Scheme Features: 1、Adopts mature television broadcasting system trunk line microwave 8G frequency for transmitting, has a little power loss and is suitable for medium and long distance transmission while can meet the transmission demands. 2、AGC module is extra installed inside 8G transmitter. It can adapt to the normal fluctuation of input level to make sure the machine can operate steadily. 3、The system divides into Indoor Unit and Outdoor Unit. The Indoor Unit contains encoder, modulator, multiplexer, audio Codec, ect., which are all standard 1U chassis. And the Outdoor transmitting (receiving) module, at the back of antenna waveguide feed, contains AGC, local oscillator, hybrid frequency, amplifier, ect., which are all in one cavity, adapting coaxial-cable feed. 4、The scheme design has function of smooth upgrade, with the maximum transmission speed of 60M. If it needs to increase program, it can simply increase the corresponding encoder (multiplexer) instead. One packet can only transmit a maximum of 16 sets of program. The whole system needn’t to be adjusted. 5、Compared with other scheme, this scheme has higher flexibility, reliability, and cost performance, and is easy to install and test. The System Structure Technical Index: The technical index of MK serial digital transmission system under 6Mbps video coding rate 6Mbps and 384K audio coding rate. Video index: Item | Unit | Technical Index | Audio Output Range | mV | 700±15 | Line Synchronization Amplitude | mV | 300±5 | Burst Synchronization Amplitude | mV | 300±5 | Video Amplitude-frequency Characteristic | dB | ±0.5(≤4.8MHz) | ≤0.5、≥-0.8(4.8~5MHz) | ≤0.5、≥-3(5~5.5MHz) | K Factor | % | ≤1.5 | Luminance Nonlinearity | % | ≤3 | DG Differential Gain | % | ±2 | Differential Phase Shift | o | ±1 | Chroma Gain | % | ±3 | Chroma Delay | ns | ±20 | Video signal to Noise Ratio | dB | ≥65(weighted value) |
Audio Index: Item | Unit | Technical Index | Audio Signal to Noise Ratio | dB | ≥70(Un-weighted value) | Audio Amplitude-frequency Response | dB | -0.08(20Hz~10KHz) | -0.3(15KHz) | -0.3 (18KHz) | -0.5 (20KHz) | Audio Harmonic Distortion | % | ≤0.22(20Hz~1KHz) | 0.13(5KHz) | 0.26(10KHz) | 0.65(15KHz) | 0.82(20KHz) | Left and Right Channel Crosstalk | dB | ≥-60 | Electric Adjustment Left and Right Channels | dB | ≤0.3 | Phase Left and Right Channels | o | ≤3 | |