May 03, 2023
The public address system is now needed by all walks of life and will be used in hotels, shopping malls, parks, scenic spots and other places.
In actual use, we will find that some broadcast systems are pleasing to ear, natural and smooth, while others are noisy and wailing. Faced with this situation, how should we deal with it?
1. Buy Quality Broadcast Equipment
Products with good performance and strong noise immunity are selected as system broadcast equipment. The anti-interference capability of broadcast equipment depends on ability to suppress noise, which is limited by circuitry, manufacturing process, and materials used in broadcast equipment.
Therefore, if budget allows and you want better results, it is recommended to buy better broadcast equipment.
2. Correctly connect signal lines between devicesThe quality of equipment should be up to standard, but also pay attention to connection between signal lines of equipment. Even a well-functioning device can have difficulty working if it is not connected properly or incorrectly.
Grounding is an important technical measure to suppress noise, prevent interference and improve reliability. Proper grounding can suppress effect of interference on system, and may also prevent broadcast equipment from emitting interference; on contrary, improper grounding will cause serious interference and even render broadcast equipment unable to operate normally.
All power and signal cables are protected by metal tubes that can play a role in protection.
3. Do not solder shielded wires at will
During installation of equipment in machine room, do not weld shielded wire at will for convenience, otherwise it is easy to form a closed loop and cause noise problems in system. An effective loop prevention method is: (1) One end of shield layer is grounded (usually at signal input end) and other end is open; (2) There are several chassis ground points. ground point and signal ground point.
4. Clean power supplyWhen designing power supply, a separate power transformer should be provided, if unconditional, a separate power source separated from air conditioners, lighting and other equipment can be used to supply power, or an isolated power transformer can be used, or a filter can be installed at input power supply for broadcasting equipment that filters out noise.
5. System isolation
Radio stations often use telephone lines to transmit audio and live broadcast signals. Because different subsystems have their own independent grounding systems, after connecting ground wires of two systems, ground noise is inevitably generated.
On other hand, since two subsystems in plane are interconnected, even if one-sided shield grounding and long-line segment grounding are used, it is impossible to solve problem of radiation interference caused by long distances. transmission, especially when used to transmit a huge telephone network. Currently, best measure is to apply an isolation method and install an audio isolation transformer between two systems to isolate them from each other.
6. Daily MaintenanceRegularly check and test background music function to ensure that system functions can be used normally;
Check speaker circuit regularly to ensure that speaker circuit is in a normal state, effectively avoiding normal use in emergency situations;
Given that electronic equipment can be damaged by dust, etc., it should be cleaned regularly during use. transfer of dust to equipment.
The final effect of a public address system depends on quality of equipment, installation and commissioning, and subsequent maintenance. To prevent noise and howling, the above 6 points must be paid attention to.
