Let's just say that all the low-grade ones I used have been dismantled, and the welding of the parts inside is just a cursory matter, such as Shenzhen Kaide, which is just like 30 yuan. Just make good use of it Of course, the signal is not very strong, the short-wave receiving ability is weak, there is no secondary frequency conversion (secondary frequency conversion is to amplify the input signal and optimize the receiving quality), and the antenna is still very short.

A good radio, such as Desheng PL350, uses a chip (Samsung) imported from abroad, with fine workmanship and no short wave drift. In a low-end radio, the short wave drifts seriously because of the filter, and the sound is large and small. )

The second is the difference between stereo.

As long as the high-end radio has a good antenna, its sensitivity will be enhanced, unlike the low-end radio, because the short wave is repeatedly refracted by sky waves and ground waves. Once the sensitivity is improved, there will be a phenomenon that two stations are connected in series.

Some radio manufacturers will make use of this feature of students' listening test to publicize their products in large quantities or let students order radios from exclusive manufacturers through schools, which will make a profit. I hate this. They are all radios, but they have different uses. That good radio, with high sensitivity, is played by radio lovers. So I think it's best to proceed from reality.