Bert, I specifically and for a very good reason said "demonstrated at the 2000 NAB." The LP (high capacity) stream was received on the convention floor using a Radio Shack double bow tie set top antenna, albeit carefully aimed, while the Nokia Mediascreen toured every nook and cranny in the Greater Las Vegas Area to receive the HP (robust) stream. (There was some controversy about passive repeaters in the convention hall or active repeaters in the DVB booth, but I think those were proved false.) No 8-VSB was receivable on the convention floor at all. Implementations of DVB-T in Great Britain are at much lower ERPs than are allocated here, thus the difference in performance. Also, Great Britain has not yet attempted to use HM modulation at all. Their Freeview deployment of DVB, like the onDigital network it is built upon, calls for a broadcast model where the collective bits of several broadcast channels are used in aggregate to deliver a multi-channel service, so HM is less attractive in that situation. It is perfectly acceptable to have a fragile LP stream targeted at huge immovable HDTV screens, and a second stream targeted at portable and mobile use. What I find more and more every day with practical ATSC reception of our own station, is that it is not so great to have one system that is fixed for one application and has no flexibility at all. And I am perfectly aware that the original ATSC standard was specifically designed to deliver the maximum number of bits to a fixed outdoor antenna, and it fulfilled it's design criteria. It was just the wrong criteria. Cheers, John Shutt ----- Original Message ----- From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx> > The European implementations of non-HM DVB-T have not been > able to use such high spectral efficiency effectively. And > worse, this combination is even less robust than it would > appear, when it is transmitted in an HM channel. It requires > a theoretical 24.5 dB of C/N for successful decoding in > Rayleigh fading, and 21 dB in a Gaussian channel. ---------------------------------------------------------------------- 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.