Common sense of use of transistor radios Maintenance of transistor radios
One, common sense of use of transistor radios
1. Selection of power supply
The power supply of transistor radios generally adopts three methods: – using dry batteries; second, using transformers, rectifier circuits and regulated power supplies inside or outside the radio , using DC power supply; the third is a combination of the above two methods.
When the volume of the radio decreases, the sensitivity decreases, and the noise increases, it may be a sign that the battery will be exhausted. The battery should be replaced in time to avoid battery leakage and corrosion of the internal parts.
For radios powered by a special regulated power supply, the maximum power supply of the regulated power supply should have a certain margin compared with the current consumption of the radio, so as to ensure that the radio and the regulated power supply can work normally Work. The DC output voltage of the regulated power supply must be exactly in line with the working voltage of the radio. If the voltage is high, the radio will be easily damaged; if the voltage is low, not only the output power will drop, but other properties will also change.
2. Use of Antenna
The directivity of the radio receiving stations depends on the magnetic antenna in the machine. When receiving, the magnetic antenna rod in the machine should be aimed at the direction of the radio station, and the sensitivity of receiving is the highest at this time. When receiving short-band and FM bands, the rod antenna should be pulled out. In an environment with poor reception conditions, an external antenna can be used to improve the listening performance of the radio, but a lightning arrester must be installed at the same time. During thunderstorms, do not radio to prevent lightning strikes.
3. Volume volume
For transistor radios using dry batteries, the power consumption increases sharply as the volume increases. Therefore, in order to prolong battery life, it is not advisable to turn the volume too high. At the same time, in order to make the sound emitted by the speaker soft and pleasant, it is better to open the volume appropriately to reach 70% to 80% of the maximum volume.
4. Pay attention to matching external headphones or speakers
2. Precautions for using transistors
The impedance of the external earphone or speaker should be equal to or slightly greater than the impedance of the original speaker inside the radio, and should not be lower than the impedance of the original speaker.
Transistor radios generally use magnetic antennas, which have obvious directivity. When the magnetic antenna is perpendicular to the direction of the station, the radio receives the strongest signal and the sound is louder, otherwise the sound is weaker.
When using the radio, keep away from objects such as hair dryers, electric stoves, electric drills, motors, high-voltage wires, etc. to prevent noise and interference. After the radio is used for a period of time, the volume drops greatly and the sound is distorted, which means that the battery is almost exhausted, and a new battery should be replaced at this time.
The radio should not be placed in a place with high temperature and humidity, and should not be placed under heavy pressure and collision. When using switches and knobs, do not use excessive force, so as not to damage the parts.
The radio should be stored in a ventilated and dry place. If you do not listen to it for a long time, the battery must be removed to prevent the battery from leaking and corroding the parts. The radio should not be used for a long time, and it should be turned on at intervals, especially in the rainy season.
When replacing the battery of the radio, pay attention to the positive (+) and negative (1) poles of the battery, and do not install it in reverse, otherwise the components will be damaged.
3. Maintenance of transistor radios
1. The radio should be placed in a dry and ventilated place to avoid moisture damage to the components and mildew of the coil. It is also not suitable to be close to stoves, radiators, etc., to prevent the plastic casing from being deformed by heat. After the radio accidentally enters the water, it must be allowed to dry naturally before it can be powered on and used. Do not expose it to the sun or fire it.
2. Pay attention to dust prevention. Dust entering the radio can cause noise and reduce sensitivity. When not in use, the radio should be covered with a cloth cover or put in a leather case. When too much dust accumulates inside the radio, cut off the power supply and remove the back cover; blow the dust off with an air pump or a soft brush. Do not wipe with a damp cloth to prevent corrosion of metal components or circuit leakage. If there is dirt on the case, wipe it with a clean soft cloth. Never use gasoline, solvents, or chemicals to scrub the case.
3. When replacing the battery, the positive and negative polarities should not be wrongly connected. If an external power supply is used, pay attention to whether the current and voltage meet the requirements. The batteries should be replaced in time when they are used up. Do not mix old and new batteries, otherwise it will speed up the consumption of the new batteries and make the listening effect poor.
4. If the radio fails and cannot be eliminated by itself, please ask a professional to repair it. Do not disassemble and adjust the internal parts of the machine, especially the coil on the magnetic core and the magnetic rod. Location. After random adjustment, it is more difficult to restore without special equipment.
