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View Full Version : Satellite Transponders, How do they Work, How our Receivers Use Them


TROOPER
09-29-2008, 02:20 PM
The satellites transmit the signals to us on with their transmitters known as Transponders(TP's). Each satellite has up to 32 Transponder frequencys. The Transponder's send a data stream on each frequency, this data stream can carry a number of channels. The faster the data stream the more channels it can carry, the speed of the data stream is rated as "Symbol Rate" (SR) per second. Most satellite Transponders use 20,000 symbols per second, which translates into 10 to 20 video/audio channels per Transponder, depending on the video resolution. Hi-Def. uses more Symbol rate. Thus the Transponder can carry fewer Hi-Def. channels. Not all Transponders's are used for TV/Radio entertainment, they are used for other commerical purposes, this is why our receivers can get a Transponder that indicates "S"trenght but no "Q"uality, our receiver with its current TV/Radio software can not decode these non-video/audio signals.

How our receivers use the transponders;
The satellites signal is captured by our dish, and reflected into the LNB. The LNB processes, amplifies the signal and sends it up the cable to our receiver. The receiver looks at the signal frequency according to the Transponder frequency data that is stored in the receivers memory for that satellite. If your receiver does not have a current transponder data list in its memory, you will be missing TV/Radio channels. We get the transponder frequency lists from 2 different sources. First, we load it into our receivers as a data file, it can be buried in a upgrade file (.bin) or a seperate channel file. Second, we can do a "Blind Scan", the receiver scans the satellite for the transponders frequencys, puts these frequencys into the receivers memory and then using this frequency list, it scans each frequency for Video/audio channels, that we know as our TV/Radio channels. If you have a current receiver, it should have a fast blind scan ability (usually 10 minutes or less per satellite). I recommend a blind scan monthly, for optium reception.