One of the equipment that all radio enthusiasts will not be unfamiliar with: the microphone. Some people call it a microphone, and among domestic enthusiasts, it is more common to call it a "hand microphone". We spend a lot of time every day holding a microphone to communicate, but few people will carefully study this little thing.
Generally speaking, we can simply divide microphones into two types: dynamic and condenser. The "electret" microphone that we usually hear is a type of condenser microphone. The main difference between them lies in the way in which sound is converted into electrical signals.
The principle of a dynamic microphone is similar to that of a speaker. The coil attached to the diaphragm generates a changing current by cutting the magnetic lines of induction of the magnet in the microphone. Because it contains moving parts, its sensitivity is not as high as that of condenser microphones of the same level.
The condenser microphone uses the change in capacitance brought about by the change in the distance between two metal partitions, and under the action of a constant voltage, the change in the sound is reflected by the change in the amount of electricity charged between the plates. This is why condenser microphones need to have a constant voltage input.
In general, most of the better recording studios use condenser microphones, and we usually think that the source of the advantages of dynamic microphones mainly comes from the electret microphones of the original radio stations. The electret microphone is also a type of condenser microphone. But it uses electret material, eliminating the need to charge the capacitor. But we still have to power the amplifier circuit in the microphone. This is why most radios have their own power supply in their microphone plugs.
At present, most of the original microphones of UV radio stations are electret microphones, but the original microphones of many shortwave radio stations are dynamic coils. This requires you to pay more attention when changing a new microphone. If the interface of the radio is universal, the signal level may be slightly lower when the dynamic microphone is installed on the radio with the original condenser microphone. The improvement method is to adjust the Mic Gain microphone gain. When the condenser microphone is installed on a radio station that can only use dynamic microphones, you need to supply the microphone with an external power source.