The design of small point frequency modulation receiver

Installation of wireless FM sound post in No. 1, 2, 3 and 4 teaching buildings, so that the teaching buildings can listen to campus broadcasting programs;

Around the teaching buildings, according to the actual situation, the configuration of wireless FM sound post or lawn speakers, students can enjoy the ingenious outdoor modeling of the speakers when listening to beautiful music;

Installation of wireless FM sound post and lawn speakers in the ring road and outdoor lawn, so that the Students can hear the campus broadcast anytime and anywhere;

Wireless FM sound post is installed in the student dormitory area, which is used to maintain the daily order and background music playback;

FM to fixed-voltage equipment is installed in the cafeteria, so that the cafeteria can listen to campus broadcasting through the existing speakers;

Wireless FM sound post is installed in the basketball court, so that the students can listen to campus broadcasting when they are playing ball games;

The main control system is designed to provide a high level of control over the campus broadcasting system, so that students can enjoy the campus broadcasting.

The main control room is temporarily located in the No. 1 teaching building, to be moved to the office building after the completion of the administrative office building repairs;

Requirements for the sound columns and lawn speakers with high sensitivity, good sound quality, and reliable control;

Setting up the audio pickup and audio broadcasting and control of the two broadcasting units, each unit should be advanced and economical, reflecting the modernization and intelligence, and compatibility;

The construction of the campus radio and foreign language radio automated broadcast control system. The construction of campus broadcasting and foreign language radio automated broadcast control system, should use digital audio playback, can be set according to the timer playback, in the management of the real intelligent unattended.

According to the specific needs of the college's construction of campus broadcasting and foreign language radio, combined with the status quo and development direction of campus broadcasting, after the actual survey, and in-depth technical debates, and ultimately decided to use the Beijing Stellar Koton HX-2000 wireless addressable intelligent FM broadcasting system and the HX-8000 university foreign language radio automatic broadcasting and intelligent control system to set up the campus broadcasting system of a college.

The HX-8000 is a wireless addressable intelligent FM broadcasting system and HX-8000 university foreign language radio automatic broadcasting and intelligent control system to set up a campus broadcasting system for a college.

HX-2000 Wireless Addressable Intelligent FM Broadcasting System is a set of all-digital intelligent campus broadcasting system with leading technology level in China designed by using advanced technology such as microcomputer phase-locking, digital error correction, flash storage, SCA remote control coding, VB software programming, etc. The system adopts FM-SCA sub-systems, and the system uses FM-SCA sub-systems to control the broadcasting of the radio station. The system adopts FM-SCA subcarrier coding remote control technology, using a radio frequency, the use of audio carriers other than the subcarrier transmission of coding control signals, without the need to apply for the control frequency, not only saves the frequency resources, but also to achieve the control of the terminal point, and improve the stability and reliability of the system.

HX-8000 University foreign language radio automatic broadcasting and intelligent control system using microcomputer phase-locked loop transmitter to ensure stable and reliable transmission frequency without frequency drift; HX-8000 digital hard disk automatic broadcasting software to achieve the digital audio source can be set up according to the year, month, week and day of the regular automatic playlist, daily automatic broadcasting automatic power on and off; HX-7000 multi-channel broadcasting intelligent management controller to achieve intelligent management of FM radio transmitters. HX-7000 Multi-Channel Broadcasting Intelligent Management Controller realizes the intelligent management and control of FM broadcasting transmitter, realizing the real unattended broadcasting and control.

Technical Program Part

(I) Design Basis

The formulation and design of the engineering program are in accordance with the relevant national documents, standards and regulations, including:

● National Standard GB-4311 1-84 FM Radio Transmitter Calibration

● Ministry of Radio, Film and Television Standard GY15-84 FM Receiver Standard

● Building Communication Comprehensive Cabling System

● Building Communications Comprehensive Cabling System

The HX-7000 Multi-way Radio Intelligent Management Controller realizes intelligent management and control of FM radio transmitters to realize broadcasting and control of truly unmanned. >Building Communication Comprehensive Wiring Standard (YD/T926-1997)

● Code for Electrical Design of Civil Buildings GBJ/T16-1992.

● ITU-T related standards.

● Building, communication related industry standards.

● "Professional Recording and Broadcasting Structure Standards"

(2) Design Principles

When designing the system, the principle of unification of "advancement, scientificity, stability, and economy" is adopted.

Advanced: the system adopts the most advanced FM-SCA FM broadcasting technology, all-solid-state transmitter using the latest microcomputer PLL phase-locking technology to ensure that there is no frequency drift phenomenon, accurate and reliable remote control of the speaker on and off, can be realized for different areas of the zoning control. Transmitter wireless indicators are strictly in line with the relevant requirements of the National Radio Regulatory Commission promulgated standards.

Scientific: the system design is scientific and reliable, the system will ensure the independence of the wireless frequency, will not occur with other radio wave sources inside and outside the campus mutual interference phenomenon, remote control speakers to receive the frequency is flexible and adjustable, and to ensure that the speakers will not interfere with the phenomenon. In addition, the system ensures strong maintainability, while having full scalability, currently only the college to consider the outdoor broadcasting function, later if you need indoor broadcasting, through the indoor and then install the remote control speakers can be very convenient to realize the indoor broadcasting function.

Stability: As the system uses wireless FM broadcasting, eliminating a large number of wiring systems, so it also eliminates the most likely to occur as a broadcasting system in the line failure caused by line failure of the broadcasting system line failure phenomenon; at the same time, the equipment adopts the FM-SCA subcarrier coding control technology, interference signals can not open the speakers, greatly improving the stability and reliability of the system; as the transmitter adopts the domestic advanced microcomputer locking transmitter, it is very easy to realize the indoor broadcasting function. Transmitter adopts domestic advanced microcomputer phase-locking technology to make the frequency launch stable and drift-free.

Economy: the economy of the wireless broadcasting system can be seen for all to see, in the construction period can save a lot of transmission line materials and line laying costs, in the use of the process can save a lot of line maintenance work, saving a lot of maintenance costs. Foreign language teaching radio intelligent control management, saving power, greatly reducing the workload.

(3) System Principle and Composition

The system adopts the new concept of "digital editing and broadcasting, wireless FM transmission, addressable coding reception, intelligent management and broadcasting control" to build a digital campus intelligent broadcasting platform.

The system broadcasts audio sources collected, edited and produced by audio workstations, and the processed audio sources are transmitted to the digital hard disk multi-channel audio automatic broadcasting host through network switches. By the digital program source or analog program source output single or multi-channel audio signals, through the VAS audio matrix switcher switching output, sent to the FM radio transmitter for campus broadcasting or radio broadcasting programs. At the same time, the control signal from the main control computer through the RS-232 serial port and HX-5000 coding controller communication, coding controller SCA subcarrier channel will control the signal modulation to the 87-108MHz FM subcarrier, and audio signals **** cable transmission. Wireless FM transmit addressable campus broadcasting, university foreign language radio station automatic broadcast control. The main equipment has a digital audio workstation, full digital hard disk multiplexing automatic broadcasting host, network switch (special industrial PC), the main control and digital hard disk multiplexing software, FM radio transmitter, SCA addressable coding board, power supply intelligent management controller, wireless FM sound post, outdoor wireless receivers and amplifiers, lawn speakers and other components.

(D) Design

The program is divided into audio source and switching unit, audio acquisition unit, wireless addressable intelligent broadcasting unit to introduce three parts.

1, the audio source and master switching unit

The audio source consists of a digital program source master computer and HX-8000 multi-channel digital playback software; analog program source VCD, recording card holder, radio head, mixer, microphone and other components. Colleges can choose according to the actual use of the card holder 1-3, used to play tape programs; configuration of a VCD, used to play VCD, CD, MP3 CD-ROM programs; radio head TU313 a transmitting local radio programs; configuration of a mixer for announcers to broadcast their own programs, but also in the foreign language exams on the tape tone to correct the volume of the volume to adjust, in order to achieve the best auditory The effect.

The main control and switching by the audio matrix switcher, HX-5000 SCA addressable coding control host, HX-5000 system broadcast control software, HX-8000 digital hard disk multi-channel audio automation software and other components. Audio matrix switcher will audio source broadcast audio signal selection switch to the campus broadcast or foreign language radio transmitter. HX-5000 SCA addressable coding controller, can receive the main control computer RS-232 communication, the designated user through the operation of the main control computer, to achieve automatic or manual addressable coding intelligent control of the terminal equipment switch.

2, digital audio acquisition and editing unit

Digital audio acquisition and editing unit is a professional audio acquisition and editing production system, using professional audio processing software, can be the card holder, VCD, digital tuner and other output of the analog audio source for high sampling rate recording, and its mixing, synthesis, flanging, cutting, copying and other non-linear editing and processing operations, and converted to digital audio format, can be The main control or digital hard disk multi-channel audio automatic broadcasting software is used to automatically broadcast at regular intervals.

The audio editing studio is set up in the No. 1 teaching building to collect and edit the audio, and output it to the playback host for playback after completion.

GB2000 digital audio editing system is a set of professional digital recording and a variety of effects synthesis processing in one of the audio processing software for analog sources of high-quality digital recording and audio editing and processing and effects of synthesis, or digital audio editing and processing and conversion of file formats. This software can cassette player, CD player, radio head, vocals and other audio digital recording into the computer, and stored in digital format to the computer. Capture or existing audio files for a variety of sound effects, such as inversion, echo, fade in, fade out, flanger, distortion, insertion, deletion, movement and other operations, for the original monotonous and dry audio to add background music to add a variety of sound effects, so that the audio diversification, stylization, special features; for the broadcast of the track to add notes, explanations to make the audio more comprehensible to the reception of the audio; the audio file format conversion, saving the occupied Hard disk space is saved by format conversion of audio files. In addition, it supports SCSI CDROM to directly extract audio files without outputting them to the sound card and record them for editing.

Features: Support various input audio for high-quality digital recording; support a variety of formats for audio editing effects synthesis processing; support a variety of audio file format conversion, with batch processing capabilities; support a variety of sound cards and a variety of professional audio editing card recording output; support for sophisticated filters to repair the sound files; support for dual-channel sound file synthesis processing; can be widely used in a variety of audio editing It can be widely used in various audio editing workstations for audio modification.