I'm not sure what that means, Barry. Indeed, having sub-channels can rob performance of both channels if the bit-budget exceeds 19.39 mb/second. If somebody is telling you this, they basically don't know what they are talking about, since having null packets to spare is a good thing. However, it's important to know what is happening. Dan installed an external antenna and experienced macroblocking and some lockups at channel changes. Given his conditions, he might try to insert a 3- or 6-dB l- or t-pad into his antenna line and see if too much power is the problem. It usually is. Lockups at channel changes could be cause by too much power, or could be caused by bad PSI/PSIP mismatch (some of the middleware stacks in mid and low cost receivers haven't implemented this properly or in a way that deals with real-world situations.) It can also be caused by overshooting the bit budget, in inartfully designed receivers. A spectrum analyzer might help diagnosing power issues, but a PSI/PSIP analyzer will help (someone with knowledge) diagnosing any mismatches. PSI/PSIP problems are still quite common. And, FCC fines can result; PSIP and PSI are mandatory, and it's somewhat rare to have everything okay. I can safely say that KYES-DT Anchorage Alaska has near-perfect PSIP. The "big issue" right now is System Time Table jitter. The STT should be issued at least once per 1000 ms. Every once in a while, it comes out to 1006 ms. The error isn't cumulative (hence, jitter, not offset) and I am trying and testing various tweaks to eliminate it. John Willkie _____ De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En nombre de Barry Brown Enviado el: Tuesday, December 23, 2008 9:45 AM Para: opendtv@xxxxxxxxxxxxx Asunto: [opendtv] Re: It's Not Just The Antenna On Dec 23, 2008, at 12:23 PM, dan.grimes@xxxxxxxx wrote: And one of the sub-channels (NBC 3.2, Weather) doesn't display at all. In my area of Virginia, some of the broadcasters maintain sub-channels without video to preserve the performance on the main DT channel.