[rauschpfeife]

I haven't looked tonight, but I commonly see and hear many more glitches on F2 (once every two hours or so) than F1 (almost never). I happen to have two 505s with R5000 mods that allow me to record the original transport streams. A month ago I tried an interesting test over a 24 hour period.

I normally use a fixed 1.2m dish with two dual output LNBs and a 4x8 switch for Shaw and left that wired to the first 505. I ran the second 505 to a 1.8m motorized dish through a completely independent signal path and switch. These dishes are separated by a considerable distance, meaning any object flying in-between them and the satellite is unlikely to interrupt both in an identical manner. I then recorded a number of movies and programs, all from F2 TP 32 (Encore Avenue HD, Movie Central HD and HBO Canada West), which appears to give me more problems than others. But it's also what I watch the most.

Of the roughly dozen glitches I detected in the transport streams, the vast majority were identical. The same packets corrupted and the same continuity errors. The remaining glitches were close, but not identical. My conclusion was the majority of the errors were caused by a marginal uplink, or Shaw were uplinking already corrupted transport streams. It's hard to say what happened with the rest, that could have been caused by a plane/helicopter flying through the downlink signal path, or some other interruption of the uplink or downlink. Presumably the differences in these errors were caused by slight variances in signal re-acquisition by the 505s.

At the time I measured an ebno of about 9 dB off TP 32 for the 1.2m (I live in Colorado) and 10 dB off the 1.8m. One should expect a larger difference for the 1.8m over the 1.2m, but the on-axis LNB for the 1.8m dish is a universal LNB, meaning the 505s won't work with it. I have a traditional North American LNBF sidecared for this purpose, and that is what I used for the test. This accounts for a 1-2 dB loss in ebno vs. the on-axis feed.

This result was a little disappointing because I had hoped to identify an issue with my receiving system that could be fixed. However if the errors are really Shaw's, there's nothing I can do. The rate of errors does vary slowly across a week or two. I keep hoping that Shaw is getting a handle on them and getting them corrected, but the errors creep back every time. Has anyone else noticed this?

 

[rauschpfeife]

To be fair, the glitches I've noticed are quite minor. They only affect a very tiny fraction of a single frame and are separated by hours. The receiver does a good job of concealing them, to the point I would miss many with casual viewing. However scanning the original transport streams for errors makes them more apparent.

 

[rauschpfeife]

Thanks and I wish this was a simple alignment problem. But I have 15 dishes from 0.76-3.2m, some professional meters and a spectrum analyzer. I've tried a 90cm toroid (where I started), a 1.2m Geosatpro steel and a 1.8m Prodelin commercial fiberglass dishes and all have been peaked to within 0.1 dB.

F1 is not a problem. The lowest ebnos I see for it on the 1.2m are better than 13 dB. F2's footprint drops off much faster going south to here, and originally I thought low ebnos were my problem with the toroid. Hence the 1.2m, which delivers 9 dB or better on F2. But the glitches I saw on the toroid didn't go away.

I next theorized that TP 1 on EchoStar 11 (110W) might be interfering with TP 32 on F2, which is where I see most of my problems. The Dish Network bird is screaming with power into Colorado and F2 is several dB lower than in Canada. That's why I tried the 1.8m, because it has a beamwidth of around 0.9 degrees and higher gain. This should have given some relief with the Shaw and Dish birds only 1.1 degrees apart. Originally I used its sidecar LNBF, but that only improved my ebnos by about a dB over the 1.2m. I didn't like doing this, but I pulled the universal LNB off the Prodelin feed and put on a 'normal' LNB to use with the Shaw receivers. That boosted the worst ebno on F2 up to nearly 13 dB, but I still had glitches with a completely different cable running to the receiver.

I'd be the first to admit some of these glitches could still be caused by 110W interference. If I lived farther north, F2 would be stronger and 110W would be weaker. There is the possibility these could be caused by a plane/helicopter flying in front of the satellite far away from here. But I also subscribe to Dish Network and I almost never see a glitch off 110W, 119W or 129W which are at similar look angles. That argues air traffic is not the likely root cause. My comparison test a month ago with two receivers, two dishes and completely separate signal paths was a bit of a relief as it suggested not all of the problems are mine. But it's also a downer in that I can't do anything about them if it's true.

I haven't given up yet, but I'm running out of things to try. Fortunately the glitches are not visible for the most part.