On Sat, Apr 17, 2010 at 10:27 AM, hteller <[email protected]> wrote:
> Compared Thor to Contestia yesterday and Thor did not do well either > compared to Contestia, and because of the more limited case, Constestia was > faster for the about the same minimum S/N. > > We developed Thor in order to survive lightning crashes during the summer > (the name is Norse for the God of Thunder), and after three months of tests > on 80m during the summer, MFSK16 actually did better than Thor. It is just > harder to tune, as you know. > > Did not compare DominoEx FEC to Contestia, but compared with Thor instead. > The problem with comparing these things is knowing wheter you are comparing apples to apples. What is the block size? What is the interleave factor? What is the amount of redundancy (FEC rate)? Is the base modulation MFSK or IFK? This is not magic. One is not better than the other; each is just different. (Well, there are exceptions to that statement -- RTTY just sucks and should be outlawed. :-) I would be willing to bet that, with a few minor changes, THOR or DominoEX/FEC would perform as well or better under most conditions. But what are those conditions? By your implication, the characteristics of the path you use on UHF favor MFSK over IFK but since we are dealing with different levels of FEC we just don't know. It may be that, properly tweaked, modes using IFK (DominoEX/Thor) will outperform MFSK. Remember, we can apply the same FEC to both. But then, they will likely have different bit error patterns which means optimization will require different parameters. -- 73 de Brian, WB6RQN/J79BPL
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