Hi I'm a uni student currently investigating spectrum usage on the Optus Satellies A3, B1, B3 and C1. When I look at the tables from LyngSat, I found I'm a bit confused and so can you help me <br />resolve those issues?<br /><br />Firstly, on the first left column of the table, does "Tp" denote transponders? And does the frequency in the table representing the "centre frequencies"? As I know, each channel should occupy a bandwidth e.g. DVB channel occupies 8 <br />MHz.<br /><br />Second, take A3 for example, there is only one frequency used (12501 H) but it provides several services like DVB, FM and TV. Does that mean the extent of the centre frequency has been divided into sections to operate services that consumes <br />less bandwidth? I also noted there is no transponder number under the frequency.<br /><br />Thirdly, there are some gray colour rows in B1 saying "feeds" and is there more explanation about that?<br /><br />Lastly, some transponders are in the form of "tp 4L". What does "L" mean??<br /><br />I would really appreciate if someone could help me resolve this!!

In brief.<br />Grey means Feeds only<br />TP 4L or say 4H, means low or high in other words there half transponders, Need biggers dishes as you're about 6 dB down on power.<br />A3 is not much in use as all DTH (direct to home) receivers need Auto tracking to follow the Satellite.<br />LyngSat is not 100% accurate but good enough<br />Phil

Have a look here<br />http://www.al7barnews.tk/modules/news/article.php?storyid=5

Yes, Tp is the transponder number<br /><br />Transponders are generally 40MHz wide. It varies between satellites and bands. Sometimes transponders on the satellites are actually just one transponder in hardware, but my be split into segments and given seperate transponder numbers for whatever reason.<br /><br />There are also many more tiny carriers on satellites that aren't listed on Lyngsat, if they fill up the whole transponder, it may not be listed.