There are roughly two reasons for the noise of the radio: one is caused by external interference, such as lightning, electrical appliances, etc; The other is the internal failure of the radio, such as some parts are damaged or not welded well, and the current flow is affected.
To eliminate the noise, first check the cause of the noise. The method is to contact the end of the antenna with the metal platform. If the noise and radio broadcasting disappear at the same time, it indicates that the noise is caused by external factors and is caused by external influence; Conversely, if the radio broadcast disappears and the noise still exists, this is the internal fault of the radio. Note: during this inspection, the power plug should be pulled out first, and then the power plug should be inserted after the antenna is connected to the bottom platform to prevent electric shock.
Generators, elevators, telephones, bells, electric welding, trams, cars, fluorescent lamps, fans, blowers, hair dryers and other electrical equipment will produce sparks and generate electric waves when in use. When the radio receives these electric waves, it will cause the noise interference of "Gaga" or "brushing". If it is the noise generated by the above equipment, the noise will be eliminated naturally as long as it is avoided to use with or away from these equipment.
The noise from the sky is caused by the discharge in the atmosphere, which is called celestial interference. On rainy days, when positively charged clouds and negatively charged clouds meet in the sky, they will thunder and discharge. When the wind blows, it will also make the atmosphere emit electricity. When discharging, there are sparks and radio waves. When they are transmitted to the radio, noise occurs. The radio noise caused by lightning is more in spring and summer than in winter, and it is more serious in wet places than in dry places. The change of weather will not only bring noise interference, but also damage the parts. Therefore, in case of thunderstorm, it is best not to listen for the time being.
If it is an internal fault of the radio, further check to see whether the contact between the power plug and the power socket is compact; Whether the power plug is rusty; Are there any dirt on the electronic tube socket, potential switch, etc? Check clearly and deal with it in time, and the noise can be eliminated. In addition, the poor quality or damaged components such as capacitors and vacuum tubes will also produce noise, which must be sent to the repair department for inspection and repair, or replaced components.