Design And Improvement Of On-site Production System For Provincial TV Station

In the current entertainment industry, the shows with high mobility are taking larger and larger proportion, while the Outdoor Broadcasting Vehicles (OBV) currently equipped by TV stations show great limitations. This situation calls for a real-time, small scale broadcasting record system with comprehensive functionalities, namely the Electronic Field Production (EFP).The EFP systems currently applied in the domestic industry differs significantly in the outside appearance, but subtle in the inside structure. The system consists of Video Switch Set as its core, portable photographing and recording camera, battery or utility power adapter, tape recorder, multiple small size monitors, coaxial cable which can transfer signal within 50m, isolated tuning system and interior telephone system.The traditional EFP has three main limitations. First of all, as it does not include CCU, the connection between cameras is very complicated. This requires special connections for video output signal and PGM video signal respectively, and also a solution for the power supply for each camera. There are two coaxial cables on the cable reel. As a result, the manipulation of the cables is energy consuming. In the second place, the coaxial cables used for signal transfer only have one single layer of copper shield net as shield layer. If the length of cables is sufficiently long the electro-magnetic interface will affect the system's normal functionalities. Thirdly, the video is recorded with tape recorders, thus the videos are vulnerable to recorder malfunctions.This paper addresses the following improvements to the limitation of the current EFP system, and implements an EFP system suitable for installation and transportation.1. The direct current integrated power supply system A core power supply is designed in the control core of the EFP system, utilizing the three-in-one coaxial cable to supply low voltage DC current to the cameras and monitors. The reasons why we do not choose AC are, first the voltage is too high, which will easily destroy the low voltage power electrical devices, as the power cable is fairly close to the video signal cable; secondly the electro-magnetic eradiation will affect the stability of video signal transfer.2. Overcoming the weakness of the coaxial cables to resist interface. Not only do we implement the anti-interface solution on the coaxial cables, but also we introduce the digital regenerated system using clock cycle renew technique. This technique is based on the feature of the base-band transfer of the digital component of series signals, and the way how electro-magnetic interface affects the signal in coaxial cable. We grant the EFP system with strong anti electro-magnetic interface ability from hardware point of view.3. A safe record backup system. We get rid of the disadvantages of the traditional tape record system, and implement a P2 card based semiconductor record backup system. This system is insensitive to the environment, anti-vibration. It can record for a long time and has no medium consuming. This system brings a significant improvement on the safety of EFP recording.In practice, our proposed system sufficiently shows how technique innovation can bring to the TV broadcasting. The installation of the system is rapid, takes only 10 min. The system can work as long as the Utility Power is supplied. The overall power is no more than 1000W. The camera is 100 meters apart. It can resist the strong interface sources such as cell phones. During the broadcasting the backup system can provide continuous backup for 20 hours. This will ensure the safety of video against any unexpected conditions.This paper will introduce the system constitution and detailed technique specifications of the provincial level television EFP system, and discuss the future improvement plans.