One of those devices that all radio enthusiasts are familiar with: the microphone. Some people call it a microphone, and in the mouths of domestic enthusiasts, a more common name is called "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 categories: dynamic and condenser. The "electret" microphone we often hear is a type of condenser microphone. They differ mainly in the way in which the sound is converted into an electrical signal.
The principle of a dynamic microphone is similar to that of a speaker. Coils attached to the diaphragm generate varying electrical currents by cutting the magnetic field lines of the magnets in the microphone. Due to the moving parts in it, its sensitivity is not as high as the same level of condenser microphones.
The condenser microphone uses the change in the capacitance caused by the change in the distance between the two metal separators. 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 that are usually brought by the original radio station. Electret microphones are also a type of condenser microphones. But it uses an 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.
Most of the original microphones of UV radio stations are electret microphones, but the original microphones of many shortwave radio stations are dynamic. This requires you to pay more attention when changing to a new mic. If the interface of the radio is universal, the signal level may be slightly lower when the moving coil microphone is installed on the radio with the original condenser microphone. The improvement is to adjust the Mic Gain microphone gain. When a condenser mic is installed on a radio that can only use dynamic mics, you need to supply the mic with a power source from the outside.