[Vintage Radio Collection]How to use the old-fashioned radios
What are the old-fashioned radios strong>
In terms of size, it can be basically divided into pocket, portable and desktop radios.
In terms of functions, it can be basically divided into traditional mechanical pointer radios, non-storage analog tuning digital display radios, PLL synthetic digital tuning radios that can store radio frequencies, and DSP electronic digital tuning machines.
From the production base, it can be basically divided into imported machines and domestic machines.
From the degree of fever, it can be basically divided into popular machines and fever machines.
From the frequency band, it is basically divided into FM and medium wave two-band radios, short wave and FM two-band radios, short wave and medium wave two-band radios, 3-4 multi-band radios (FM | medium wave | 1- 2 SW), 5-14 multi-band radios (FM|AM|3-12 SW), full band. At present, there are few single-band and two-band radios on the market, and there are many multi-band radios that integrate FM, medium wave and short wave.
How old-fashioned radios work
A radio, also called radio or radio, is a A machine that is constructed of mechanical devices, electronic devices and magnets, converts radio wave signals with electrical energy, and can listen to the audio signals emitted by radio stations. Since the application of DSP technology, traditional analog radios have been replaced by digital radios. The radio is to restore the high-frequency signal received from the antenna into an audio signal after detection, and send it to the earphone or speaker to become a sound wave.
But with the advancement of technology, there are more and more radio waves in the sky, more and more complex, so when we use the radio to listen to the radio, it often appears If the station cannot be received or there is noise, this is the reason why the radio is interfered by other radio waves when it receives radio waves. In order to avoid this situation, the radio has a selective circuit. The function of this circuit is to filter unwanted signals, and the radio’s channel selection is displayed on the radio. How does this line receive the signal? Everyone needs to know this.
Specifically, the radio station first converts the sound into an audio signal through the microphone, and then when high-frequency current flows through the antenna, the signal forms radio waves and is emitted outward, and the radio receives the high-frequency signals of many radio stations from the antenna. Select the required radio signal through the input loop and send it to the base of the frequency conversion stage, and at the same time convert the high-frequency AM wave into an intermediate-frequency amplitude-modulated wave signal with a carrier wave of 465KHz, and then amplify it from the intermediate frequency amplifier, and then send it to the detector. The audio signal is restored by the amplitude detection of the amplifier, and through low-frequency voltage amplification and power amplification, the speaker can be restored to restore the sound for the longest time.
How to use old-fashioned radios
The correct use of radios should pay attention to the three problems of dustproof, anti-wear and anti-shock. The radio relies on speakers and speakers to produce sound. If dust blocks these components, it will affect the playback effect of the radio. Therefore, when using it, pay attention to listening in a clean place as much as possible, and do not place it anywhere. The radio is made of metal and is not resistant to wear and tear, so do not frequently put it in a box or a plastic bag, or in a holster, it is better to put it in a flat and smooth place. As for anti-shock, don’t put the radio in a place with a lot of vibration to better ensure the safety of the radio.
