Installation and commissioning of public address system equipment

1) assemble the cabinet according to the instructions of the cabinet. (then keep the instructions and related attachments well below.

2) Broadcasting equipment should be installed on the cabinet from top to bottom according to the signal flow, and heavy equipment such as broadcasting power amplifier should be placed at the bottom of the cabinet. After the installation, the order is generally: the top is the sound source, followed by the signal finishing equipment and preamplifier, then listeners, power dividers, plug-in power, telephone interface, fire interface and other equipment, and then down is the power sequence controller and the main and backup power amplifier switcher, the bottom device broadcast power amplifier. Broadcast power amplifier off the bottom of the cabinet sometimes leaves 2U (2 units) of free space, facilitating line passing and air convection. (U) is the abbreviation of "Unit". It is called "unit". It is an international standard for the design of professional electronic equipment. 1U is 1.75 inches, or about 44.4 millimeters. )

3) Many engineers install equipment in the reverse sequence, gradually upward from the bottom of the cabinet, which is to ensure that the equipment on the cabinet does not stop at the top of the empty space, and make the cabinet installed equipment after the lowest center of gravity. The endless gap of the device is usually sealed with a special cabinet baffle. This will be more beautiful. Experienced engineers often fall down the cabinet when installing equipment, the front of the cabinet (facing the vertical plane of the broadcasting crew) is placed upward, and the cabinet is erected after installing the equipment. This experience is worth learning.

4) Be careful not to touch the appearance of the flower cabinet or the broadcasting equipment during the process of the installation, and ensure the stability of the structure, such as the bracket or tray of the bearing equipment to fasten it on the cabinet (screw down its screws), which is particularly important when the device broadcasting power amplifier and other heavy equipment, is something that some engineers often overlook.

5) after the equipment is completed, clean up the site and leave all instructions, attachments and packages away.

Link line

The connection line is very important in the whole process of the equipment. On the one hand, it is necessary to ensure the correctness of the connection logic, on the other hand, it is necessary to ensure the reliability of the connection. This point should be paid attention to. Some phenomena such as bad contact and noise caused by poor connection are often seen. We should pay attention to the links of connecting lines.

1) use high quality connectors and wires. If you want to make wire rods on the spot, it is necessary to ensure that the power and heat of the soldering iron are satisfied when welding the connectors, and that special wire rods are prepared to make things so as to ensure the reliability of the wire rods.

2) optimize the wiring structure and shorten the cable length as far as possible.

3) the connector should be inserted by hand to see whether the tightness is suitable.

4) Digital cables, analog cables, speaker cables, power lines and other cables should be clearly separated and placed; weak signals must be separated from strong signal lines;

5) attach symbols to all cables. In a few months, when you begin to forget what cable is doing, symbols will show its usefulness.

6) tie the cables in different categories to make them stable and beautiful.

Debugging of public broadcasting

After the equipment is installed and wired, the system will be debugged. The debugging process and key are generally as follows.

1) Do not turn on the power supply of broadcasting power amplifier for the time being, turn on the power supply of other equipment one by one, and check if there are abnormal phenomena such as power-on, overheating or smoking. If not, let us see further whether their functions are basically available. Sources can be allowed to broadcast programs, to investigate whether signal finishing processing equipment (signal compression, expansion equipment, equalizers, preamplifiers, etc.) has a signal indication, if any, that these equipment is fundamentally normal. The volume of the equipment that the program signal flows through is about 70% off the full output, so that the quality of the program signal and the signal-to-noise ratio of the system can be guaranteed. After that, look at the functions of the partition device, listener and other devices, and close all the partitions of the partition device.

2) switch the switch and knob of the above equipment to the corresponding position, especially the volume should be appropriate.

3) Close the volume of the amplifier and turn it on. Wait for a moment to find out if there are abnormal phenomena such as power-on, overheating or smoking. Then gradually turn the volume up and check the output of the power amplifier by investigating the signal indicator. Then turn on the corresponding partition one by one, and see if there is any sound in all partitions. Finally, turn the volume of the power amplifier to the proper position.

4) If you pass these tests normally, the first task is done, and finally the detailed functions of the equipment and systems will be tested in detail.

5) carry out electrical aging at a longer time, for at least 60 minutes. During the aging process, it is necessary for someone to take charge of the investigation and to check the temperature rise every few minutes.