1. Design principle of FM common cable rural broadcasting system 3. Design Scheme of FM Common Cable Rural Broadcasting Pallet Shuttle System,Shuttle Carrier Racking System,Pallet Shuttle Carrier System,Shuttle Carrier System Changchun Rochiev Intelligent Equipment Manufacturing Co., Ltd. , https://www.rochiev-en.com
Analog audio sources such as digital tuners, microphones, decks, etc. broadcast analog audio, and digital audio such as digital intelligent broadcast control mainframes are fed into the audio switcher. After the output audio signal is modulated into an FM high-frequency carrier signal by the FM modulator, It is sent to the mixer to multiplex the broadcast signal to the CATV coaxial network in the existing / under construction in rural areas.
CATV FM shared cable transmission rural broadcast signals are transmitted in RF form in the HFC photoelectric hybrid closed circuit TV network. The terminal can play through the FM speaker, or can use the FM receiver controller to demodulate the audio signal and pass the power amplification after the constant pressure sound Columns and lawn speakers can also be played through treble speakers using FM radio amplifiers.
Townships and villages can use interleaved FM modulators (applicable to electrical signals inserted into the ground) and fiber-optic FM modulators (applicable to optical signals inserted into the ground) to perform secondary and tertiary rural broadcast signal insertion.
Second, the principle diagram of FM common cable rural broadcasting 
1. Design of county intelligent broadcasting center
The county broadcasting room broadcasts the program source from the broadcast control host, DVD / VCD, digital tuner, deck, broadcast microphone, etc., adjusts the audio modification through the mixer, and outputs it to the FM modulator, which modulates the audio to the FM high frequency carrier In order to share the cable with the cable TV signal. DVD / VCD, digital tuner, deck, etc. can be managed by the system timer to automatically relay / broadcast audio programs regularly.
The modulated broadcast signal is frequency-division multiplexed to the cable TV network through a mixer for transmission.
The schematic diagram of the county broadcasting center system is as follows:
2. Township Broadcasting Center
2.1 Township second-level rural radio insertion method
The Township Broadcasting Center inserts broadcast signals such as township-level broadcast microphones and DVDs through a multi-function FM modulator (also known as a plug-and-play FM modulator) to achieve instant secondary broadcasting to the administrative villages and natural villages under its jurisdiction.
2.2 Township secondary rural broadcast optical insertion method
The Township Broadcasting Center inserts township-level broadcast microphones, DVDs and other broadcast signals into the HFC cable television optical transmission network downstream to the administrative village through the fiber-optic FM modulator, realizing instant secondary broadcasting to the administrative village and natural village under its jurisdiction.
3. Design of the administrative village broadcasting center
The administrative village broadcasting center inserts village-level broadcasting microphones, DVDs and other broadcast signals into the HFC cable television optical transmission network downstream to the natural village through the optical fiber FM modulator, and realizes instant three-level broadcasting to the natural village under its jurisdiction. At the same time, the administrative village can listen to the broadcast signals from the county, township and village through the multi-functional FM radio receiver and broadcast it through the tweeter.
4. Natural Village Broadcasting Design
The natural village realizes the reception of the three-level broadcast signal of the county, township and village through the multi-function FM receiver and amplifier, and broadcasts it through the tweeter.