when wiring, and the two ends of the cable TV network socket should not touch each other. Otherwise, it may affect the normal operation of the cable TV line.

The signal from the radio is sent from the spine radio station, and then it is received by a hidden antenna on the surface of the window glass, and then processed by the antenna amplifier before entering the radio. The strength of the received signal depends on the following factors, all of which may affect the reception of the station when they change. a, the power output of the radio station (small power radio broadcasting transmission distance and range are limited) b, the position of the vehicle relative to the transmission tower (the closer the vehicle is to the transmission tower, the stronger the signal) c, atmospheric conditions (such as the presence of strong electromagnetic fields in the atmosphere will interfere with the signal) d, the frequency band of the radio (FM FM or AM amplitude modulation) e, ground conditions (such as tall buildings, hills or surrounding vehicles will interfere with the FM FM signal, which may lead to the sound from time to time) F, Obstruction between the tower and the vehicle Why does it sometimes happen that the vehicle position displayed by the navigation system is inaccurate (the vehicle position is off the road surface) when driving under an elevated road or in a tunnel?

When this happens, the navigation system is unable to receive a valid satellite signal, usually when the vehicle is driving under an elevated road or in a tunnel. The navigation system uses GPS satellite positioning signals to locate the vehicle. When the GPS satellite positioning signal is strong, the navigation system can calculate the precise position of the vehicle.

When the satellite signal is weak and lasts for more than a period of time, or when the signal is interrupted, the navigation system will not be able to accurately judge the driving position of the vehicle, and the calculated vehicle position will be inaccurate, and in certain cases, the vehicle's position will not be on the road. When the vehicle leaves the tunnel or elevated road, it will quickly relocate the vehicle position after receiving a valid GPS satellite positioning signal.