Nowadays, the way to receive satellite programs varies from the way before. It is not just by digital machine no longer, but has been developed to multimedia. That can be divided into four kinds: Free digital machine, also called FTA, which can only receive free programs but not receive encoded channels; Card machine; Computer card, which is to watch satellite TV with computer; Module machine, one of card machines, has external module. If you just want to watch free channels, it will be easy, because the ordinary digital machine is cheap.
A set of high-quality FTA digital machine should posses the following functions: S terminal video output(Image resolution can reach 500 lines, but AV output can only reach 400 lines, and RF output can just reach 350 lines); Installation help menu( There must be signal strength and signal quality instructions, which is necessary for personal adjusting; Audio part can decode two layers of accompany sound, and left and right channel can switch freely; Receiving all the programs without system halted; The symbol rate should be 2-45Mbps; P/N system compatibility;0/22KHz switch; 0/12V; DiSEqC switch(namely so-called four-in-one-out switch); PID; It can delete the programs not required or not preferred and move the arrangement of channels in receiver at will; Low threshold value. For cable television dealers, we should consider the broad voltage support to adapt different areas; the electrical specification should be stable and not lead to IRD damage because of long time. When using digital machine, we just need to input local frequency, down converter frequency, symbol rate and polarization mode according to the guide of menu.