How to reasonably use audio processor in broadcasting system

Everyone knows that public broadcasting plays a more important role in our daily life, such as various natural disasters, geological disasters, etc. Therefore, the effective maintenance of the system is also an important guarantee for the safety of the people ’s personal property. The audio processor is one of the key devices in the link of the broadcast transmission system, and it has a great influence on the quality of the broadcast. In daily work, there are three issues that radio station technicians are most concerned about: One is the matching problem between the transmitting antenna and the network. The second is the three major technical indicators of broadcast transmitters. The third is the noise and attenuation of audio signals during transmission. There is little concern about the working status and setting of the audio processor. Let us look at the reasonable application of the audio processor in the broadcast system.

Broadcast audio signals have a large nonlinearity in the processing process. For audio processing equipment, it includes not only the compression, limitation, clipping, expansion and other processing methods of the signal, but also the installation location and leads of the audio processing equipment. There are strict requirements on the length and anti-interference ability in the environment of high electromagnetic field radiation. In response to this situation, I explored the working principle, setting method, placement location, and additional functions of the audio processor in order to adopt a variety of effective measures to make the audio processor play a greater role in future work.

1. Requirements for audio processing

(1) The audio processing method for broadcast transmission is relatively complicated, mainly to compress or limit the frequency range audible to the human ear, while preventing it from being over-modulated, it is also necessary to ensure that the best signal-to-noise ratio and Audio bandwidth. The audio signal is processed on the basis of maintaining the original program material characteristics, making it a brand new and characteristic timbre for listeners to receive and enjoy.

(2) In broadcast programs, the loudness of audio signals is improved by reducing the ratio of "peak" to "average" (peak / average ratio) in dynamic audio. Within the allowable modulation range, adjust the relationship between the peak value and the average value to avoid harmful side effects such as distortion caused by clipping during audio signal processing, and process the audio to make it within the limits of peak modulation. Try to increase the loudness effect of subjective feeling.

2. Basic principles of audio processing

Audio processing equipment mainly uses the method of reducing the dynamic range to suppress noise, which includes program signal compression, peak limiting and clipping, multi-band compression and frequency-selective limiting and equalization. The main purpose of compression is to reduce the dynamic range of the program, increase the density of the sound, and try to make the amplitude of the peak point of the audio signal uniform. Peak limiting is an extreme form of compression, but it has a high compression ratio and a fast start-up and recovery time. The main purpose is to protect the transmission of the rear channel from overload. The peak clipping process is a process to prevent distortion caused by overload of the channel processing circuit and instantaneously "cut off" the peak part of the high level exceeding the threshold. If the peak limit and clipping can be perfectly matched, it will be able to deal with the problems of harmonic distortion and intermodulation distortion and the negative impact of signal bandwidth between the density and loudness of the audio program signal.

In the audio processing process, the audio spectrum is divided into several frequency bands, and each frequency band is compressed and limited separately. That is, "multi-band compression and selectable limits", if set correctly and reasonably, will effectively eliminate the intermodulation of spectral gain. For equalization in audio processing, its role is to use an equalizer to change the balance of related frequencies in the overall frequency band of the audio signal on the one hand, and to create certain acoustic characteristics by changing the loudness of the "sensitive frequency" to increase the program. In addition, it can also be used for frequency response correction in transmission systems.



Introduction

SCOTECH manufactures a full range of furnace transformers including arc furnace transformer(EAF), ladle Furnace Transformer, Induction Furnace Transformer, electroslag furnace transformer, blast furnace transformer, calcium carbide furnace transformer, and other more kinds of furnace transformer. With the advanced design and thorough quality management system, we had become one of the most reliable furnace transformer manufacturers in China. we do not compromise on the quality, we ensure that each one of our delivered units has passed the most strictly testing and that makes us confidently to provide the longest quality warranty to our customers. We export our furnace transformers to all major global markets.

 

Application

Electric arc furnace (EAF) transformers are normally used in steel plant for smelting the scrap iron and for refining steel, also required for many different furnace processes and applications, such as smelting glasses and ceramics, manufacturing or refining many other materials, such as ferrochromium, ferromanganese, different abrasive materials (oxides and nitrides), semiconducting base materials.

 

Duty

Steel arc furnace transformers operate under very severe conditions with regard to frequent over-currents and over-voltages generated by short-circuits in the furnace and the operation of the high voltage (HV) circuit breaker (furnace breaker). The continuous at high utilization. loading is cyclic, while in other applications the loading is more

 

Scope of supply

SCOTECH`s furnace transformers Including Arc Furnace Transformer, ladle furnace transformer, induction furnace transformer, electroslag furnace transformer, blast furnace transformer, calcium carbide furnace transformer, and other more kinds of furnace transformer

Voltage level: up to 220KV

Rating level: up to 100MVA

 

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