Ken; When you make these measurements are you capturing transport streams? Are you able to discern if there are dropped packets (continuity_counter errors)? I ask this because that's one of the basic criteria that I use to determine good reception, and it is a level of detail that stb and tv set users cannot answer. Once you know you are getting all the packets, the next step is to measure jitter of the program clock reference. The MPEG-2 specification requires this to be +/- 500 ns. In the station I'm most familiar with, last time we measured, pcr jitter was 400,000 ns. Because my customer is experiencing missing packets, the slew rate bothers me, because 400,000 ns is enough to slip a packet. "Some" of the reception issues are actually simple, basic, MPEG-2 errors on the transmission side. Once you know the transmission is within specification (8-VSB is more critical here than DVB-T) then you can move on to receiver issues. Depending on other issues, I know from recent experience that some receivers are better at rendering out-of-spec broadcasts than are others. I suspect that some reception issues are actually signs of stations not having good enough test equipment, or not measuring the signal at the appropriate points. John Willkie -----Mensaje original----- De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En nombre de Hunold, Ken Enviado el: Wednesday, November 28, 2007 7:32 AM Para: opendtv@xxxxxxxxxxxxx Asunto: [opendtv] Re: New Thread: What becomes of Legacy Analog Equipment Well, "proven" requires a bit more rigorous test, but I have two different types of off-the-shelf tuners (USB-style, not integrated into receivers) that I routinely use at my desk in the "canyons" of NYC and in random locations in hotels in almost two dozen cities, so far. They work fine. Anecdotally, I would venture a success rate of greater than 90%, and in most of these locations cable TV has been the only alternative for tolerable NTSC reception. I recently checked an older, first generation tuner and it still didn't work any better at my office than it did about seven years ago, so nothing has "improved" on the transmission side (power, location, etc.) My guess is that the improved ability to deal with signal reflections is the reason that these new tuners work so well, but other improvements might have been put in as well. I should also add that I don't do these tests just to check the performance of the 8VSB system. However, I do need to receive the signals to perform other measurements. Regards, Ken Hunold ---------------------------------------------------------------------- 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.