John Shutt wrote: > Sorry, I deal in the number of bits I can transmit. Delivering > those bits with the lowest possible amount of power may be a > fun mental exercise, but I'll buy a bigger transmitter if I > can deliver more bits. It's the bitrate that is most important > to a broadcaster. Sorry, that doesn't cut it for a couple of reasons. First of all, because you haven't seen that you buy a lot of extra C/N margin when the cost in b/s appears to be high. And secondly, because in principle, using E-VSB or A-VSB, you can do a lot more fine-tuning of the amount of wide vs narrow channel than you can with HM. (Consider, for example, that they only demoed 1/2 rate and 1/4 rate, layered over the existing 2/3 rate. You could add more options just in that parameter alone.) Changing the modulation is sort of a meat axe approach to creating the narrow channel. Like everything else, there are advantages and also disadvantages. HM has the advantage of not depending on fancy processing to extract the extra robustness. That's why it was available years ago. But it has the disadvantage of creating a robust channel that may be far wider than you need, and simultaneously degrading the wide channel more than you might want. Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.