Starz finally seems fixed!
Finally, the problem with the missing channels (204, 206, 226, 229, 261, 262, 301, and 305), seems to be fixed with the installation of a 24" dish.
mike528 said:
My service call history is as follows:
1. Initial installation. Sketchy Starz -- sometimes present but pixellating, often missing completely
2. Replaced the diplexers, the LNB, and the STB, and repointed dish. Starz still does not work.
3. Removed diplexers completely, ran a second line. Still no Starz.
4. Replaced 18" dish with a 24" dish. All missing channels began coming in!
The larger dish improved my signal quality dramatically. On the previously working channels, signal quality went from 78-80 up to 94-95. On the previously missing channels, the quality went from the 60s (no picture at all) to 88-89. (All of these numbers are for slightly hazy skies on a hot, humid day).
The problem for me seemed to be that signal quality is substanially weaker on my system on the previously missing channels than on the others. Even with the bigger dish, it is still about 6 points weaker, but it is now well within an acceptable range. I assume that this larger dish will help a lot with rain too, and I suspect that if rain fade occurs, it will be the Starz channels that are first to drop out.
The installer remarked that he has done very few 24" dish installs for any satellite company; they are more common with commercial customers. He said he thought all the satellite companies should start making them standard equipment -- they are a little more expensive initially, but the greatly improved signal quality would eliminate a lot of service calls for people having rain fade issues, etc.
I know that removing diplexers has solved the missing Starz problem for many people, but it didn't solve it for me. The larger dish did it. However, here is a detail I didn't post previously: Removing the diplexers and running a second line did improve my OTA reception somewhat. Channels that I used to get are now even more stable and easy to tune, and a couple of weaker stations that I could not get at all now come in fine. So I have no quarrel with those who say that its best not to use diplexers if you can avoid it. I am definitely glad that Voom ran the second line for my antenna.
Thanks to everyone who provided advice and suggestions. I hope that my experience is helpful to someone who may encounter problems like this.
And a big thanks to Joe Harkins of Installs, Inc., who followed up with this problem and got the larger dish ordered for me before his departure.